drm/imx: Add initial support for DCSS on iMX8MQ

This adds initial support for iMX8MQ's Display Controller Subsystem (DCSS).
Some of its capabilities include:
 * 4K@60fps;
 * HDR10;
 * one graphics and 2 video pipelines;
 * on-the-fly decompression of compressed video and graphics;

The reference manual can be found here:
https://www.nxp.com/webapp/Download?colCode=IMX8MDQLQRM

The current patch adds only basic functionality: one primary plane for
graphics, linear, tiled and super-tiled buffers support (no graphics
decompression yet), no HDR10 and no video planes.

Video planes support and HDR10 will be added in subsequent patches once
per-plane de-gamma/CSC/gamma support is in.
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731081836.3048-3-laurentiu.palcu@oss.nxp.com

drivers/gpu/drm/imx/Kconfig

@@ -39,3 +39,5 @@ config DRM_IMX_HDMI
 	depends on DRM_IMX
 	help
 	  Choose this if you want to use HDMI on i.MX6.
+
+source "drivers/gpu/drm/imx/dcss/Kconfig"

drivers/gpu/drm/imx/Makefile

@@ -9,3 +9,4 @@ obj-$(CONFIG_DRM_IMX_TVE) += imx-tve.o
 obj-$(CONFIG_DRM_IMX_LDB) += imx-ldb.o
 
 obj-$(CONFIG_DRM_IMX_HDMI) += dw_hdmi-imx.o
+obj-$(CONFIG_DRM_IMX_DCSS) += dcss/

drivers/gpu/drm/imx/dcss/Kconfig

+config DRM_IMX_DCSS
+	tristate "i.MX8MQ DCSS"
+	select IMX_IRQSTEER
+	select DRM_KMS_CMA_HELPER
+	select VIDEOMODE_HELPERS
+	depends on DRM && ARCH_MXC
+	help
+	  Choose this if you have a NXP i.MX8MQ based system and want to use the
+	  Display Controller Subsystem. This option enables DCSS support.

drivers/gpu/drm/imx/dcss/Makefile

+imx-dcss-objs := dcss-drv.o dcss-dev.o dcss-blkctl.o dcss-ctxld.o dcss-dtg.o \
+				 dcss-ss.o dcss-dpr.o dcss-scaler.o dcss-kms.o dcss-crtc.o \
+				 dcss-plane.o
+
+obj-$(CONFIG_DRM_IMX_DCSS) += imx-dcss.o
+

drivers/gpu/drm/imx/dcss/dcss-blkctl.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_BLKCTL_RESET_CTRL		0x00
+#define   B_CLK_RESETN			BIT(0)
+#define   APB_CLK_RESETN		BIT(1)
+#define   P_CLK_RESETN			BIT(2)
+#define   RTR_CLK_RESETN		BIT(4)
+#define DCSS_BLKCTL_CONTROL0		0x10
+#define   HDMI_MIPI_CLK_SEL		BIT(0)
+#define   DISPMIX_REFCLK_SEL_POS	4
+#define   DISPMIX_REFCLK_SEL_MASK	GENMASK(5, 4)
+#define   DISPMIX_PIXCLK_SEL		BIT(8)
+#define   HDMI_SRC_SECURE_EN		BIT(16)
+
+struct dcss_blkctl {
+	struct dcss_dev *dcss;
+	void __iomem *base_reg;
+};
+
+void dcss_blkctl_cfg(struct dcss_blkctl *blkctl)
+{
+	if (blkctl->dcss->hdmi_output)
+		dcss_writel(0, blkctl->base_reg + DCSS_BLKCTL_CONTROL0);
+	else
+		dcss_writel(DISPMIX_PIXCLK_SEL,
+			    blkctl->base_reg + DCSS_BLKCTL_CONTROL0);
+
+	dcss_set(B_CLK_RESETN | APB_CLK_RESETN | P_CLK_RESETN | RTR_CLK_RESETN,
+		 blkctl->base_reg + DCSS_BLKCTL_RESET_CTRL);
+}
+
+int dcss_blkctl_init(struct dcss_dev *dcss, unsigned long blkctl_base)
+{
+	struct dcss_blkctl *blkctl;
+
+	blkctl = kzalloc(sizeof(*blkctl), GFP_KERNEL);
+	if (!blkctl)
+		return -ENOMEM;
+
+	blkctl->base_reg = ioremap(blkctl_base, SZ_4K);
+	if (!blkctl->base_reg) {
+		dev_err(dcss->dev, "unable to remap BLK CTRL base\n");
+		kfree(blkctl);
+		return -ENOMEM;
+	}
+
+	dcss->blkctl = blkctl;
+	blkctl->dcss = dcss;
+
+	dcss_blkctl_cfg(blkctl);
+
+	return 0;
+}
+
+void dcss_blkctl_exit(struct dcss_blkctl *blkctl)
+{
+	if (blkctl->base_reg)
+		iounmap(blkctl->base_reg);
+
+	kfree(blkctl);
+}

drivers/gpu/drm/imx/dcss/dcss-crtc.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_vblank.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include "dcss-dev.h"
+#include "dcss-kms.h"
+
+static int dcss_enable_vblank(struct drm_crtc *crtc)
+{
+	struct dcss_crtc *dcss_crtc = container_of(crtc, struct dcss_crtc,
+						   base);
+	struct dcss_dev *dcss = crtc->dev->dev_private;
+
+	dcss_dtg_vblank_irq_enable(dcss->dtg, true);
+
+	dcss_dtg_ctxld_kick_irq_enable(dcss->dtg, true);
+
+	enable_irq(dcss_crtc->irq);
+
+	return 0;
+}
+
+static void dcss_disable_vblank(struct drm_crtc *crtc)
+{
+	struct dcss_crtc *dcss_crtc = container_of(crtc, struct dcss_crtc,
+						   base);
+	struct dcss_dev *dcss = dcss_crtc->base.dev->dev_private;
+
+	disable_irq_nosync(dcss_crtc->irq);
+
+	dcss_dtg_vblank_irq_enable(dcss->dtg, false);
+
+	if (dcss_crtc->disable_ctxld_kick_irq)
+		dcss_dtg_ctxld_kick_irq_enable(dcss->dtg, false);
+}
+
+static const struct drm_crtc_funcs dcss_crtc_funcs = {
+	.set_config = drm_atomic_helper_set_config,
+	.destroy = drm_crtc_cleanup,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+	.enable_vblank = dcss_enable_vblank,
+	.disable_vblank = dcss_disable_vblank,
+};
+
+static void dcss_crtc_atomic_begin(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state)
+{
+	drm_crtc_vblank_on(crtc);
+}
+
+static void dcss_crtc_atomic_flush(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state)
+{
+	struct dcss_crtc *dcss_crtc = container_of(crtc, struct dcss_crtc,
+						   base);
+	struct dcss_dev *dcss = dcss_crtc->base.dev->dev_private;
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	if (crtc->state->event) {
+		WARN_ON(drm_crtc_vblank_get(crtc));
+		drm_crtc_arm_vblank_event(crtc, crtc->state->event);
+		crtc->state->event = NULL;
+	}
+	spin_unlock_irq(&crtc->dev->event_lock);
+
+	if (dcss_dtg_is_enabled(dcss->dtg))
+		dcss_ctxld_enable(dcss->ctxld);
+}
+
+static void dcss_crtc_atomic_enable(struct drm_crtc *crtc,
+				    struct drm_crtc_state *old_crtc_state)
+{
+	struct dcss_crtc *dcss_crtc = container_of(crtc, struct dcss_crtc,
+						   base);
+	struct dcss_dev *dcss = dcss_crtc->base.dev->dev_private;
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	struct drm_display_mode *old_mode = &old_crtc_state->adjusted_mode;
+	struct videomode vm;
+
+	drm_display_mode_to_videomode(mode, &vm);
+
+	pm_runtime_get_sync(dcss->dev);
+
+	vm.pixelclock = mode->crtc_clock * 1000;
+
+	dcss_ss_subsam_set(dcss->ss);
+	dcss_dtg_css_set(dcss->dtg);
+
+	if (!drm_mode_equal(mode, old_mode) || !old_crtc_state->active) {
+		dcss_dtg_sync_set(dcss->dtg, &vm);
+		dcss_ss_sync_set(dcss->ss, &vm,
+				 mode->flags & DRM_MODE_FLAG_PHSYNC,
+				 mode->flags & DRM_MODE_FLAG_PVSYNC);
+	}
+
+	dcss_enable_dtg_and_ss(dcss);
+
+	dcss_ctxld_enable(dcss->ctxld);
+
+	/* Allow CTXLD kick interrupt to be disabled when VBLANK is disabled. */
+	dcss_crtc->disable_ctxld_kick_irq = true;
+}
+
+static void dcss_crtc_atomic_disable(struct drm_crtc *crtc,
+				     struct drm_crtc_state *old_crtc_state)
+{
+	struct dcss_crtc *dcss_crtc = container_of(crtc, struct dcss_crtc,
+						   base);
+	struct dcss_dev *dcss = dcss_crtc->base.dev->dev_private;
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	struct drm_display_mode *old_mode = &old_crtc_state->adjusted_mode;
+
+	drm_atomic_helper_disable_planes_on_crtc(old_crtc_state, false);
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	if (crtc->state->event) {
+		drm_crtc_send_vblank_event(crtc, crtc->state->event);
+		crtc->state->event = NULL;
+	}
+	spin_unlock_irq(&crtc->dev->event_lock);
+
+	dcss_dtg_ctxld_kick_irq_enable(dcss->dtg, true);
+
+	reinit_completion(&dcss->disable_completion);
+
+	dcss_disable_dtg_and_ss(dcss);
+
+	dcss_ctxld_enable(dcss->ctxld);
+
+	if (!drm_mode_equal(mode, old_mode) || !crtc->state->active)
+		if (!wait_for_completion_timeout(&dcss->disable_completion,
+						 msecs_to_jiffies(100)))
+			dev_err(dcss->dev, "Shutting off DTG timed out.\n");
+
+	/*
+	 * Do not shut off CTXLD kick interrupt when shutting VBLANK off. It
+	 * will be needed to commit the last changes, before going to suspend.
+	 */
+	dcss_crtc->disable_ctxld_kick_irq = false;
+
+	drm_crtc_vblank_off(crtc);
+
+	pm_runtime_mark_last_busy(dcss->dev);
+	pm_runtime_put_autosuspend(dcss->dev);
+}
+
+static const struct drm_crtc_helper_funcs dcss_helper_funcs = {
+	.atomic_begin = dcss_crtc_atomic_begin,
+	.atomic_flush = dcss_crtc_atomic_flush,
+	.atomic_enable = dcss_crtc_atomic_enable,
+	.atomic_disable = dcss_crtc_atomic_disable,
+};
+
+static irqreturn_t dcss_crtc_irq_handler(int irq, void *dev_id)
+{
+	struct dcss_crtc *dcss_crtc = dev_id;
+	struct dcss_dev *dcss = dcss_crtc->base.dev->dev_private;
+
+	if (!dcss_dtg_vblank_irq_valid(dcss->dtg))
+		return IRQ_NONE;
+
+	if (dcss_ctxld_is_flushed(dcss->ctxld))
+		drm_crtc_handle_vblank(&dcss_crtc->base);
+
+	dcss_dtg_vblank_irq_clear(dcss->dtg);
+
+	return IRQ_HANDLED;
+}
+
+int dcss_crtc_init(struct dcss_crtc *crtc, struct drm_device *drm)
+{
+	struct dcss_dev *dcss = drm->dev_private;
+	struct platform_device *pdev = to_platform_device(dcss->dev);
+	int ret;
+
+	crtc->plane[0] = dcss_plane_init(drm, drm_crtc_mask(&crtc->base),
+					 DRM_PLANE_TYPE_PRIMARY, 0);
+	if (IS_ERR(crtc->plane[0]))
+		return PTR_ERR(crtc->plane[0]);
+
+	crtc->base.port = dcss->of_port;
+
+	drm_crtc_helper_add(&crtc->base, &dcss_helper_funcs);
+	ret = drm_crtc_init_with_planes(drm, &crtc->base, &crtc->plane[0]->base,
+					NULL, &dcss_crtc_funcs, NULL);
+	if (ret) {
+		dev_err(dcss->dev, "failed to init crtc\n");
+		return ret;
+	}
+
+	crtc->irq = platform_get_irq_byname(pdev, "vblank");
+	if (crtc->irq < 0)
+		return crtc->irq;
+
+	ret = request_irq(crtc->irq, dcss_crtc_irq_handler,
+			  0, "dcss_drm", crtc);
+	if (ret) {
+		dev_err(dcss->dev, "irq request failed with %d.\n", ret);
+		return ret;
+	}
+
+	disable_irq(crtc->irq);
+
+	return 0;
+}
+
+void dcss_crtc_deinit(struct dcss_crtc *crtc, struct drm_device *drm)
+{
+	free_irq(crtc->irq, crtc);
+}

drivers/gpu/drm/imx/dcss/dcss-ctxld.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_CTXLD_CONTROL_STATUS	0x0
+#define   CTXLD_ENABLE			BIT(0)
+#define   ARB_SEL			BIT(1)
+#define   RD_ERR_EN			BIT(2)
+#define   DB_COMP_EN			BIT(3)
+#define   SB_HP_COMP_EN			BIT(4)
+#define   SB_LP_COMP_EN			BIT(5)
+#define   DB_PEND_SB_REC_EN		BIT(6)
+#define   SB_PEND_DISP_ACTIVE_EN	BIT(7)
+#define   AHB_ERR_EN			BIT(8)
+#define   RD_ERR			BIT(16)
+#define   DB_COMP			BIT(17)
+#define   SB_HP_COMP			BIT(18)
+#define   SB_LP_COMP			BIT(19)
+#define   DB_PEND_SB_REC		BIT(20)
+#define   SB_PEND_DISP_ACTIVE		BIT(21)
+#define   AHB_ERR			BIT(22)
+#define DCSS_CTXLD_DB_BASE_ADDR		0x10
+#define DCSS_CTXLD_DB_COUNT		0x14
+#define DCSS_CTXLD_SB_BASE_ADDR		0x18
+#define DCSS_CTXLD_SB_COUNT		0x1C
+#define   SB_HP_COUNT_POS		0
+#define   SB_HP_COUNT_MASK		0xffff
+#define   SB_LP_COUNT_POS		16
+#define   SB_LP_COUNT_MASK		0xffff0000
+#define DCSS_AHB_ERR_ADDR		0x20
+
+#define CTXLD_IRQ_COMPLETION		(DB_COMP | SB_HP_COMP | SB_LP_COMP)
+#define CTXLD_IRQ_ERROR			(RD_ERR | DB_PEND_SB_REC | AHB_ERR)
+
+/* The following sizes are in context loader entries, 8 bytes each. */
+#define CTXLD_DB_CTX_ENTRIES		1024	/* max 65536 */
+#define CTXLD_SB_LP_CTX_ENTRIES		10240	/* max 65536 */
+#define CTXLD_SB_HP_CTX_ENTRIES		20000	/* max 65536 */
+#define CTXLD_SB_CTX_ENTRIES		(CTXLD_SB_LP_CTX_ENTRIES + \
+					 CTXLD_SB_HP_CTX_ENTRIES)
+
+/* Sizes, in entries, of the DB, SB_HP and SB_LP context regions. */
+static u16 dcss_ctxld_ctx_size[3] = {
+	CTXLD_DB_CTX_ENTRIES,
+	CTXLD_SB_HP_CTX_ENTRIES,
+	CTXLD_SB_LP_CTX_ENTRIES
+};
+
+/* this represents an entry in the context loader map */
+struct dcss_ctxld_item {
+	u32 val;
+	u32 ofs;
+};
+
+#define CTX_ITEM_SIZE			sizeof(struct dcss_ctxld_item)
+
+struct dcss_ctxld {
+	struct device *dev;
+	void __iomem *ctxld_reg;
+	int irq;
+	bool irq_en;
+
+	struct dcss_ctxld_item *db[2];
+	struct dcss_ctxld_item *sb_hp[2];
+	struct dcss_ctxld_item *sb_lp[2];
+
+	dma_addr_t db_paddr[2];
+	dma_addr_t sb_paddr[2];
+
+	u16 ctx_size[2][3]; /* holds the sizes of DB, SB_HP and SB_LP ctx */
+	u8 current_ctx;
+
+	bool in_use;
+	bool armed;
+
+	spinlock_t lock; /* protects concurent access to private data */
+};
+
+static irqreturn_t dcss_ctxld_irq_handler(int irq, void *data)
+{
+	struct dcss_ctxld *ctxld = data;
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(ctxld->dev);
+	u32 irq_status;
+
+	irq_status = dcss_readl(ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
+
+	if (irq_status & CTXLD_IRQ_COMPLETION &&
+	    !(irq_status & CTXLD_ENABLE) && ctxld->in_use) {
+		ctxld->in_use = false;
+
+		if (dcss && dcss->disable_callback)
+			dcss->disable_callback(dcss);
+	} else if (irq_status & CTXLD_IRQ_ERROR) {
+		/*
+		 * Except for throwing an error message and clearing the status
+		 * register, there's not much we can do here.
+		 */
+		dev_err(ctxld->dev, "ctxld: error encountered: %08x\n",
+			irq_status);
+		dev_err(ctxld->dev, "ctxld: db=%d, sb_hp=%d, sb_lp=%d\n",
+			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_DB],
+			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_SB_HP],
+			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_SB_LP]);
+	}
+
+	dcss_clr(irq_status & (CTXLD_IRQ_ERROR | CTXLD_IRQ_COMPLETION),
+		 ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
+
+	return IRQ_HANDLED;
+}
+
+static int dcss_ctxld_irq_config(struct dcss_ctxld *ctxld,
+				 struct platform_device *pdev)
+{
+	int ret;
+
+	ctxld->irq = platform_get_irq_byname(pdev, "ctxld");
+	if (ctxld->irq < 0)
+		return ctxld->irq;
+
+	ret = request_irq(ctxld->irq, dcss_ctxld_irq_handler,
+			  0, "dcss_ctxld", ctxld);
+	if (ret) {
+		dev_err(ctxld->dev, "ctxld: irq request failed.\n");
+		return ret;
+	}
+
+	ctxld->irq_en = true;
+
+	return 0;
+}
+
+static void dcss_ctxld_hw_cfg(struct dcss_ctxld *ctxld)
+{
+	dcss_writel(RD_ERR_EN | SB_HP_COMP_EN |
+		    DB_PEND_SB_REC_EN | AHB_ERR_EN | RD_ERR | AHB_ERR,
+		    ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
+}
+
+static void dcss_ctxld_free_ctx(struct dcss_ctxld *ctxld)
+{
+	struct dcss_ctxld_item *ctx;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		if (ctxld->db[i]) {
+			dma_free_coherent(ctxld->dev,
+					  CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
+					  ctxld->db[i], ctxld->db_paddr[i]);
+			ctxld->db[i] = NULL;
+			ctxld->db_paddr[i] = 0;
+		}
+
+		if (ctxld->sb_hp[i]) {
+			dma_free_coherent(ctxld->dev,
+					  CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
+					  ctxld->sb_hp[i], ctxld->sb_paddr[i]);
+			ctxld->sb_hp[i] = NULL;
+			ctxld->sb_paddr[i] = 0;
+		}
+	}
+}
+
+static int dcss_ctxld_alloc_ctx(struct dcss_ctxld *ctxld)
+{
+	struct dcss_ctxld_item *ctx;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		ctx = dma_alloc_coherent(ctxld->dev,
+					 CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
+					 &ctxld->db_paddr[i], GFP_KERNEL);
+		if (!ctx)
+			return -ENOMEM;
+
+		ctxld->db[i] = ctx;
+
+		ctx = dma_alloc_coherent(ctxld->dev,
+					 CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
+					 &ctxld->sb_paddr[i], GFP_KERNEL);
+		if (!ctx)
+			return -ENOMEM;
+
+		ctxld->sb_hp[i] = ctx;
+		ctxld->sb_lp[i] = ctx + CTXLD_SB_HP_CTX_ENTRIES;
+	}
+
+	return 0;
+}
+
+int dcss_ctxld_init(struct dcss_dev *dcss, unsigned long ctxld_base)
+{
+	struct dcss_ctxld *ctxld;
+	int ret;
+
+	ctxld = kzalloc(sizeof(*ctxld), GFP_KERNEL);
+	if (!ctxld)
+		return -ENOMEM;
+
+	dcss->ctxld = ctxld;
+	ctxld->dev = dcss->dev;
+
+	spin_lock_init(&ctxld->lock);
+
+	ret = dcss_ctxld_alloc_ctx(ctxld);
+	if (ret) {
+		dev_err(dcss->dev, "ctxld: cannot allocate context memory.\n");
+		goto err;
+	}
+
+	ctxld->ctxld_reg = ioremap(ctxld_base, SZ_4K);
+	if (!ctxld->ctxld_reg) {
+		dev_err(dcss->dev, "ctxld: unable to remap ctxld base\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ret = dcss_ctxld_irq_config(ctxld, to_platform_device(dcss->dev));
+	if (ret)
+		goto err_irq;
+
+	dcss_ctxld_hw_cfg(ctxld);
+
+	return 0;
+
+err_irq:
+	iounmap(ctxld->ctxld_reg);
+
+err:
+	dcss_ctxld_free_ctx(ctxld);
+	kfree(ctxld);
+
+	return ret;
+}
+
+void dcss_ctxld_exit(struct dcss_ctxld *ctxld)
+{
+	free_irq(ctxld->irq, ctxld);
+
+	if (ctxld->ctxld_reg)
+		iounmap(ctxld->ctxld_reg);
+
+	dcss_ctxld_free_ctx(ctxld);
+	kfree(ctxld);
+}
+
+static int dcss_ctxld_enable_locked(struct dcss_ctxld *ctxld)
+{
+	int curr_ctx = ctxld->current_ctx;
+	u32 db_base, sb_base, sb_count;
+	u32 sb_hp_cnt, sb_lp_cnt, db_cnt;
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(ctxld->dev);
+
+	if (!dcss)
+		return 0;
+
+	dcss_dpr_write_sysctrl(dcss->dpr);
+
+	dcss_scaler_write_sclctrl(dcss->scaler);
+
+	sb_hp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_HP];
+	sb_lp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_LP];
+	db_cnt = ctxld->ctx_size[curr_ctx][CTX_DB];
+
+	/* make sure SB_LP context area comes after SB_HP */
+	if (sb_lp_cnt &&
+	    ctxld->sb_lp[curr_ctx] != ctxld->sb_hp[curr_ctx] + sb_hp_cnt) {
+		struct dcss_ctxld_item *sb_lp_adjusted;
+
+		sb_lp_adjusted = ctxld->sb_hp[curr_ctx] + sb_hp_cnt;
+
+		memcpy(sb_lp_adjusted, ctxld->sb_lp[curr_ctx],
+		       sb_lp_cnt * CTX_ITEM_SIZE);
+	}
+
+	db_base = db_cnt ? ctxld->db_paddr[curr_ctx] : 0;
+
+	dcss_writel(db_base, ctxld->ctxld_reg + DCSS_CTXLD_DB_BASE_ADDR);
+	dcss_writel(db_cnt, ctxld->ctxld_reg + DCSS_CTXLD_DB_COUNT);
+
+	if (sb_hp_cnt)
+		sb_count = ((sb_hp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK) |
+			   ((sb_lp_cnt << SB_LP_COUNT_POS) & SB_LP_COUNT_MASK);
+	else
+		sb_count = (sb_lp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK;
+
+	sb_base = sb_count ? ctxld->sb_paddr[curr_ctx] : 0;
+
+	dcss_writel(sb_base, ctxld->ctxld_reg + DCSS_CTXLD_SB_BASE_ADDR);
+	dcss_writel(sb_count, ctxld->ctxld_reg + DCSS_CTXLD_SB_COUNT);
+
+	/* enable the context loader */
+	dcss_set(CTXLD_ENABLE, ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
+
+	ctxld->in_use = true;
+
+	/*
+	 * Toggle the current context to the alternate one so that any updates
+	 * in the modules' settings take place there.
+	 */
+	ctxld->current_ctx ^= 1;
+
+	ctxld->ctx_size[ctxld->current_ctx][CTX_DB] = 0;
+	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] = 0;
+	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] = 0;
+
+	return 0;
+}
+
+int dcss_ctxld_enable(struct dcss_ctxld *ctxld)
+{
+	spin_lock_irq(&ctxld->lock);
+	ctxld->armed = true;
+	spin_unlock_irq(&ctxld->lock);
+
+	return 0;
+}
+
+void dcss_ctxld_kick(struct dcss_ctxld *ctxld)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctxld->lock, flags);
+	if (ctxld->armed && !ctxld->in_use) {
+		ctxld->armed = false;
+		dcss_ctxld_enable_locked(ctxld);
+	}
+	spin_unlock_irqrestore(&ctxld->lock, flags);
+}
+
+void dcss_ctxld_write_irqsafe(struct dcss_ctxld *ctxld, u32 ctx_id, u32 val,
+			      u32 reg_ofs)
+{
+	int curr_ctx = ctxld->current_ctx;
+	struct dcss_ctxld_item *ctx[] = {
+		[CTX_DB] = ctxld->db[curr_ctx],
+		[CTX_SB_HP] = ctxld->sb_hp[curr_ctx],
+		[CTX_SB_LP] = ctxld->sb_lp[curr_ctx]
+	};
+	int item_idx = ctxld->ctx_size[curr_ctx][ctx_id];
+
+	if (item_idx + 1 > dcss_ctxld_ctx_size[ctx_id]) {
+		WARN_ON(1);
+		return;
+	}
+
+	ctx[ctx_id][item_idx].val = val;
+	ctx[ctx_id][item_idx].ofs = reg_ofs;
+	ctxld->ctx_size[curr_ctx][ctx_id] += 1;
+}
+
+void dcss_ctxld_write(struct dcss_ctxld *ctxld, u32 ctx_id,
+		      u32 val, u32 reg_ofs)
+{
+	spin_lock_irq(&ctxld->lock);
+	dcss_ctxld_write_irqsafe(ctxld, ctx_id, val, reg_ofs);
+	spin_unlock_irq(&ctxld->lock);
+}
+
+bool dcss_ctxld_is_flushed(struct dcss_ctxld *ctxld)
+{
+	return ctxld->ctx_size[ctxld->current_ctx][CTX_DB] == 0 &&
+		ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] == 0 &&
+		ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] == 0;
+}
+
+int dcss_ctxld_resume(struct dcss_ctxld *ctxld)
+{
+	dcss_ctxld_hw_cfg(ctxld);
+
+	if (!ctxld->irq_en) {
+		enable_irq(ctxld->irq);
+		ctxld->irq_en = true;
+	}
+
+	return 0;
+}
+
+int dcss_ctxld_suspend(struct dcss_ctxld *ctxld)
+{
+	int ret = 0;
+	unsigned long timeout = jiffies + msecs_to_jiffies(500);
+
+	if (!dcss_ctxld_is_flushed(ctxld)) {
+		dcss_ctxld_kick(ctxld);
+
+		while (!time_after(jiffies, timeout) && ctxld->in_use)
+			msleep(20);
+
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+	}
+
+	spin_lock_irq(&ctxld->lock);
+
+	if (ctxld->irq_en) {
+		disable_irq_nosync(ctxld->irq);
+		ctxld->irq_en = false;
+	}
+
+	/* reset context region and sizes */
+	ctxld->current_ctx = 0;
+	ctxld->ctx_size[0][CTX_DB] = 0;
+	ctxld->ctx_size[0][CTX_SB_HP] = 0;
+	ctxld->ctx_size[0][CTX_SB_LP] = 0;
+
+	spin_unlock_irq(&ctxld->lock);
+
+	return ret;
+}
+
+void dcss_ctxld_assert_locked(struct dcss_ctxld *ctxld)
+{
+	lockdep_assert_held(&ctxld->lock);
+}

drivers/gpu/drm/imx/dcss/dcss-dev.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <drm/drm_modeset_helper.h>
+
+#include "dcss-dev.h"
+
+static void dcss_clocks_enable(struct dcss_dev *dcss)
+{
+	clk_prepare_enable(dcss->axi_clk);
+	clk_prepare_enable(dcss->apb_clk);
+	clk_prepare_enable(dcss->rtrm_clk);
+	clk_prepare_enable(dcss->dtrc_clk);
+	clk_prepare_enable(dcss->pix_clk);
+}
+
+static void dcss_clocks_disable(struct dcss_dev *dcss)
+{
+	clk_disable_unprepare(dcss->pix_clk);
+	clk_disable_unprepare(dcss->dtrc_clk);
+	clk_disable_unprepare(dcss->rtrm_clk);
+	clk_disable_unprepare(dcss->apb_clk);
+	clk_disable_unprepare(dcss->axi_clk);
+}
+
+static void dcss_disable_dtg_and_ss_cb(void *data)
+{
+	struct dcss_dev *dcss = data;
+
+	dcss->disable_callback = NULL;
+
+	dcss_ss_shutoff(dcss->ss);
+	dcss_dtg_shutoff(dcss->dtg);
+
+	complete(&dcss->disable_completion);
+}
+
+void dcss_disable_dtg_and_ss(struct dcss_dev *dcss)
+{
+	dcss->disable_callback = dcss_disable_dtg_and_ss_cb;
+}
+
+void dcss_enable_dtg_and_ss(struct dcss_dev *dcss)
+{
+	if (dcss->disable_callback)
+		dcss->disable_callback = NULL;
+
+	dcss_dtg_enable(dcss->dtg);
+	dcss_ss_enable(dcss->ss);
+}
+
+static int dcss_submodules_init(struct dcss_dev *dcss)
+{
+	int ret = 0;
+	u32 base_addr = dcss->start_addr;
+	const struct dcss_type_data *devtype = dcss->devtype;
+
+	dcss_clocks_enable(dcss);
+
+	ret = dcss_blkctl_init(dcss, base_addr + devtype->blkctl_ofs);
+	if (ret)
+		return ret;
+
+	ret = dcss_ctxld_init(dcss, base_addr + devtype->ctxld_ofs);
+	if (ret)
+		goto ctxld_err;
+
+	ret = dcss_dtg_init(dcss, base_addr + devtype->dtg_ofs);
+	if (ret)
+		goto dtg_err;
+
+	ret = dcss_ss_init(dcss, base_addr + devtype->ss_ofs);
+	if (ret)
+		goto ss_err;
+
+	ret = dcss_dpr_init(dcss, base_addr + devtype->dpr_ofs);
+	if (ret)
+		goto dpr_err;
+
+	ret = dcss_scaler_init(dcss, base_addr + devtype->scaler_ofs);
+	if (ret)
+		goto scaler_err;
+
+	dcss_clocks_disable(dcss);
+
+	return 0;
+
+scaler_err:
+	dcss_dpr_exit(dcss->dpr);
+
+dpr_err:
+	dcss_ss_exit(dcss->ss);
+
+ss_err:
+	dcss_dtg_exit(dcss->dtg);
+
+dtg_err:
+	dcss_ctxld_exit(dcss->ctxld);
+
+ctxld_err:
+	dcss_blkctl_exit(dcss->blkctl);
+
+	dcss_clocks_disable(dcss);
+
+	return ret;
+}
+
+static void dcss_submodules_stop(struct dcss_dev *dcss)
+{
+	dcss_clocks_enable(dcss);
+	dcss_scaler_exit(dcss->scaler);
+	dcss_dpr_exit(dcss->dpr);
+	dcss_ss_exit(dcss->ss);
+	dcss_dtg_exit(dcss->dtg);
+	dcss_ctxld_exit(dcss->ctxld);
+	dcss_blkctl_exit(dcss->blkctl);
+	dcss_clocks_disable(dcss);
+}
+
+static int dcss_clks_init(struct dcss_dev *dcss)
+{
+	int i;
+	struct {
+		const char *id;
+		struct clk **clk;
+	} clks[] = {
+		{"apb",   &dcss->apb_clk},
+		{"axi",   &dcss->axi_clk},
+		{"pix",   &dcss->pix_clk},
+		{"rtrm",  &dcss->rtrm_clk},
+		{"dtrc",  &dcss->dtrc_clk},
+	};
+
+	for (i = 0; i < ARRAY_SIZE(clks); i++) {
+		*clks[i].clk = devm_clk_get(dcss->dev, clks[i].id);
+		if (IS_ERR(*clks[i].clk)) {
+			dev_err(dcss->dev, "failed to get %s clock\n",
+				clks[i].id);
+			return PTR_ERR(*clks[i].clk);
+		}
+	}
+
+	return 0;
+}
+
+static void dcss_clks_release(struct dcss_dev *dcss)
+{
+	devm_clk_put(dcss->dev, dcss->dtrc_clk);
+	devm_clk_put(dcss->dev, dcss->rtrm_clk);
+	devm_clk_put(dcss->dev, dcss->pix_clk);
+	devm_clk_put(dcss->dev, dcss->axi_clk);
+	devm_clk_put(dcss->dev, dcss->apb_clk);
+}
+
+struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	int ret;
+	struct resource *res;
+	struct dcss_dev *dcss;
+	const struct dcss_type_data *devtype;
+
+	devtype = of_device_get_match_data(dev);
+	if (!devtype) {
+		dev_err(dev, "no device match found\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "cannot get memory resource\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	dcss = kzalloc(sizeof(*dcss), GFP_KERNEL);
+	if (!dcss)
+		return ERR_PTR(-ENOMEM);
+
+	dcss->dev = dev;
+	dcss->devtype = devtype;
+	dcss->hdmi_output = hdmi_output;
+
+	ret = dcss_clks_init(dcss);
+	if (ret) {
+		dev_err(dev, "clocks initialization failed\n");
+		goto err;
+	}
+
+	dcss->of_port = of_graph_get_port_by_id(dev->of_node, 0);
+	if (!dcss->of_port) {
+		dev_err(dev, "no port@0 node in %s\n", dev->of_node->full_name);
+		ret = -ENODEV;
+		goto clks_err;
+	}
+
+	dcss->start_addr = res->start;
+
+	ret = dcss_submodules_init(dcss);
+	if (ret) {
+		dev_err(dev, "submodules initialization failed\n");
+		goto clks_err;
+	}
+
+	init_completion(&dcss->disable_completion);
+
+	pm_runtime_set_autosuspend_delay(dev, 100);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_allow(dev);
+	pm_runtime_enable(dev);
+
+	return dcss;
+
+clks_err:
+	dcss_clks_release(dcss);
+
+err:
+	kfree(dcss);
+
+	return ERR_PTR(ret);
+}
+
+void dcss_dev_destroy(struct dcss_dev *dcss)
+{
+	if (!pm_runtime_suspended(dcss->dev)) {
+		dcss_ctxld_suspend(dcss->ctxld);
+		dcss_clocks_disable(dcss);
+	}
+
+	pm_runtime_disable(dcss->dev);
+
+	dcss_submodules_stop(dcss);
+
+	dcss_clks_release(dcss);
+
+	kfree(dcss);
+}
+
+#ifdef CONFIG_PM_SLEEP
+int dcss_dev_suspend(struct device *dev)
+{
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dev);
+	int ret;
+
+	drm_mode_config_helper_suspend(dcss_drv_dev_to_drm(dev));
+
+	if (pm_runtime_suspended(dev))
+		return 0;
+
+	ret = dcss_ctxld_suspend(dcss->ctxld);
+	if (ret)
+		return ret;
+
+	dcss_clocks_disable(dcss);
+
+	return 0;
+}
+
+int dcss_dev_resume(struct device *dev)
+{
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dev);
+
+	if (pm_runtime_suspended(dev)) {
+		drm_mode_config_helper_resume(dcss_drv_dev_to_drm(dev));
+		return 0;
+	}
+
+	dcss_clocks_enable(dcss);
+
+	dcss_blkctl_cfg(dcss->blkctl);
+
+	dcss_ctxld_resume(dcss->ctxld);
+
+	drm_mode_config_helper_resume(dcss_drv_dev_to_drm(dev));
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM
+int dcss_dev_runtime_suspend(struct device *dev)
+{
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dev);
+	int ret;
+
+	ret = dcss_ctxld_suspend(dcss->ctxld);
+	if (ret)
+		return ret;
+
+	dcss_clocks_disable(dcss);
+
+	return 0;
+}
+
+int dcss_dev_runtime_resume(struct device *dev)
+{
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dev);
+
+	dcss_clocks_enable(dcss);
+
+	dcss_blkctl_cfg(dcss->blkctl);
+
+	dcss_ctxld_resume(dcss->ctxld);
+
+	return 0;
+}
+#endif /* CONFIG_PM */

drivers/gpu/drm/imx/dcss/dcss-dev.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 NXP.
+ */
+
+#ifndef __DCSS_PRV_H__
+#define __DCSS_PRV_H__
+
+#include <drm/drm_fourcc.h>
+#include <linux/io.h>
+#include <video/videomode.h>
+
+#define SET			0x04
+#define CLR			0x08
+#define TGL			0x0C
+
+#define dcss_writel(v, c)	writel((v), (c))
+#define dcss_readl(c)		readl(c)
+#define dcss_set(v, c)		writel((v), (c) + SET)
+#define dcss_clr(v, c)		writel((v), (c) + CLR)
+#define dcss_toggle(v, c)	writel((v), (c) + TGL)
+
+static inline void dcss_update(u32 v, u32 m, void __iomem *c)
+{
+	writel((readl(c) & ~(m)) | (v), (c));
+}
+
+#define DCSS_DBG_REG(reg)	{.name = #reg, .ofs = reg}
+
+enum {
+	DCSS_IMX8MQ = 0,
+};
+
+struct dcss_type_data {
+	const char *name;
+	u32 blkctl_ofs;
+	u32 ctxld_ofs;
+	u32 rdsrc_ofs;
+	u32 wrscl_ofs;
+	u32 dtg_ofs;
+	u32 scaler_ofs;
+	u32 ss_ofs;
+	u32 dpr_ofs;
+	u32 dtrc_ofs;
+	u32 dec400d_ofs;
+	u32 hdr10_ofs;
+};
+
+struct dcss_debug_reg {
+	char *name;
+	u32 ofs;
+};
+
+enum dcss_ctxld_ctx_type {
+	CTX_DB,
+	CTX_SB_HP, /* high-priority */
+	CTX_SB_LP, /* low-priority  */
+};
+
+struct dcss_dev {
+	struct device *dev;
+	const struct dcss_type_data *devtype;
+	struct device_node *of_port;
+
+	u32 start_addr;
+
+	struct dcss_blkctl *blkctl;
+	struct dcss_ctxld *ctxld;
+	struct dcss_dpr *dpr;
+	struct dcss_dtg *dtg;
+	struct dcss_ss *ss;
+	struct dcss_hdr10 *hdr10;
+	struct dcss_scaler *scaler;
+	struct dcss_dtrc *dtrc;
+	struct dcss_dec400d *dec400d;
+	struct dcss_wrscl *wrscl;
+	struct dcss_rdsrc *rdsrc;
+
+	struct clk *apb_clk;
+	struct clk *axi_clk;
+	struct clk *pix_clk;
+	struct clk *rtrm_clk;
+	struct clk *dtrc_clk;
+	struct clk *pll_src_clk;
+	struct clk *pll_phy_ref_clk;
+
+	bool hdmi_output;
+
+	void (*disable_callback)(void *data);
+	struct completion disable_completion;
+};
+
+struct dcss_dev *dcss_drv_dev_to_dcss(struct device *dev);
+struct drm_device *dcss_drv_dev_to_drm(struct device *dev);
+struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output);
+void dcss_dev_destroy(struct dcss_dev *dcss);
+int dcss_dev_runtime_suspend(struct device *dev);
+int dcss_dev_runtime_resume(struct device *dev);
+int dcss_dev_suspend(struct device *dev);
+int dcss_dev_resume(struct device *dev);
+void dcss_enable_dtg_and_ss(struct dcss_dev *dcss);
+void dcss_disable_dtg_and_ss(struct dcss_dev *dcss);
+
+/* BLKCTL */
+int dcss_blkctl_init(struct dcss_dev *dcss, unsigned long blkctl_base);
+void dcss_blkctl_cfg(struct dcss_blkctl *blkctl);
+void dcss_blkctl_exit(struct dcss_blkctl *blkctl);
+
+/* CTXLD */
+int dcss_ctxld_init(struct dcss_dev *dcss, unsigned long ctxld_base);
+void dcss_ctxld_exit(struct dcss_ctxld *ctxld);
+void dcss_ctxld_write(struct dcss_ctxld *ctxld, u32 ctx_id,
+		      u32 val, u32 reg_idx);
+int dcss_ctxld_resume(struct dcss_ctxld *dcss_ctxld);
+int dcss_ctxld_suspend(struct dcss_ctxld *dcss_ctxld);
+void dcss_ctxld_write_irqsafe(struct dcss_ctxld *ctlxd, u32 ctx_id, u32 val,
+			      u32 reg_ofs);
+void dcss_ctxld_kick(struct dcss_ctxld *ctxld);
+bool dcss_ctxld_is_flushed(struct dcss_ctxld *ctxld);
+int dcss_ctxld_enable(struct dcss_ctxld *ctxld);
+void dcss_ctxld_register_completion(struct dcss_ctxld *ctxld,
+				    struct completion *dis_completion);
+void dcss_ctxld_assert_locked(struct dcss_ctxld *ctxld);
+
+/* DPR */
+int dcss_dpr_init(struct dcss_dev *dcss, unsigned long dpr_base);
+void dcss_dpr_exit(struct dcss_dpr *dpr);
+void dcss_dpr_write_sysctrl(struct dcss_dpr *dpr);
+void dcss_dpr_set_res(struct dcss_dpr *dpr, int ch_num, u32 xres, u32 yres);
+void dcss_dpr_addr_set(struct dcss_dpr *dpr, int ch_num, u32 luma_base_addr,
+		       u32 chroma_base_addr, u16 pitch);
+void dcss_dpr_enable(struct dcss_dpr *dpr, int ch_num, bool en);
+void dcss_dpr_format_set(struct dcss_dpr *dpr, int ch_num,
+			 const struct drm_format_info *format, u64 modifier);
+void dcss_dpr_set_rotation(struct dcss_dpr *dpr, int ch_num, u32 rotation);
+
+/* DTG */
+int dcss_dtg_init(struct dcss_dev *dcss, unsigned long dtg_base);
+void dcss_dtg_exit(struct dcss_dtg *dtg);
+bool dcss_dtg_vblank_irq_valid(struct dcss_dtg *dtg);
+void dcss_dtg_vblank_irq_enable(struct dcss_dtg *dtg, bool en);
+void dcss_dtg_vblank_irq_clear(struct dcss_dtg *dtg);
+void dcss_dtg_sync_set(struct dcss_dtg *dtg, struct videomode *vm);
+void dcss_dtg_css_set(struct dcss_dtg *dtg);
+void dcss_dtg_enable(struct dcss_dtg *dtg);
+void dcss_dtg_shutoff(struct dcss_dtg *dtg);
+bool dcss_dtg_is_enabled(struct dcss_dtg *dtg);
+void dcss_dtg_ctxld_kick_irq_enable(struct dcss_dtg *dtg, bool en);
+bool dcss_dtg_global_alpha_changed(struct dcss_dtg *dtg, int ch_num, int alpha);
+void dcss_dtg_plane_alpha_set(struct dcss_dtg *dtg, int ch_num,
+			      const struct drm_format_info *format, int alpha);
+void dcss_dtg_plane_pos_set(struct dcss_dtg *dtg, int ch_num,
+			    int px, int py, int pw, int ph);
+void dcss_dtg_ch_enable(struct dcss_dtg *dtg, int ch_num, bool en);
+
+/* SUBSAM */
+int dcss_ss_init(struct dcss_dev *dcss, unsigned long subsam_base);
+void dcss_ss_exit(struct dcss_ss *ss);
+void dcss_ss_enable(struct dcss_ss *ss);
+void dcss_ss_shutoff(struct dcss_ss *ss);
+void dcss_ss_subsam_set(struct dcss_ss *ss);
+void dcss_ss_sync_set(struct dcss_ss *ss, struct videomode *vm,
+		      bool phsync, bool pvsync);
+
+/* SCALER */
+int dcss_scaler_init(struct dcss_dev *dcss, unsigned long scaler_base);
+void dcss_scaler_exit(struct dcss_scaler *scl);
+void dcss_scaler_setup(struct dcss_scaler *scl, int ch_num,
+		       const struct drm_format_info *format,
+		       int src_xres, int src_yres, int dst_xres, int dst_yres,
+		       u32 vrefresh_hz);
+void dcss_scaler_ch_enable(struct dcss_scaler *scl, int ch_num, bool en);
+int dcss_scaler_get_min_max_ratios(struct dcss_scaler *scl, int ch_num,
+				   int *min, int *max);
+void dcss_scaler_write_sclctrl(struct dcss_scaler *scl);
+
+#endif /* __DCSS_PRV_H__ */

drivers/gpu/drm/imx/dcss/dcss-dpr.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_DPR_SYSTEM_CTRL0			0x000
+#define   RUN_EN				BIT(0)
+#define   SOFT_RESET				BIT(1)
+#define   REPEAT_EN				BIT(2)
+#define   SHADOW_LOAD_EN			BIT(3)
+#define   SW_SHADOW_LOAD_SEL			BIT(4)
+#define   BCMD2AXI_MSTR_ID_CTRL			BIT(16)
+#define DCSS_DPR_IRQ_MASK			0x020
+#define DCSS_DPR_IRQ_MASK_STATUS		0x030
+#define DCSS_DPR_IRQ_NONMASK_STATUS		0x040
+#define   IRQ_DPR_CTRL_DONE			BIT(0)
+#define   IRQ_DPR_RUN				BIT(1)
+#define   IRQ_DPR_SHADOW_LOADED			BIT(2)
+#define   IRQ_AXI_READ_ERR			BIT(3)
+#define   DPR2RTR_YRGB_FIFO_OVFL		BIT(4)
+#define   DPR2RTR_UV_FIFO_OVFL			BIT(5)
+#define   DPR2RTR_FIFO_LD_BUF_RDY_YRGB_ERR	BIT(6)
+#define   DPR2RTR_FIFO_LD_BUF_RDY_UV_ERR	BIT(7)
+#define DCSS_DPR_MODE_CTRL0			0x050
+#define   RTR_3BUF_EN				BIT(0)
+#define   RTR_4LINE_BUF_EN			BIT(1)
+#define   TILE_TYPE_POS				2
+#define   TILE_TYPE_MASK			GENMASK(4, 2)
+#define   YUV_EN				BIT(6)
+#define   COMP_2PLANE_EN			BIT(7)
+#define   PIX_SIZE_POS				8
+#define   PIX_SIZE_MASK				GENMASK(9, 8)
+#define   PIX_LUMA_UV_SWAP			BIT(10)
+#define   PIX_UV_SWAP				BIT(11)
+#define   B_COMP_SEL_POS			12
+#define   B_COMP_SEL_MASK			GENMASK(13, 12)
+#define   G_COMP_SEL_POS			14
+#define   G_COMP_SEL_MASK			GENMASK(15, 14)
+#define   R_COMP_SEL_POS			16
+#define   R_COMP_SEL_MASK			GENMASK(17, 16)
+#define   A_COMP_SEL_POS			18
+#define   A_COMP_SEL_MASK			GENMASK(19, 18)
+#define DCSS_DPR_FRAME_CTRL0			0x070
+#define   HFLIP_EN				BIT(0)
+#define   VFLIP_EN				BIT(1)
+#define   ROT_ENC_POS				2
+#define   ROT_ENC_MASK				GENMASK(3, 2)
+#define   ROT_FLIP_ORDER_EN			BIT(4)
+#define   PITCH_POS				16
+#define   PITCH_MASK				GENMASK(31, 16)
+#define DCSS_DPR_FRAME_1P_CTRL0			0x090
+#define DCSS_DPR_FRAME_1P_PIX_X_CTRL		0x0A0
+#define DCSS_DPR_FRAME_1P_PIX_Y_CTRL		0x0B0
+#define DCSS_DPR_FRAME_1P_BASE_ADDR		0x0C0
+#define DCSS_DPR_FRAME_2P_CTRL0			0x0E0
+#define DCSS_DPR_FRAME_2P_PIX_X_CTRL		0x0F0
+#define DCSS_DPR_FRAME_2P_PIX_Y_CTRL		0x100
+#define DCSS_DPR_FRAME_2P_BASE_ADDR		0x110
+#define DCSS_DPR_STATUS_CTRL0			0x130
+#define   STATUS_MUX_SEL_MASK			GENMASK(2, 0)
+#define   STATUS_SRC_SEL_POS			16
+#define   STATUS_SRC_SEL_MASK			GENMASK(18, 16)
+#define DCSS_DPR_STATUS_CTRL1			0x140
+#define DCSS_DPR_RTRAM_CTRL0			0x200
+#define   NUM_ROWS_ACTIVE			BIT(0)
+#define   THRES_HIGH_POS			1
+#define   THRES_HIGH_MASK			GENMASK(3, 1)
+#define   THRES_LOW_POS				4
+#define   THRES_LOW_MASK			GENMASK(6, 4)
+#define   ABORT_SEL				BIT(7)
+
+enum dcss_tile_type {
+	TILE_LINEAR = 0,
+	TILE_GPU_STANDARD,
+	TILE_GPU_SUPER,
+	TILE_VPU_YUV420,
+	TILE_VPU_VP9,
+};
+
+enum dcss_pix_size {
+	PIX_SIZE_8,
+	PIX_SIZE_16,
+	PIX_SIZE_32,
+};
+
+struct dcss_dpr_ch {
+	struct dcss_dpr *dpr;
+	void __iomem *base_reg;
+	u32 base_ofs;
+
+	struct drm_format_info format;
+	enum dcss_pix_size pix_size;
+	enum dcss_tile_type tile;
+	bool rtram_4line_en;
+	bool rtram_3buf_en;
+
+	u32 frame_ctrl;
+	u32 mode_ctrl;
+	u32 sys_ctrl;
+	u32 rtram_ctrl;
+
+	bool sys_ctrl_chgd;
+
+	int ch_num;
+	int irq;
+};
+
+struct dcss_dpr {
+	struct device *dev;
+	struct dcss_ctxld *ctxld;
+	u32  ctx_id;
+
+	struct dcss_dpr_ch ch[3];
+};
+
+static void dcss_dpr_write(struct dcss_dpr_ch *ch, u32 val, u32 ofs)
+{
+	struct dcss_dpr *dpr = ch->dpr;
+
+	dcss_ctxld_write(dpr->ctxld, dpr->ctx_id, val, ch->base_ofs + ofs);
+}
+
+static int dcss_dpr_ch_init_all(struct dcss_dpr *dpr, unsigned long dpr_base)
+{
+	struct dcss_dpr_ch *ch;
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		ch = &dpr->ch[i];
+
+		ch->base_ofs = dpr_base + i * 0x1000;
+
+		ch->base_reg = ioremap(ch->base_ofs, SZ_4K);
+		if (!ch->base_reg) {
+			dev_err(dpr->dev, "dpr: unable to remap ch %d base\n",
+				i);
+			return -ENOMEM;
+		}
+
+		ch->dpr = dpr;
+		ch->ch_num = i;
+
+		dcss_writel(0xff, ch->base_reg + DCSS_DPR_IRQ_MASK);
+	}
+
+	return 0;
+}
+
+int dcss_dpr_init(struct dcss_dev *dcss, unsigned long dpr_base)
+{
+	struct dcss_dpr *dpr;
+
+	dpr = kzalloc(sizeof(*dpr), GFP_KERNEL);
+	if (!dpr)
+		return -ENOMEM;
+
+	dcss->dpr = dpr;
+	dpr->dev = dcss->dev;
+	dpr->ctxld = dcss->ctxld;
+	dpr->ctx_id = CTX_SB_HP;
+
+	if (dcss_dpr_ch_init_all(dpr, dpr_base)) {
+		int i;
+
+		for (i = 0; i < 3; i++) {
+			if (dpr->ch[i].base_reg)
+				iounmap(dpr->ch[i].base_reg);
+		}
+
+		kfree(dpr);
+
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void dcss_dpr_exit(struct dcss_dpr *dpr)
+{
+	int ch_no;
+
+	/* stop DPR on all channels */
+	for (ch_no = 0; ch_no < 3; ch_no++) {
+		struct dcss_dpr_ch *ch = &dpr->ch[ch_no];
+
+		dcss_writel(0, ch->base_reg + DCSS_DPR_SYSTEM_CTRL0);
+
+		if (ch->base_reg)
+			iounmap(ch->base_reg);
+	}
+
+	kfree(dpr);
+}
+
+static u32 dcss_dpr_x_pix_wide_adjust(struct dcss_dpr_ch *ch, u32 pix_wide,
+				      u32 pix_format)
+{
+	u8 pix_in_64byte_map[3][5] = {
+		/* LIN, GPU_STD, GPU_SUP, VPU_YUV420, VPU_VP9 */
+		{   64,       8,       8,          8,     16}, /* PIX_SIZE_8  */
+		{   32,       8,       8,          8,      8}, /* PIX_SIZE_16 */
+		{   16,       4,       4,          8,      8}, /* PIX_SIZE_32 */
+	};
+	u32 offset;
+	u32 div_64byte_mod, pix_in_64byte;
+
+	pix_in_64byte = pix_in_64byte_map[ch->pix_size][ch->tile];
+
+	div_64byte_mod = pix_wide % pix_in_64byte;
+	offset = (div_64byte_mod == 0) ? 0 : (pix_in_64byte - div_64byte_mod);
+
+	return pix_wide + offset;
+}
+
+static u32 dcss_dpr_y_pix_high_adjust(struct dcss_dpr_ch *ch, u32 pix_high,
+				      u32 pix_format)
+{
+	u8 num_rows_buf = ch->rtram_4line_en ? 4 : 8;
+	u32 offset, pix_y_mod;
+
+	pix_y_mod = pix_high % num_rows_buf;
+	offset = pix_y_mod ? (num_rows_buf - pix_y_mod) : 0;
+
+	return pix_high + offset;
+}
+
+void dcss_dpr_set_res(struct dcss_dpr *dpr, int ch_num, u32 xres, u32 yres)
+{
+	struct dcss_dpr_ch *ch = &dpr->ch[ch_num];
+	u32 pix_format = ch->format.format;
+	u32 gap = DCSS_DPR_FRAME_2P_BASE_ADDR - DCSS_DPR_FRAME_1P_BASE_ADDR;
+	int plane, max_planes = 1;
+	u32 pix_x_wide, pix_y_high;
+
+	if (pix_format == DRM_FORMAT_NV12 ||
+	    pix_format == DRM_FORMAT_NV21)
+		max_planes = 2;
+
+	for (plane = 0; plane < max_planes; plane++) {
+		yres = plane == 1 ? yres >> 1 : yres;
+
+		pix_x_wide = dcss_dpr_x_pix_wide_adjust(ch, xres, pix_format);
+		pix_y_high = dcss_dpr_y_pix_high_adjust(ch, yres, pix_format);
+
+		dcss_dpr_write(ch, pix_x_wide,
+			       DCSS_DPR_FRAME_1P_PIX_X_CTRL + plane * gap);
+		dcss_dpr_write(ch, pix_y_high,
+			       DCSS_DPR_FRAME_1P_PIX_Y_CTRL + plane * gap);
+
+		dcss_dpr_write(ch, 2, DCSS_DPR_FRAME_1P_CTRL0 + plane * gap);
+	}
+}
+
+void dcss_dpr_addr_set(struct dcss_dpr *dpr, int ch_num, u32 luma_base_addr,
+		       u32 chroma_base_addr, u16 pitch)
+{
+	struct dcss_dpr_ch *ch = &dpr->ch[ch_num];
+
+	dcss_dpr_write(ch, luma_base_addr, DCSS_DPR_FRAME_1P_BASE_ADDR);
+
+	dcss_dpr_write(ch, chroma_base_addr, DCSS_DPR_FRAME_2P_BASE_ADDR);
+
+	ch->frame_ctrl &= ~PITCH_MASK;
+	ch->frame_ctrl |= (((u32)pitch << PITCH_POS) & PITCH_MASK);
+}
+
+static void dcss_dpr_argb_comp_sel(struct dcss_dpr_ch *ch, int a_sel, int r_sel,
+				   int g_sel, int b_sel)
+{
+	u32 sel;
+
+	sel = ((a_sel << A_COMP_SEL_POS) & A_COMP_SEL_MASK) |
+	      ((r_sel << R_COMP_SEL_POS) & R_COMP_SEL_MASK) |
+	      ((g_sel << G_COMP_SEL_POS) & G_COMP_SEL_MASK) |
+	      ((b_sel << B_COMP_SEL_POS) & B_COMP_SEL_MASK);
+
+	ch->mode_ctrl &= ~(A_COMP_SEL_MASK | R_COMP_SEL_MASK |
+			   G_COMP_SEL_MASK | B_COMP_SEL_MASK);
+	ch->mode_ctrl |= sel;
+}
+
+static void dcss_dpr_pix_size_set(struct dcss_dpr_ch *ch,
+				  const struct drm_format_info *format)
+{
+	u32 val;
+
+	switch (format->format) {
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV21:
+		val = PIX_SIZE_8;
+		break;
+
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_YVYU:
+		val = PIX_SIZE_16;
+		break;
+
+	default:
+		val = PIX_SIZE_32;
+		break;
+	}
+
+	ch->pix_size = val;
+
+	ch->mode_ctrl &= ~PIX_SIZE_MASK;
+	ch->mode_ctrl |= ((val << PIX_SIZE_POS) & PIX_SIZE_MASK);
+}
+
+static void dcss_dpr_uv_swap(struct dcss_dpr_ch *ch, bool swap)
+{
+	ch->mode_ctrl &= ~PIX_UV_SWAP;
+	ch->mode_ctrl |= (swap ? PIX_UV_SWAP : 0);
+}
+
+static void dcss_dpr_y_uv_swap(struct dcss_dpr_ch *ch, bool swap)
+{
+	ch->mode_ctrl &= ~PIX_LUMA_UV_SWAP;
+	ch->mode_ctrl |= (swap ? PIX_LUMA_UV_SWAP : 0);
+}
+
+static void dcss_dpr_2plane_en(struct dcss_dpr_ch *ch, bool en)
+{
+	ch->mode_ctrl &= ~COMP_2PLANE_EN;
+	ch->mode_ctrl |= (en ? COMP_2PLANE_EN : 0);
+}
+
+static void dcss_dpr_yuv_en(struct dcss_dpr_ch *ch, bool en)
+{
+	ch->mode_ctrl &= ~YUV_EN;
+	ch->mode_ctrl |= (en ? YUV_EN : 0);
+}
+
+void dcss_dpr_enable(struct dcss_dpr *dpr, int ch_num, bool en)
+{
+	struct dcss_dpr_ch *ch = &dpr->ch[ch_num];
+	u32 sys_ctrl;
+
+	sys_ctrl = (en ? REPEAT_EN | RUN_EN : 0);
+
+	if (en) {
+		dcss_dpr_write(ch, ch->mode_ctrl, DCSS_DPR_MODE_CTRL0);
+		dcss_dpr_write(ch, ch->frame_ctrl, DCSS_DPR_FRAME_CTRL0);
+		dcss_dpr_write(ch, ch->rtram_ctrl, DCSS_DPR_RTRAM_CTRL0);
+	}
+
+	if (ch->sys_ctrl != sys_ctrl)
+		ch->sys_ctrl_chgd = true;
+
+	ch->sys_ctrl = sys_ctrl;
+}
+
+struct rgb_comp_sel {
+	u32 drm_format;
+	int a_sel;
+	int r_sel;
+	int g_sel;
+	int b_sel;
+};
+
+static struct rgb_comp_sel comp_sel_map[] = {
+	{DRM_FORMAT_ARGB8888, 3, 2, 1, 0},
+	{DRM_FORMAT_XRGB8888, 3, 2, 1, 0},
+	{DRM_FORMAT_ABGR8888, 3, 0, 1, 2},
+	{DRM_FORMAT_XBGR8888, 3, 0, 1, 2},
+	{DRM_FORMAT_RGBA8888, 0, 3, 2, 1},
+	{DRM_FORMAT_RGBX8888, 0, 3, 2, 1},
+	{DRM_FORMAT_BGRA8888, 0, 1, 2, 3},
+	{DRM_FORMAT_BGRX8888, 0, 1, 2, 3},
+};
+
+static int to_comp_sel(u32 pix_fmt, int *a_sel, int *r_sel, int *g_sel,
+		       int *b_sel)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(comp_sel_map); i++) {
+		if (comp_sel_map[i].drm_format == pix_fmt) {
+			*a_sel = comp_sel_map[i].a_sel;
+			*r_sel = comp_sel_map[i].r_sel;
+			*g_sel = comp_sel_map[i].g_sel;
+			*b_sel = comp_sel_map[i].b_sel;
+
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+static void dcss_dpr_rtram_set(struct dcss_dpr_ch *ch, u32 pix_format)
+{
+	u32 val, mask;
+
+	switch (pix_format) {
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV12:
+		ch->rtram_3buf_en = true;
+		ch->rtram_4line_en = false;
+		break;
+
+	default:
+		ch->rtram_3buf_en = true;
+		ch->rtram_4line_en = true;
+		break;
+	}
+
+	val = (ch->rtram_4line_en ? RTR_4LINE_BUF_EN : 0);
+	val |= (ch->rtram_3buf_en ? RTR_3BUF_EN : 0);
+	mask = RTR_4LINE_BUF_EN | RTR_3BUF_EN;
+
+	ch->mode_ctrl &= ~mask;
+	ch->mode_ctrl |= (val & mask);
+
+	val = (ch->rtram_4line_en ? 0 : NUM_ROWS_ACTIVE);
+	val |= (3 << THRES_LOW_POS) & THRES_LOW_MASK;
+	val |= (4 << THRES_HIGH_POS) & THRES_HIGH_MASK;
+	mask = THRES_LOW_MASK | THRES_HIGH_MASK | NUM_ROWS_ACTIVE;
+
+	ch->rtram_ctrl &= ~mask;
+	ch->rtram_ctrl |= (val & mask);
+}
+
+static void dcss_dpr_setup_components(struct dcss_dpr_ch *ch,
+				      const struct drm_format_info *format)
+{
+	int a_sel, r_sel, g_sel, b_sel;
+	bool uv_swap, y_uv_swap;
+
+	switch (format->format) {
+	case DRM_FORMAT_YVYU:
+		uv_swap = true;
+		y_uv_swap = true;
+		break;
+
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_NV21:
+		uv_swap = true;
+		y_uv_swap = false;
+		break;
+
+	case DRM_FORMAT_YUYV:
+		uv_swap = false;
+		y_uv_swap = true;
+		break;
+
+	default:
+		uv_swap = false;
+		y_uv_swap = false;
+		break;
+	}
+
+	dcss_dpr_uv_swap(ch, uv_swap);
+
+	dcss_dpr_y_uv_swap(ch, y_uv_swap);
+
+	if (!format->is_yuv) {
+		if (!to_comp_sel(format->format, &a_sel, &r_sel,
+				 &g_sel, &b_sel)) {
+			dcss_dpr_argb_comp_sel(ch, a_sel, r_sel, g_sel, b_sel);
+		} else {
+			dcss_dpr_argb_comp_sel(ch, 3, 2, 1, 0);
+		}
+	} else {
+		dcss_dpr_argb_comp_sel(ch, 0, 0, 0, 0);
+	}
+}
+
+static void dcss_dpr_tile_set(struct dcss_dpr_ch *ch, uint64_t modifier)
+{
+	switch (ch->ch_num) {
+	case 0:
+		switch (modifier) {
+		case DRM_FORMAT_MOD_LINEAR:
+			ch->tile = TILE_LINEAR;
+			break;
+		case DRM_FORMAT_MOD_VIVANTE_TILED:
+			ch->tile = TILE_GPU_STANDARD;
+			break;
+		case DRM_FORMAT_MOD_VIVANTE_SUPER_TILED:
+			ch->tile = TILE_GPU_SUPER;
+			break;
+		default:
+			WARN_ON(1);
+			break;
+		}
+		break;
+	case 1:
+	case 2:
+		ch->tile = TILE_LINEAR;
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
+
+	ch->mode_ctrl &= ~TILE_TYPE_MASK;
+	ch->mode_ctrl |= ((ch->tile << TILE_TYPE_POS) & TILE_TYPE_MASK);
+}
+
+void dcss_dpr_format_set(struct dcss_dpr *dpr, int ch_num,
+			 const struct drm_format_info *format, u64 modifier)
+{
+	struct dcss_dpr_ch *ch = &dpr->ch[ch_num];
+
+	ch->format = *format;
+
+	dcss_dpr_yuv_en(ch, format->is_yuv);
+
+	dcss_dpr_pix_size_set(ch, format);
+
+	dcss_dpr_setup_components(ch, format);
+
+	dcss_dpr_2plane_en(ch, format->num_planes == 2);
+
+	dcss_dpr_rtram_set(ch, format->format);
+
+	dcss_dpr_tile_set(ch, modifier);
+}
+
+/* This function will be called from interrupt context. */
+void dcss_dpr_write_sysctrl(struct dcss_dpr *dpr)
+{
+	int chnum;
+
+	dcss_ctxld_assert_locked(dpr->ctxld);
+
+	for (chnum = 0; chnum < 3; chnum++) {
+		struct dcss_dpr_ch *ch = &dpr->ch[chnum];
+
+		if (ch->sys_ctrl_chgd) {
+			dcss_ctxld_write_irqsafe(dpr->ctxld, dpr->ctx_id,
+						 ch->sys_ctrl,
+						 ch->base_ofs +
+						 DCSS_DPR_SYSTEM_CTRL0);
+			ch->sys_ctrl_chgd = false;
+		}
+	}
+}
+
+void dcss_dpr_set_rotation(struct dcss_dpr *dpr, int ch_num, u32 rotation)
+{
+	struct dcss_dpr_ch *ch = &dpr->ch[ch_num];
+
+	ch->frame_ctrl &= ~(HFLIP_EN | VFLIP_EN | ROT_ENC_MASK);
+
+	ch->frame_ctrl |= rotation & DRM_MODE_REFLECT_X ? HFLIP_EN : 0;
+	ch->frame_ctrl |= rotation & DRM_MODE_REFLECT_Y ? VFLIP_EN : 0;
+
+	if (rotation & DRM_MODE_ROTATE_90)
+		ch->frame_ctrl |= 1 << ROT_ENC_POS;
+	else if (rotation & DRM_MODE_ROTATE_180)
+		ch->frame_ctrl |= 2 << ROT_ENC_POS;
+	else if (rotation & DRM_MODE_ROTATE_270)
+		ch->frame_ctrl |= 3 << ROT_ENC_POS;
+}

drivers/gpu/drm/imx/dcss/dcss-drv.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <drm/drm_of.h>
+
+#include "dcss-dev.h"
+#include "dcss-kms.h"
+
+struct dcss_drv {
+	struct dcss_dev *dcss;
+	struct dcss_kms_dev *kms;
+};
+
+struct dcss_dev *dcss_drv_dev_to_dcss(struct device *dev)
+{
+	struct dcss_drv *mdrv = dev_get_drvdata(dev);
+
+	return mdrv ? mdrv->dcss : NULL;
+}
+
+struct drm_device *dcss_drv_dev_to_drm(struct device *dev)
+{
+	struct dcss_drv *mdrv = dev_get_drvdata(dev);
+
+	return mdrv ? &mdrv->kms->base : NULL;
+}
+
+static int dcss_drv_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *remote;
+	struct dcss_drv *mdrv;
+	int err = 0;
+	bool hdmi_output = true;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	remote = of_graph_get_remote_node(dev->of_node, 0, 0);
+	if (!remote)
+		return -ENODEV;
+
+	hdmi_output = !of_device_is_compatible(remote, "fsl,imx8mq-nwl-dsi");
+
+	of_node_put(remote);
+
+	mdrv = kzalloc(sizeof(*mdrv), GFP_KERNEL);
+	if (!mdrv)
+		return -ENOMEM;
+
+	mdrv->dcss = dcss_dev_create(dev, hdmi_output);
+	if (IS_ERR(mdrv->dcss)) {
+		err = PTR_ERR(mdrv->dcss);
+		goto err;
+	}
+
+	dev_set_drvdata(dev, mdrv);
+
+	mdrv->kms = dcss_kms_attach(mdrv->dcss);
+	if (IS_ERR(mdrv->kms)) {
+		err = PTR_ERR(mdrv->kms);
+		goto dcss_shutoff;
+	}
+
+	return 0;
+
+dcss_shutoff:
+	dcss_dev_destroy(mdrv->dcss);
+
+	dev_set_drvdata(dev, NULL);
+
+err:
+	kfree(mdrv);
+	return err;
+}
+
+static int dcss_drv_platform_remove(struct platform_device *pdev)
+{
+	struct dcss_drv *mdrv = dev_get_drvdata(&pdev->dev);
+
+	if (!mdrv)
+		return 0;
+
+	dcss_kms_detach(mdrv->kms);
+	dcss_dev_destroy(mdrv->dcss);
+
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	kfree(mdrv);
+
+	return 0;
+}
+
+static struct dcss_type_data dcss_types[] = {
+	[DCSS_IMX8MQ] = {
+		.name = "DCSS_IMX8MQ",
+		.blkctl_ofs = 0x2F000,
+		.ctxld_ofs = 0x23000,
+		.dtg_ofs = 0x20000,
+		.scaler_ofs = 0x1C000,
+		.ss_ofs = 0x1B000,
+		.dpr_ofs = 0x18000,
+	},
+};
+
+static const struct of_device_id dcss_of_match[] = {
+	{ .compatible = "nxp,imx8mq-dcss", .data = &dcss_types[DCSS_IMX8MQ], },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, dcss_of_match);
+
+static const struct dev_pm_ops dcss_dev_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(dcss_dev_suspend, dcss_dev_resume)
+	SET_RUNTIME_PM_OPS(dcss_dev_runtime_suspend,
+			   dcss_dev_runtime_resume, NULL)
+};
+
+static struct platform_driver dcss_platform_driver = {
+	.probe	= dcss_drv_platform_probe,
+	.remove	= dcss_drv_platform_remove,
+	.driver	= {
+		.name = "imx-dcss",
+		.of_match_table	= dcss_of_match,
+		.pm = &dcss_dev_pm,
+	},
+};
+
+module_platform_driver(dcss_platform_driver);
+
+MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@nxp.com>");
+MODULE_DESCRIPTION("DCSS driver for i.MX8MQ");
+MODULE_LICENSE("GPL v2");

drivers/gpu/drm/imx/dcss/dcss-dtg.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_DTG_TC_CONTROL_STATUS			0x00
+#define   CH3_EN					BIT(0)
+#define   CH2_EN					BIT(1)
+#define   CH1_EN					BIT(2)
+#define   OVL_DATA_MODE					BIT(3)
+#define   BLENDER_VIDEO_ALPHA_SEL			BIT(7)
+#define   DTG_START					BIT(8)
+#define   DBY_MODE_EN					BIT(9)
+#define   CH1_ALPHA_SEL					BIT(10)
+#define   CSS_PIX_COMP_SWAP_POS				12
+#define   CSS_PIX_COMP_SWAP_MASK			GENMASK(14, 12)
+#define   DEFAULT_FG_ALPHA_POS				24
+#define   DEFAULT_FG_ALPHA_MASK				GENMASK(31, 24)
+#define DCSS_DTG_TC_DTG					0x04
+#define DCSS_DTG_TC_DISP_TOP				0x08
+#define DCSS_DTG_TC_DISP_BOT				0x0C
+#define DCSS_DTG_TC_CH1_TOP				0x10
+#define DCSS_DTG_TC_CH1_BOT				0x14
+#define DCSS_DTG_TC_CH2_TOP				0x18
+#define DCSS_DTG_TC_CH2_BOT				0x1C
+#define DCSS_DTG_TC_CH3_TOP				0x20
+#define DCSS_DTG_TC_CH3_BOT				0x24
+#define   TC_X_POS					0
+#define   TC_X_MASK					GENMASK(12, 0)
+#define   TC_Y_POS					16
+#define   TC_Y_MASK					GENMASK(28, 16)
+#define DCSS_DTG_TC_CTXLD				0x28
+#define   TC_CTXLD_DB_Y_POS				0
+#define   TC_CTXLD_DB_Y_MASK				GENMASK(12, 0)
+#define   TC_CTXLD_SB_Y_POS				16
+#define   TC_CTXLD_SB_Y_MASK				GENMASK(28, 16)
+#define DCSS_DTG_TC_CH1_BKRND				0x2C
+#define DCSS_DTG_TC_CH2_BKRND				0x30
+#define   BKRND_R_Y_COMP_POS				20
+#define   BKRND_R_Y_COMP_MASK				GENMASK(29, 20)
+#define   BKRND_G_U_COMP_POS				10
+#define   BKRND_G_U_COMP_MASK				GENMASK(19, 10)
+#define   BKRND_B_V_COMP_POS				0
+#define   BKRND_B_V_COMP_MASK				GENMASK(9, 0)
+#define DCSS_DTG_BLENDER_DBY_RANGEINV			0x38
+#define DCSS_DTG_BLENDER_DBY_RANGEMIN			0x3C
+#define DCSS_DTG_BLENDER_DBY_BDP			0x40
+#define DCSS_DTG_BLENDER_BKRND_I			0x44
+#define DCSS_DTG_BLENDER_BKRND_P			0x48
+#define DCSS_DTG_BLENDER_BKRND_T			0x4C
+#define DCSS_DTG_LINE0_INT				0x50
+#define DCSS_DTG_LINE1_INT				0x54
+#define DCSS_DTG_BG_ALPHA_DEFAULT			0x58
+#define DCSS_DTG_INT_STATUS				0x5C
+#define DCSS_DTG_INT_CONTROL				0x60
+#define DCSS_DTG_TC_CH3_BKRND				0x64
+#define DCSS_DTG_INT_MASK				0x68
+#define   LINE0_IRQ					BIT(0)
+#define   LINE1_IRQ					BIT(1)
+#define   LINE2_IRQ					BIT(2)
+#define   LINE3_IRQ					BIT(3)
+#define DCSS_DTG_LINE2_INT				0x6C
+#define DCSS_DTG_LINE3_INT				0x70
+#define DCSS_DTG_DBY_OL					0x74
+#define DCSS_DTG_DBY_BL					0x78
+#define DCSS_DTG_DBY_EL					0x7C
+
+struct dcss_dtg {
+	struct device *dev;
+	struct dcss_ctxld *ctxld;
+	void __iomem *base_reg;
+	u32 base_ofs;
+
+	u32 ctx_id;
+
+	bool in_use;
+
+	u32 dis_ulc_x;
+	u32 dis_ulc_y;
+
+	u32 control_status;
+	u32 alpha;
+	u32 alpha_cfg;
+
+	int ctxld_kick_irq;
+	bool ctxld_kick_irq_en;
+};
+
+static void dcss_dtg_write(struct dcss_dtg *dtg, u32 val, u32 ofs)
+{
+	if (!dtg->in_use)
+		dcss_writel(val, dtg->base_reg + ofs);
+
+	dcss_ctxld_write(dtg->ctxld, dtg->ctx_id,
+			 val, dtg->base_ofs + ofs);
+}
+
+static irqreturn_t dcss_dtg_irq_handler(int irq, void *data)
+{
+	struct dcss_dtg *dtg = data;
+	u32 status;
+
+	status = dcss_readl(dtg->base_reg + DCSS_DTG_INT_STATUS);
+
+	if (!(status & LINE0_IRQ))
+		return IRQ_NONE;
+
+	dcss_ctxld_kick(dtg->ctxld);
+
+	dcss_writel(status & LINE0_IRQ, dtg->base_reg + DCSS_DTG_INT_CONTROL);
+
+	return IRQ_HANDLED;
+}
+
+static int dcss_dtg_irq_config(struct dcss_dtg *dtg,
+			       struct platform_device *pdev)
+{
+	int ret;
+
+	dtg->ctxld_kick_irq = platform_get_irq_byname(pdev, "ctxld_kick");
+	if (dtg->ctxld_kick_irq < 0)
+		return dtg->ctxld_kick_irq;
+
+	dcss_update(0, LINE0_IRQ | LINE1_IRQ,
+		    dtg->base_reg + DCSS_DTG_INT_MASK);
+
+	ret = request_irq(dtg->ctxld_kick_irq, dcss_dtg_irq_handler,
+			  0, "dcss_ctxld_kick", dtg);
+	if (ret) {
+		dev_err(dtg->dev, "dtg: irq request failed.\n");
+		return ret;
+	}
+
+	disable_irq(dtg->ctxld_kick_irq);
+
+	dtg->ctxld_kick_irq_en = false;
+
+	return 0;
+}
+
+int dcss_dtg_init(struct dcss_dev *dcss, unsigned long dtg_base)
+{
+	int ret = 0;
+	struct dcss_dtg *dtg;
+
+	dtg = kzalloc(sizeof(*dtg), GFP_KERNEL);
+	if (!dtg)
+		return -ENOMEM;
+
+	dcss->dtg = dtg;
+	dtg->dev = dcss->dev;
+	dtg->ctxld = dcss->ctxld;
+
+	dtg->base_reg = ioremap(dtg_base, SZ_4K);
+	if (!dtg->base_reg) {
+		dev_err(dcss->dev, "dtg: unable to remap dtg base\n");
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	dtg->base_ofs = dtg_base;
+	dtg->ctx_id = CTX_DB;
+
+	dtg->alpha = 255;
+
+	dtg->control_status |= OVL_DATA_MODE | BLENDER_VIDEO_ALPHA_SEL |
+		((dtg->alpha << DEFAULT_FG_ALPHA_POS) & DEFAULT_FG_ALPHA_MASK);
+
+	ret = dcss_dtg_irq_config(dtg, to_platform_device(dcss->dev));
+	if (ret)
+		goto err_irq;
+
+	return 0;
+
+err_irq:
+	iounmap(dtg->base_reg);
+
+err_ioremap:
+	kfree(dtg);
+
+	return ret;
+}
+
+void dcss_dtg_exit(struct dcss_dtg *dtg)
+{
+	free_irq(dtg->ctxld_kick_irq, dtg);
+
+	if (dtg->base_reg)
+		iounmap(dtg->base_reg);
+
+	kfree(dtg);
+}
+
+void dcss_dtg_sync_set(struct dcss_dtg *dtg, struct videomode *vm)
+{
+	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dtg->dev);
+	u16 dtg_lrc_x, dtg_lrc_y;
+	u16 dis_ulc_x, dis_ulc_y;
+	u16 dis_lrc_x, dis_lrc_y;
+	u32 sb_ctxld_trig, db_ctxld_trig;
+	u32 pixclock = vm->pixelclock;
+	u32 actual_clk;
+
+	dtg_lrc_x = vm->hfront_porch + vm->hback_porch + vm->hsync_len +
+		    vm->hactive - 1;
+	dtg_lrc_y = vm->vfront_porch + vm->vback_porch + vm->vsync_len +
+		    vm->vactive - 1;
+	dis_ulc_x = vm->hsync_len + vm->hback_porch - 1;
+	dis_ulc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch - 1;
+	dis_lrc_x = vm->hsync_len + vm->hback_porch + vm->hactive - 1;
+	dis_lrc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch +
+		    vm->vactive - 1;
+
+	clk_disable_unprepare(dcss->pix_clk);
+	clk_set_rate(dcss->pix_clk, vm->pixelclock);
+	clk_prepare_enable(dcss->pix_clk);
+
+	actual_clk = clk_get_rate(dcss->pix_clk);
+	if (pixclock != actual_clk) {
+		dev_info(dtg->dev,
+			 "Pixel clock set to %u kHz instead of %u kHz.\n",
+			 (actual_clk / 1000), (pixclock / 1000));
+	}
+
+	dcss_dtg_write(dtg, ((dtg_lrc_y << TC_Y_POS) | dtg_lrc_x),
+		       DCSS_DTG_TC_DTG);
+	dcss_dtg_write(dtg, ((dis_ulc_y << TC_Y_POS) | dis_ulc_x),
+		       DCSS_DTG_TC_DISP_TOP);
+	dcss_dtg_write(dtg, ((dis_lrc_y << TC_Y_POS) | dis_lrc_x),
+		       DCSS_DTG_TC_DISP_BOT);
+
+	dtg->dis_ulc_x = dis_ulc_x;
+	dtg->dis_ulc_y = dis_ulc_y;
+
+	sb_ctxld_trig = ((0 * dis_lrc_y / 100) << TC_CTXLD_SB_Y_POS) &
+							TC_CTXLD_SB_Y_MASK;
+	db_ctxld_trig = ((99 * dis_lrc_y / 100) << TC_CTXLD_DB_Y_POS) &
+							TC_CTXLD_DB_Y_MASK;
+
+	dcss_dtg_write(dtg, sb_ctxld_trig | db_ctxld_trig, DCSS_DTG_TC_CTXLD);
+
+	/* vblank trigger */
+	dcss_dtg_write(dtg, 0, DCSS_DTG_LINE1_INT);
+
+	/* CTXLD trigger */
+	dcss_dtg_write(dtg, ((90 * dis_lrc_y) / 100) << 16, DCSS_DTG_LINE0_INT);
+}
+
+void dcss_dtg_plane_pos_set(struct dcss_dtg *dtg, int ch_num,
+			    int px, int py, int pw, int ph)
+{
+	u16 p_ulc_x, p_ulc_y;
+	u16 p_lrc_x, p_lrc_y;
+
+	p_ulc_x = dtg->dis_ulc_x + px;
+	p_ulc_y = dtg->dis_ulc_y + py;
+	p_lrc_x = p_ulc_x + pw;
+	p_lrc_y = p_ulc_y + ph;
+
+	if (!px && !py && !pw && !ph) {
+		dcss_dtg_write(dtg, 0, DCSS_DTG_TC_CH1_TOP + 0x8 * ch_num);
+		dcss_dtg_write(dtg, 0, DCSS_DTG_TC_CH1_BOT + 0x8 * ch_num);
+	} else {
+		dcss_dtg_write(dtg, ((p_ulc_y << TC_Y_POS) | p_ulc_x),
+			       DCSS_DTG_TC_CH1_TOP + 0x8 * ch_num);
+		dcss_dtg_write(dtg, ((p_lrc_y << TC_Y_POS) | p_lrc_x),
+			       DCSS_DTG_TC_CH1_BOT + 0x8 * ch_num);
+	}
+}
+
+bool dcss_dtg_global_alpha_changed(struct dcss_dtg *dtg, int ch_num, int alpha)
+{
+	if (ch_num)
+		return false;
+
+	return alpha != dtg->alpha;
+}
+
+void dcss_dtg_plane_alpha_set(struct dcss_dtg *dtg, int ch_num,
+			      const struct drm_format_info *format, int alpha)
+{
+	/* we care about alpha only when channel 0 is concerned */
+	if (ch_num)
+		return;
+
+	/*
+	 * Use global alpha if pixel format does not have alpha channel or the
+	 * user explicitly chose to use global alpha (i.e. alpha is not OPAQUE).
+	 */
+	if (!format->has_alpha || alpha != 255)
+		dtg->alpha_cfg = (alpha << DEFAULT_FG_ALPHA_POS) & DEFAULT_FG_ALPHA_MASK;
+	else /* use per-pixel alpha otherwise */
+		dtg->alpha_cfg = CH1_ALPHA_SEL;
+
+	dtg->alpha = alpha;
+}
+
+void dcss_dtg_css_set(struct dcss_dtg *dtg)
+{
+	dtg->control_status |=
+			(0x5 << CSS_PIX_COMP_SWAP_POS) & CSS_PIX_COMP_SWAP_MASK;
+}
+
+void dcss_dtg_enable(struct dcss_dtg *dtg)
+{
+	dtg->control_status |= DTG_START;
+
+	dtg->control_status &= ~(CH1_ALPHA_SEL | DEFAULT_FG_ALPHA_MASK);
+	dtg->control_status |= dtg->alpha_cfg;
+
+	dcss_dtg_write(dtg, dtg->control_status, DCSS_DTG_TC_CONTROL_STATUS);
+
+	dtg->in_use = true;
+}
+
+void dcss_dtg_shutoff(struct dcss_dtg *dtg)
+{
+	dtg->control_status &= ~DTG_START;
+
+	dcss_writel(dtg->control_status,
+		    dtg->base_reg + DCSS_DTG_TC_CONTROL_STATUS);
+
+	dtg->in_use = false;
+}
+
+bool dcss_dtg_is_enabled(struct dcss_dtg *dtg)
+{
+	return dtg->in_use;
+}
+
+void dcss_dtg_ch_enable(struct dcss_dtg *dtg, int ch_num, bool en)
+{
+	u32 ch_en_map[] = {CH1_EN, CH2_EN, CH3_EN};
+	u32 control_status;
+
+	control_status = dtg->control_status & ~ch_en_map[ch_num];
+	control_status |= en ? ch_en_map[ch_num] : 0;
+
+	control_status &= ~(CH1_ALPHA_SEL | DEFAULT_FG_ALPHA_MASK);
+	control_status |= dtg->alpha_cfg;
+
+	if (dtg->control_status != control_status)
+		dcss_dtg_write(dtg, control_status, DCSS_DTG_TC_CONTROL_STATUS);
+
+	dtg->control_status = control_status;
+}
+
+void dcss_dtg_vblank_irq_enable(struct dcss_dtg *dtg, bool en)
+{
+	u32 status;
+	u32 mask = en ? LINE1_IRQ : 0;
+
+	if (en) {
+		status = dcss_readl(dtg->base_reg + DCSS_DTG_INT_STATUS);
+		dcss_writel(status & LINE1_IRQ,
+			    dtg->base_reg + DCSS_DTG_INT_CONTROL);
+	}
+
+	dcss_update(mask, LINE1_IRQ, dtg->base_reg + DCSS_DTG_INT_MASK);
+}
+
+void dcss_dtg_ctxld_kick_irq_enable(struct dcss_dtg *dtg, bool en)
+{
+	u32 status;
+	u32 mask = en ? LINE0_IRQ : 0;
+
+	if (en) {
+		status = dcss_readl(dtg->base_reg + DCSS_DTG_INT_STATUS);
+
+		if (!dtg->ctxld_kick_irq_en) {
+			dcss_writel(status & LINE0_IRQ,
+				    dtg->base_reg + DCSS_DTG_INT_CONTROL);
+			enable_irq(dtg->ctxld_kick_irq);
+			dtg->ctxld_kick_irq_en = true;
+			dcss_update(mask, LINE0_IRQ,
+				    dtg->base_reg + DCSS_DTG_INT_MASK);
+		}
+
+		return;
+	}
+
+	if (!dtg->ctxld_kick_irq_en)
+		return;
+
+	disable_irq_nosync(dtg->ctxld_kick_irq);
+	dtg->ctxld_kick_irq_en = false;
+
+	dcss_update(mask, LINE0_IRQ, dtg->base_reg + DCSS_DTG_INT_MASK);
+}
+
+void dcss_dtg_vblank_irq_clear(struct dcss_dtg *dtg)
+{
+	dcss_update(LINE1_IRQ, LINE1_IRQ, dtg->base_reg + DCSS_DTG_INT_CONTROL);
+}
+
+bool dcss_dtg_vblank_irq_valid(struct dcss_dtg *dtg)
+{
+	return !!(dcss_readl(dtg->base_reg + DCSS_DTG_INT_STATUS) & LINE1_IRQ);
+}
+

drivers/gpu/drm/imx/dcss/dcss-kms.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "dcss-dev.h"
+#include "dcss-kms.h"
+
+DEFINE_DRM_GEM_CMA_FOPS(dcss_cma_fops);
+
+static const struct drm_mode_config_funcs dcss_drm_mode_config_funcs = {
+	.fb_create = drm_gem_fb_create,
+	.output_poll_changed = drm_fb_helper_output_poll_changed,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static struct drm_driver dcss_kms_driver = {
+	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+	.gem_free_object_unlocked = drm_gem_cma_free_object,
+	.gem_vm_ops		= &drm_gem_cma_vm_ops,
+	.dumb_create		= drm_gem_cma_dumb_create,
+
+	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
+	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
+	.gem_prime_import	= drm_gem_prime_import,
+	.gem_prime_export	= drm_gem_prime_export,
+	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
+	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
+	.gem_prime_vmap		= drm_gem_cma_prime_vmap,
+	.gem_prime_vunmap	= drm_gem_cma_prime_vunmap,
+	.gem_prime_mmap		= drm_gem_cma_prime_mmap,
+	.fops			= &dcss_cma_fops,
+	.name			= "imx-dcss",
+	.desc			= "i.MX8MQ Display Subsystem",
+	.date			= "20190917",
+	.major			= 1,
+	.minor			= 0,
+	.patchlevel		= 0,
+};
+
+static const struct drm_mode_config_helper_funcs dcss_mode_config_helpers = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+static void dcss_kms_mode_config_init(struct dcss_kms_dev *kms)
+{
+	struct drm_mode_config *config = &kms->base.mode_config;
+
+	drm_mode_config_init(&kms->base);
+
+	config->min_width = 1;
+	config->min_height = 1;
+	config->max_width = 4096;
+	config->max_height = 4096;
+	config->allow_fb_modifiers = true;
+	config->normalize_zpos = true;
+
+	config->funcs = &dcss_drm_mode_config_funcs;
+	config->helper_private = &dcss_mode_config_helpers;
+}
+
+static const struct drm_encoder_funcs dcss_kms_simple_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static int dcss_kms_setup_encoder(struct dcss_kms_dev *kms)
+{
+	struct drm_device *ddev = &kms->base;
+	struct drm_encoder *encoder = &kms->encoder;
+	struct drm_crtc *crtc = (struct drm_crtc *)&kms->crtc;
+	struct drm_panel *panel;
+	struct drm_bridge *bridge;
+	int ret;
+
+	ret = drm_of_find_panel_or_bridge(ddev->dev->of_node, 0, 0,
+					  &panel, &bridge);
+	if (ret)
+		return ret;
+
+	if (!bridge) {
+		dev_err(ddev->dev, "No bridge found %d.\n", ret);
+		return -ENODEV;
+	}
+
+	encoder->possible_crtcs = drm_crtc_mask(crtc);
+
+	ret = drm_encoder_init(&kms->base, encoder,
+			       &dcss_kms_simple_encoder_funcs,
+			       DRM_MODE_ENCODER_NONE, NULL);
+	if (ret) {
+		dev_err(ddev->dev, "Failed initializing encoder %d.\n", ret);
+		return ret;
+	}
+
+	return drm_bridge_attach(encoder, bridge, NULL, 0);
+}
+
+struct dcss_kms_dev *dcss_kms_attach(struct dcss_dev *dcss)
+{
+	struct dcss_kms_dev *kms;
+	struct drm_device *drm;
+	struct dcss_crtc *crtc;
+	int ret;
+
+	kms = devm_drm_dev_alloc(dcss->dev, &dcss_kms_driver,
+				 struct dcss_kms_dev, base);
+	if (IS_ERR(kms))
+		return kms;
+
+	drm = &kms->base;
+	crtc = &kms->crtc;
+
+	drm->dev_private = dcss;
+
+	dcss_kms_mode_config_init(kms);
+
+	ret = drm_vblank_init(drm, 1);
+	if (ret)
+		goto cleanup_mode_config;
+
+	drm->irq_enabled = true;
+
+	ret = dcss_crtc_init(crtc, drm);
+	if (ret)
+		goto cleanup_mode_config;
+
+	ret = dcss_kms_setup_encoder(kms);
+	if (ret)
+		goto cleanup_crtc;
+
+	drm_mode_config_reset(drm);
+
+	drm_kms_helper_poll_init(drm);
+
+	ret = drm_dev_register(drm, 0);
+	if (ret)
+		goto cleanup_crtc;
+
+	drm_fbdev_generic_setup(drm, 32);
+
+	return kms;
+
+cleanup_crtc:
+	drm_kms_helper_poll_fini(drm);
+	dcss_crtc_deinit(crtc, drm);
+
+cleanup_mode_config:
+	drm_mode_config_cleanup(drm);
+	drm->dev_private = NULL;
+
+	return ERR_PTR(ret);
+}
+
+void dcss_kms_detach(struct dcss_kms_dev *kms)
+{
+	struct drm_device *drm = &kms->base;
+
+	drm_dev_unregister(drm);
+	drm_kms_helper_poll_fini(drm);
+	drm_atomic_helper_shutdown(drm);
+	drm_crtc_vblank_off(&kms->crtc.base);
+	drm->irq_enabled = false;
+	drm_mode_config_cleanup(drm);
+	dcss_crtc_deinit(&kms->crtc, drm);
+	drm->dev_private = NULL;
+}

drivers/gpu/drm/imx/dcss/dcss-kms.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 NXP.
+ */
+
+#ifndef _DCSS_KMS_H_
+#define _DCSS_KMS_H_
+
+#include <drm/drm_encoder.h>
+
+struct dcss_plane {
+	struct drm_plane base;
+
+	int ch_num;
+};
+
+struct dcss_crtc {
+	struct drm_crtc		base;
+	struct drm_crtc_state	*state;
+
+	struct dcss_plane	*plane[3];
+
+	int			irq;
+
+	bool disable_ctxld_kick_irq;
+};
+
+struct dcss_kms_dev {
+	struct drm_device base;
+	struct dcss_crtc crtc;
+	struct drm_encoder encoder;
+};
+
+struct dcss_kms_dev *dcss_kms_attach(struct dcss_dev *dcss);
+void dcss_kms_detach(struct dcss_kms_dev *kms);
+int dcss_crtc_init(struct dcss_crtc *crtc, struct drm_device *drm);
+void dcss_crtc_deinit(struct dcss_crtc *crtc, struct drm_device *drm);
+struct dcss_plane *dcss_plane_init(struct drm_device *drm,
+				   unsigned int possible_crtcs,
+				   enum drm_plane_type type,
+				   unsigned int zpos);
+
+#endif

drivers/gpu/drm/imx/dcss/dcss-plane.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include "dcss-dev.h"
+#include "dcss-kms.h"
+
+static const u32 dcss_common_formats[] = {
+	/* RGB */
+	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ABGR8888,
+	DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_RGBA8888,
+	DRM_FORMAT_RGBX8888,
+	DRM_FORMAT_BGRA8888,
+	DRM_FORMAT_BGRX8888,
+	DRM_FORMAT_XRGB2101010,
+	DRM_FORMAT_XBGR2101010,
+	DRM_FORMAT_RGBX1010102,
+	DRM_FORMAT_BGRX1010102,
+	DRM_FORMAT_ARGB2101010,
+	DRM_FORMAT_ABGR2101010,
+	DRM_FORMAT_RGBA1010102,
+	DRM_FORMAT_BGRA1010102,
+};
+
+static const u64 dcss_video_format_modifiers[] = {
+	DRM_FORMAT_MOD_LINEAR,
+	DRM_FORMAT_MOD_INVALID,
+};
+
+static const u64 dcss_graphics_format_modifiers[] = {
+	DRM_FORMAT_MOD_VIVANTE_TILED,
+	DRM_FORMAT_MOD_VIVANTE_SUPER_TILED,
+	DRM_FORMAT_MOD_LINEAR,
+	DRM_FORMAT_MOD_INVALID,
+};
+
+static inline struct dcss_plane *to_dcss_plane(struct drm_plane *p)
+{
+	return container_of(p, struct dcss_plane, base);
+}
+
+static inline bool dcss_plane_fb_is_linear(const struct drm_framebuffer *fb)
+{
+	return ((fb->flags & DRM_MODE_FB_MODIFIERS) == 0) ||
+	       ((fb->flags & DRM_MODE_FB_MODIFIERS) != 0 &&
+		fb->modifier == DRM_FORMAT_MOD_LINEAR);
+}
+
+static void dcss_plane_destroy(struct drm_plane *plane)
+{
+	struct dcss_plane *dcss_plane = container_of(plane, struct dcss_plane,
+						     base);
+
+	drm_plane_cleanup(plane);
+	kfree(dcss_plane);
+}
+
+static bool dcss_plane_format_mod_supported(struct drm_plane *plane,
+					    u32 format,
+					    u64 modifier)
+{
+	switch (plane->type) {
+	case DRM_PLANE_TYPE_PRIMARY:
+		switch (format) {
+		case DRM_FORMAT_ARGB8888:
+		case DRM_FORMAT_XRGB8888:
+		case DRM_FORMAT_ARGB2101010:
+			return modifier == DRM_FORMAT_MOD_LINEAR ||
+			       modifier == DRM_FORMAT_MOD_VIVANTE_TILED ||
+			       modifier == DRM_FORMAT_MOD_VIVANTE_SUPER_TILED;
+		default:
+			return modifier == DRM_FORMAT_MOD_LINEAR;
+		}
+		break;
+	case DRM_PLANE_TYPE_OVERLAY:
+		return modifier == DRM_FORMAT_MOD_LINEAR;
+	default:
+		return false;
+	}
+}
+
+static const struct drm_plane_funcs dcss_plane_funcs = {
+	.update_plane		= drm_atomic_helper_update_plane,
+	.disable_plane		= drm_atomic_helper_disable_plane,
+	.destroy		= dcss_plane_destroy,
+	.reset			= drm_atomic_helper_plane_reset,
+	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+	.format_mod_supported	= dcss_plane_format_mod_supported,
+};
+
+static bool dcss_plane_can_rotate(const struct drm_format_info *format,
+				  bool mod_present, u64 modifier,
+				  unsigned int rotation)
+{
+	bool linear_format = !mod_present ||
+			     (mod_present && modifier == DRM_FORMAT_MOD_LINEAR);
+	u32 supported_rotation = DRM_MODE_ROTATE_0;
+
+	if (!format->is_yuv && linear_format)
+		supported_rotation = DRM_MODE_ROTATE_0 | DRM_MODE_ROTATE_180 |
+				     DRM_MODE_REFLECT_MASK;
+	else if (!format->is_yuv &&
+		 modifier == DRM_FORMAT_MOD_VIVANTE_TILED)
+		supported_rotation = DRM_MODE_ROTATE_MASK |
+				     DRM_MODE_REFLECT_MASK;
+	else if (format->is_yuv && linear_format &&
+		 (format->format == DRM_FORMAT_NV12 ||
+		  format->format == DRM_FORMAT_NV21))
+		supported_rotation = DRM_MODE_ROTATE_0 | DRM_MODE_ROTATE_180 |
+				     DRM_MODE_REFLECT_MASK;
+
+	return !!(rotation & supported_rotation);
+}
+
+static bool dcss_plane_is_source_size_allowed(u16 src_w, u16 src_h, u32 pix_fmt)
+{
+	if (src_w < 64 &&
+	    (pix_fmt == DRM_FORMAT_NV12 || pix_fmt == DRM_FORMAT_NV21))
+		return false;
+	else if (src_w < 32 &&
+		 (pix_fmt == DRM_FORMAT_UYVY || pix_fmt == DRM_FORMAT_VYUY ||
+		  pix_fmt == DRM_FORMAT_YUYV || pix_fmt == DRM_FORMAT_YVYU))
+		return false;
+
+	return src_w >= 16 && src_h >= 8;
+}
+
+static int dcss_plane_atomic_check(struct drm_plane *plane,
+				   struct drm_plane_state *state)
+{
+	struct dcss_plane *dcss_plane = to_dcss_plane(plane);
+	struct dcss_dev *dcss = plane->dev->dev_private;
+	struct drm_framebuffer *fb = state->fb;
+	bool is_primary_plane = plane->type == DRM_PLANE_TYPE_PRIMARY;
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_crtc_state *crtc_state;
+	int hdisplay, vdisplay;
+	int min, max;
+	int ret;
+
+	if (!fb || !state->crtc)
+		return 0;
+
+	cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+	WARN_ON(!cma_obj);
+
+	crtc_state = drm_atomic_get_existing_crtc_state(state->state,
+							state->crtc);
+
+	hdisplay = crtc_state->adjusted_mode.hdisplay;
+	vdisplay = crtc_state->adjusted_mode.vdisplay;
+
+	if (!dcss_plane_is_source_size_allowed(state->src_w >> 16,
+					       state->src_h >> 16,
+					       fb->format->format)) {
+		DRM_DEBUG_KMS("Source plane size is not allowed!\n");
+		return -EINVAL;
+	}
+
+	dcss_scaler_get_min_max_ratios(dcss->scaler, dcss_plane->ch_num,
+				       &min, &max);
+
+	ret = drm_atomic_helper_check_plane_state(state, crtc_state,
+						  min, max, !is_primary_plane,
+						  false);
+	if (ret)
+		return ret;
+
+	if (!state->visible)
+		return 0;
+
+	if (!dcss_plane_can_rotate(fb->format,
+				   !!(fb->flags & DRM_MODE_FB_MODIFIERS),
+				   fb->modifier,
+				   state->rotation)) {
+		DRM_DEBUG_KMS("requested rotation is not allowed!\n");
+		return -EINVAL;
+	}
+
+	if ((state->crtc_x < 0 || state->crtc_y < 0 ||
+	     state->crtc_x + state->crtc_w > hdisplay ||
+	     state->crtc_y + state->crtc_h > vdisplay) &&
+	    !dcss_plane_fb_is_linear(fb)) {
+		DRM_DEBUG_KMS("requested cropping operation is not allowed!\n");
+		return -EINVAL;
+	}
+
+	if ((fb->flags & DRM_MODE_FB_MODIFIERS) &&
+	    !plane->funcs->format_mod_supported(plane,
+				fb->format->format,
+				fb->modifier)) {
+		DRM_DEBUG_KMS("Invalid modifier: %llx", fb->modifier);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void dcss_plane_atomic_set_base(struct dcss_plane *dcss_plane)
+{
+	struct drm_plane *plane = &dcss_plane->base;
+	struct drm_plane_state *state = plane->state;
+	struct dcss_dev *dcss = plane->dev->dev_private;
+	struct drm_framebuffer *fb = state->fb;
+	const struct drm_format_info *format = fb->format;
+	struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+	unsigned long p1_ba = 0, p2_ba = 0;
+
+	if (!format->is_yuv ||
+	    format->format == DRM_FORMAT_NV12 ||
+	    format->format == DRM_FORMAT_NV21)
+		p1_ba = cma_obj->paddr + fb->offsets[0] +
+			fb->pitches[0] * (state->src.y1 >> 16) +
+			format->char_per_block[0] * (state->src.x1 >> 16);
+	else if (format->format == DRM_FORMAT_UYVY ||
+		 format->format == DRM_FORMAT_VYUY ||
+		 format->format == DRM_FORMAT_YUYV ||
+		 format->format == DRM_FORMAT_YVYU)
+		p1_ba = cma_obj->paddr + fb->offsets[0] +
+			fb->pitches[0] * (state->src.y1 >> 16) +
+			2 * format->char_per_block[0] * (state->src.x1 >> 17);
+
+	if (format->format == DRM_FORMAT_NV12 ||
+	    format->format == DRM_FORMAT_NV21)
+		p2_ba = cma_obj->paddr + fb->offsets[1] +
+			(((fb->pitches[1] >> 1) * (state->src.y1 >> 17) +
+			(state->src.x1 >> 17)) << 1);
+
+	dcss_dpr_addr_set(dcss->dpr, dcss_plane->ch_num, p1_ba, p2_ba,
+			  fb->pitches[0]);
+}
+
+static bool dcss_plane_needs_setup(struct drm_plane_state *state,
+				   struct drm_plane_state *old_state)
+{
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_framebuffer *old_fb = old_state->fb;
+
+	return state->crtc_x != old_state->crtc_x ||
+	       state->crtc_y != old_state->crtc_y ||
+	       state->crtc_w != old_state->crtc_w ||
+	       state->crtc_h != old_state->crtc_h ||
+	       state->src_x  != old_state->src_x  ||
+	       state->src_y  != old_state->src_y  ||
+	       state->src_w  != old_state->src_w  ||
+	       state->src_h  != old_state->src_h  ||
+	       fb->format->format != old_fb->format->format ||
+	       fb->modifier  != old_fb->modifier ||
+	       state->rotation != old_state->rotation;
+}
+
+static void dcss_plane_atomic_update(struct drm_plane *plane,
+				     struct drm_plane_state *old_state)
+{
+	struct drm_plane_state *state = plane->state;
+	struct dcss_plane *dcss_plane = to_dcss_plane(plane);
+	struct dcss_dev *dcss = plane->dev->dev_private;
+	struct drm_framebuffer *fb = state->fb;
+	u32 pixel_format;
+	struct drm_crtc_state *crtc_state;
+	bool modifiers_present;
+	u32 src_w, src_h, dst_w, dst_h;
+	struct drm_rect src, dst;
+	bool enable = true;
+
+	if (!fb || !state->crtc || !state->visible)
+		return;
+
+	pixel_format = state->fb->format->format;
+	crtc_state = state->crtc->state;
+	modifiers_present = !!(fb->flags & DRM_MODE_FB_MODIFIERS);
+
+	if (old_state->fb && !drm_atomic_crtc_needs_modeset(crtc_state) &&
+	    !dcss_plane_needs_setup(state, old_state)) {
+		dcss_plane_atomic_set_base(dcss_plane);
+		return;
+	}
+
+	src = plane->state->src;
+	dst = plane->state->dst;
+
+	/*
+	 * The width and height after clipping.
+	 */
+	src_w = drm_rect_width(&src) >> 16;
+	src_h = drm_rect_height(&src) >> 16;
+	dst_w = drm_rect_width(&dst);
+	dst_h = drm_rect_height(&dst);
+
+	if (plane->type == DRM_PLANE_TYPE_OVERLAY &&
+	    modifiers_present && fb->modifier == DRM_FORMAT_MOD_LINEAR)
+		modifiers_present = false;
+
+	dcss_dpr_format_set(dcss->dpr, dcss_plane->ch_num, state->fb->format,
+			    modifiers_present ? fb->modifier :
+						DRM_FORMAT_MOD_LINEAR);
+	dcss_dpr_set_res(dcss->dpr, dcss_plane->ch_num, src_w, src_h);
+	dcss_dpr_set_rotation(dcss->dpr, dcss_plane->ch_num,
+			      state->rotation);
+
+	dcss_plane_atomic_set_base(dcss_plane);
+
+	dcss_scaler_setup(dcss->scaler, dcss_plane->ch_num,
+			  state->fb->format, src_w, src_h,
+			  dst_w, dst_h,
+			  drm_mode_vrefresh(&crtc_state->mode));
+
+	dcss_dtg_plane_pos_set(dcss->dtg, dcss_plane->ch_num,
+			       dst.x1, dst.y1, dst_w, dst_h);
+	dcss_dtg_plane_alpha_set(dcss->dtg, dcss_plane->ch_num,
+				 fb->format, state->alpha >> 8);
+
+	if (!dcss_plane->ch_num && (state->alpha >> 8) == 0)
+		enable = false;
+
+	dcss_dpr_enable(dcss->dpr, dcss_plane->ch_num, enable);
+	dcss_scaler_ch_enable(dcss->scaler, dcss_plane->ch_num, enable);
+
+	if (!enable)
+		dcss_dtg_plane_pos_set(dcss->dtg, dcss_plane->ch_num,
+				       0, 0, 0, 0);
+
+	dcss_dtg_ch_enable(dcss->dtg, dcss_plane->ch_num, enable);
+}
+
+static void dcss_plane_atomic_disable(struct drm_plane *plane,
+				      struct drm_plane_state *old_state)
+{
+	struct dcss_plane *dcss_plane = to_dcss_plane(plane);
+	struct dcss_dev *dcss = plane->dev->dev_private;
+
+	dcss_dpr_enable(dcss->dpr, dcss_plane->ch_num, false);
+	dcss_scaler_ch_enable(dcss->scaler, dcss_plane->ch_num, false);
+	dcss_dtg_plane_pos_set(dcss->dtg, dcss_plane->ch_num, 0, 0, 0, 0);
+	dcss_dtg_ch_enable(dcss->dtg, dcss_plane->ch_num, false);
+}
+
+static const struct drm_plane_helper_funcs dcss_plane_helper_funcs = {
+	.prepare_fb = drm_gem_fb_prepare_fb,
+	.atomic_check = dcss_plane_atomic_check,
+	.atomic_update = dcss_plane_atomic_update,
+	.atomic_disable = dcss_plane_atomic_disable,
+};
+
+struct dcss_plane *dcss_plane_init(struct drm_device *drm,
+				   unsigned int possible_crtcs,
+				   enum drm_plane_type type,
+				   unsigned int zpos)
+{
+	struct dcss_plane *dcss_plane;
+	const u64 *format_modifiers = dcss_video_format_modifiers;
+	int ret;
+
+	if (zpos > 2)
+		return ERR_PTR(-EINVAL);
+
+	dcss_plane = kzalloc(sizeof(*dcss_plane), GFP_KERNEL);
+	if (!dcss_plane) {
+		DRM_ERROR("failed to allocate plane\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	if (type == DRM_PLANE_TYPE_PRIMARY)
+		format_modifiers = dcss_graphics_format_modifiers;
+
+	ret = drm_universal_plane_init(drm, &dcss_plane->base, possible_crtcs,
+				       &dcss_plane_funcs, dcss_common_formats,
+				       ARRAY_SIZE(dcss_common_formats),
+				       format_modifiers, type, NULL);
+	if (ret) {
+		DRM_ERROR("failed to initialize plane\n");
+		kfree(dcss_plane);
+		return ERR_PTR(ret);
+	}
+
+	drm_plane_helper_add(&dcss_plane->base, &dcss_plane_helper_funcs);
+
+	ret = drm_plane_create_zpos_immutable_property(&dcss_plane->base, zpos);
+	if (ret)
+		return ERR_PTR(ret);
+
+	drm_plane_create_rotation_property(&dcss_plane->base,
+					   DRM_MODE_ROTATE_0,
+					   DRM_MODE_ROTATE_0   |
+					   DRM_MODE_ROTATE_90  |
+					   DRM_MODE_ROTATE_180 |
+					   DRM_MODE_ROTATE_270 |
+					   DRM_MODE_REFLECT_X  |
+					   DRM_MODE_REFLECT_Y);
+
+	dcss_plane->ch_num = zpos;
+
+	return dcss_plane;
+}

drivers/gpu/drm/imx/dcss/dcss-scaler.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ *
+ * Scaling algorithms were contributed by Dzung Hoang <dzung.hoang@nxp.com>
+ */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_SCALER_CTRL			0x00
+#define   SCALER_EN				BIT(0)
+#define   REPEAT_EN				BIT(4)
+#define   SCALE2MEM_EN				BIT(8)
+#define   MEM2OFIFO_EN				BIT(12)
+#define DCSS_SCALER_OFIFO_CTRL			0x04
+#define   OFIFO_LOW_THRES_POS			0
+#define   OFIFO_LOW_THRES_MASK			GENMASK(9, 0)
+#define   OFIFO_HIGH_THRES_POS			16
+#define   OFIFO_HIGH_THRES_MASK			GENMASK(25, 16)
+#define   UNDERRUN_DETECT_CLR			BIT(26)
+#define   LOW_THRES_DETECT_CLR			BIT(27)
+#define   HIGH_THRES_DETECT_CLR			BIT(28)
+#define   UNDERRUN_DETECT_EN			BIT(29)
+#define   LOW_THRES_DETECT_EN			BIT(30)
+#define   HIGH_THRES_DETECT_EN			BIT(31)
+#define DCSS_SCALER_SDATA_CTRL			0x08
+#define   YUV_EN				BIT(0)
+#define   RTRAM_8LINES				BIT(1)
+#define   Y_UV_BYTE_SWAP			BIT(4)
+#define   A2R10G10B10_FORMAT_POS		8
+#define   A2R10G10B10_FORMAT_MASK		GENMASK(11, 8)
+#define DCSS_SCALER_BIT_DEPTH			0x0C
+#define   LUM_BIT_DEPTH_POS			0
+#define   LUM_BIT_DEPTH_MASK			GENMASK(1, 0)
+#define   CHR_BIT_DEPTH_POS			4
+#define   CHR_BIT_DEPTH_MASK			GENMASK(5, 4)
+#define DCSS_SCALER_SRC_FORMAT			0x10
+#define DCSS_SCALER_DST_FORMAT			0x14
+#define   FORMAT_MASK				GENMASK(1, 0)
+#define DCSS_SCALER_SRC_LUM_RES			0x18
+#define DCSS_SCALER_SRC_CHR_RES			0x1C
+#define DCSS_SCALER_DST_LUM_RES			0x20
+#define DCSS_SCALER_DST_CHR_RES			0x24
+#define   WIDTH_POS				0
+#define   WIDTH_MASK				GENMASK(11, 0)
+#define   HEIGHT_POS				16
+#define   HEIGHT_MASK				GENMASK(27, 16)
+#define DCSS_SCALER_V_LUM_START			0x48
+#define   V_START_MASK				GENMASK(15, 0)
+#define DCSS_SCALER_V_LUM_INC			0x4C
+#define   V_INC_MASK				GENMASK(15, 0)
+#define DCSS_SCALER_H_LUM_START			0x50
+#define   H_START_MASK				GENMASK(18, 0)
+#define DCSS_SCALER_H_LUM_INC			0x54
+#define   H_INC_MASK				GENMASK(15, 0)
+#define DCSS_SCALER_V_CHR_START			0x58
+#define DCSS_SCALER_V_CHR_INC			0x5C
+#define DCSS_SCALER_H_CHR_START			0x60
+#define DCSS_SCALER_H_CHR_INC			0x64
+#define DCSS_SCALER_COEF_VLUM			0x80
+#define DCSS_SCALER_COEF_HLUM			0x140
+#define DCSS_SCALER_COEF_VCHR			0x200
+#define DCSS_SCALER_COEF_HCHR			0x300
+
+struct dcss_scaler_ch {
+	void __iomem *base_reg;
+	u32 base_ofs;
+	struct dcss_scaler *scl;
+
+	u32 sdata_ctrl;
+	u32 scaler_ctrl;
+
+	bool scaler_ctrl_chgd;
+
+	u32 c_vstart;
+	u32 c_hstart;
+};
+
+struct dcss_scaler {
+	struct device *dev;
+
+	struct dcss_ctxld *ctxld;
+	u32 ctx_id;
+
+	struct dcss_scaler_ch ch[3];
+};
+
+/* scaler coefficients generator */
+#define PSC_FRAC_BITS 30
+#define PSC_FRAC_SCALE BIT(PSC_FRAC_BITS)
+#define PSC_BITS_FOR_PHASE 4
+#define PSC_NUM_PHASES 16
+#define PSC_STORED_PHASES (PSC_NUM_PHASES / 2 + 1)
+#define PSC_NUM_TAPS 7
+#define PSC_NUM_TAPS_RGBA 5
+#define PSC_COEFF_PRECISION 10
+#define PSC_PHASE_FRACTION_BITS 13
+#define PSC_PHASE_MASK (PSC_NUM_PHASES - 1)
+#define PSC_Q_FRACTION 19
+#define PSC_Q_ROUND_OFFSET (1 << (PSC_Q_FRACTION - 1))
+
+/**
+ * mult_q() - Performs fixed-point multiplication.
+ * @A: multiplier
+ * @B: multiplicand
+ */
+static int mult_q(int A, int B)
+{
+	int result;
+	s64 temp;
+
+	temp = (int64_t)A * (int64_t)B;
+	temp += PSC_Q_ROUND_OFFSET;
+	result = (int)(temp >> PSC_Q_FRACTION);
+	return result;
+}
+
+/**
+ * div_q() - Performs fixed-point division.
+ * @A: dividend
+ * @B: divisor
+ */
+static int div_q(int A, int B)
+{
+	int result;
+	s64 temp;
+
+	temp = (int64_t)A << PSC_Q_FRACTION;
+	if ((temp >= 0 && B >= 0) || (temp < 0 && B < 0))
+		temp += B / 2;
+	else
+		temp -= B / 2;
+
+	result = (int)(temp / B);
+	return result;
+}
+
+/**
+ * exp_approx_q() - Compute approximation to exp(x) function using Taylor
+ *		    series.
+ * @x: fixed-point argument of exp function
+ */
+static int exp_approx_q(int x)
+{
+	int sum = 1 << PSC_Q_FRACTION;
+	int term = 1 << PSC_Q_FRACTION;
+
+	term = mult_q(term, div_q(x, 1 << PSC_Q_FRACTION));
+	sum += term;
+	term = mult_q(term, div_q(x, 2 << PSC_Q_FRACTION));
+	sum += term;
+	term = mult_q(term, div_q(x, 3 << PSC_Q_FRACTION));
+	sum += term;
+	term = mult_q(term, div_q(x, 4 << PSC_Q_FRACTION));
+	sum += term;
+
+	return sum;
+}
+
+/**
+ * dcss_scaler_gaussian_filter() - Generate gaussian prototype filter.
+ * @fc_q: fixed-point cutoff frequency normalized to range [0, 1]
+ * @use_5_taps: indicates whether to use 5 taps or 7 taps
+ * @coef: output filter coefficients
+ */
+static void dcss_scaler_gaussian_filter(int fc_q, bool use_5_taps,
+					bool phase0_identity,
+					int coef[][PSC_NUM_TAPS])
+{
+	int sigma_q, g0_q, g1_q, g2_q;
+	int tap_cnt1, tap_cnt2, tap_idx, phase_cnt;
+	int mid;
+	int phase;
+	int i;
+	int taps;
+
+	if (use_5_taps)
+		for (phase = 0; phase < PSC_STORED_PHASES; phase++) {
+			coef[phase][0] = 0;
+			coef[phase][PSC_NUM_TAPS - 1] = 0;
+		}
+
+	/* seed coefficient scanner */
+	taps = use_5_taps ? PSC_NUM_TAPS_RGBA : PSC_NUM_TAPS;
+	mid = (PSC_NUM_PHASES * taps) / 2 - 1;
+	phase_cnt = (PSC_NUM_PHASES * (PSC_NUM_TAPS + 1)) / 2;
+	tap_cnt1 = (PSC_NUM_PHASES * PSC_NUM_TAPS) / 2;
+	tap_cnt2 = (PSC_NUM_PHASES * PSC_NUM_TAPS) / 2;
+
+	/* seed gaussian filter generator */
+	sigma_q = div_q(PSC_Q_ROUND_OFFSET, fc_q);
+	g0_q = 1 << PSC_Q_FRACTION;
+	g1_q = exp_approx_q(div_q(-PSC_Q_ROUND_OFFSET,
+				  mult_q(sigma_q, sigma_q)));
+	g2_q = mult_q(g1_q, g1_q);
+	coef[phase_cnt & PSC_PHASE_MASK][tap_cnt1 >> PSC_BITS_FOR_PHASE] = g0_q;
+
+	for (i = 0; i < mid; i++) {
+		phase_cnt++;
+		tap_cnt1--;
+		tap_cnt2++;
+
+		g0_q = mult_q(g0_q, g1_q);
+		g1_q = mult_q(g1_q, g2_q);
+
+		if ((phase_cnt & PSC_PHASE_MASK) <= 8) {
+			tap_idx = tap_cnt1 >> PSC_BITS_FOR_PHASE;
+			coef[phase_cnt & PSC_PHASE_MASK][tap_idx] = g0_q;
+		}
+		if (((-phase_cnt) & PSC_PHASE_MASK) <= 8) {
+			tap_idx = tap_cnt2 >> PSC_BITS_FOR_PHASE;
+			coef[(-phase_cnt) & PSC_PHASE_MASK][tap_idx] = g0_q;
+		}
+	}
+
+	phase_cnt++;
+	tap_cnt1--;
+	coef[phase_cnt & PSC_PHASE_MASK][tap_cnt1 >> PSC_BITS_FOR_PHASE] = 0;
+
+	/* override phase 0 with identity filter if specified */
+	if (phase0_identity)
+		for (i = 0; i < PSC_NUM_TAPS; i++)
+			coef[0][i] = i == (PSC_NUM_TAPS >> 1) ?
+						(1 << PSC_COEFF_PRECISION) : 0;
+
+	/* normalize coef */
+	for (phase = 0; phase < PSC_STORED_PHASES; phase++) {
+		int sum = 0;
+		s64 ll_temp;
+
+		for (i = 0; i < PSC_NUM_TAPS; i++)
+			sum += coef[phase][i];
+		for (i = 0; i < PSC_NUM_TAPS; i++) {
+			ll_temp = coef[phase][i];
+			ll_temp <<= PSC_COEFF_PRECISION;
+			ll_temp += sum >> 1;
+			ll_temp /= sum;
+			coef[phase][i] = (int)ll_temp;
+		}
+	}
+}
+
+/**
+ * dcss_scaler_filter_design() - Compute filter coefficients using
+ *				 Gaussian filter.
+ * @src_length: length of input
+ * @dst_length: length of output
+ * @use_5_taps: 0 for 7 taps per phase, 1 for 5 taps
+ * @coef: output coefficients
+ */
+static void dcss_scaler_filter_design(int src_length, int dst_length,
+				      bool use_5_taps, bool phase0_identity,
+				      int coef[][PSC_NUM_TAPS])
+{
+	int fc_q;
+
+	/* compute cutoff frequency */
+	if (dst_length >= src_length)
+		fc_q = div_q(1, PSC_NUM_PHASES);
+	else
+		fc_q = div_q(dst_length, src_length * PSC_NUM_PHASES);
+
+	/* compute gaussian filter coefficients */
+	dcss_scaler_gaussian_filter(fc_q, use_5_taps, phase0_identity, coef);
+}
+
+static void dcss_scaler_write(struct dcss_scaler_ch *ch, u32 val, u32 ofs)
+{
+	struct dcss_scaler *scl = ch->scl;
+
+	dcss_ctxld_write(scl->ctxld, scl->ctx_id, val, ch->base_ofs + ofs);
+}
+
+static int dcss_scaler_ch_init_all(struct dcss_scaler *scl,
+				   unsigned long scaler_base)
+{
+	struct dcss_scaler_ch *ch;
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		ch = &scl->ch[i];
+
+		ch->base_ofs = scaler_base + i * 0x400;
+
+		ch->base_reg = ioremap(ch->base_ofs, SZ_4K);
+		if (!ch->base_reg) {
+			dev_err(scl->dev, "scaler: unable to remap ch base\n");
+			return -ENOMEM;
+		}
+
+		ch->scl = scl;
+	}
+
+	return 0;
+}
+
+int dcss_scaler_init(struct dcss_dev *dcss, unsigned long scaler_base)
+{
+	struct dcss_scaler *scaler;
+
+	scaler = kzalloc(sizeof(*scaler), GFP_KERNEL);
+	if (!scaler)
+		return -ENOMEM;
+
+	dcss->scaler = scaler;
+	scaler->dev = dcss->dev;
+	scaler->ctxld = dcss->ctxld;
+	scaler->ctx_id = CTX_SB_HP;
+
+	if (dcss_scaler_ch_init_all(scaler, scaler_base)) {
+		int i;
+
+		for (i = 0; i < 3; i++) {
+			if (scaler->ch[i].base_reg)
+				iounmap(scaler->ch[i].base_reg);
+		}
+
+		kfree(scaler);
+
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void dcss_scaler_exit(struct dcss_scaler *scl)
+{
+	int ch_no;
+
+	for (ch_no = 0; ch_no < 3; ch_no++) {
+		struct dcss_scaler_ch *ch = &scl->ch[ch_no];
+
+		dcss_writel(0, ch->base_reg + DCSS_SCALER_CTRL);
+
+		if (ch->base_reg)
+			iounmap(ch->base_reg);
+	}
+
+	kfree(scl);
+}
+
+void dcss_scaler_ch_enable(struct dcss_scaler *scl, int ch_num, bool en)
+{
+	struct dcss_scaler_ch *ch = &scl->ch[ch_num];
+	u32 scaler_ctrl;
+
+	scaler_ctrl = en ? SCALER_EN | REPEAT_EN : 0;
+
+	if (en)
+		dcss_scaler_write(ch, ch->sdata_ctrl, DCSS_SCALER_SDATA_CTRL);
+
+	if (ch->scaler_ctrl != scaler_ctrl)
+		ch->scaler_ctrl_chgd = true;
+
+	ch->scaler_ctrl = scaler_ctrl;
+}
+
+static void dcss_scaler_yuv_enable(struct dcss_scaler_ch *ch, bool en)
+{
+	ch->sdata_ctrl &= ~YUV_EN;
+	ch->sdata_ctrl |= en ? YUV_EN : 0;
+}
+
+static void dcss_scaler_rtr_8lines_enable(struct dcss_scaler_ch *ch, bool en)
+{
+	ch->sdata_ctrl &= ~RTRAM_8LINES;
+	ch->sdata_ctrl |= en ? RTRAM_8LINES : 0;
+}
+
+static void dcss_scaler_bit_depth_set(struct dcss_scaler_ch *ch, int depth)
+{
+	u32 val;
+
+	val = depth == 30 ? 2 : 0;
+
+	dcss_scaler_write(ch,
+			  ((val << CHR_BIT_DEPTH_POS) & CHR_BIT_DEPTH_MASK) |
+			  ((val << LUM_BIT_DEPTH_POS) & LUM_BIT_DEPTH_MASK),
+			  DCSS_SCALER_BIT_DEPTH);
+}
+
+enum buffer_format {
+	BUF_FMT_YUV420,
+	BUF_FMT_YUV422,
+	BUF_FMT_ARGB8888_YUV444,
+};
+
+enum chroma_location {
+	PSC_LOC_HORZ_0_VERT_1_OVER_4 = 0,
+	PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_4 = 1,
+	PSC_LOC_HORZ_0_VERT_0 = 2,
+	PSC_LOC_HORZ_1_OVER_4_VERT_0 = 3,
+	PSC_LOC_HORZ_0_VERT_1_OVER_2 = 4,
+	PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_2 = 5
+};
+
+static void dcss_scaler_format_set(struct dcss_scaler_ch *ch,
+				   enum buffer_format src_fmt,
+				   enum buffer_format dst_fmt)
+{
+	dcss_scaler_write(ch, src_fmt, DCSS_SCALER_SRC_FORMAT);
+	dcss_scaler_write(ch, dst_fmt, DCSS_SCALER_DST_FORMAT);
+}
+
+static void dcss_scaler_res_set(struct dcss_scaler_ch *ch,
+				int src_xres, int src_yres,
+				int dst_xres, int dst_yres,
+				u32 pix_format, enum buffer_format dst_format)
+{
+	u32 lsrc_xres, lsrc_yres, csrc_xres, csrc_yres;
+	u32 ldst_xres, ldst_yres, cdst_xres, cdst_yres;
+	bool src_is_444 = true;
+
+	lsrc_xres = src_xres;
+	csrc_xres = src_xres;
+	lsrc_yres = src_yres;
+	csrc_yres = src_yres;
+	ldst_xres = dst_xres;
+	cdst_xres = dst_xres;
+	ldst_yres = dst_yres;
+	cdst_yres = dst_yres;
+
+	if (pix_format == DRM_FORMAT_UYVY || pix_format == DRM_FORMAT_VYUY ||
+	    pix_format == DRM_FORMAT_YUYV || pix_format == DRM_FORMAT_YVYU) {
+		csrc_xres >>= 1;
+		src_is_444 = false;
+	} else if (pix_format == DRM_FORMAT_NV12 ||
+		   pix_format == DRM_FORMAT_NV21) {
+		csrc_xres >>= 1;
+		csrc_yres >>= 1;
+		src_is_444 = false;
+	}
+
+	if (dst_format == BUF_FMT_YUV422)
+		cdst_xres >>= 1;
+
+	/* for 4:4:4 to 4:2:2 conversion, source height should be 1 less */
+	if (src_is_444 && dst_format == BUF_FMT_YUV422) {
+		lsrc_yres--;
+		csrc_yres--;
+	}
+
+	dcss_scaler_write(ch, (((lsrc_yres - 1) << HEIGHT_POS) & HEIGHT_MASK) |
+			       (((lsrc_xres - 1) << WIDTH_POS) & WIDTH_MASK),
+			  DCSS_SCALER_SRC_LUM_RES);
+	dcss_scaler_write(ch, (((csrc_yres - 1) << HEIGHT_POS) & HEIGHT_MASK) |
+			       (((csrc_xres - 1) << WIDTH_POS) & WIDTH_MASK),
+			  DCSS_SCALER_SRC_CHR_RES);
+	dcss_scaler_write(ch, (((ldst_yres - 1) << HEIGHT_POS) & HEIGHT_MASK) |
+			       (((ldst_xres - 1) << WIDTH_POS) & WIDTH_MASK),
+			  DCSS_SCALER_DST_LUM_RES);
+	dcss_scaler_write(ch, (((cdst_yres - 1) << HEIGHT_POS) & HEIGHT_MASK) |
+			       (((cdst_xres - 1) << WIDTH_POS) & WIDTH_MASK),
+			  DCSS_SCALER_DST_CHR_RES);
+}
+
+#define downscale_fp(factor, fp_pos)		((factor) << (fp_pos))
+#define upscale_fp(factor, fp_pos)		((1 << (fp_pos)) / (factor))
+
+struct dcss_scaler_factors {
+	int downscale;
+	int upscale;
+};
+
+static const struct dcss_scaler_factors dcss_scaler_factors[] = {
+	{3, 8}, {5, 8}, {5, 8},
+};
+
+static void dcss_scaler_fractions_set(struct dcss_scaler_ch *ch,
+				      int src_xres, int src_yres,
+				      int dst_xres, int dst_yres,
+				      u32 src_format, u32 dst_format,
+				      enum chroma_location src_chroma_loc)
+{
+	int src_c_xres, src_c_yres, dst_c_xres, dst_c_yres;
+	u32 l_vinc, l_hinc, c_vinc, c_hinc;
+	u32 c_vstart, c_hstart;
+
+	src_c_xres = src_xres;
+	src_c_yres = src_yres;
+	dst_c_xres = dst_xres;
+	dst_c_yres = dst_yres;
+
+	c_vstart = 0;
+	c_hstart = 0;
+
+	/* adjustments for source chroma location */
+	if (src_format == BUF_FMT_YUV420) {
+		/* vertical input chroma position adjustment */
+		switch (src_chroma_loc) {
+		case PSC_LOC_HORZ_0_VERT_1_OVER_4:
+		case PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_4:
+			/*
+			 * move chroma up to first luma line
+			 * (1/4 chroma input line spacing)
+			 */
+			c_vstart -= (1 << (PSC_PHASE_FRACTION_BITS - 2));
+			break;
+		case PSC_LOC_HORZ_0_VERT_1_OVER_2:
+		case PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_2:
+			/*
+			 * move chroma up to first luma line
+			 * (1/2 chroma input line spacing)
+			 */
+			c_vstart -= (1 << (PSC_PHASE_FRACTION_BITS - 1));
+			break;
+		default:
+			break;
+		}
+		/* horizontal input chroma position adjustment */
+		switch (src_chroma_loc) {
+		case PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_4:
+		case PSC_LOC_HORZ_1_OVER_4_VERT_0:
+		case PSC_LOC_HORZ_1_OVER_4_VERT_1_OVER_2:
+			/* move chroma left 1/4 chroma input sample spacing */
+			c_hstart -= (1 << (PSC_PHASE_FRACTION_BITS - 2));
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* adjustments to chroma resolution */
+	if (src_format == BUF_FMT_YUV420) {
+		src_c_xres >>= 1;
+		src_c_yres >>= 1;
+	} else if (src_format == BUF_FMT_YUV422) {
+		src_c_xres >>= 1;
+	}
+
+	if (dst_format == BUF_FMT_YUV422)
+		dst_c_xres >>= 1;
+
+	l_vinc = ((src_yres << 13) + (dst_yres >> 1)) / dst_yres;
+	c_vinc = ((src_c_yres << 13) + (dst_c_yres >> 1)) / dst_c_yres;
+	l_hinc = ((src_xres << 13) + (dst_xres >> 1)) / dst_xres;
+	c_hinc = ((src_c_xres << 13) + (dst_c_xres >> 1)) / dst_c_xres;
+
+	/* save chroma start phase */
+	ch->c_vstart = c_vstart;
+	ch->c_hstart = c_hstart;
+
+	dcss_scaler_write(ch, 0, DCSS_SCALER_V_LUM_START);
+	dcss_scaler_write(ch, l_vinc, DCSS_SCALER_V_LUM_INC);
+
+	dcss_scaler_write(ch, 0, DCSS_SCALER_H_LUM_START);
+	dcss_scaler_write(ch, l_hinc, DCSS_SCALER_H_LUM_INC);
+
+	dcss_scaler_write(ch, c_vstart, DCSS_SCALER_V_CHR_START);
+	dcss_scaler_write(ch, c_vinc, DCSS_SCALER_V_CHR_INC);
+
+	dcss_scaler_write(ch, c_hstart, DCSS_SCALER_H_CHR_START);
+	dcss_scaler_write(ch, c_hinc, DCSS_SCALER_H_CHR_INC);
+}
+
+int dcss_scaler_get_min_max_ratios(struct dcss_scaler *scl, int ch_num,
+				   int *min, int *max)
+{
+	*min = upscale_fp(dcss_scaler_factors[ch_num].upscale, 16);
+	*max = downscale_fp(dcss_scaler_factors[ch_num].downscale, 16);
+
+	return 0;
+}
+
+static void dcss_scaler_program_5_coef_set(struct dcss_scaler_ch *ch,
+					   int base_addr,
+					   int coef[][PSC_NUM_TAPS])
+{
+	int i, phase;
+
+	for (i = 0; i < PSC_STORED_PHASES; i++) {
+		dcss_scaler_write(ch, ((coef[i][1] & 0xfff) << 16 |
+				       (coef[i][2] & 0xfff) << 4  |
+				       (coef[i][3] & 0xf00) >> 8),
+				  base_addr + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[i][3] & 0x0ff) << 20 |
+				       (coef[i][4] & 0xfff) << 8  |
+				       (coef[i][5] & 0xff0) >> 4),
+				  base_addr + 0x40 + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[i][5] & 0x00f) << 24),
+				  base_addr + 0x80 + i * sizeof(u32));
+	}
+
+	/* reverse both phase and tap orderings */
+	for (phase = (PSC_NUM_PHASES >> 1) - 1;
+			i < PSC_NUM_PHASES; i++, phase--) {
+		dcss_scaler_write(ch, ((coef[phase][5] & 0xfff) << 16 |
+				       (coef[phase][4] & 0xfff) << 4  |
+				       (coef[phase][3] & 0xf00) >> 8),
+				  base_addr + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[phase][3] & 0x0ff) << 20 |
+				       (coef[phase][2] & 0xfff) << 8  |
+				       (coef[phase][1] & 0xff0) >> 4),
+				  base_addr + 0x40 + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[phase][1] & 0x00f) << 24),
+				  base_addr + 0x80 + i * sizeof(u32));
+	}
+}
+
+static void dcss_scaler_program_7_coef_set(struct dcss_scaler_ch *ch,
+					   int base_addr,
+					   int coef[][PSC_NUM_TAPS])
+{
+	int i, phase;
+
+	for (i = 0; i < PSC_STORED_PHASES; i++) {
+		dcss_scaler_write(ch, ((coef[i][0] & 0xfff) << 16 |
+				       (coef[i][1] & 0xfff) << 4  |
+				       (coef[i][2] & 0xf00) >> 8),
+				  base_addr + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[i][2] & 0x0ff) << 20 |
+				       (coef[i][3] & 0xfff) << 8  |
+				       (coef[i][4] & 0xff0) >> 4),
+				  base_addr + 0x40 + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[i][4] & 0x00f) << 24 |
+				       (coef[i][5] & 0xfff) << 12 |
+				       (coef[i][6] & 0xfff)),
+				  base_addr + 0x80 + i * sizeof(u32));
+	}
+
+	/* reverse both phase and tap orderings */
+	for (phase = (PSC_NUM_PHASES >> 1) - 1;
+			i < PSC_NUM_PHASES; i++, phase--) {
+		dcss_scaler_write(ch, ((coef[phase][6] & 0xfff) << 16 |
+				       (coef[phase][5] & 0xfff) << 4  |
+				       (coef[phase][4] & 0xf00) >> 8),
+				  base_addr + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[phase][4] & 0x0ff) << 20 |
+				       (coef[phase][3] & 0xfff) << 8  |
+				       (coef[phase][2] & 0xff0) >> 4),
+				  base_addr + 0x40 + i * sizeof(u32));
+		dcss_scaler_write(ch, ((coef[phase][2] & 0x00f) << 24 |
+				       (coef[phase][1] & 0xfff) << 12 |
+				       (coef[phase][0] & 0xfff)),
+				  base_addr + 0x80 + i * sizeof(u32));
+	}
+}
+
+static void dcss_scaler_yuv_coef_set(struct dcss_scaler_ch *ch,
+				     enum buffer_format src_format,
+				     enum buffer_format dst_format,
+				     bool use_5_taps,
+				     int src_xres, int src_yres, int dst_xres,
+				     int dst_yres)
+{
+	int coef[PSC_STORED_PHASES][PSC_NUM_TAPS];
+	bool program_5_taps = use_5_taps ||
+			      (dst_format == BUF_FMT_YUV422 &&
+			       src_format == BUF_FMT_ARGB8888_YUV444);
+
+	/* horizontal luma */
+	dcss_scaler_filter_design(src_xres, dst_xres, false,
+				  src_xres == dst_xres, coef);
+	dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HLUM, coef);
+
+	/* vertical luma */
+	dcss_scaler_filter_design(src_yres, dst_yres, program_5_taps,
+				  src_yres == dst_yres, coef);
+
+	if (program_5_taps)
+		dcss_scaler_program_5_coef_set(ch, DCSS_SCALER_COEF_VLUM, coef);
+	else
+		dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_VLUM, coef);
+
+	/* adjust chroma resolution */
+	if (src_format != BUF_FMT_ARGB8888_YUV444)
+		src_xres >>= 1;
+	if (src_format == BUF_FMT_YUV420)
+		src_yres >>= 1;
+	if (dst_format != BUF_FMT_ARGB8888_YUV444)
+		dst_xres >>= 1;
+	if (dst_format == BUF_FMT_YUV420) /* should not happen */
+		dst_yres >>= 1;
+
+	/* horizontal chroma */
+	dcss_scaler_filter_design(src_xres, dst_xres, false,
+				  (src_xres == dst_xres) && (ch->c_hstart == 0),
+				  coef);
+
+	dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HCHR, coef);
+
+	/* vertical chroma */
+	dcss_scaler_filter_design(src_yres, dst_yres, program_5_taps,
+				  (src_yres == dst_yres) && (ch->c_vstart == 0),
+				  coef);
+	if (program_5_taps)
+		dcss_scaler_program_5_coef_set(ch, DCSS_SCALER_COEF_VCHR, coef);
+	else
+		dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_VCHR, coef);
+}
+
+static void dcss_scaler_rgb_coef_set(struct dcss_scaler_ch *ch,
+				     int src_xres, int src_yres, int dst_xres,
+				     int dst_yres)
+{
+	int coef[PSC_STORED_PHASES][PSC_NUM_TAPS];
+
+	/* horizontal RGB */
+	dcss_scaler_filter_design(src_xres, dst_xres, false,
+				  src_xres == dst_xres, coef);
+	dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HLUM, coef);
+
+	/* vertical RGB */
+	dcss_scaler_filter_design(src_yres, dst_yres, false,
+				  src_yres == dst_yres, coef);
+	dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_VLUM, coef);
+}
+
+static void dcss_scaler_set_rgb10_order(struct dcss_scaler_ch *ch,
+					const struct drm_format_info *format)
+{
+	u32 a2r10g10b10_format;
+
+	if (format->is_yuv)
+		return;
+
+	ch->sdata_ctrl &= ~A2R10G10B10_FORMAT_MASK;
+
+	if (format->depth != 30)
+		return;
+
+	switch (format->format) {
+	case DRM_FORMAT_ARGB2101010:
+	case DRM_FORMAT_XRGB2101010:
+		a2r10g10b10_format = 0;
+		break;
+
+	case DRM_FORMAT_ABGR2101010:
+	case DRM_FORMAT_XBGR2101010:
+		a2r10g10b10_format = 5;
+		break;
+
+	case DRM_FORMAT_RGBA1010102:
+	case DRM_FORMAT_RGBX1010102:
+		a2r10g10b10_format = 6;
+		break;
+
+	case DRM_FORMAT_BGRA1010102:
+	case DRM_FORMAT_BGRX1010102:
+		a2r10g10b10_format = 11;
+		break;
+
+	default:
+		a2r10g10b10_format = 0;
+		break;
+	}
+
+	ch->sdata_ctrl |= a2r10g10b10_format << A2R10G10B10_FORMAT_POS;
+}
+
+void dcss_scaler_setup(struct dcss_scaler *scl, int ch_num,
+		       const struct drm_format_info *format,
+		       int src_xres, int src_yres, int dst_xres, int dst_yres,
+		       u32 vrefresh_hz)
+{
+	struct dcss_scaler_ch *ch = &scl->ch[ch_num];
+	unsigned int pixel_depth = 0;
+	bool rtr_8line_en = false;
+	bool use_5_taps = false;
+	enum buffer_format src_format = BUF_FMT_ARGB8888_YUV444;
+	enum buffer_format dst_format = BUF_FMT_ARGB8888_YUV444;
+	u32 pix_format = format->format;
+
+	if (format->is_yuv) {
+		dcss_scaler_yuv_enable(ch, true);
+
+		if (pix_format == DRM_FORMAT_NV12 ||
+		    pix_format == DRM_FORMAT_NV21) {
+			rtr_8line_en = true;
+			src_format = BUF_FMT_YUV420;
+		} else if (pix_format == DRM_FORMAT_UYVY ||
+			   pix_format == DRM_FORMAT_VYUY ||
+			   pix_format == DRM_FORMAT_YUYV ||
+			   pix_format == DRM_FORMAT_YVYU) {
+			src_format = BUF_FMT_YUV422;
+		}
+
+		use_5_taps = !rtr_8line_en;
+	} else {
+		dcss_scaler_yuv_enable(ch, false);
+
+		pixel_depth = format->depth;
+	}
+
+	dcss_scaler_fractions_set(ch, src_xres, src_yres, dst_xres,
+				  dst_yres, src_format, dst_format,
+				  PSC_LOC_HORZ_0_VERT_1_OVER_4);
+
+	if (format->is_yuv)
+		dcss_scaler_yuv_coef_set(ch, src_format, dst_format,
+					 use_5_taps, src_xres, src_yres,
+					 dst_xres, dst_yres);
+	else
+		dcss_scaler_rgb_coef_set(ch, src_xres, src_yres,
+					 dst_xres, dst_yres);
+
+	dcss_scaler_rtr_8lines_enable(ch, rtr_8line_en);
+	dcss_scaler_bit_depth_set(ch, pixel_depth);
+	dcss_scaler_set_rgb10_order(ch, format);
+	dcss_scaler_format_set(ch, src_format, dst_format);
+	dcss_scaler_res_set(ch, src_xres, src_yres, dst_xres, dst_yres,
+			    pix_format, dst_format);
+}
+
+/* This function will be called from interrupt context. */
+void dcss_scaler_write_sclctrl(struct dcss_scaler *scl)
+{
+	int chnum;
+
+	dcss_ctxld_assert_locked(scl->ctxld);
+
+	for (chnum = 0; chnum < 3; chnum++) {
+		struct dcss_scaler_ch *ch = &scl->ch[chnum];
+
+		if (ch->scaler_ctrl_chgd) {
+			dcss_ctxld_write_irqsafe(scl->ctxld, scl->ctx_id,
+						 ch->scaler_ctrl,
+						 ch->base_ofs +
+						 DCSS_SCALER_CTRL);
+			ch->scaler_ctrl_chgd = false;
+		}
+	}
+}

drivers/gpu/drm/imx/dcss/dcss-ss.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_SS_SYS_CTRL			0x00
+#define   RUN_EN				BIT(0)
+#define DCSS_SS_DISPLAY				0x10
+#define   LRC_X_POS				0
+#define   LRC_X_MASK				GENMASK(12, 0)
+#define   LRC_Y_POS				16
+#define   LRC_Y_MASK				GENMASK(28, 16)
+#define DCSS_SS_HSYNC				0x20
+#define DCSS_SS_VSYNC				0x30
+#define   SYNC_START_POS			0
+#define   SYNC_START_MASK			GENMASK(12, 0)
+#define   SYNC_END_POS				16
+#define   SYNC_END_MASK				GENMASK(28, 16)
+#define   SYNC_POL				BIT(31)
+#define DCSS_SS_DE_ULC				0x40
+#define   ULC_X_POS				0
+#define   ULC_X_MASK				GENMASK(12, 0)
+#define   ULC_Y_POS				16
+#define   ULC_Y_MASK				GENMASK(28, 16)
+#define   ULC_POL				BIT(31)
+#define DCSS_SS_DE_LRC				0x50
+#define DCSS_SS_MODE				0x60
+#define   PIPE_MODE_POS				0
+#define   PIPE_MODE_MASK			GENMASK(1, 0)
+#define DCSS_SS_COEFF				0x70
+#define   HORIZ_A_POS				0
+#define   HORIZ_A_MASK				GENMASK(3, 0)
+#define   HORIZ_B_POS				4
+#define   HORIZ_B_MASK				GENMASK(7, 4)
+#define   HORIZ_C_POS				8
+#define   HORIZ_C_MASK				GENMASK(11, 8)
+#define   HORIZ_H_NORM_POS			12
+#define   HORIZ_H_NORM_MASK			GENMASK(14, 12)
+#define   VERT_A_POS				16
+#define   VERT_A_MASK				GENMASK(19, 16)
+#define   VERT_B_POS				20
+#define   VERT_B_MASK				GENMASK(23, 20)
+#define   VERT_C_POS				24
+#define   VERT_C_MASK				GENMASK(27, 24)
+#define   VERT_H_NORM_POS			28
+#define   VERT_H_NORM_MASK			GENMASK(30, 28)
+#define DCSS_SS_CLIP_CB				0x80
+#define DCSS_SS_CLIP_CR				0x90
+#define   CLIP_MIN_POS				0
+#define   CLIP_MIN_MASK				GENMASK(9, 0)
+#define   CLIP_MAX_POS				0
+#define   CLIP_MAX_MASK				GENMASK(23, 16)
+#define DCSS_SS_INTER_MODE			0xA0
+#define   INT_EN				BIT(0)
+#define   VSYNC_SHIFT				BIT(1)
+
+struct dcss_ss {
+	struct device *dev;
+	void __iomem *base_reg;
+	u32 base_ofs;
+
+	struct dcss_ctxld *ctxld;
+	u32 ctx_id;
+
+	bool in_use;
+};
+
+static void dcss_ss_write(struct dcss_ss *ss, u32 val, u32 ofs)
+{
+	if (!ss->in_use)
+		dcss_writel(val, ss->base_reg + ofs);
+
+	dcss_ctxld_write(ss->ctxld, ss->ctx_id, val,
+			 ss->base_ofs + ofs);
+}
+
+int dcss_ss_init(struct dcss_dev *dcss, unsigned long ss_base)
+{
+	struct dcss_ss *ss;
+
+	ss = kzalloc(sizeof(*ss), GFP_KERNEL);
+	if (!ss)
+		return -ENOMEM;
+
+	dcss->ss = ss;
+	ss->dev = dcss->dev;
+	ss->ctxld = dcss->ctxld;
+
+	ss->base_reg = ioremap(ss_base, SZ_4K);
+	if (!ss->base_reg) {
+		dev_err(dcss->dev, "ss: unable to remap ss base\n");
+		kfree(ss);
+		return -ENOMEM;
+	}
+
+	ss->base_ofs = ss_base;
+	ss->ctx_id = CTX_SB_HP;
+
+	return 0;
+}
+
+void dcss_ss_exit(struct dcss_ss *ss)
+{
+	/* stop SS */
+	dcss_writel(0, ss->base_reg + DCSS_SS_SYS_CTRL);
+
+	if (ss->base_reg)
+		iounmap(ss->base_reg);
+
+	kfree(ss);
+}
+
+void dcss_ss_subsam_set(struct dcss_ss *ss)
+{
+	dcss_ss_write(ss, 0x41614161, DCSS_SS_COEFF);
+	dcss_ss_write(ss, 0, DCSS_SS_MODE);
+	dcss_ss_write(ss, 0x03ff0000, DCSS_SS_CLIP_CB);
+	dcss_ss_write(ss, 0x03ff0000, DCSS_SS_CLIP_CR);
+}
+
+void dcss_ss_sync_set(struct dcss_ss *ss, struct videomode *vm,
+		      bool phsync, bool pvsync)
+{
+	u16 lrc_x, lrc_y;
+	u16 hsync_start, hsync_end;
+	u16 vsync_start, vsync_end;
+	u16 de_ulc_x, de_ulc_y;
+	u16 de_lrc_x, de_lrc_y;
+
+	lrc_x = vm->hfront_porch + vm->hback_porch + vm->hsync_len +
+		vm->hactive - 1;
+	lrc_y = vm->vfront_porch + vm->vback_porch + vm->vsync_len +
+		vm->vactive - 1;
+
+	dcss_ss_write(ss, (lrc_y << LRC_Y_POS) | lrc_x, DCSS_SS_DISPLAY);
+
+	hsync_start = vm->hfront_porch + vm->hback_porch + vm->hsync_len +
+		      vm->hactive - 1;
+	hsync_end = vm->hsync_len - 1;
+
+	dcss_ss_write(ss, (phsync ? SYNC_POL : 0) |
+		      ((u32)hsync_end << SYNC_END_POS) | hsync_start,
+		      DCSS_SS_HSYNC);
+
+	vsync_start = vm->vfront_porch - 1;
+	vsync_end = vm->vfront_porch + vm->vsync_len - 1;
+
+	dcss_ss_write(ss, (pvsync ? SYNC_POL : 0) |
+		      ((u32)vsync_end << SYNC_END_POS) | vsync_start,
+		      DCSS_SS_VSYNC);
+
+	de_ulc_x = vm->hsync_len + vm->hback_porch - 1;
+	de_ulc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch;
+
+	dcss_ss_write(ss, SYNC_POL | ((u32)de_ulc_y << ULC_Y_POS) | de_ulc_x,
+		      DCSS_SS_DE_ULC);
+
+	de_lrc_x = vm->hsync_len + vm->hback_porch + vm->hactive - 1;
+	de_lrc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch +
+		   vm->vactive - 1;
+
+	dcss_ss_write(ss, (de_lrc_y << LRC_Y_POS) | de_lrc_x, DCSS_SS_DE_LRC);
+}
+
+void dcss_ss_enable(struct dcss_ss *ss)
+{
+	dcss_ss_write(ss, RUN_EN, DCSS_SS_SYS_CTRL);
+	ss->in_use = true;
+}
+
+void dcss_ss_shutoff(struct dcss_ss *ss)
+{
+	dcss_writel(0, ss->base_reg + DCSS_SS_SYS_CTRL);
+	ss->in_use = false;
+}