drm/kmb: Add support for KeemBay Display

This is a basic KMS atomic modesetting display driver for KeemBay family of
SOCs. Driver has no 2D or 3D graphics. It calls into the ADV bridge
driver at the connector level.

Single CRTC with LCD controller->mipi DSI->ADV bridge

Only 1080p resolution and single plane is supported at this time.

v2: moved extern to .h, removed license text
    use drm_dev_init, upclassed dev_private, removed HAVE_IRQ.(Sam)

v3: Squashed all 59 commits to one

v4: review changes from Sam Ravnborg
	renamed dev_p to kmb
	moved clocks under kmb_clock, consolidated clk initializations
	use drmm functions
	use DRM_GEM_CMA_DRIVER_OPS_VMAP

v5: corrected spellings
v6: corrected checkpatch warnings
v7: review changes Sam Ravnborg and Thomas Zimmerman
	removed kmb_crtc.h kmb_crtc_cleanup (Thomas)
	renamed mode_set, kmb_load, inlined unload (Thomas)
	moved remaining logging to drm_*(Thomas)
	re-orged driver initialization (Thomas)
	moved plane_status to drm_private (Sam)
	removed unnecessary logs and defines and ifdef codes (Sam)
	call helper_check in plane_atomic_check (Sam)
	renamed set to get for bpp and format functions(Sam)
	use drm helper functions for reset, duplicate/destroy state instead
	of kmb functions (Sam)
	removed kmb_priv from kmb_plane and removed kmb_plane_state (Sam)
v8: get clk_pll0 from display node in dt
v9: moved csc_coef_lcd to plane.c (Daniel Vetter)
    call drm_atomic_helper_shutdown in remove (Daniel V)
    use drm_crtc_handle_vblank (Daniel V)
    renamed kmb_dsi_hw_init to kmb_dsi_mode_set (Daniel V)
    complimentary changes to device tree changes (Rob)
v10: call drm_crtc_arm_vblank_event in atomic_flush (Daniel V)
     moved global vars to kmb_private and added locks (Daniel V)
     changes in driver to accommodate changes in DT to separate DSI
     entries (Sam R)
     review changes to separate mipi DSI (Sam R)
v11: review changes to separate msscam (Neil A,Sam R)
v12: fixed warnings Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1604538931-26726-6-git-send-email-anitha.chrisanthus@intel.com

drivers/gpu/drm/kmb/kmb_crtc.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#include <linux/clk.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_print.h>
+#include <drm/drm_vblank.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#include "kmb_drv.h"
+#include "kmb_dsi.h"
+#include "kmb_plane.h"
+#include "kmb_regs.h"
+
+struct kmb_crtc_timing {
+	u32 vfront_porch;
+	u32 vback_porch;
+	u32 vsync_len;
+	u32 hfront_porch;
+	u32 hback_porch;
+	u32 hsync_len;
+};
+
+static int kmb_crtc_enable_vblank(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	/* Clear interrupt */
+	kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+	/* Set which interval to generate vertical interrupt */
+	kmb_write_lcd(kmb, LCD_VSTATUS_COMPARE,
+		      LCD_VSTATUS_COMPARE_VSYNC);
+	/* Enable vertical interrupt */
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+	return 0;
+}
+
+static void kmb_crtc_disable_vblank(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	/* Clear interrupt */
+	kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+	/* Disable vertical interrupt */
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+}
+
+static const struct drm_crtc_funcs kmb_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.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 = kmb_crtc_enable_vblank,
+	.disable_vblank = kmb_crtc_disable_vblank,
+};
+
+static void kmb_crtc_set_mode(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_display_mode *m = &crtc->state->adjusted_mode;
+	struct kmb_crtc_timing vm;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+	unsigned int val = 0;
+
+	/* Initialize mipi */
+	kmb_dsi_mode_set(kmb->kmb_dsi, m, kmb->sys_clk_mhz);
+	drm_info(dev,
+		 "vfp= %d vbp= %d vsyc_len=%d hfp=%d hbp=%d hsync_len=%d\n",
+		 m->crtc_vsync_start - m->crtc_vdisplay,
+		 m->crtc_vtotal - m->crtc_vsync_end,
+		 m->crtc_vsync_end - m->crtc_vsync_start,
+		 m->crtc_hsync_start - m->crtc_hdisplay,
+		 m->crtc_htotal - m->crtc_hsync_end,
+		 m->crtc_hsync_end - m->crtc_hsync_start);
+	val = kmb_read_lcd(kmb, LCD_INT_ENABLE);
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE, val);
+	kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR, ~0x0);
+	vm.vfront_porch = 2;
+	vm.vback_porch = 2;
+	vm.vsync_len = 8;
+	vm.hfront_porch = 0;
+	vm.hback_porch = 0;
+	vm.hsync_len = 28;
+
+	drm_dbg(dev, "%s : %dactive height= %d vbp=%d vfp=%d vsync-w=%d h-active=%d h-bp=%d h-fp=%d hysnc-l=%d",
+		__func__, __LINE__,
+			m->crtc_vdisplay, vm.vback_porch, vm.vfront_porch,
+			vm.vsync_len, m->crtc_hdisplay, vm.hback_porch,
+			vm.hfront_porch, vm.hsync_len);
+	kmb_write_lcd(kmb, LCD_V_ACTIVEHEIGHT,
+		      m->crtc_vdisplay - 1);
+	kmb_write_lcd(kmb, LCD_V_BACKPORCH, vm.vback_porch);
+	kmb_write_lcd(kmb, LCD_V_FRONTPORCH, vm.vfront_porch);
+	kmb_write_lcd(kmb, LCD_VSYNC_WIDTH, vm.vsync_len - 1);
+	kmb_write_lcd(kmb, LCD_H_ACTIVEWIDTH,
+		      m->crtc_hdisplay - 1);
+	kmb_write_lcd(kmb, LCD_H_BACKPORCH, vm.hback_porch);
+	kmb_write_lcd(kmb, LCD_H_FRONTPORCH, vm.hfront_porch);
+	kmb_write_lcd(kmb, LCD_HSYNC_WIDTH, vm.hsync_len - 1);
+	/* This is hardcoded as 0 in the Myriadx code */
+	kmb_write_lcd(kmb, LCD_VSYNC_START, 0);
+	kmb_write_lcd(kmb, LCD_VSYNC_END, 0);
+	/* Back ground color */
+	kmb_write_lcd(kmb, LCD_BG_COLOUR_LS, 0x4);
+	if (m->flags == DRM_MODE_FLAG_INTERLACE) {
+		kmb_write_lcd(kmb,
+			      LCD_VSYNC_WIDTH_EVEN, vm.vsync_len - 1);
+		kmb_write_lcd(kmb,
+			      LCD_V_BACKPORCH_EVEN, vm.vback_porch);
+		kmb_write_lcd(kmb,
+			      LCD_V_FRONTPORCH_EVEN, vm.vfront_porch);
+		kmb_write_lcd(kmb, LCD_V_ACTIVEHEIGHT_EVEN,
+			      m->crtc_vdisplay - 1);
+		/* This is hardcoded as 10 in the Myriadx code */
+		kmb_write_lcd(kmb, LCD_VSYNC_START_EVEN, 10);
+		kmb_write_lcd(kmb, LCD_VSYNC_END_EVEN, 10);
+	}
+	kmb_write_lcd(kmb, LCD_TIMING_GEN_TRIG, 1);
+	kmb_set_bitmask_lcd(kmb, LCD_CONTROL, LCD_CTRL_ENABLE);
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE, val);
+}
+
+static void kmb_crtc_atomic_enable(struct drm_crtc *crtc,
+				   struct drm_atomic_state *state)
+{
+	struct kmb_drm_private *kmb = crtc_to_kmb_priv(crtc);
+
+	clk_prepare_enable(kmb->kmb_clk.clk_lcd);
+	kmb_crtc_set_mode(crtc);
+	drm_crtc_vblank_on(crtc);
+}
+
+static void kmb_crtc_atomic_disable(struct drm_crtc *crtc,
+				    struct drm_atomic_state *state)
+{
+	struct kmb_drm_private *kmb = crtc_to_kmb_priv(crtc);
+	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state, crtc);
+
+	/* due to hw limitations, planes need to be off when crtc is off */
+	drm_atomic_helper_disable_planes_on_crtc(old_state, false);
+
+	drm_crtc_vblank_off(crtc);
+	clk_disable_unprepare(kmb->kmb_clk.clk_lcd);
+}
+
+static void kmb_crtc_atomic_begin(struct drm_crtc *crtc,
+				  struct drm_atomic_state *state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+}
+
+static void kmb_crtc_atomic_flush(struct drm_crtc *crtc,
+				  struct drm_atomic_state *state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	if (crtc->state->event) {
+		if (drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
+		else
+			drm_crtc_send_vblank_event(crtc, crtc->state->event);
+	}
+	crtc->state->event = NULL;
+	spin_unlock_irq(&crtc->dev->event_lock);
+}
+
+static const struct drm_crtc_helper_funcs kmb_crtc_helper_funcs = {
+	.atomic_begin = kmb_crtc_atomic_begin,
+	.atomic_enable = kmb_crtc_atomic_enable,
+	.atomic_disable = kmb_crtc_atomic_disable,
+	.atomic_flush = kmb_crtc_atomic_flush,
+};
+
+int kmb_setup_crtc(struct drm_device *drm)
+{
+	struct kmb_drm_private *kmb = to_kmb(drm);
+	struct kmb_plane *primary;
+	int ret;
+
+	primary = kmb_plane_init(drm);
+	if (IS_ERR(primary))
+		return PTR_ERR(primary);
+
+	ret = drm_crtc_init_with_planes(drm, &kmb->crtc, &primary->base_plane,
+					NULL, &kmb_crtc_funcs, NULL);
+	if (ret) {
+		kmb_plane_destroy(&primary->base_plane);
+		return ret;
+	}
+
+	drm_crtc_helper_add(&kmb->crtc, &kmb_crtc_helper_funcs);
+	return 0;
+}

drivers/gpu/drm/kmb/kmb_drv.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_irq.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "kmb_drv.h"
+#include "kmb_dsi.h"
+#include "kmb_regs.h"
+
+static int kmb_display_clk_enable(struct kmb_drm_private *kmb)
+{
+	int ret = 0;
+
+	ret = clk_prepare_enable(kmb->kmb_clk.clk_lcd);
+	if (ret) {
+		drm_err(&kmb->drm, "Failed to enable LCD clock: %d\n", ret);
+		return ret;
+	}
+	DRM_INFO("SUCCESS : enabled LCD clocks\n");
+	return 0;
+}
+
+static int kmb_initialize_clocks(struct kmb_drm_private *kmb, struct device *dev)
+{
+	int ret = 0;
+	struct regmap *msscam;
+
+	kmb->kmb_clk.clk_lcd = devm_clk_get(dev, "clk_lcd");
+	if (IS_ERR(kmb->kmb_clk.clk_lcd)) {
+		drm_err(&kmb->drm, "clk_get() failed clk_lcd\n");
+		return PTR_ERR(kmb->kmb_clk.clk_lcd);
+	}
+
+	kmb->kmb_clk.clk_pll0 = devm_clk_get(dev, "clk_pll0");
+	if (IS_ERR(kmb->kmb_clk.clk_pll0)) {
+		drm_err(&kmb->drm, "clk_get() failed clk_pll0 ");
+		return PTR_ERR(kmb->kmb_clk.clk_pll0);
+	}
+	kmb->sys_clk_mhz = clk_get_rate(kmb->kmb_clk.clk_pll0) / 1000000;
+	drm_info(&kmb->drm, "system clk = %d Mhz", kmb->sys_clk_mhz);
+
+	ret =  kmb_dsi_clk_init(kmb->kmb_dsi);
+
+	/* Set LCD clock to 200 Mhz */
+	clk_set_rate(kmb->kmb_clk.clk_lcd, KMB_LCD_DEFAULT_CLK);
+	if (clk_get_rate(kmb->kmb_clk.clk_lcd) != KMB_LCD_DEFAULT_CLK) {
+		drm_err(&kmb->drm, "failed to set to clk_lcd to %d\n",
+			KMB_LCD_DEFAULT_CLK);
+		return -1;
+	}
+	drm_dbg(&kmb->drm, "clk_lcd = %ld\n", clk_get_rate(kmb->kmb_clk.clk_lcd));
+
+	ret = kmb_display_clk_enable(kmb);
+	if (ret)
+		return ret;
+
+	msscam = syscon_regmap_lookup_by_compatible("intel,keembay-msscam");
+	if (IS_ERR(msscam)) {
+		drm_err(&kmb->drm, "failed to get msscam syscon");
+		return -1;
+	}
+
+	/* Enable MSS_CAM_CLK_CTRL for MIPI TX and LCD */
+	regmap_update_bits(msscam, MSS_CAM_CLK_CTRL, 0x1fff, 0x1fff);
+	regmap_update_bits(msscam, MSS_CAM_RSTN_CTRL, 0xffffffff, 0xffffffff);
+	return 0;
+}
+
+static void kmb_display_clk_disable(struct kmb_drm_private *kmb)
+{
+	clk_disable_unprepare(kmb->kmb_clk.clk_lcd);
+}
+
+static void __iomem *kmb_map_mmio(struct drm_device *drm,
+				  struct platform_device *pdev,
+				  char *name)
+{
+	struct resource *res;
+	void __iomem *mem;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+	if (!res) {
+		drm_err(drm, "failed to get resource for %s", name);
+		return ERR_PTR(-ENOMEM);
+	}
+	mem = devm_ioremap_resource(drm->dev, res);
+	if (IS_ERR(mem))
+		drm_err(drm, "failed to ioremap %s registers", name);
+	return mem;
+}
+
+static int kmb_hw_init(struct drm_device *drm, unsigned long flags)
+{
+	struct kmb_drm_private *kmb = to_kmb(drm);
+	struct platform_device *pdev = to_platform_device(drm->dev);
+	int irq_lcd;
+	int ret = 0;
+
+	/* Map LCD MMIO registers */
+	kmb->lcd_mmio = kmb_map_mmio(drm, pdev, "lcd");
+	if (IS_ERR(kmb->lcd_mmio)) {
+		drm_err(&kmb->drm, "failed to map LCD registers\n");
+		return -ENOMEM;
+	}
+
+	/* Map MIPI MMIO registers */
+	ret = kmb_dsi_map_mmio(kmb->kmb_dsi);
+	if (ret)
+		return ret;
+
+	/* Enable display clocks */
+	kmb_initialize_clocks(kmb, &pdev->dev);
+
+	/* Register irqs here - section 17.3 in databook
+	 * lists LCD at 79 and 82 for MIPI under MSS CPU -
+	 * firmware has redirected 79 to A53 IRQ 33
+	 */
+
+	/* Allocate LCD interrupt resources */
+	irq_lcd = platform_get_irq(pdev, 0);
+	if (irq_lcd < 0) {
+		drm_err(&kmb->drm, "irq_lcd not found");
+		goto setup_fail;
+	}
+
+	/* Get the optional framebuffer memory resource */
+	ret = of_reserved_mem_device_init(drm->dev);
+	if (ret && ret != -ENODEV)
+		return ret;
+
+	spin_lock_init(&kmb->irq_lock);
+
+	kmb->irq_lcd = irq_lcd;
+
+	return 0;
+
+ setup_fail:
+	of_reserved_mem_device_release(drm->dev);
+
+	return ret;
+}
+
+static const struct drm_mode_config_funcs kmb_mode_config_funcs = {
+	.fb_create = drm_gem_fb_create,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static int kmb_setup_mode_config(struct drm_device *drm)
+{
+	int ret;
+	struct kmb_drm_private *kmb = to_kmb(drm);
+
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ret;
+	drm->mode_config.min_width = KMB_MIN_WIDTH;
+	drm->mode_config.min_height = KMB_MIN_HEIGHT;
+	drm->mode_config.max_width = KMB_MAX_WIDTH;
+	drm->mode_config.max_height = KMB_MAX_HEIGHT;
+	drm->mode_config.funcs = &kmb_mode_config_funcs;
+
+	ret = kmb_setup_crtc(drm);
+	if (ret < 0) {
+		drm_err(drm, "failed to create crtc\n");
+		return ret;
+	}
+	ret = kmb_dsi_encoder_init(drm, kmb->kmb_dsi);
+	/* Set the CRTC's port so that the encoder component can find it */
+	kmb->crtc.port = of_graph_get_port_by_id(drm->dev->of_node, 0);
+	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
+	if (ret < 0) {
+		drm_err(drm, "failed to initialize vblank\n");
+		pm_runtime_disable(drm->dev);
+		return ret;
+	}
+
+	drm_mode_config_reset(drm);
+	return 0;
+}
+
+static irqreturn_t handle_lcd_irq(struct drm_device *dev)
+{
+	unsigned long status, val, val1;
+	int plane_id, dma0_state, dma1_state;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	status = kmb_read_lcd(kmb, LCD_INT_STATUS);
+
+	spin_lock(&kmb->irq_lock);
+	if (status & LCD_INT_EOF) {
+		kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_EOF);
+
+		/* When disabling/enabling LCD layers, the change takes effect
+		 * immediately and does not wait for EOF (end of frame).
+		 * When kmb_plane_atomic_disable is called, mark the plane as
+		 * disabled but actually disable the plane when EOF irq is
+		 * being handled.
+		 */
+		for (plane_id = LAYER_0;
+				plane_id < KMB_MAX_PLANES; plane_id++) {
+			if (kmb->plane_status[plane_id].disable) {
+				kmb_clr_bitmask_lcd(kmb,
+						    LCD_LAYERn_DMA_CFG
+						    (plane_id),
+						    LCD_DMA_LAYER_ENABLE);
+
+				kmb_clr_bitmask_lcd(kmb, LCD_CONTROL,
+						    kmb->plane_status[plane_id].ctrl);
+
+				kmb->plane_status[plane_id].disable = false;
+			}
+		}
+		if (kmb->kmb_under_flow) {
+			/* DMA Recovery after underflow */
+			dma0_state = (kmb->layer_no == 0) ?
+			    LCD_VIDEO0_DMA0_STATE : LCD_VIDEO1_DMA0_STATE;
+			dma1_state = (kmb->layer_no == 0) ?
+			    LCD_VIDEO0_DMA1_STATE : LCD_VIDEO1_DMA1_STATE;
+
+			do {
+				kmb_write_lcd(kmb, LCD_FIFO_FLUSH, 1);
+				val = kmb_read_lcd(kmb, dma0_state)
+				    & LCD_DMA_STATE_ACTIVE;
+				val1 = kmb_read_lcd(kmb, dma1_state)
+				    & LCD_DMA_STATE_ACTIVE;
+			} while ((val || val1));
+			/* disable dma */
+			kmb_clr_bitmask_lcd(kmb,
+					    LCD_LAYERn_DMA_CFG(kmb->layer_no),
+					    LCD_DMA_LAYER_ENABLE);
+			kmb_write_lcd(kmb, LCD_FIFO_FLUSH, 1);
+			kmb->kmb_flush_done = 1;
+			kmb->kmb_under_flow = 0;
+		}
+	}
+
+	if (status & LCD_INT_LINE_CMP) {
+		/* clear line compare interrupt */
+		kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_LINE_CMP);
+	}
+
+	if (status & LCD_INT_VERT_COMP) {
+		/* Read VSTATUS */
+		val = kmb_read_lcd(kmb, LCD_VSTATUS);
+		val = (val & LCD_VSTATUS_VERTICAL_STATUS_MASK);
+		switch (val) {
+		case LCD_VSTATUS_COMPARE_VSYNC:
+			/* Clear vertical compare interrupt */
+			kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+			if (kmb->kmb_flush_done) {
+				kmb_set_bitmask_lcd(kmb,
+						    LCD_LAYERn_DMA_CFG
+						    (kmb->layer_no),
+						    LCD_DMA_LAYER_ENABLE);
+				kmb->kmb_flush_done = 0;
+			}
+			drm_crtc_handle_vblank(&kmb->crtc);
+			break;
+		case LCD_VSTATUS_COMPARE_BACKPORCH:
+		case LCD_VSTATUS_COMPARE_ACTIVE:
+		case LCD_VSTATUS_COMPARE_FRONT_PORCH:
+			kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+			break;
+		}
+	}
+	if (status & LCD_INT_DMA_ERR) {
+		val =
+		    (status & LCD_INT_DMA_ERR &
+		     kmb_read_lcd(kmb, LCD_INT_ENABLE));
+		/* LAYER0 - VL0 */
+		if (val & (LAYER0_DMA_FIFO_UNDERFLOW |
+			   LAYER0_DMA_CB_FIFO_UNDERFLOW |
+			   LAYER0_DMA_CR_FIFO_UNDERFLOW)) {
+			kmb->kmb_under_flow++;
+			drm_info(&kmb->drm,
+				 "!LAYER0:VL0 DMA UNDERFLOW val = 0x%lx,under_flow=%d",
+			     val, kmb->kmb_under_flow);
+			/* disable underflow interrupt */
+			kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+					    LAYER0_DMA_FIFO_UNDERFLOW |
+					    LAYER0_DMA_CB_FIFO_UNDERFLOW |
+					    LAYER0_DMA_CR_FIFO_UNDERFLOW);
+			kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR,
+					    LAYER0_DMA_CB_FIFO_UNDERFLOW |
+					    LAYER0_DMA_FIFO_UNDERFLOW |
+					    LAYER0_DMA_CR_FIFO_UNDERFLOW);
+			/* disable auto restart mode */
+			kmb_clr_bitmask_lcd(kmb, LCD_LAYERn_DMA_CFG(0),
+					    LCD_DMA_LAYER_CONT_PING_PONG_UPDATE);
+
+			kmb->layer_no = 0;
+		}
+
+		if (val & LAYER0_DMA_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER0:VL0 DMA OVERFLOW val = 0x%lx", val);
+		if (val & LAYER0_DMA_CB_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER0:VL0 DMA CB OVERFLOW val = 0x%lx", val);
+		if (val & LAYER0_DMA_CR_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER0:VL0 DMA CR OVERFLOW val = 0x%lx", val);
+
+		/* LAYER1 - VL1 */
+		if (val & (LAYER1_DMA_FIFO_UNDERFLOW |
+			   LAYER1_DMA_CB_FIFO_UNDERFLOW |
+			   LAYER1_DMA_CR_FIFO_UNDERFLOW)) {
+			kmb->kmb_under_flow++;
+			drm_info(&kmb->drm,
+				 "!LAYER1:VL1 DMA UNDERFLOW val = 0x%lx, under_flow=%d",
+			     val, kmb->kmb_under_flow);
+			/* disable underflow interrupt */
+			kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+					    LAYER1_DMA_FIFO_UNDERFLOW |
+					    LAYER1_DMA_CB_FIFO_UNDERFLOW |
+					    LAYER1_DMA_CR_FIFO_UNDERFLOW);
+			kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR,
+					    LAYER1_DMA_CB_FIFO_UNDERFLOW |
+					    LAYER1_DMA_FIFO_UNDERFLOW |
+					    LAYER1_DMA_CR_FIFO_UNDERFLOW);
+			/* disable auto restart mode */
+			kmb_clr_bitmask_lcd(kmb, LCD_LAYERn_DMA_CFG(1),
+					    LCD_DMA_LAYER_CONT_PING_PONG_UPDATE);
+			kmb->layer_no = 1;
+		}
+
+		/* LAYER1 - VL1 */
+		if (val & LAYER1_DMA_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER1:VL1 DMA OVERFLOW val = 0x%lx", val);
+		if (val & LAYER1_DMA_CB_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER1:VL1 DMA CB OVERFLOW val = 0x%lx", val);
+		if (val & LAYER1_DMA_CR_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER1:VL1 DMA CR OVERFLOW val = 0x%lx", val);
+
+		/* LAYER2 - GL0 */
+		if (val & LAYER2_DMA_FIFO_UNDERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER2:GL0 DMA UNDERFLOW val = 0x%lx", val);
+		if (val & LAYER2_DMA_FIFO_OVERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER2:GL0 DMA OVERFLOW val = 0x%lx", val);
+
+		/* LAYER3 - GL1 */
+		if (val & LAYER3_DMA_FIFO_UNDERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER3:GL1 DMA UNDERFLOW val = 0x%lx", val);
+		if (val & LAYER3_DMA_FIFO_UNDERFLOW)
+			drm_dbg(&kmb->drm,
+				"LAYER3:GL1 DMA OVERFLOW val = 0x%lx", val);
+	}
+
+	spin_unlock(&kmb->irq_lock);
+
+	if (status & LCD_INT_LAYER) {
+		/* Clear layer interrupts */
+		kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_LAYER);
+	}
+
+	/* Clear all interrupts */
+	kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR, 1);
+	return IRQ_HANDLED;
+}
+
+/* IRQ handler */
+static irqreturn_t kmb_isr(int irq, void *arg)
+{
+	struct drm_device *dev = (struct drm_device *)arg;
+
+	handle_lcd_irq(dev);
+	return IRQ_HANDLED;
+}
+
+static void kmb_irq_reset(struct drm_device *drm)
+{
+	kmb_write_lcd(to_kmb(drm), LCD_INT_CLEAR, 0xFFFF);
+	kmb_write_lcd(to_kmb(drm), LCD_INT_ENABLE, 0);
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(fops);
+
+static struct drm_driver kmb_driver = {
+	.driver_features = DRIVER_GEM |
+	    DRIVER_MODESET | DRIVER_ATOMIC,
+	.irq_handler = kmb_isr,
+	.irq_preinstall = kmb_irq_reset,
+	.irq_uninstall = kmb_irq_reset,
+	/* GEM Operations */
+	.fops = &fops,
+	DRM_GEM_CMA_DRIVER_OPS_VMAP,
+	.name = "kmb-drm",
+	.desc = "KEEMBAY DISPLAY DRIVER ",
+	.date = "20201008",
+	.major = 1,
+	.minor = 0,
+};
+
+static int kmb_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct drm_device *drm = dev_get_drvdata(dev);
+	struct kmb_drm_private *kmb = to_kmb(drm);
+
+	drm_dev_unregister(drm);
+	drm_kms_helper_poll_fini(drm);
+	of_node_put(kmb->crtc.port);
+	kmb->crtc.port = NULL;
+	pm_runtime_get_sync(drm->dev);
+	drm_irq_uninstall(drm);
+	pm_runtime_put_sync(drm->dev);
+	pm_runtime_disable(drm->dev);
+
+	of_reserved_mem_device_release(drm->dev);
+
+	/* Release clks */
+	kmb_display_clk_disable(kmb);
+
+	dev_set_drvdata(dev, NULL);
+
+	/* Unregister DSI host */
+	kmb_dsi_host_unregister(kmb->kmb_dsi);
+	drm_atomic_helper_shutdown(drm);
+	return 0;
+}
+
+static int kmb_probe(struct platform_device *pdev)
+{
+	struct device *dev = get_device(&pdev->dev);
+	struct kmb_drm_private *kmb;
+	int ret = 0;
+	struct device_node *dsi_in;
+	struct device_node *dsi_node;
+	struct platform_device *dsi_pdev;
+
+	/* The bridge (ADV 7535) will return -EPROBE_DEFER until it
+	 * has a mipi_dsi_host to register its device to. So, we
+	 * first register the DSI host during probe time, and then return
+	 * -EPROBE_DEFER until the bridge is loaded. Probe will be called again
+	 *  and then the rest of the driver initialization can proceed
+	 *  afterwards and the bridge can be successfully attached.
+	 */
+	dsi_in = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+	if (!dsi_in) {
+		DRM_ERROR("Failed to get dsi_in node info from DT");
+		return -EINVAL;
+	}
+	dsi_node = of_graph_get_remote_port_parent(dsi_in);
+	if (!dsi_node) {
+		of_node_put(dsi_in);
+		DRM_ERROR("Failed to get dsi node from DT\n");
+		return -EINVAL;
+	}
+
+	dsi_pdev = of_find_device_by_node(dsi_node);
+	if (!dsi_pdev) {
+		of_node_put(dsi_in);
+		of_node_put(dsi_node);
+		DRM_ERROR("Failed to get dsi platform device\n");
+		return -EINVAL;
+	}
+
+	of_node_put(dsi_in);
+	of_node_put(dsi_node);
+	ret = kmb_dsi_host_bridge_init(get_device(&dsi_pdev->dev));
+
+	if (ret == -EPROBE_DEFER) {
+		return -EPROBE_DEFER;
+	} else if (ret) {
+		DRM_ERROR("probe failed to initialize DSI host bridge\n");
+		return ret;
+	}
+
+	/* Create DRM device */
+	kmb = devm_drm_dev_alloc(dev, &kmb_driver,
+				 struct kmb_drm_private, drm);
+	if (IS_ERR(kmb))
+		return PTR_ERR(kmb);
+
+	dev_set_drvdata(dev, &kmb->drm);
+
+	/* Initialize MIPI DSI */
+	kmb->kmb_dsi = kmb_dsi_init(dsi_pdev);
+	if (IS_ERR(kmb->kmb_dsi)) {
+		drm_err(&kmb->drm, "failed to initialize DSI\n");
+		ret = PTR_ERR(kmb->kmb_dsi);
+		goto err_free1;
+	}
+
+	kmb->kmb_dsi->dev = &dsi_pdev->dev;
+	kmb->kmb_dsi->pdev = dsi_pdev;
+	ret = kmb_hw_init(&kmb->drm, 0);
+	if (ret)
+		goto err_free1;
+
+	ret = kmb_setup_mode_config(&kmb->drm);
+	if (ret)
+		goto err_free;
+
+	ret = drm_irq_install(&kmb->drm, kmb->irq_lcd);
+	if (ret < 0) {
+		drm_err(&kmb->drm, "failed to install IRQ handler\n");
+		goto err_irq;
+	}
+
+	drm_kms_helper_poll_init(&kmb->drm);
+
+	/* Register graphics device with the kernel */
+	ret = drm_dev_register(&kmb->drm, 0);
+	if (ret)
+		goto err_register;
+
+	return 0;
+
+ err_register:
+	drm_kms_helper_poll_fini(&kmb->drm);
+ err_irq:
+	pm_runtime_disable(kmb->drm.dev);
+ err_free:
+	drm_crtc_cleanup(&kmb->crtc);
+	drm_mode_config_cleanup(&kmb->drm);
+ err_free1:
+	dev_set_drvdata(dev, NULL);
+	kmb_dsi_host_unregister(kmb->kmb_dsi);
+
+	return ret;
+}
+
+static const struct of_device_id kmb_of_match[] = {
+	{.compatible = "intel,keembay-display"},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, kmb_of_match);
+
+static int __maybe_unused kmb_pm_suspend(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+	struct kmb_drm_private *kmb = drm ? to_kmb(drm) : NULL;
+
+	drm_kms_helper_poll_disable(drm);
+
+	kmb->state = drm_atomic_helper_suspend(drm);
+	if (IS_ERR(kmb->state)) {
+		drm_kms_helper_poll_enable(drm);
+		return PTR_ERR(kmb->state);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused kmb_pm_resume(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+	struct kmb_drm_private *kmb = drm ? to_kmb(drm) : NULL;
+
+	if (!kmb)
+		return 0;
+
+	drm_atomic_helper_resume(drm, kmb->state);
+	drm_kms_helper_poll_enable(drm);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(kmb_pm_ops, kmb_pm_suspend, kmb_pm_resume);
+
+static struct platform_driver kmb_platform_driver = {
+	.probe = kmb_probe,
+	.remove = kmb_remove,
+	.driver = {
+		.name = "kmb-drm",
+		.pm = &kmb_pm_ops,
+		.of_match_table = kmb_of_match,
+	},
+};
+
+module_platform_driver(kmb_platform_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Keembay Display driver");
+MODULE_LICENSE("GPL v2");

drivers/gpu/drm/kmb/kmb_drv.h

+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#ifndef __KMB_DRV_H__
+#define __KMB_DRV_H__
+
+#include <drm/drm_device.h>
+
+#include "kmb_plane.h"
+#include "kmb_regs.h"
+
+#define KMB_MAX_WIDTH			1920 /*Max width in pixels */
+#define KMB_MAX_HEIGHT			1080 /*Max height in pixels */
+#define KMB_MIN_WIDTH                   1920 /*Max width in pixels */
+#define KMB_MIN_HEIGHT                  1080 /*Max height in pixels */
+#define KMB_LCD_DEFAULT_CLK		200000000
+#define KMB_SYS_CLK_MHZ			500
+
+#define ICAM_MMIO		0x3b100000
+#define ICAM_LCD_OFFSET		0x1080
+#define ICAM_MMIO_SIZE		0x2000
+
+struct kmb_dsi;
+
+struct kmb_clock {
+	struct clk *clk_lcd;
+	struct clk *clk_pll0;
+};
+
+struct kmb_drm_private {
+	struct drm_device		drm;
+	struct kmb_dsi			*kmb_dsi;
+	void __iomem			*lcd_mmio;
+	struct kmb_clock		kmb_clk;
+	struct drm_crtc			crtc;
+	struct kmb_plane		*plane;
+	struct drm_atomic_state		*state;
+	spinlock_t			irq_lock;
+	int				irq_lcd;
+	int				sys_clk_mhz;
+	struct layer_status		plane_status[KMB_MAX_PLANES];
+	int				kmb_under_flow;
+	int				kmb_flush_done;
+	int				layer_no;
+};
+
+static inline struct kmb_drm_private *to_kmb(const struct drm_device *dev)
+{
+	return container_of(dev, struct kmb_drm_private, drm);
+}
+
+static inline struct kmb_drm_private *crtc_to_kmb_priv(const struct drm_crtc *x)
+{
+	return container_of(x, struct kmb_drm_private, crtc);
+}
+
+static inline void kmb_write_lcd(struct kmb_drm_private *dev_p,
+				 unsigned int reg, u32 value)
+{
+	writel(value, (dev_p->lcd_mmio + reg));
+}
+
+static inline u32 kmb_read_lcd(struct kmb_drm_private *dev_p, unsigned int reg)
+{
+	return readl(dev_p->lcd_mmio + reg);
+}
+
+static inline void kmb_set_bitmask_lcd(struct kmb_drm_private *dev_p,
+				       unsigned int reg, u32 mask)
+{
+	u32 reg_val = kmb_read_lcd(dev_p, reg);
+
+	kmb_write_lcd(dev_p, reg, (reg_val | mask));
+}
+
+static inline void kmb_clr_bitmask_lcd(struct kmb_drm_private *dev_p,
+				       unsigned int reg, u32 mask)
+{
+	u32 reg_val = kmb_read_lcd(dev_p, reg);
+
+	kmb_write_lcd(dev_p, reg, (reg_val & (~mask)));
+}
+
+int kmb_setup_crtc(struct drm_device *dev);
+void kmb_set_scanout(struct kmb_drm_private *lcd);
+#endif /* __KMB_DRV_H__ */

drivers/gpu/drm/kmb/kmb_plane.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_plane_helper.h>
+
+#include "kmb_drv.h"
+#include "kmb_plane.h"
+#include "kmb_regs.h"
+
+const u32 layer_irqs[] = {
+	LCD_INT_VL0,
+	LCD_INT_VL1,
+	LCD_INT_GL0,
+	LCD_INT_GL1
+};
+
+/* Conversion (yuv->rgb) matrix from myriadx */
+static const u32 csc_coef_lcd[] = {
+	1024, 0, 1436,
+	1024, -352, -731,
+	1024, 1814, 0,
+	-179, 125, -226
+};
+
+static unsigned int check_pixel_format(struct drm_plane *plane, u32 format)
+{
+	int i;
+
+	for (i = 0; i < plane->format_count; i++) {
+		if (plane->format_types[i] == format)
+			return 0;
+	}
+	return -EINVAL;
+}
+
+static int kmb_plane_atomic_check(struct drm_plane *plane,
+				  struct drm_plane_state *state)
+{
+	struct drm_framebuffer *fb;
+	int ret;
+	struct drm_crtc_state *crtc_state;
+	bool can_position;
+
+	fb = state->fb;
+	if (!fb || !state->crtc)
+		return 0;
+
+	ret = check_pixel_format(plane, fb->format->format);
+	if (ret)
+		return ret;
+
+	if (state->crtc_w > KMB_MAX_WIDTH || state->crtc_h > KMB_MAX_HEIGHT)
+		return -EINVAL;
+	if (state->crtc_w < KMB_MIN_WIDTH || state->crtc_h < KMB_MIN_HEIGHT)
+		return -EINVAL;
+	can_position = (plane->type == DRM_PLANE_TYPE_OVERLAY);
+	crtc_state =
+		drm_atomic_get_existing_crtc_state(state->state, state->crtc);
+	return drm_atomic_helper_check_plane_state(state, crtc_state,
+						 DRM_PLANE_HELPER_NO_SCALING,
+						 DRM_PLANE_HELPER_NO_SCALING,
+						 can_position, true);
+}
+
+static void kmb_plane_atomic_disable(struct drm_plane *plane,
+				     struct drm_plane_state *state)
+{
+	struct kmb_plane *kmb_plane = to_kmb_plane(plane);
+	int plane_id = kmb_plane->id;
+	struct kmb_drm_private *kmb;
+
+	kmb = to_kmb(plane->dev);
+
+	switch (plane_id) {
+	case LAYER_0:
+		kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL1_ENABLE;
+		break;
+	case LAYER_1:
+		kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL2_ENABLE;
+		break;
+	case LAYER_2:
+		kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE;
+		break;
+	case LAYER_3:
+		kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
+		break;
+	}
+
+	kmb->plane_status[plane_id].disable = true;
+}
+
+static unsigned int get_pixel_format(u32 format)
+{
+	unsigned int val = 0;
+
+	switch (format) {
+		/* planar formats */
+	case DRM_FORMAT_YUV444:
+		val = LCD_LAYER_FORMAT_YCBCR444PLAN | LCD_LAYER_PLANAR_STORAGE;
+		break;
+	case DRM_FORMAT_YVU444:
+		val = LCD_LAYER_FORMAT_YCBCR444PLAN | LCD_LAYER_PLANAR_STORAGE
+		    | LCD_LAYER_CRCB_ORDER;
+		break;
+	case DRM_FORMAT_YUV422:
+		val = LCD_LAYER_FORMAT_YCBCR422PLAN | LCD_LAYER_PLANAR_STORAGE;
+		break;
+	case DRM_FORMAT_YVU422:
+		val = LCD_LAYER_FORMAT_YCBCR422PLAN | LCD_LAYER_PLANAR_STORAGE
+		    | LCD_LAYER_CRCB_ORDER;
+		break;
+	case DRM_FORMAT_YUV420:
+		val = LCD_LAYER_FORMAT_YCBCR420PLAN | LCD_LAYER_PLANAR_STORAGE;
+		break;
+	case DRM_FORMAT_YVU420:
+		val = LCD_LAYER_FORMAT_YCBCR420PLAN | LCD_LAYER_PLANAR_STORAGE
+		    | LCD_LAYER_CRCB_ORDER;
+		break;
+	case DRM_FORMAT_NV12:
+		val = LCD_LAYER_FORMAT_NV12 | LCD_LAYER_PLANAR_STORAGE;
+		break;
+	case DRM_FORMAT_NV21:
+		val = LCD_LAYER_FORMAT_NV12 | LCD_LAYER_PLANAR_STORAGE
+		    | LCD_LAYER_CRCB_ORDER;
+		break;
+		/* packed formats */
+		/* looks hw requires B & G to be swapped when RGB */
+	case DRM_FORMAT_RGB332:
+		val = LCD_LAYER_FORMAT_RGB332 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_XBGR4444:
+		val = LCD_LAYER_FORMAT_RGBX4444;
+		break;
+	case DRM_FORMAT_ARGB4444:
+		val = LCD_LAYER_FORMAT_RGBA4444 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_ABGR4444:
+		val = LCD_LAYER_FORMAT_RGBA4444;
+		break;
+	case DRM_FORMAT_XRGB1555:
+		val = LCD_LAYER_FORMAT_XRGB1555 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_XBGR1555:
+		val = LCD_LAYER_FORMAT_XRGB1555;
+		break;
+	case DRM_FORMAT_ARGB1555:
+		val = LCD_LAYER_FORMAT_RGBA1555 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_ABGR1555:
+		val = LCD_LAYER_FORMAT_RGBA1555;
+		break;
+	case DRM_FORMAT_RGB565:
+		val = LCD_LAYER_FORMAT_RGB565 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_BGR565:
+		val = LCD_LAYER_FORMAT_RGB565;
+		break;
+	case DRM_FORMAT_RGB888:
+		val = LCD_LAYER_FORMAT_RGB888 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_BGR888:
+		val = LCD_LAYER_FORMAT_RGB888;
+		break;
+	case DRM_FORMAT_XRGB8888:
+		val = LCD_LAYER_FORMAT_RGBX8888 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_XBGR8888:
+		val = LCD_LAYER_FORMAT_RGBX8888;
+		break;
+	case DRM_FORMAT_ARGB8888:
+		val = LCD_LAYER_FORMAT_RGBA8888 | LCD_LAYER_BGR_ORDER;
+		break;
+	case DRM_FORMAT_ABGR8888:
+		val = LCD_LAYER_FORMAT_RGBA8888;
+		break;
+	}
+	DRM_INFO_ONCE("%s : %d format=0x%x val=0x%x\n",
+		      __func__, __LINE__, format, val);
+	return val;
+}
+
+static unsigned int get_bits_per_pixel(const struct drm_format_info *format)
+{
+	u32 bpp = 0;
+	unsigned int val = 0;
+
+	if (format->num_planes > 1) {
+		val = LCD_LAYER_8BPP;
+		return val;
+	}
+
+	bpp += 8 * format->cpp[0];
+
+	switch (bpp) {
+	case 8:
+		val = LCD_LAYER_8BPP;
+		break;
+	case 16:
+		val = LCD_LAYER_16BPP;
+		break;
+	case 24:
+		val = LCD_LAYER_24BPP;
+		break;
+	case 32:
+		val = LCD_LAYER_32BPP;
+		break;
+	}
+
+	DRM_DEBUG("bpp=%d val=0x%x\n", bpp, val);
+	return val;
+}
+
+static void config_csc(struct kmb_drm_private *kmb, int plane_id)
+{
+	/* YUV to RGB conversion using the fixed matrix csc_coef_lcd */
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF11(plane_id), csc_coef_lcd[0]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF12(plane_id), csc_coef_lcd[1]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF13(plane_id), csc_coef_lcd[2]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF21(plane_id), csc_coef_lcd[3]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF22(plane_id), csc_coef_lcd[4]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF23(plane_id), csc_coef_lcd[5]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF31(plane_id), csc_coef_lcd[6]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF32(plane_id), csc_coef_lcd[7]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_COEFF33(plane_id), csc_coef_lcd[8]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_OFF1(plane_id), csc_coef_lcd[9]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_OFF2(plane_id), csc_coef_lcd[10]);
+	kmb_write_lcd(kmb, LCD_LAYERn_CSC_OFF3(plane_id), csc_coef_lcd[11]);
+}
+
+static void kmb_plane_atomic_update(struct drm_plane *plane,
+				    struct drm_plane_state *state)
+{
+	struct drm_framebuffer *fb;
+	struct kmb_drm_private *kmb;
+	unsigned int width;
+	unsigned int height;
+	unsigned int dma_len;
+	struct kmb_plane *kmb_plane;
+	unsigned int dma_cfg;
+	unsigned int ctrl = 0, val = 0, out_format = 0;
+	unsigned int src_w, src_h, crtc_x, crtc_y;
+	unsigned char plane_id;
+	int num_planes;
+	static dma_addr_t addr[MAX_SUB_PLANES];
+
+	if (!plane || !plane->state || !state)
+		return;
+
+	fb = plane->state->fb;
+	if (!fb)
+		return;
+	num_planes = fb->format->num_planes;
+	kmb_plane = to_kmb_plane(plane);
+	plane_id = kmb_plane->id;
+
+	kmb = to_kmb(plane->dev);
+
+	spin_lock_irq(&kmb->irq_lock);
+	if (kmb->kmb_under_flow || kmb->kmb_flush_done) {
+		spin_unlock_irq(&kmb->irq_lock);
+		drm_dbg(&kmb->drm, "plane_update:underflow!!!! returning");
+		return;
+	}
+	spin_unlock_irq(&kmb->irq_lock);
+
+	src_w = (plane->state->src_w >> 16);
+	src_h = plane->state->src_h >> 16;
+	crtc_x = plane->state->crtc_x;
+	crtc_y = plane->state->crtc_y;
+
+	drm_dbg(&kmb->drm,
+		"src_w=%d src_h=%d, fb->format->format=0x%x fb->flags=0x%x\n",
+		  src_w, src_h, fb->format->format, fb->flags);
+
+	width = fb->width;
+	height = fb->height;
+	dma_len = (width * height * fb->format->cpp[0]);
+	drm_dbg(&kmb->drm, "dma_len=%d ", dma_len);
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_LEN(plane_id), dma_len);
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_LEN_SHADOW(plane_id), dma_len);
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_LINE_VSTRIDE(plane_id),
+		      fb->pitches[0]);
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_LINE_WIDTH(plane_id),
+		      (width * fb->format->cpp[0]));
+
+	addr[Y_PLANE] = drm_fb_cma_get_gem_addr(fb, plane->state, 0);
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_START_ADDR(plane_id),
+		      addr[Y_PLANE] + fb->offsets[0]);
+	val = get_pixel_format(fb->format->format);
+	val |= get_bits_per_pixel(fb->format);
+	/* Program Cb/Cr for planar formats */
+	if (num_planes > 1) {
+		kmb_write_lcd(kmb, LCD_LAYERn_DMA_CB_LINE_VSTRIDE(plane_id),
+			      width * fb->format->cpp[0]);
+		kmb_write_lcd(kmb, LCD_LAYERn_DMA_CB_LINE_WIDTH(plane_id),
+			      (width * fb->format->cpp[0]));
+
+		addr[U_PLANE] = drm_fb_cma_get_gem_addr(fb, plane->state,
+							U_PLANE);
+		/* check if Cb/Cr is swapped*/
+		if (num_planes == 3 && (val & LCD_LAYER_CRCB_ORDER))
+			kmb_write_lcd(kmb,
+				      LCD_LAYERn_DMA_START_CR_ADR(plane_id),
+					addr[U_PLANE]);
+		else
+			kmb_write_lcd(kmb,
+				      LCD_LAYERn_DMA_START_CB_ADR(plane_id),
+					addr[U_PLANE]);
+
+		if (num_planes == 3) {
+			kmb_write_lcd(kmb,
+				      LCD_LAYERn_DMA_CR_LINE_VSTRIDE(plane_id),
+				      ((width) * fb->format->cpp[0]));
+
+			kmb_write_lcd(kmb,
+				      LCD_LAYERn_DMA_CR_LINE_WIDTH(plane_id),
+				      ((width) * fb->format->cpp[0]));
+
+			addr[V_PLANE] = drm_fb_cma_get_gem_addr(fb,
+								plane->state,
+								V_PLANE);
+
+			/* check if Cb/Cr is swapped*/
+			if (val & LCD_LAYER_CRCB_ORDER)
+				kmb_write_lcd(kmb,
+					      LCD_LAYERn_DMA_START_CB_ADR(plane_id),
+					      addr[V_PLANE]);
+			else
+				kmb_write_lcd(kmb,
+					      LCD_LAYERn_DMA_START_CR_ADR(plane_id),
+					      addr[V_PLANE]);
+		}
+	}
+
+	kmb_write_lcd(kmb, LCD_LAYERn_WIDTH(plane_id), src_w - 1);
+	kmb_write_lcd(kmb, LCD_LAYERn_HEIGHT(plane_id), src_h - 1);
+	kmb_write_lcd(kmb, LCD_LAYERn_COL_START(plane_id), crtc_x);
+	kmb_write_lcd(kmb, LCD_LAYERn_ROW_START(plane_id), crtc_y);
+
+	val |= LCD_LAYER_FIFO_100;
+
+	if (val & LCD_LAYER_PLANAR_STORAGE) {
+		val |= LCD_LAYER_CSC_EN;
+
+		/* Enable CSC if input is planar and output is RGB */
+		config_csc(kmb, plane_id);
+	}
+
+	kmb_write_lcd(kmb, LCD_LAYERn_CFG(plane_id), val);
+
+	switch (plane_id) {
+	case LAYER_0:
+		ctrl = LCD_CTRL_VL1_ENABLE;
+		break;
+	case LAYER_1:
+		ctrl = LCD_CTRL_VL2_ENABLE;
+		break;
+	case LAYER_2:
+		ctrl = LCD_CTRL_GL1_ENABLE;
+		break;
+	case LAYER_3:
+		ctrl = LCD_CTRL_GL2_ENABLE;
+		break;
+	}
+
+	ctrl |= LCD_CTRL_PROGRESSIVE | LCD_CTRL_TIM_GEN_ENABLE
+	    | LCD_CTRL_CONTINUOUS | LCD_CTRL_OUTPUT_ENABLED;
+
+	/* LCD is connected to MIPI on kmb
+	 * Therefore this bit is required for DSI Tx
+	 */
+	ctrl |= LCD_CTRL_VHSYNC_IDLE_LVL;
+
+	kmb_set_bitmask_lcd(kmb, LCD_CONTROL, ctrl);
+
+	/* FIXME no doc on how to set output format,these values are
+	 * taken from the Myriadx tests
+	 */
+	out_format |= LCD_OUTF_FORMAT_RGB888;
+
+	/* Leave RGB order,conversion mode and clip mode to default */
+	/* do not interleave RGB channels for mipi Tx compatibility */
+	out_format |= LCD_OUTF_MIPI_RGB_MODE;
+	kmb_write_lcd(kmb, LCD_OUT_FORMAT_CFG, out_format);
+
+	dma_cfg = LCD_DMA_LAYER_ENABLE | LCD_DMA_LAYER_VSTRIDE_EN |
+	    LCD_DMA_LAYER_CONT_UPDATE | LCD_DMA_LAYER_AXI_BURST_16;
+
+	/* Enable DMA */
+	kmb_write_lcd(kmb, LCD_LAYERn_DMA_CFG(plane_id), dma_cfg);
+	drm_dbg(&kmb->drm, "dma_cfg=0x%x LCD_DMA_CFG=0x%x\n", dma_cfg,
+		kmb_read_lcd(kmb, LCD_LAYERn_DMA_CFG(plane_id)));
+
+	kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR, LCD_INT_EOF |
+			LCD_INT_DMA_ERR);
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE, LCD_INT_EOF |
+			LCD_INT_DMA_ERR);
+}
+
+static const struct drm_plane_helper_funcs kmb_plane_helper_funcs = {
+	.atomic_check = kmb_plane_atomic_check,
+	.atomic_update = kmb_plane_atomic_update,
+	.atomic_disable = kmb_plane_atomic_disable
+};
+
+void kmb_plane_destroy(struct drm_plane *plane)
+{
+	struct kmb_plane *kmb_plane = to_kmb_plane(plane);
+
+	drm_plane_cleanup(plane);
+	kfree(kmb_plane);
+}
+
+static const struct drm_plane_funcs kmb_plane_funcs = {
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = kmb_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,
+};
+
+struct kmb_plane *kmb_plane_init(struct drm_device *drm)
+{
+	struct kmb_drm_private *kmb = to_kmb(drm);
+	struct kmb_plane *plane = NULL;
+	struct kmb_plane *primary = NULL;
+	int i = 0;
+	int ret = 0;
+	enum drm_plane_type plane_type;
+	const u32 *plane_formats;
+	int num_plane_formats;
+
+	for (i = 0; i < KMB_MAX_PLANES; i++) {
+		plane = drmm_kzalloc(drm, sizeof(*plane), GFP_KERNEL);
+
+		if (!plane) {
+			drm_err(drm, "Failed to allocate plane\n");
+			return ERR_PTR(-ENOMEM);
+		}
+
+		plane_type = (i == 0) ? DRM_PLANE_TYPE_PRIMARY :
+		    DRM_PLANE_TYPE_OVERLAY;
+		if (i < 2) {
+			plane_formats = kmb_formats_v;
+			num_plane_formats = ARRAY_SIZE(kmb_formats_v);
+		} else {
+			plane_formats = kmb_formats_g;
+			num_plane_formats = ARRAY_SIZE(kmb_formats_g);
+		}
+
+		ret = drm_universal_plane_init(drm, &plane->base_plane,
+					       POSSIBLE_CRTCS, &kmb_plane_funcs,
+					       plane_formats, num_plane_formats,
+					       NULL, plane_type, "plane %d", i);
+		if (ret < 0) {
+			drm_err(drm, "drm_universal_plane_init failed (ret=%d)",
+				ret);
+			goto cleanup;
+		}
+		drm_dbg(drm, "%s : %d i=%d type=%d",
+			__func__, __LINE__,
+			  i, plane_type);
+		drm_plane_helper_add(&plane->base_plane,
+				     &kmb_plane_helper_funcs);
+		if (plane_type == DRM_PLANE_TYPE_PRIMARY) {
+			primary = plane;
+			kmb->plane = plane;
+		}
+		drm_dbg(drm, "%s : %d primary=%p\n", __func__, __LINE__,
+			&primary->base_plane);
+		plane->id = i;
+	}
+
+	return primary;
+cleanup:
+	drmm_kfree(drm, plane);
+	return ERR_PTR(ret);
+}

drivers/gpu/drm/kmb/kmb_plane.h

+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#ifndef __KMB_PLANE_H__
+#define __KMB_PLANE_H__
+
+#include <drm/drm_fourcc.h>
+#include <drm/drm_plane.h>
+
+#define LCD_INT_VL0_ERR ((LAYER0_DMA_FIFO_UNDERFLOW) | \
+			(LAYER0_DMA_FIFO_OVERFLOW) | \
+			(LAYER0_DMA_CB_FIFO_OVERFLOW) | \
+			(LAYER0_DMA_CB_FIFO_UNDERFLOW) | \
+			(LAYER0_DMA_CR_FIFO_OVERFLOW) | \
+			(LAYER0_DMA_CR_FIFO_UNDERFLOW))
+
+#define LCD_INT_VL1_ERR ((LAYER1_DMA_FIFO_UNDERFLOW) | \
+			(LAYER1_DMA_FIFO_OVERFLOW) | \
+			(LAYER1_DMA_CB_FIFO_OVERFLOW) | \
+			(LAYER1_DMA_CB_FIFO_UNDERFLOW) | \
+			(LAYER1_DMA_CR_FIFO_OVERFLOW) | \
+			(LAYER1_DMA_CR_FIFO_UNDERFLOW))
+
+#define LCD_INT_GL0_ERR (LAYER2_DMA_FIFO_OVERFLOW | LAYER2_DMA_FIFO_UNDERFLOW)
+#define LCD_INT_GL1_ERR (LAYER3_DMA_FIFO_OVERFLOW | LAYER3_DMA_FIFO_UNDERFLOW)
+#define LCD_INT_VL0 (LAYER0_DMA_DONE | LAYER0_DMA_IDLE | LCD_INT_VL0_ERR)
+#define LCD_INT_VL1 (LAYER1_DMA_DONE | LAYER1_DMA_IDLE | LCD_INT_VL1_ERR)
+#define LCD_INT_GL0 (LAYER2_DMA_DONE | LAYER2_DMA_IDLE | LCD_INT_GL0_ERR)
+#define LCD_INT_GL1 (LAYER3_DMA_DONE | LAYER3_DMA_IDLE | LCD_INT_GL1_ERR)
+#define LCD_INT_DMA_ERR (LCD_INT_VL0_ERR | LCD_INT_VL1_ERR \
+		| LCD_INT_GL0_ERR | LCD_INT_GL1_ERR)
+
+#define POSSIBLE_CRTCS 1
+#define to_kmb_plane(x) container_of(x, struct kmb_plane, base_plane)
+
+enum layer_id {
+	LAYER_0,
+	LAYER_1,
+	LAYER_2,
+	LAYER_3,
+	/* KMB_MAX_PLANES */
+};
+
+#define KMB_MAX_PLANES 1
+
+enum sub_plane_id {
+	Y_PLANE,
+	U_PLANE,
+	V_PLANE,
+	MAX_SUB_PLANES,
+};
+
+struct kmb_plane {
+	struct drm_plane base_plane;
+	unsigned char id;
+};
+
+/* Graphics layer (layers 2 & 3) formats, only packed formats  are supported */
+static const u32 kmb_formats_g[] = {
+	DRM_FORMAT_RGB332,
+	DRM_FORMAT_XRGB4444, DRM_FORMAT_XBGR4444,
+	DRM_FORMAT_ARGB4444, DRM_FORMAT_ABGR4444,
+	DRM_FORMAT_XRGB1555, DRM_FORMAT_XBGR1555,
+	DRM_FORMAT_ARGB1555, DRM_FORMAT_ABGR1555,
+	DRM_FORMAT_RGB565, DRM_FORMAT_BGR565,
+	DRM_FORMAT_RGB888, DRM_FORMAT_BGR888,
+	DRM_FORMAT_XRGB8888, DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_ARGB8888, DRM_FORMAT_ABGR8888,
+};
+
+/* Video layer ( 0 & 1) formats, packed and planar formats are supported */
+static const u32 kmb_formats_v[] = {
+	/* packed formats */
+	DRM_FORMAT_RGB332,
+	DRM_FORMAT_XRGB4444, DRM_FORMAT_XBGR4444,
+	DRM_FORMAT_ARGB4444, DRM_FORMAT_ABGR4444,
+	DRM_FORMAT_XRGB1555, DRM_FORMAT_XBGR1555,
+	DRM_FORMAT_ARGB1555, DRM_FORMAT_ABGR1555,
+	DRM_FORMAT_RGB565, DRM_FORMAT_BGR565,
+	DRM_FORMAT_RGB888, DRM_FORMAT_BGR888,
+	DRM_FORMAT_XRGB8888, DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_ARGB8888, DRM_FORMAT_ABGR8888,
+	/*planar formats */
+	DRM_FORMAT_YUV420, DRM_FORMAT_YVU420,
+	DRM_FORMAT_YUV422, DRM_FORMAT_YVU422,
+	DRM_FORMAT_YUV444, DRM_FORMAT_YVU444,
+	DRM_FORMAT_NV12, DRM_FORMAT_NV21,
+};
+
+struct layer_status {
+	bool disable;
+	u32 ctrl;
+};
+
+struct kmb_plane *kmb_plane_init(struct drm_device *drm);
+void kmb_plane_destroy(struct drm_plane *plane);
+#endif /* __KMB_PLANE_H__ */