drm/bridge: imx: add driver for HDMI TX Parallel Video Interface

This IP block is found in the HDMI subsystem of the i.MX8MP SoC. It has a
full timing generator and can switch between different video sources. On
the i.MX8MP however the only supported source is the LCDIF. The block
just needs to be powered up and told about the polarity of the video
sync signals to act in bypass mode.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Marek Vasut <marex@denx.de>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/20240203165307.7806-9-aford173@gmail.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240203165307.7806-9-aford173@gmail.com

drivers/gpu/drm/bridge/imx/Kconfig

@@ -3,6 +3,13 @@ if ARCH_MXC || COMPILE_TEST
 config DRM_IMX_LDB_HELPER
 	tristate
 
+config DRM_IMX8MP_HDMI_PVI
+	tristate "Freescale i.MX8MP HDMI PVI bridge support"
+	depends on OF
+	help
+	  Choose this to enable support for the internal HDMI TX Parallel
+	  Video Interface found on the Freescale i.MX8MP SoC.
+
 config DRM_IMX8QM_LDB
 	tristate "Freescale i.MX8QM LVDS display bridge"
 	depends on OF

drivers/gpu/drm/bridge/imx/Makefile

 obj-$(CONFIG_DRM_IMX_LDB_HELPER) += imx-ldb-helper.o
+obj-$(CONFIG_DRM_IMX8MP_HDMI_PVI) += imx8mp-hdmi-pvi.o
 obj-$(CONFIG_DRM_IMX8QM_LDB) += imx8qm-ldb.o
 obj-$(CONFIG_DRM_IMX8QXP_LDB) += imx8qxp-ldb.o
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o

drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c

+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright (C) 2022 Pengutronix, Lucas Stach <kernel@pengutronix.de>
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_crtc.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#define HTX_PVI_CTRL			0x0
+#define  PVI_CTRL_OP_VSYNC_POL		BIT(18)
+#define  PVI_CTRL_OP_HSYNC_POL		BIT(17)
+#define  PVI_CTRL_OP_DE_POL		BIT(16)
+#define  PVI_CTRL_INP_VSYNC_POL		BIT(14)
+#define  PVI_CTRL_INP_HSYNC_POL		BIT(13)
+#define  PVI_CTRL_INP_DE_POL		BIT(12)
+#define  PVI_CTRL_MODE_MASK		GENMASK(2, 1)
+#define  PVI_CTRL_MODE_LCDIF		2
+#define  PVI_CTRL_EN			BIT(0)
+
+struct imx8mp_hdmi_pvi {
+	struct drm_bridge	bridge;
+	struct device		*dev;
+	struct drm_bridge	*next_bridge;
+	void __iomem		*regs;
+};
+
+static inline struct imx8mp_hdmi_pvi *
+to_imx8mp_hdmi_pvi(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct imx8mp_hdmi_pvi, bridge);
+}
+
+static int imx8mp_hdmi_pvi_bridge_attach(struct drm_bridge *bridge,
+					 enum drm_bridge_attach_flags flags)
+{
+	struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
+
+	return drm_bridge_attach(bridge->encoder, pvi->next_bridge,
+				 bridge, flags);
+}
+
+static void imx8mp_hdmi_pvi_bridge_enable(struct drm_bridge *bridge,
+					  struct drm_bridge_state *bridge_state)
+{
+	struct drm_atomic_state *state = bridge_state->base.state;
+	struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
+	struct drm_connector_state *conn_state;
+	const struct drm_display_mode *mode;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	u32 bus_flags, val;
+
+	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
+
+	if (WARN_ON(pm_runtime_resume_and_get(pvi->dev)))
+		return;
+
+	mode = &crtc_state->adjusted_mode;
+
+	val = FIELD_PREP(PVI_CTRL_MODE_MASK, PVI_CTRL_MODE_LCDIF) | PVI_CTRL_EN;
+
+	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+		val |= PVI_CTRL_OP_VSYNC_POL | PVI_CTRL_INP_VSYNC_POL;
+
+	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+		val |= PVI_CTRL_OP_HSYNC_POL | PVI_CTRL_INP_HSYNC_POL;
+
+	if (pvi->next_bridge->timings)
+		bus_flags = pvi->next_bridge->timings->input_bus_flags;
+	else if (bridge_state)
+		bus_flags = bridge_state->input_bus_cfg.flags;
+
+	if (bus_flags & DRM_BUS_FLAG_DE_HIGH)
+		val |= PVI_CTRL_OP_DE_POL | PVI_CTRL_INP_DE_POL;
+
+	writel(val, pvi->regs + HTX_PVI_CTRL);
+}
+
+static void imx8mp_hdmi_pvi_bridge_disable(struct drm_bridge *bridge,
+					   struct drm_bridge_state *bridge_state)
+{
+	struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
+
+	writel(0x0, pvi->regs + HTX_PVI_CTRL);
+
+	pm_runtime_put(pvi->dev);
+}
+
+static u32 *
+imx8mp_hdmi_pvi_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
+					  struct drm_bridge_state *bridge_state,
+					  struct drm_crtc_state *crtc_state,
+					  struct drm_connector_state *conn_state,
+					  u32 output_fmt,
+					  unsigned int *num_input_fmts)
+{
+	struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
+	struct drm_bridge *next_bridge = pvi->next_bridge;
+	struct drm_bridge_state *next_state;
+
+	if (!next_bridge->funcs->atomic_get_input_bus_fmts)
+		return 0;
+
+	next_state = drm_atomic_get_new_bridge_state(crtc_state->state,
+						     next_bridge);
+
+	return next_bridge->funcs->atomic_get_input_bus_fmts(next_bridge,
+							     next_state,
+							     crtc_state,
+							     conn_state,
+							     output_fmt,
+							     num_input_fmts);
+}
+
+static const struct drm_bridge_funcs imx_hdmi_pvi_bridge_funcs = {
+	.attach		= imx8mp_hdmi_pvi_bridge_attach,
+	.atomic_enable	= imx8mp_hdmi_pvi_bridge_enable,
+	.atomic_disable	= imx8mp_hdmi_pvi_bridge_disable,
+	.atomic_get_input_bus_fmts = imx8mp_hdmi_pvi_bridge_get_input_bus_fmts,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+};
+
+static int imx8mp_hdmi_pvi_probe(struct platform_device *pdev)
+{
+	struct device_node *remote;
+	struct imx8mp_hdmi_pvi *pvi;
+
+	pvi = devm_kzalloc(&pdev->dev, sizeof(*pvi), GFP_KERNEL);
+	if (!pvi)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, pvi);
+	pvi->dev = &pdev->dev;
+
+	pvi->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pvi->regs))
+		return PTR_ERR(pvi->regs);
+
+	/* Get the next bridge in the pipeline. */
+	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
+	if (!remote)
+		return -EINVAL;
+
+	pvi->next_bridge = of_drm_find_bridge(remote);
+	of_node_put(remote);
+
+	if (!pvi->next_bridge)
+		return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
+				     "could not find next bridge\n");
+
+	pm_runtime_enable(&pdev->dev);
+
+	/* Register the bridge. */
+	pvi->bridge.funcs = &imx_hdmi_pvi_bridge_funcs;
+	pvi->bridge.of_node = pdev->dev.of_node;
+	pvi->bridge.timings = pvi->next_bridge->timings;
+
+	drm_bridge_add(&pvi->bridge);
+
+	return 0;
+}
+
+static int imx8mp_hdmi_pvi_remove(struct platform_device *pdev)
+{
+	struct imx8mp_hdmi_pvi *pvi = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&pvi->bridge);
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id imx8mp_hdmi_pvi_match[] = {
+	{
+		.compatible = "fsl,imx8mp-hdmi-pvi",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, imx8mp_hdmi_pvi_match);
+
+static struct platform_driver imx8mp_hdmi_pvi_driver = {
+	.probe	= imx8mp_hdmi_pvi_probe,
+	.remove	= imx8mp_hdmi_pvi_remove,
+	.driver		= {
+		.name = "imx-hdmi-pvi",
+		.of_match_table	= imx8mp_hdmi_pvi_match,
+	},
+};
+module_platform_driver(imx8mp_hdmi_pvi_driver);
+
+MODULE_DESCRIPTION("i.MX8MP HDMI TX Parallel Video Interface bridge driver");
+MODULE_LICENSE("GPL");