[v5,04/14] drm/bridge: imx: Add i.MX8qm/qxp pixel combiner support

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index e4110d6c..84944e0 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -256,6 +256,8 @@  source "drivers/gpu/drm/bridge/adv7511/Kconfig"
 
 source "drivers/gpu/drm/bridge/cadence/Kconfig"
 
+source "drivers/gpu/drm/bridge/imx/Kconfig"
+
 source "drivers/gpu/drm/bridge/synopsys/Kconfig"
 
 endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 86e7acc..bc80cae 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -27,4 +27,5 @@  obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o
 
 obj-y += analogix/
 obj-y += cadence/
+obj-y += imx/
 obj-y += synopsys/
diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
new file mode 100644
index 00000000..f1c91b6
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/Kconfig
@@ -0,0 +1,8 @@ 
+config DRM_IMX8QXP_PIXEL_COMBINER
+	tristate "Freescale i.MX8QM/QXP pixel combiner"
+	depends on OF
+	depends on COMMON_CLK
+	select DRM_KMS_HELPER
+	help
+	  Choose this to enable pixel combiner found in
+	  Freescale i.MX8qm/qxp processors.
diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
new file mode 100644
index 00000000..7d7c8d6
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c
new file mode 100644
index 00000000..0b9403a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c
@@ -0,0 +1,448 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2020 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_print.h>
+
+#define PC_CTRL_REG			0x0
+#define  PC_COMBINE_ENABLE		BIT(0)
+#define  PC_DISP_BYPASS(n)		BIT(1 + 21 * (n))
+#define  PC_DISP_HSYNC_POLARITY(n)	BIT(2 + 11 * (n))
+#define  PC_DISP_HSYNC_POLARITY_POS(n)	DISP_HSYNC_POLARITY(n)
+#define  PC_DISP_VSYNC_POLARITY(n)	BIT(3 + 11 * (n))
+#define  PC_DISP_VSYNC_POLARITY_POS(n)	DISP_VSYNC_POLARITY(n)
+#define  PC_DISP_DVALID_POLARITY(n)	BIT(4 + 11 * (n))
+#define  PC_DISP_DVALID_POLARITY_POS(n)	DISP_DVALID_POLARITY(n)
+#define  PC_VSYNC_MASK_ENABLE		BIT(5)
+#define  PC_SKIP_MODE			BIT(6)
+#define  PC_SKIP_NUMBER_MASK		GENMASK(12, 7)
+#define  PC_SKIP_NUMBER(n)		FIELD_PREP(PC_SKIP_NUMBER_MASK, (n))
+#define  PC_DISP0_PIX_DATA_FORMAT_MASK	GENMASK(18, 16)
+#define  PC_DISP0_PIX_DATA_FORMAT(fmt)	\
+				FIELD_PREP(PC_DISP0_PIX_DATA_FORMAT_MASK, (fmt))
+#define  PC_DISP1_PIX_DATA_FORMAT_MASK	GENMASK(21, 19)
+#define  PC_DISP1_PIX_DATA_FORMAT(fmt)	\
+				FIELD_PREP(PC_DISP1_PIX_DATA_FORMAT_MASK, (fmt))
+
+#define PC_SW_RESET_REG			0x20
+#define  PC_SW_RESET_N			BIT(0)
+#define  PC_DISP_SW_RESET_N(n)		BIT(1 + (n))
+#define  PC_FULL_RESET_N		(PC_SW_RESET_N |		\
+					 PC_DISP_SW_RESET_N(0) |	\
+					 PC_DISP_SW_RESET_N(1))
+
+#define PC_REG_SET			0x4
+#define PC_REG_CLR			0x8
+
+#define DRIVER_NAME			"imx8qxp-pixel-combiner"
+
+enum imx8qxp_pc_pix_data_format {
+	RGB,
+	YUV444,
+	YUV422,
+	SPLIT_RGB,
+};
+
+struct imx8qxp_pc_channel {
+	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
+	struct imx8qxp_pc *pc;
+	unsigned int stream_id;
+	bool is_available;
+};
+
+struct imx8qxp_pc {
+	struct device *dev;
+	struct imx8qxp_pc_channel ch[2];
+	struct clk *clk_apb;
+	void __iomem *base;
+};
+
+static inline u32 imx8qxp_pc_read(struct imx8qxp_pc *pc, unsigned int offset)
+{
+	return readl(pc->base + offset);
+}
+
+static inline void
+imx8qxp_pc_write(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+	writel(value, pc->base + offset);
+}
+
+static inline void
+imx8qxp_pc_write_set(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+	imx8qxp_pc_write(pc, offset + PC_REG_SET, value);
+}
+
+static inline void
+imx8qxp_pc_write_clr(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+	imx8qxp_pc_write(pc, offset + PC_REG_CLR, value);
+}
+
+static enum drm_mode_status
+imx8qxp_pc_bridge_mode_valid(struct drm_bridge *bridge,
+			     const struct drm_display_info *info,
+			     const struct drm_display_mode *mode)
+{
+	if (mode->hdisplay > 2560)
+		return MODE_BAD_HVALUE;
+
+	return MODE_OK;
+}
+
+static int imx8qxp_pc_bridge_attach(struct drm_bridge *bridge,
+				    enum drm_bridge_attach_flags flags)
+{
+	struct imx8qxp_pc_channel *ch = bridge->driver_private;
+	struct imx8qxp_pc *pc = ch->pc;
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+		DRM_DEV_ERROR(pc->dev,
+			      "do not support creating a drm_connector\n");
+		return -EINVAL;
+	}
+
+	if (!bridge->encoder) {
+		DRM_DEV_ERROR(pc->dev, "missing encoder\n");
+		return -ENODEV;
+	}
+
+	return drm_bridge_attach(bridge->encoder,
+				 ch->next_bridge, bridge,
+				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+static void
+imx8qxp_pc_bridge_mode_set(struct drm_bridge *bridge,
+			   const struct drm_display_mode *mode,
+			   const struct drm_display_mode *adjusted_mode)
+{
+	struct imx8qxp_pc_channel *ch = bridge->driver_private;
+	struct imx8qxp_pc *pc = ch->pc;
+	u32 val;
+	int ret;
+
+	ret = pm_runtime_get_sync(pc->dev);
+	if (ret < 0)
+		DRM_DEV_ERROR(pc->dev,
+			      "failed to get runtime PM sync: %d\n", ret);
+
+	ret = clk_prepare_enable(pc->clk_apb);
+	if (ret)
+		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+								__func__,  ret);
+
+	/* HSYNC to pixel link is active low. */
+	imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
+				PC_DISP_HSYNC_POLARITY(ch->stream_id));
+
+	/* VSYNC to pixel link is active low. */
+	imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
+				PC_DISP_VSYNC_POLARITY(ch->stream_id));
+
+	/* Data enable to pixel link is active high. */
+	imx8qxp_pc_write_set(pc, PC_CTRL_REG,
+				PC_DISP_DVALID_POLARITY(ch->stream_id));
+
+	/* Mask the first frame output which may be incomplete. */
+	imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_VSYNC_MASK_ENABLE);
+
+	/* Only support RGB currently. */
+	val = imx8qxp_pc_read(pc, PC_CTRL_REG);
+	if (ch->stream_id == 0) {
+		val &= ~PC_DISP0_PIX_DATA_FORMAT_MASK;
+		val |= PC_DISP0_PIX_DATA_FORMAT(RGB);
+	} else {
+		val &= ~PC_DISP1_PIX_DATA_FORMAT_MASK;
+		val |= PC_DISP1_PIX_DATA_FORMAT(RGB);
+	}
+	imx8qxp_pc_write(pc, PC_CTRL_REG, val);
+
+	/* Only support bypass mode currently. */
+	imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_DISP_BYPASS(ch->stream_id));
+
+	clk_disable_unprepare(pc->clk_apb);
+}
+
+static void imx8qxp_pc_bridge_atomic_disable(struct drm_bridge *bridge,
+				struct drm_bridge_state *old_bridge_state)
+{
+	struct imx8qxp_pc_channel *ch = bridge->driver_private;
+	struct imx8qxp_pc *pc = ch->pc;
+	int ret;
+
+	ret = pm_runtime_put(pc->dev);
+	if (ret < 0)
+		DRM_DEV_ERROR(pc->dev, "failed to put runtime PM: %d\n", ret);
+}
+
+static const u32 imx8qxp_pc_bus_output_fmts[] = {
+	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
+	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
+};
+
+static bool imx8qxp_pc_bus_output_fmt_supported(u32 fmt)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(imx8qxp_pc_bus_output_fmts); i++) {
+		if (imx8qxp_pc_bus_output_fmts[i] == fmt)
+			return true;
+	}
+
+	return false;
+}
+
+static u32 *
+imx8qxp_pc_bridge_atomic_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)
+{
+	u32 *input_fmts;
+
+	if (!imx8qxp_pc_bus_output_fmt_supported(output_fmt))
+		return NULL;
+
+	*num_input_fmts = 1;
+
+	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	switch (output_fmt) {
+	case MEDIA_BUS_FMT_RGB888_1X36_CPADLO:
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X30_CPADLO;
+		break;
+	case MEDIA_BUS_FMT_RGB666_1X36_CPADLO:
+		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X30_CPADLO;
+		break;
+	default:
+		kfree(input_fmts);
+		input_fmts = NULL;
+		break;
+	}
+
+	return input_fmts;
+}
+
+static u32 *
+imx8qxp_pc_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					unsigned int *num_output_fmts)
+{
+	*num_output_fmts = ARRAY_SIZE(imx8qxp_pc_bus_output_fmts);
+	return kmemdup(imx8qxp_pc_bus_output_fmts,
+			sizeof(imx8qxp_pc_bus_output_fmts), GFP_KERNEL);
+}
+
+static const struct drm_bridge_funcs imx8qxp_pc_bridge_funcs = {
+	.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,
+	.mode_valid		= imx8qxp_pc_bridge_mode_valid,
+	.attach			= imx8qxp_pc_bridge_attach,
+	.mode_set		= imx8qxp_pc_bridge_mode_set,
+	.atomic_disable		= imx8qxp_pc_bridge_atomic_disable,
+	.atomic_get_input_bus_fmts =
+				imx8qxp_pc_bridge_atomic_get_input_bus_fmts,
+	.atomic_get_output_bus_fmts =
+				imx8qxp_pc_bridge_atomic_get_output_bus_fmts,
+};
+
+static int imx8qxp_pc_bridge_probe(struct platform_device *pdev)
+{
+	struct imx8qxp_pc *pc;
+	struct imx8qxp_pc_channel *ch;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *child, *remote;
+	u32 i;
+	int ret;
+
+	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	pc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pc->base))
+		return PTR_ERR(pc->base);
+
+	pc->dev = dev;
+
+	pc->clk_apb = devm_clk_get(dev, "apb");
+	if (IS_ERR(pc->clk_apb)) {
+		ret = PTR_ERR(pc->clk_apb);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "failed to get apb clock: %d\n",
+									ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pc);
+	pm_runtime_enable(dev);
+
+	for_each_available_child_of_node(np, child) {
+		ret = of_property_read_u32(child, "reg", &i);
+		if (ret || i > 1) {
+			ret = -EINVAL;
+			DRM_DEV_ERROR(dev,
+				      "invalid channel(%u) node address\n", i);
+			goto free_child;
+		}
+
+		ch = &pc->ch[i];
+		ch->pc = pc;
+		ch->stream_id = i;
+
+		remote = of_graph_get_remote_node(child, 1, 0);
+		if (!remote) {
+			ret = -ENODEV;
+			DRM_DEV_ERROR(dev,
+			    "channel%u failed to get port1's remote node: %d\n",
+									i, ret);
+			goto free_child;
+		}
+
+		ch->next_bridge = of_drm_find_bridge(remote);
+		if (!ch->next_bridge) {
+			of_node_put(remote);
+			ret = -EPROBE_DEFER;
+			DRM_DEV_DEBUG_DRIVER(dev,
+				"channel%u failed to find next bridge: %d\n",
+									i, ret);
+			goto free_child;
+		}
+
+		of_node_put(remote);
+
+		ch->bridge.driver_private = ch;
+		ch->bridge.funcs = &imx8qxp_pc_bridge_funcs;
+		ch->bridge.of_node = child;
+		ch->is_available = true;
+
+		drm_bridge_add(&ch->bridge);
+	}
+
+	return 0;
+
+free_child:
+	of_node_put(child);
+
+	if (i == 1 && pc->ch[0].next_bridge)
+		drm_bridge_remove(&pc->ch[0].bridge);
+
+	pm_runtime_disable(dev);
+	return ret;
+}
+
+static int imx8qxp_pc_bridge_remove(struct platform_device *pdev)
+{
+	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+	struct imx8qxp_pc_channel *ch;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		ch = &pc->ch[i];
+
+		if (!ch->is_available)
+			continue;
+
+		drm_bridge_remove(&ch->bridge);
+		ch->is_available = false;
+	}
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused imx8qxp_pc_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_prepare_enable(pc->clk_apb);
+	if (ret)
+		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+								__func__,  ret);
+
+	/* Disable pixel combiner by full reset. */
+	imx8qxp_pc_write_clr(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
+
+	clk_disable_unprepare(pc->clk_apb);
+
+	/* Ensure the reset takes effect. */
+	usleep_range(10, 20);
+
+	return ret;
+}
+
+static int __maybe_unused imx8qxp_pc_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_prepare_enable(pc->clk_apb);
+	if (ret) {
+		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+								__func__, ret);
+		return ret;
+	}
+
+	/* out of reset */
+	imx8qxp_pc_write_set(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
+
+	clk_disable_unprepare(pc->clk_apb);
+
+	return ret;
+}
+
+static const struct dev_pm_ops imx8qxp_pc_pm_ops = {
+	SET_RUNTIME_PM_OPS(imx8qxp_pc_runtime_suspend,
+			   imx8qxp_pc_runtime_resume, NULL)
+};
+
+static const struct of_device_id imx8qxp_pc_dt_ids[] = {
+	{ .compatible = "fsl,imx8qm-pixel-combiner", },
+	{ .compatible = "fsl,imx8qxp-pixel-combiner", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx8qxp_pc_dt_ids);
+
+static struct platform_driver imx8qxp_pc_bridge_driver = {
+	.probe	= imx8qxp_pc_bridge_probe,
+	.remove = imx8qxp_pc_bridge_remove,
+	.driver	= {
+		.pm = &imx8qxp_pc_pm_ops,
+		.name = DRIVER_NAME,
+		.of_match_table = imx8qxp_pc_dt_ids,
+	},
+};
+module_platform_driver(imx8qxp_pc_bridge_driver);
+
+MODULE_DESCRIPTION("i.MX8QM/QXP pixel combiner bridge driver");
+MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);