[PATCH v5 2/2] drm/bridge: imx: Add i.MX93 parallel display format configuration support

[Liu Ying <victor.liu@nxp.com>]

NXP i.MX93 mediamix blk-ctrl contains one DISPLAY_MUX register which
configures parallel display format by using the "PARALLEL_DISP_FORMAT"
field. Add a DRM bridge driver to support the display format configuration.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v4->v5:
* Rebase upon next-20250303.  This causes the drop of .remove_new by using
  devm_drm_bridge_add().  Also, this causes API change for
  imx93_pdfc_bridge_atomic_enable().
* Update year of copyright.

v3->v4:
* Use dev_err_probe() in imx93_pdfc_bridge_probe(). (Krzysztof)
* Drop MODULE_ALIAS(). (Krzysztof)
* Update year of Copyright.

v2->v3:
* No change.
* Resend with the patch rebased upon v6.11-rc1.

v1->v2:
* Set *num_input_fmts to zero in case
  imx93_pdfc_bridge_atomic_get_input_bus_fmts() returns NULL.
* Replace .remove callback with .remove_new callback in
  imx93_pdfc_bridge_driver.

 drivers/gpu/drm/bridge/imx/Kconfig      |   8 +
 drivers/gpu/drm/bridge/imx/Makefile     |   1 +
 drivers/gpu/drm/bridge/imx/imx93-pdfc.c | 186 ++++++++++++++++++++++++
 3 files changed, 195 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/imx/imx93-pdfc.c

diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
index 9a480c6abb85..51138d74ddfb 100644
--- a/drivers/gpu/drm/bridge/imx/Kconfig
+++ b/drivers/gpu/drm/bridge/imx/Kconfig
@@ -88,4 +88,12 @@ config DRM_IMX93_MIPI_DSI
 	  Choose this to enable MIPI DSI controller found in Freescale i.MX93
 	  processor.
 
+config DRM_IMX93_PARALLEL_DISP_FMT_CONFIG
+	tristate "NXP i.MX93 parallel display format configuration"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  Choose this to enable parallel display format configuration
+	  found in NXP i.MX93 processor.
+
 endif # ARCH_MXC || COMPILE_TEST
diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
index dd5d48584806..f4ccc5cbef72 100644
--- a/drivers/gpu/drm/bridge/imx/Makefile
+++ b/drivers/gpu/drm/bridge/imx/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK_TO_DPI) += imx8qxp-pxl2dpi.o
 obj-$(CONFIG_DRM_IMX93_MIPI_DSI) += imx93-mipi-dsi.o
+obj-$(CONFIG_DRM_IMX93_PARALLEL_DISP_FMT_CONFIG) += imx93-pdfc.o
diff --git a/drivers/gpu/drm/bridge/imx/imx93-pdfc.c b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
new file mode 100644
index 000000000000..7dfb87e64197
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2022-2025 NXP
+ */
+
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_print.h>
+
+#define DISPLAY_MUX		0x60
+#define  PARALLEL_DISP_FORMAT	0x700
+
+enum imx93_pdfc_format {
+	RGB888_TO_RGB888 = 0x0,
+	RGB888_TO_RGB666 = 0x1 << 8,
+	RGB565_TO_RGB565 = 0x2 << 8,
+};
+
+struct imx93_pdfc {
+	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
+	struct device *dev;
+	struct regmap *regmap;
+	u32 format;
+};
+
+static int imx93_pdfc_bridge_attach(struct drm_bridge *bridge,
+				    enum drm_bridge_attach_flags flags)
+{
+	struct imx93_pdfc *pdfc = bridge->driver_private;
+
+	return drm_bridge_attach(bridge->encoder, pdfc->next_bridge, bridge, flags);
+}
+
+static void imx93_pdfc_bridge_atomic_enable(struct drm_bridge *bridge,
+					    struct drm_atomic_state *state)
+{
+	struct imx93_pdfc *pdfc = bridge->driver_private;
+
+	regmap_update_bits(pdfc->regmap, DISPLAY_MUX, PARALLEL_DISP_FORMAT,
+			   pdfc->format);
+}
+
+static const u32 imx93_pdfc_bus_output_fmts[] = {
+	MEDIA_BUS_FMT_RGB888_1X24,
+	MEDIA_BUS_FMT_RGB666_1X18,
+	MEDIA_BUS_FMT_RGB565_1X16,
+	MEDIA_BUS_FMT_FIXED
+};
+
+static bool imx93_pdfc_bus_output_fmt_supported(u32 fmt)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(imx93_pdfc_bus_output_fmts); i++) {
+		if (imx93_pdfc_bus_output_fmts[i] == fmt)
+			return true;
+	}
+
+	return false;
+}
+
+static u32 *
+imx93_pdfc_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;
+
+	*num_input_fmts = 0;
+
+	if (!imx93_pdfc_bus_output_fmt_supported(output_fmt))
+		return NULL;
+
+	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	switch (output_fmt) {
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB565_1X16:
+		input_fmts[0] = output_fmt;
+		break;
+	case MEDIA_BUS_FMT_RGB666_1X18:
+	case MEDIA_BUS_FMT_FIXED:
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+		break;
+	}
+
+	*num_input_fmts = 1;
+
+	return input_fmts;
+}
+
+static int imx93_pdfc_bridge_atomic_check(struct drm_bridge *bridge,
+					  struct drm_bridge_state *bridge_state,
+					  struct drm_crtc_state *crtc_state,
+					  struct drm_connector_state *conn_state)
+{
+	struct imx93_pdfc *pdfc = bridge->driver_private;
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB888_1X24:
+		pdfc->format = RGB888_TO_RGB888;
+		break;
+	case MEDIA_BUS_FMT_RGB666_1X18:
+		pdfc->format = RGB888_TO_RGB666;
+		break;
+	case MEDIA_BUS_FMT_RGB565_1X16:
+		pdfc->format = RGB565_TO_RGB565;
+		break;
+	default:
+		DRM_DEV_DEBUG_DRIVER(pdfc->dev, "Unsupported output bus format: 0x%x\n",
+				     bridge_state->output_bus_cfg.format);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct drm_bridge_funcs imx93_pdfc_bridge_funcs = {
+	.attach			= imx93_pdfc_bridge_attach,
+	.atomic_enable		= imx93_pdfc_bridge_atomic_enable,
+	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts	= imx93_pdfc_bridge_atomic_get_input_bus_fmts,
+	.atomic_check		= imx93_pdfc_bridge_atomic_check,
+	.atomic_reset		= drm_atomic_helper_bridge_reset,
+};
+
+static int imx93_pdfc_bridge_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imx93_pdfc *pdfc;
+
+	pdfc = devm_kzalloc(dev, sizeof(*pdfc), GFP_KERNEL);
+	if (!pdfc)
+		return -ENOMEM;
+
+	pdfc->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(pdfc->regmap))
+		return dev_err_probe(dev, PTR_ERR(pdfc->regmap),
+				     "failed to get regmap\n");
+
+	pdfc->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
+	if (IS_ERR(pdfc->next_bridge))
+		return dev_err_probe(dev, PTR_ERR(pdfc->next_bridge),
+				     "failed to get next bridge\n");
+
+	pdfc->dev = dev;
+	pdfc->bridge.driver_private = pdfc;
+	pdfc->bridge.funcs = &imx93_pdfc_bridge_funcs;
+	pdfc->bridge.of_node = dev->of_node;
+
+	return devm_drm_bridge_add(dev, &pdfc->bridge);
+}
+
+static const struct of_device_id imx93_pdfc_dt_ids[] = {
+	{ .compatible = "nxp,imx93-pdfc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx93_pdfc_dt_ids);
+
+static struct platform_driver imx93_pdfc_bridge_driver = {
+	.probe	= imx93_pdfc_bridge_probe,
+	.driver	= {
+		.of_match_table = imx93_pdfc_dt_ids,
+		.name = "imx93_pdfc",
+	},
+};
+module_platform_driver(imx93_pdfc_bridge_driver);
+
+MODULE_DESCRIPTION("NXP i.MX93 parallel display format configuration driver");
+MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1