Re: [PATCH v11 2/3] drm/bridge: imx: Add i.MX93 parallel display format configuration support

Alexander Stein
2026-03-05T15:06:49Z

[-- Attachment #1: Type: text/plain, Size: 10304 bytes --]

Am Dienstag, 3. März 2026, 11:34:27 CET schrieb Marco Felsch:
> From: 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.
>
> Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> [m.felsch@pengutronix.de: port to v7.0-rc1]
> [m.felsch@pengutronix.de: add review feedback (Alexander)]
> [m.felsch@pengutronix.de: fix to short Kconfig description (checkpath)]
> [m.felsch@pengutronix.de: use "GPL" instead of "GPL v2" (checkpatch)]
> [m.felsch@pengutronix.de: add bus-width support]
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>

Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>

on TQMa93xxCA on MBa91xxCA

> ---
> drivers/gpu/drm/bridge/imx/Kconfig | 11 ++
> drivers/gpu/drm/bridge/imx/Makefile | 1 +
> drivers/gpu/drm/bridge/imx/imx93-pdfc.c | 225 ++++++++++++++++++++++++++++++++
> 3 files changed, 237 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
> index b9028a5e5a065c3237b404111d8df57e8e017f9d..47829300a4486a090514ebe914b7667a703039a9 100644
> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> @@ -99,4 +99,15 @@ config DRM_IMX93_MIPI_DSI
> Choose this to enable MIPI DSI controller found in Freescale i.MX93
> processor.
>
> +config DRM_IMX93_PARALLEL_DISP_FMT_CONVERTER
> + tristate "NXP i.MX91/i.MX93 parallel display format converter"
> + depends on OF
> + select DRM_KMS_HELPER
> + help
> + On i.MX93 and i.MX91 SoCs the parallel display format output is
> + controlled via the MEDIAMIX BLK-CTRL DISPLAY_MUX.
> +
> + Say 'Y' or 'M' if you use the parallel display output path on a
> + i.MX93 or i.MX91 SoC.
> +
> endif # ARCH_MXC || COMPILE_TEST
> diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
> index 8d01fda25451aaa1bf51a068da18948094327116..da57fde2d813b88cdde89115ca801b4cfc69afbd 100644
> --- a/drivers/gpu/drm/bridge/imx/Makefile
> +++ b/drivers/gpu/drm/bridge/imx/Makefile
> @@ -9,3 +9,4 @@ 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_CONVERTER) += 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 0000000000000000000000000000000000000000..27a54424319838517b206ab7d7447538aa1489eb
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Copyright 2022-2025 NXP
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_bridge.h>
> +
> +#define IMX93_DISPLAY_MUX_REG 0x60
> +#define PARALLEL_DISP_FORMAT GENMASK(10, 8)
> +#define FORMAT_RGB888_TO_RGB888 FIELD_PREP(PARALLEL_DISP_FORMAT, 0)
> +#define FORMAT_RGB888_TO_RGB666 FIELD_PREP(PARALLEL_DISP_FORMAT, 1)
> +#define FORMAT_RGB565_TO_RGB565 FIELD_PREP(PARALLEL_DISP_FORMAT, 2)
> +
> +struct imx93_pdfc {
> + struct drm_bridge bridge;
> + struct device *dev;
> + struct regmap *regmap;
> + u32 phy_bus_width;
> +};
> +
> +static struct imx93_pdfc *bridge_to_imx93_pdfc(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct imx93_pdfc, bridge);
> +}
> +
> +static int
> +imx93_pdfc_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder,
> + enum drm_bridge_attach_flags flags)
> +{
> + return drm_bridge_attach(bridge->encoder, bridge->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_to_imx93_pdfc(bridge);
> + const struct drm_bridge_state *bridge_state;
> + unsigned int mask = PARALLEL_DISP_FORMAT;
> + unsigned int val;
> +
> + bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
> +
> + switch (bridge_state->output_bus_cfg.format) {
> + case MEDIA_BUS_FMT_RGB888_1X24:
> + case MEDIA_BUS_FMT_FIXED:
> + val = FORMAT_RGB888_TO_RGB888;
> + if (pdfc->phy_bus_width == 18) {
> + /*
> + * Can be valid if physical bus limitation exists,
> + * therefore use dev_dbg().
> + */
> + dev_dbg(pdfc->dev, "Truncate two LSBs from each color\n");
> + val = FORMAT_RGB888_TO_RGB666;
> + }
> + break;
> + case MEDIA_BUS_FMT_RGB666_1X18:
> + val = FORMAT_RGB888_TO_RGB666;
> + break;
> + case MEDIA_BUS_FMT_RGB565_1X16:
> + val = FORMAT_RGB565_TO_RGB565;
> + break;
> + }
> +
> + regmap_update_bits(pdfc->regmap, IMX93_DISPLAY_MUX_REG, mask, val);
> +}
> +
> +/* TODO: Add YUV formats */
> +static const u32 imx93_pdfc_bus_output_fmts[] = {
> + MEDIA_BUS_FMT_FIXED,
> + MEDIA_BUS_FMT_RGB888_1X24,
> + MEDIA_BUS_FMT_RGB666_1X18,
> + MEDIA_BUS_FMT_RGB565_1X16,
> +};
> +
> +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)
> +{
> + struct imx93_pdfc *pdfc = bridge_to_imx93_pdfc(bridge);
> + u32 *input_fmts;
> +
> + *num_input_fmts = 0;
> +
> + input_fmts = kmalloc_obj(*input_fmts);
> + if (!input_fmts)
> + return NULL;
> +
> + *num_input_fmts = 1;
> +
> + if (!imx93_pdfc_bus_output_fmt_supported(output_fmt)) {
> + dev_dbg(pdfc->dev, "No valid output bus-fmt detected, fallback to MEDIA_BUS_FMT_RGB888_1X24\n");
> + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
> + return input_fmts;
> + }
> +
> + 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;
> + }
> +
> + 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_to_imx93_pdfc(bridge);
> + u32 format = bridge_state->output_bus_cfg.format;
> +
> + if (imx93_pdfc_bus_output_fmt_supported(format))
> + return 0;
> +
> + dev_warn(pdfc->dev, "Unsupported output bus format: 0x%x\n", format);
> +
> + return -EINVAL;
> +}
> +
> +static const struct drm_bridge_funcs 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 drm_bridge *next_bridge;
> + struct imx93_pdfc *pdfc;
> + struct device_node *ep;
> + int err;
> +
> + pdfc = devm_drm_bridge_alloc(dev, struct imx93_pdfc, bridge, &funcs);
> + if (IS_ERR(pdfc))
> + return PTR_ERR(pdfc);
> +
> + 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");
> +
> + /* No limits per default */
> + pdfc->phy_bus_width = 24;
> +
> + /* Get output ep (port1/endpoint) */
> + ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
> + if (ep) {
> + err = of_property_read_u32(ep, "bus-width", &pdfc->phy_bus_width);
> + of_node_put(ep);
> +
> + /* bus-width is optional but it must have valid data if present */
> + if (err && err != -EINVAL)
> + return dev_err_probe(dev, err,
> + "failed to query bus-width\n");
> + }
> +
> + next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
> + if (IS_ERR(next_bridge))
> + return dev_err_probe(dev, PTR_ERR(next_bridge),
> + "failed to get next bridge\n");
> + pdfc->dev = dev;
> + pdfc->bridge.of_node = dev->of_node;
> + pdfc->bridge.type = DRM_MODE_CONNECTOR_DPI;
> + pdfc->bridge.next_bridge = next_bridge;
> +
> + 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");
>
>

--
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 488 bytes --]