Hi Marco,
On 12/02/2025, Marco Felsch wrote:
> From: Liu Ying <[email protected]>
>
> 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 <[email protected]>
> [[email protected]: port to v6.18-rc1]
> [[email protected]: add review feedback (Alexander)]
> [[email protected]: fix to short Kconfig description (checkpath)]
> [[email protected]: use "GPL" instead of "GPL v2" (checkpatch)]
> [[email protected]: make use of reg property]
> [[email protected]: add bus-width support]
> Signed-off-by: Marco Felsch <[email protected]>
> ---
> drivers/gpu/drm/bridge/imx/Kconfig | 11 ++
> drivers/gpu/drm/bridge/imx/Makefile | 1 +
> drivers/gpu/drm/bridge/imx/imx93-pdfc.c | 227
> ++++++++++++++++++++++++++++++++
> 3 files changed, 239 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig
> b/drivers/gpu/drm/bridge/imx/Kconfig
> index
> 9a480c6abb856276df9b71d23b39a43b3a9c542d..28fd7a00473a0ec50bf0ffb5d50972abc209ceec
> 100644
> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> @@ -88,4 +88,15 @@ config DRM_IMX93_MIPI_DSI
> Choose this to enable MIPI DSI controller found in Freescale i.MX93
> processor.
>
> +config DRM_IMX93_PARALLEL_DISP_FMT_CONFIG
> + tristate "NXP i.MX91/i.MX93 parallel display format configuration"
> + 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
> dd5d4858480663bade98bd58039d1cb6f8aa18da..f4ccc5cbef72a576443d5fecf666b76dfba8aa94
> 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
> 0000000000000000000000000000000000000000..624389def0ac3f24158edc64a8913375a4cc2f12
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
> @@ -0,0 +1,227 @@
> +// 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_address.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>
> +#include <drm/drm_print.h>
Drop this header file if you won't use DRM_DEV_DEBUG_DRIVER() in v5.
> +
> +#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 drm_bridge *next_bridge;
> + struct device *dev;
> + struct regmap *regmap;
> + u64 disp_mux_reg_off;
> + u32 phy_bus_width;
> +};
> +
> +static int
> +imx93_pdfc_bridge_attach(struct drm_bridge *bridge, struct drm_encoder
> *encoder,
> + 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;
> + 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:
> + val = FORMAT_RGB888_TO_RGB888;
> + if (pdfc->phy_bus_width == 18) {
> + /*
> + * Can be valid if physical bus limitation exist,
s/exist/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, pdfc->disp_mux_reg_off, mask, val);
> +}
> +
> +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:
> + case MEDIA_BUS_FMT_RGB666_1X18:
> + case MEDIA_BUS_FMT_RGB565_1X16:
The case MEDIA_BUS_FMT_FIXED is also valid.
> + return 0;
> + default:
> + dev_warn(pdfc->dev, "Unsupported output bus format: 0x%x\n",
> + bridge_state->output_bus_cfg.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 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");
> +
> + err = of_property_read_reg(dev->of_node, 0, &pdfc->disp_mux_reg_off,
> NULL);
> + if (err)
> + return dev_err_probe(dev, err,
> + "failed to get display-mux reg\n");
> +
> + /* No limits per default */
> + pdfc->phy_bus_width = 24;
> +
> + /* Get output ep (port1/endpoint0) */
> + ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
Nit: DT binding just defines endpoint not endpoint0, so set the reg parameter
to -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");
> + }
> +
> + 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.of_node = dev->of_node;
> + pdfc->bridge.type = DRM_MODE_CONNECTOR_DPI;
> +
> + return devm_drm_bridge_add(dev, &pdfc->bridge);
> +}
> +
> +static const struct of_device_id imx93_pdfc_dt_ids[] = {
> + { .compatible = "nxp,imx93-pdfc", },
The cover letter and Kconfig say that both i.MX91 and i.MX93 are supported,
so need an additional compatible string for i.MX91?
> + { /* 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 <[email protected]>");
> +MODULE_LICENSE("GPL");
>
--
Regards,
Liu Ying
