diff mbox series

[v8,06/14] drm/bridge: imx: Add i.MX8qm/qxp display pixel link support

Message ID 20220609064931.3068601-7-victor.liu@nxp.com (mailing list archive)
State New, archived
Headers show
Series Add some DRM bridge drivers support for i.MX8qm/qxp SoCs | expand

Commit Message

Ying Liu June 9, 2022, 6:49 a.m. UTC
This patch adds a drm bridge driver for i.MX8qm/qxp display pixel link.
The pixel link forms a standard asynchronous linkage between
pixel sources(display controller or camera module) and pixel
consumers(imaging or displays).  It consists of two distinct
functions, a pixel transfer function and a control interface.

Reviewed-by: Robert Foss <robert.foss@linaro.org>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # Colibri iMX8X, LT170410-2WHC, LP156WF1
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
Robert, I keep your R-b tag from v5. Let me know if you want me to drop it, as
v7 contains a fix for checkpatch complaints.
Marcel, as the fix is trivial, I add your T-b tag. Let me know if you want me
to drop it.

v7->v8:
* No change.

v6->v7:
* Fix 'Alignment should match open parenthesis' complaints from
  'checkpatch.pl --strict'.
* Add Marcel's T-b tag.

v5->v6:
* No change.

v4->v5:
* Make a comment occupy a line. (Robert)
* Add Robert's R-b tag.

v3->v4:
* No change.

v2->v3:
* Drop two macros which help define functions and define them directly.
* Properly disable all pixel link controls to POR value by calling
  imx8qxp_pixel_link_disable_all_controls() from
  imx8qxp_pixel_link_bridge_probe().

v1->v2:
* Rewrite the function to find the next bridge by properly using OF APIs
  and dropping unnecessary DT validation. (Rob)

 drivers/gpu/drm/bridge/imx/Kconfig            |   8 +
 drivers/gpu/drm/bridge/imx/Makefile           |   1 +
 .../gpu/drm/bridge/imx/imx8qxp-pixel-link.c   | 429 ++++++++++++++++++
 3 files changed, 438 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c

Comments

Laurent Pinchart June 9, 2022, 9:30 a.m. UTC | #1
Hi Liu,

Thank you for the patch.

On Thu, Jun 09, 2022 at 02:49:23PM +0800, Liu Ying wrote:
> This patch adds a drm bridge driver for i.MX8qm/qxp display pixel link.
> The pixel link forms a standard asynchronous linkage between
> pixel sources(display controller or camera module) and pixel
> consumers(imaging or displays).  It consists of two distinct
> functions, a pixel transfer function and a control interface.
> 
> Reviewed-by: Robert Foss <robert.foss@linaro.org>
> Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # Colibri iMX8X, LT170410-2WHC, LP156WF1
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> Robert, I keep your R-b tag from v5. Let me know if you want me to drop it, as
> v7 contains a fix for checkpatch complaints.
> Marcel, as the fix is trivial, I add your T-b tag. Let me know if you want me
> to drop it.
> 
> v7->v8:
> * No change.
> 
> v6->v7:
> * Fix 'Alignment should match open parenthesis' complaints from
>   'checkpatch.pl --strict'.
> * Add Marcel's T-b tag.
> 
> v5->v6:
> * No change.
> 
> v4->v5:
> * Make a comment occupy a line. (Robert)
> * Add Robert's R-b tag.
> 
> v3->v4:
> * No change.
> 
> v2->v3:
> * Drop two macros which help define functions and define them directly.
> * Properly disable all pixel link controls to POR value by calling
>   imx8qxp_pixel_link_disable_all_controls() from
>   imx8qxp_pixel_link_bridge_probe().
> 
> v1->v2:
> * Rewrite the function to find the next bridge by properly using OF APIs
>   and dropping unnecessary DT validation. (Rob)
> 
>  drivers/gpu/drm/bridge/imx/Kconfig            |   8 +
>  drivers/gpu/drm/bridge/imx/Makefile           |   1 +
>  .../gpu/drm/bridge/imx/imx8qxp-pixel-link.c   | 429 ++++++++++++++++++
>  3 files changed, 438 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> 
> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
> index f1c91b6814a5..4d1f027d07f8 100644
> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> @@ -6,3 +6,11 @@ config DRM_IMX8QXP_PIXEL_COMBINER
>  	help
>  	  Choose this to enable pixel combiner found in
>  	  Freescale i.MX8qm/qxp processors.
> +
> +config DRM_IMX8QXP_PIXEL_LINK
> +	tristate "Freescale i.MX8QM/QXP display pixel link"
> +	depends on OF
> +	select DRM_KMS_HELPER

Should this depend on (or select) IMX_SCU ?

> +	help
> +	  Choose this to enable display pixel link found in
> +	  Freescale i.MX8qm/qxp processors.
> diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
> index 7d7c8d674bf0..c15469fb5789 100644
> --- a/drivers/gpu/drm/bridge/imx/Makefile
> +++ b/drivers/gpu/drm/bridge/imx/Makefile
> @@ -1 +1,2 @@
>  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
> +obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
> diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> new file mode 100644
> index 000000000000..52b9b96549e1
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> @@ -0,0 +1,429 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Copyright 2020 NXP
> + */
> +
> +#include <linux/firmware/imx/svc/misc.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_print.h>
> +
> +#include <dt-bindings/firmware/imx/rsrc.h>
> +
> +#define DRIVER_NAME		"imx8qxp-display-pixel-link"
> +#define PL_MAX_MST_ADDR		3
> +#define PL_MAX_NEXT_BRIDGES	2
> +
> +struct imx8qxp_pixel_link {
> +	struct drm_bridge bridge;
> +	struct drm_bridge *next_bridge;
> +	struct device *dev;
> +	struct imx_sc_ipc *ipc_handle;
> +	int id;
> +	int stream_id;
> +	int dc_id;
> +	u32 sink_rsc;
> +	u32 mst_addr;
> +	u8 mst_addr_ctrl;
> +	u8 mst_en_ctrl;
> +	u8 mst_vld_ctrl;
> +	u8 sync_ctrl;
> +};
> +
> +static void imx8qxp_pixel_link_enable_mst_en(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->mst_en_ctrl, true);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to enable DC%d stream%d pixel link mst_en: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +}
> +
> +static void imx8qxp_pixel_link_enable_mst_vld(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->mst_vld_ctrl, true);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to enable DC%d stream%d pixel link mst_vld: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +}
> +
> +static void imx8qxp_pixel_link_enable_sync(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->sync_ctrl, true);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to enable DC%d stream%d pixel link sync: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +}
> +
> +static int imx8qxp_pixel_link_disable_mst_en(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->mst_en_ctrl, false);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to disable DC%d stream%d pixel link mst_en: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +
> +	return ret;
> +}
> +
> +static int imx8qxp_pixel_link_disable_mst_vld(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->mst_vld_ctrl, false);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to disable DC%d stream%d pixel link mst_vld: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +
> +	return ret;
> +}
> +
> +static int imx8qxp_pixel_link_disable_sync(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> +				      pl->sync_ctrl, false);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to disable DC%d stream%d pixel link sync: %d\n",
> +			      pl->dc_id, pl->stream_id, ret);
> +
> +	return ret;
> +}
> +
> +static void imx8qxp_pixel_link_set_mst_addr(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx_sc_misc_set_control(pl->ipc_handle,
> +				      pl->sink_rsc, pl->mst_addr_ctrl,
> +				      pl->mst_addr);
> +	if (ret)
> +		DRM_DEV_ERROR(pl->dev,
> +			      "failed to set DC%d stream%d pixel link mst addr(%u): %d\n",
> +			      pl->dc_id, pl->stream_id, pl->mst_addr, ret);
> +}
> +
> +static int imx8qxp_pixel_link_bridge_attach(struct drm_bridge *bridge,
> +					    enum drm_bridge_attach_flags flags)
> +{
> +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> +
> +	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> +		DRM_DEV_ERROR(pl->dev,
> +			      "do not support creating a drm_connector\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!bridge->encoder) {
> +		DRM_DEV_ERROR(pl->dev, "missing encoder\n");
> +		return -ENODEV;
> +	}
> +
> +	return drm_bridge_attach(bridge->encoder,
> +				 pl->next_bridge, bridge,
> +				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +}
> +
> +static void
> +imx8qxp_pixel_link_bridge_mode_set(struct drm_bridge *bridge,
> +				   const struct drm_display_mode *mode,
> +				   const struct drm_display_mode *adjusted_mode)
> +{
> +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> +
> +	imx8qxp_pixel_link_set_mst_addr(pl);
> +}
> +
> +static void
> +imx8qxp_pixel_link_bridge_atomic_enable(struct drm_bridge *bridge,
> +					struct drm_bridge_state *old_bridge_state)
> +{
> +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> +
> +	imx8qxp_pixel_link_enable_mst_en(pl);
> +	imx8qxp_pixel_link_enable_mst_vld(pl);
> +	imx8qxp_pixel_link_enable_sync(pl);
> +}
> +
> +static void
> +imx8qxp_pixel_link_bridge_atomic_disable(struct drm_bridge *bridge,
> +					 struct drm_bridge_state *old_bridge_state)
> +{
> +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> +
> +	imx8qxp_pixel_link_disable_mst_en(pl);
> +	imx8qxp_pixel_link_disable_mst_vld(pl);
> +	imx8qxp_pixel_link_disable_sync(pl);
> +}
> +
> +static const u32 imx8qxp_pixel_link_bus_output_fmts[] = {
> +	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
> +	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
> +};
> +
> +static bool imx8qxp_pixel_link_bus_output_fmt_supported(u32 fmt)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(imx8qxp_pixel_link_bus_output_fmts); i++) {
> +		if (imx8qxp_pixel_link_bus_output_fmts[i] == fmt)
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +static u32 *
> +imx8qxp_pixel_link_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_pixel_link_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;
> +
> +	input_fmts[0] = output_fmt;
> +
> +	return input_fmts;
> +}
> +
> +static u32 *
> +imx8qxp_pixel_link_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_pixel_link_bus_output_fmts);
> +	return kmemdup(imx8qxp_pixel_link_bus_output_fmts,
> +			sizeof(imx8qxp_pixel_link_bus_output_fmts), GFP_KERNEL);
> +}
> +
> +static const struct drm_bridge_funcs imx8qxp_pixel_link_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,
> +	.attach			= imx8qxp_pixel_link_bridge_attach,
> +	.mode_set		= imx8qxp_pixel_link_bridge_mode_set,
> +	.atomic_enable		= imx8qxp_pixel_link_bridge_atomic_enable,
> +	.atomic_disable		= imx8qxp_pixel_link_bridge_atomic_disable,
> +	.atomic_get_input_bus_fmts =
> +			imx8qxp_pixel_link_bridge_atomic_get_input_bus_fmts,
> +	.atomic_get_output_bus_fmts =
> +			imx8qxp_pixel_link_bridge_atomic_get_output_bus_fmts,
> +};
> +
> +static int imx8qxp_pixel_link_disable_all_controls(struct imx8qxp_pixel_link *pl)
> +{
> +	int ret;
> +
> +	ret = imx8qxp_pixel_link_disable_mst_en(pl);
> +	if (ret)
> +		return ret;
> +
> +	ret = imx8qxp_pixel_link_disable_mst_vld(pl);
> +	if (ret)
> +		return ret;
> +
> +	return imx8qxp_pixel_link_disable_sync(pl);
> +}
> +
> +static struct drm_bridge *
> +imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
> +{
> +	struct device_node *np = pl->dev->of_node;
> +	struct device_node *port, *remote;
> +	struct drm_bridge *next_bridge[PL_MAX_NEXT_BRIDGES];
> +	u32 port_id;
> +	bool found_port = false;
> +	int reg, ep_cnt = 0;
> +	/* select the first next bridge by default */
> +	int bridge_sel = 0;
> +
> +	for (port_id = 1; port_id <= PL_MAX_MST_ADDR + 1; port_id++) {
> +		port = of_graph_get_port_by_id(np, port_id);
> +		if (!port)
> +			continue;
> +
> +		if (of_device_is_available(port)) {
> +			found_port = true;
> +			of_node_put(port);
> +			break;
> +		}
> +
> +		of_node_put(port);
> +	}
> +
> +	if (!found_port) {
> +		DRM_DEV_ERROR(pl->dev, "no available output port\n");
> +		return ERR_PTR(-ENODEV);
> +	}
> +
> +	for (reg = 0; reg < PL_MAX_NEXT_BRIDGES; reg++) {
> +		remote = of_graph_get_remote_node(np, port_id, reg);
> +		if (!remote)
> +			continue;
> +
> +		if (!of_device_is_available(remote->parent)) {
> +			DRM_DEV_DEBUG(pl->dev,
> +				      "port%u endpoint%u remote parent is not available\n",
> +				      port_id, reg);
> +			of_node_put(remote);
> +			continue;
> +		}
> +
> +		next_bridge[ep_cnt] = of_drm_find_bridge(remote);
> +		if (!next_bridge[ep_cnt]) {
> +			of_node_put(remote);
> +			return ERR_PTR(-EPROBE_DEFER);
> +		}
> +
> +		/* specially select the next bridge with companion PXL2DPI */
> +		if (of_find_property(remote, "fsl,companion-pxl2dpi", NULL))
> +			bridge_sel = ep_cnt;
> +
> +		ep_cnt++;
> +
> +		of_node_put(remote);
> +	}
> +
> +	pl->mst_addr = port_id - 1;
> +
> +	return next_bridge[bridge_sel];
> +}
> +
> +static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
> +{
> +	struct imx8qxp_pixel_link *pl;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret;
> +
> +	pl = devm_kzalloc(dev, sizeof(*pl), GFP_KERNEL);
> +	if (!pl)
> +		return -ENOMEM;
> +
> +	ret = imx_scu_get_handle(&pl->ipc_handle);
> +	if (ret) {
> +		if (ret != -EPROBE_DEFER)
> +			DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
> +				      ret);
> +		return ret;
> +	}
> +
> +	pl->id = of_alias_get_id(np, "dc_pl");

Could we avoid relying on aliases ? I'd add an id property to the DT
node instead, or possibly even better a dc id and a stream id.

> +	if (pl->id < 0) {
> +		DRM_DEV_ERROR(dev,
> +			      "failed to get pixel link node alias id: %d\n",
> +			      pl->id);
> +		return pl->id;
> +	}
> +
> +	pl->dev = dev;
> +
> +	pl->dc_id = pl->id / 2;
> +	pl->stream_id = pl->id % 2;
> +
> +	pl->sink_rsc = pl->dc_id ? IMX_SC_R_DC_1 : IMX_SC_R_DC_0;
> +
> +	if (pl->stream_id == 0) {
> +		pl->mst_addr_ctrl = IMX_SC_C_PXL_LINK_MST1_ADDR;
> +		pl->mst_en_ctrl   = IMX_SC_C_PXL_LINK_MST1_ENB;
> +		pl->mst_vld_ctrl  = IMX_SC_C_PXL_LINK_MST1_VLD;
> +		pl->sync_ctrl     = IMX_SC_C_SYNC_CTRL0;
> +	} else {
> +		pl->mst_addr_ctrl = IMX_SC_C_PXL_LINK_MST2_ADDR;
> +		pl->mst_en_ctrl   = IMX_SC_C_PXL_LINK_MST2_ENB;
> +		pl->mst_vld_ctrl  = IMX_SC_C_PXL_LINK_MST2_VLD;
> +		pl->sync_ctrl     = IMX_SC_C_SYNC_CTRL1;
> +	}
> +
> +	/* disable all controls to POR default */
> +	ret = imx8qxp_pixel_link_disable_all_controls(pl);
> +	if (ret)
> +		return ret;
> +
> +	pl->next_bridge = imx8qxp_pixel_link_find_next_bridge(pl);
> +	if (IS_ERR(pl->next_bridge)) {
> +		ret = PTR_ERR(pl->next_bridge);
> +		if (ret != -EPROBE_DEFER)
> +			DRM_DEV_ERROR(dev, "failed to find next bridge: %d\n",
> +				      ret);
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, pl);
> +
> +	pl->bridge.driver_private = pl;
> +	pl->bridge.funcs = &imx8qxp_pixel_link_bridge_funcs;
> +	pl->bridge.of_node = np;
> +
> +	drm_bridge_add(&pl->bridge);
> +
> +	return ret;
> +}
> +
> +static int imx8qxp_pixel_link_bridge_remove(struct platform_device *pdev)
> +{
> +	struct imx8qxp_pixel_link *pl = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&pl->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id imx8qxp_pixel_link_dt_ids[] = {
> +	{ .compatible = "fsl,imx8qm-dc-pixel-link", },
> +	{ .compatible = "fsl,imx8qxp-dc-pixel-link", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx8qxp_pixel_link_dt_ids);
> +
> +static struct platform_driver imx8qxp_pixel_link_bridge_driver = {
> +	.probe	= imx8qxp_pixel_link_bridge_probe,
> +	.remove = imx8qxp_pixel_link_bridge_remove,
> +	.driver	= {
> +		.of_match_table = imx8qxp_pixel_link_dt_ids,
> +		.name = DRIVER_NAME,
> +	},
> +};
> +module_platform_driver(imx8qxp_pixel_link_bridge_driver);
> +
> +MODULE_DESCRIPTION("i.MX8QXP/QM display pixel link bridge driver");
> +MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
Ying Liu June 10, 2022, 2:09 a.m. UTC | #2
Hi Laurent,

On Thu, 2022-06-09 at 12:30 +0300, Laurent Pinchart wrote:
> Hi Liu,
> 
> Thank you for the patch.

Thank you for the review.

> 
> On Thu, Jun 09, 2022 at 02:49:23PM +0800, Liu Ying wrote:
> > This patch adds a drm bridge driver for i.MX8qm/qxp display pixel
> > link.
> > The pixel link forms a standard asynchronous linkage between
> > pixel sources(display controller or camera module) and pixel
> > consumers(imaging or displays).  It consists of two distinct
> > functions, a pixel transfer function and a control interface.
> > 
> > Reviewed-by: Robert Foss <robert.foss@linaro.org>
> > Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # Colibri
> > iMX8X, LT170410-2WHC, LP156WF1
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > Robert, I keep your R-b tag from v5. Let me know if you want me to
> > drop it, as
> > v7 contains a fix for checkpatch complaints.
> > Marcel, as the fix is trivial, I add your T-b tag. Let me know if
> > you want me
> > to drop it.
> > 
> > v7->v8:
> > * No change.
> > 
> > v6->v7:
> > * Fix 'Alignment should match open parenthesis' complaints from
> >   'checkpatch.pl --strict'.
> > * Add Marcel's T-b tag.
> > 
> > v5->v6:
> > * No change.
> > 
> > v4->v5:
> > * Make a comment occupy a line. (Robert)
> > * Add Robert's R-b tag.
> > 
> > v3->v4:
> > * No change.
> > 
> > v2->v3:
> > * Drop two macros which help define functions and define them
> > directly.
> > * Properly disable all pixel link controls to POR value by calling
> >   imx8qxp_pixel_link_disable_all_controls() from
> >   imx8qxp_pixel_link_bridge_probe().
> > 
> > v1->v2:
> > * Rewrite the function to find the next bridge by properly using OF
> > APIs
> >   and dropping unnecessary DT validation. (Rob)
> > 
> >  drivers/gpu/drm/bridge/imx/Kconfig            |   8 +
> >  drivers/gpu/drm/bridge/imx/Makefile           |   1 +
> >  .../gpu/drm/bridge/imx/imx8qxp-pixel-link.c   | 429
> > ++++++++++++++++++
> >  3 files changed, 438 insertions(+)
> >  create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > 
> > diff --git a/drivers/gpu/drm/bridge/imx/Kconfig
> > b/drivers/gpu/drm/bridge/imx/Kconfig
> > index f1c91b6814a5..4d1f027d07f8 100644
> > --- a/drivers/gpu/drm/bridge/imx/Kconfig
> > +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> > @@ -6,3 +6,11 @@ config DRM_IMX8QXP_PIXEL_COMBINER
> >  	help
> >  	  Choose this to enable pixel combiner found in
> >  	  Freescale i.MX8qm/qxp processors.
> > +
> > +config DRM_IMX8QXP_PIXEL_LINK
> > +	tristate "Freescale i.MX8QM/QXP display pixel link"
> > +	depends on OF
> > +	select DRM_KMS_HELPER
> 
> Should this depend on (or select) IMX_SCU ?

Will add 'depends on IMX_SCU'.

> 
> > +	help
> > +	  Choose this to enable display pixel link found in
> > +	  Freescale i.MX8qm/qxp processors.
> > diff --git a/drivers/gpu/drm/bridge/imx/Makefile
> > b/drivers/gpu/drm/bridge/imx/Makefile
> > index 7d7c8d674bf0..c15469fb5789 100644
> > --- a/drivers/gpu/drm/bridge/imx/Makefile
> > +++ b/drivers/gpu/drm/bridge/imx/Makefile
> > @@ -1 +1,2 @@
> >  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-
> > combiner.o
> > +obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
> > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > new file mode 100644
> > index 000000000000..52b9b96549e1
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > @@ -0,0 +1,429 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +
> > +/*
> > + * Copyright 2020 NXP
> > + */
> > +
> > +#include <linux/firmware/imx/svc/misc.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_graph.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <drm/drm_atomic_state_helper.h>
> > +#include <drm/drm_bridge.h>
> > +#include <drm/drm_print.h>
> > +
> > +#include <dt-bindings/firmware/imx/rsrc.h>
> > +
> > +#define DRIVER_NAME		"imx8qxp-display-pixel-link"
> > +#define PL_MAX_MST_ADDR		3
> > +#define PL_MAX_NEXT_BRIDGES	2
> > +
> > +struct imx8qxp_pixel_link {
> > +	struct drm_bridge bridge;
> > +	struct drm_bridge *next_bridge;
> > +	struct device *dev;
> > +	struct imx_sc_ipc *ipc_handle;
> > +	int id;
> > +	int stream_id;
> > +	int dc_id;
> > +	u32 sink_rsc;
> > +	u32 mst_addr;
> > +	u8 mst_addr_ctrl;
> > +	u8 mst_en_ctrl;
> > +	u8 mst_vld_ctrl;
> > +	u8 sync_ctrl;
> > +};
> > +
> > +static void imx8qxp_pixel_link_enable_mst_en(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->mst_en_ctrl, true);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to enable DC%d stream%d pixel
> > link mst_en: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +}
> > +
> > +static void imx8qxp_pixel_link_enable_mst_vld(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->mst_vld_ctrl, true);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to enable DC%d stream%d pixel
> > link mst_vld: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +}
> > +
> > +static void imx8qxp_pixel_link_enable_sync(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->sync_ctrl, true);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to enable DC%d stream%d pixel
> > link sync: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +}
> > +
> > +static int imx8qxp_pixel_link_disable_mst_en(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->mst_en_ctrl, false);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to disable DC%d stream%d pixel
> > link mst_en: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int imx8qxp_pixel_link_disable_mst_vld(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->mst_vld_ctrl, false);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to disable DC%d stream%d pixel
> > link mst_vld: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int imx8qxp_pixel_link_disable_sync(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > +				      pl->sync_ctrl, false);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to disable DC%d stream%d pixel
> > link sync: %d\n",
> > +			      pl->dc_id, pl->stream_id, ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static void imx8qxp_pixel_link_set_mst_addr(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx_sc_misc_set_control(pl->ipc_handle,
> > +				      pl->sink_rsc, pl->mst_addr_ctrl,
> > +				      pl->mst_addr);
> > +	if (ret)
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "failed to set DC%d stream%d pixel link
> > mst addr(%u): %d\n",
> > +			      pl->dc_id, pl->stream_id, pl->mst_addr,
> > ret);
> > +}
> > +
> > +static int imx8qxp_pixel_link_bridge_attach(struct drm_bridge
> > *bridge,
> > +					    enum
> > drm_bridge_attach_flags flags)
> > +{
> > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > +
> > +	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> > +		DRM_DEV_ERROR(pl->dev,
> > +			      "do not support creating a
> > drm_connector\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (!bridge->encoder) {
> > +		DRM_DEV_ERROR(pl->dev, "missing encoder\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	return drm_bridge_attach(bridge->encoder,
> > +				 pl->next_bridge, bridge,
> > +				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > +}
> > +
> > +static void
> > +imx8qxp_pixel_link_bridge_mode_set(struct drm_bridge *bridge,
> > +				   const struct drm_display_mode *mode,
> > +				   const struct drm_display_mode
> > *adjusted_mode)
> > +{
> > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > +
> > +	imx8qxp_pixel_link_set_mst_addr(pl);
> > +}
> > +
> > +static void
> > +imx8qxp_pixel_link_bridge_atomic_enable(struct drm_bridge *bridge,
> > +					struct drm_bridge_state
> > *old_bridge_state)
> > +{
> > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > +
> > +	imx8qxp_pixel_link_enable_mst_en(pl);
> > +	imx8qxp_pixel_link_enable_mst_vld(pl);
> > +	imx8qxp_pixel_link_enable_sync(pl);
> > +}
> > +
> > +static void
> > +imx8qxp_pixel_link_bridge_atomic_disable(struct drm_bridge
> > *bridge,
> > +					 struct drm_bridge_state
> > *old_bridge_state)
> > +{
> > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > +
> > +	imx8qxp_pixel_link_disable_mst_en(pl);
> > +	imx8qxp_pixel_link_disable_mst_vld(pl);
> > +	imx8qxp_pixel_link_disable_sync(pl);
> > +}
> > +
> > +static const u32 imx8qxp_pixel_link_bus_output_fmts[] = {
> > +	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
> > +	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
> > +};
> > +
> > +static bool imx8qxp_pixel_link_bus_output_fmt_supported(u32 fmt)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(imx8qxp_pixel_link_bus_output_fmts);
> > i++) {
> > +		if (imx8qxp_pixel_link_bus_output_fmts[i] == fmt)
> > +			return true;
> > +	}
> > +
> > +	return false;
> > +}
> > +
> > +static u32 *
> > +imx8qxp_pixel_link_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_pixel_link_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;
> > +
> > +	input_fmts[0] = output_fmt;
> > +
> > +	return input_fmts;
> > +}
> > +
> > +static u32 *
> > +imx8qxp_pixel_link_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_pixel_link_bus_output_fmts);
> > +	return kmemdup(imx8qxp_pixel_link_bus_output_fmts,
> > +			sizeof(imx8qxp_pixel_link_bus_output_fmts),
> > GFP_KERNEL);
> > +}
> > +
> > +static const struct drm_bridge_funcs
> > imx8qxp_pixel_link_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,
> > +	.attach			= imx8qxp_pixel_link_bridge_attach,
> > +	.mode_set		= imx8qxp_pixel_link_bridge_mode_set,
> > +	.atomic_enable		=
> > imx8qxp_pixel_link_bridge_atomic_enable,
> > +	.atomic_disable		=
> > imx8qxp_pixel_link_bridge_atomic_disable,
> > +	.atomic_get_input_bus_fmts =
> > +			imx8qxp_pixel_link_bridge_atomic_get_input_bus_
> > fmts,
> > +	.atomic_get_output_bus_fmts =
> > +			imx8qxp_pixel_link_bridge_atomic_get_output_bus
> > _fmts,
> > +};
> > +
> > +static int imx8qxp_pixel_link_disable_all_controls(struct
> > imx8qxp_pixel_link *pl)
> > +{
> > +	int ret;
> > +
> > +	ret = imx8qxp_pixel_link_disable_mst_en(pl);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = imx8qxp_pixel_link_disable_mst_vld(pl);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return imx8qxp_pixel_link_disable_sync(pl);
> > +}
> > +
> > +static struct drm_bridge *
> > +imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
> > +{
> > +	struct device_node *np = pl->dev->of_node;
> > +	struct device_node *port, *remote;
> > +	struct drm_bridge *next_bridge[PL_MAX_NEXT_BRIDGES];
> > +	u32 port_id;
> > +	bool found_port = false;
> > +	int reg, ep_cnt = 0;
> > +	/* select the first next bridge by default */
> > +	int bridge_sel = 0;
> > +
> > +	for (port_id = 1; port_id <= PL_MAX_MST_ADDR + 1; port_id++) {
> > +		port = of_graph_get_port_by_id(np, port_id);
> > +		if (!port)
> > +			continue;
> > +
> > +		if (of_device_is_available(port)) {
> > +			found_port = true;
> > +			of_node_put(port);
> > +			break;
> > +		}
> > +
> > +		of_node_put(port);
> > +	}
> > +
> > +	if (!found_port) {
> > +		DRM_DEV_ERROR(pl->dev, "no available output port\n");
> > +		return ERR_PTR(-ENODEV);
> > +	}
> > +
> > +	for (reg = 0; reg < PL_MAX_NEXT_BRIDGES; reg++) {
> > +		remote = of_graph_get_remote_node(np, port_id, reg);
> > +		if (!remote)
> > +			continue;
> > +
> > +		if (!of_device_is_available(remote->parent)) {
> > +			DRM_DEV_DEBUG(pl->dev,
> > +				      "port%u endpoint%u remote parent
> > is not available\n",
> > +				      port_id, reg);
> > +			of_node_put(remote);
> > +			continue;
> > +		}
> > +
> > +		next_bridge[ep_cnt] = of_drm_find_bridge(remote);
> > +		if (!next_bridge[ep_cnt]) {
> > +			of_node_put(remote);
> > +			return ERR_PTR(-EPROBE_DEFER);
> > +		}
> > +
> > +		/* specially select the next bridge with companion
> > PXL2DPI */
> > +		if (of_find_property(remote, "fsl,companion-pxl2dpi",
> > NULL))
> > +			bridge_sel = ep_cnt;
> > +
> > +		ep_cnt++;
> > +
> > +		of_node_put(remote);
> > +	}
> > +
> > +	pl->mst_addr = port_id - 1;
> > +
> > +	return next_bridge[bridge_sel];
> > +}
> > +
> > +static int imx8qxp_pixel_link_bridge_probe(struct platform_device
> > *pdev)
> > +{
> > +	struct imx8qxp_pixel_link *pl;
> > +	struct device *dev = &pdev->dev;
> > +	struct device_node *np = dev->of_node;
> > +	int ret;
> > +
> > +	pl = devm_kzalloc(dev, sizeof(*pl), GFP_KERNEL);
> > +	if (!pl)
> > +		return -ENOMEM;
> > +
> > +	ret = imx_scu_get_handle(&pl->ipc_handle);
> > +	if (ret) {
> > +		if (ret != -EPROBE_DEFER)
> > +			DRM_DEV_ERROR(dev, "failed to get SCU ipc
> > handle: %d\n",
> > +				      ret);
> > +		return ret;
> > +	}
> > +
> > +	pl->id = of_alias_get_id(np, "dc_pl");
> 
> Could we avoid relying on aliases ? I'd add an id property to the DT
> node instead, or possibly even better a dc id and a stream id.

Will add two properties for dc id and stream id.
Do 'fsl,dc-id' and 'fsl,dc-stream-id' look ok?

Regards,
Liu Ying
Laurent Pinchart June 10, 2022, 12:40 p.m. UTC | #3
Hi Liu,

On Fri, Jun 10, 2022 at 10:09:19AM +0800, Liu Ying wrote:
> On Thu, 2022-06-09 at 12:30 +0300, Laurent Pinchart wrote:
> > On Thu, Jun 09, 2022 at 02:49:23PM +0800, Liu Ying wrote:
> > > This patch adds a drm bridge driver for i.MX8qm/qxp display pixel
> > > link.
> > > The pixel link forms a standard asynchronous linkage between
> > > pixel sources(display controller or camera module) and pixel
> > > consumers(imaging or displays).  It consists of two distinct
> > > functions, a pixel transfer function and a control interface.
> > > 
> > > Reviewed-by: Robert Foss <robert.foss@linaro.org>
> > > Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # Colibri
> > > iMX8X, LT170410-2WHC, LP156WF1
> > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > ---
> > > Robert, I keep your R-b tag from v5. Let me know if you want me to
> > > drop it, as
> > > v7 contains a fix for checkpatch complaints.
> > > Marcel, as the fix is trivial, I add your T-b tag. Let me know if
> > > you want me
> > > to drop it.
> > > 
> > > v7->v8:
> > > * No change.
> > > 
> > > v6->v7:
> > > * Fix 'Alignment should match open parenthesis' complaints from
> > >   'checkpatch.pl --strict'.
> > > * Add Marcel's T-b tag.
> > > 
> > > v5->v6:
> > > * No change.
> > > 
> > > v4->v5:
> > > * Make a comment occupy a line. (Robert)
> > > * Add Robert's R-b tag.
> > > 
> > > v3->v4:
> > > * No change.
> > > 
> > > v2->v3:
> > > * Drop two macros which help define functions and define them
> > > directly.
> > > * Properly disable all pixel link controls to POR value by calling
> > >   imx8qxp_pixel_link_disable_all_controls() from
> > >   imx8qxp_pixel_link_bridge_probe().
> > > 
> > > v1->v2:
> > > * Rewrite the function to find the next bridge by properly using OF
> > > APIs
> > >   and dropping unnecessary DT validation. (Rob)
> > > 
> > >  drivers/gpu/drm/bridge/imx/Kconfig            |   8 +
> > >  drivers/gpu/drm/bridge/imx/Makefile           |   1 +
> > >  .../gpu/drm/bridge/imx/imx8qxp-pixel-link.c   | 429 ++++++++++++++++++
> > >  3 files changed, 438 insertions(+)
> > >  create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > > 
> > > diff --git a/drivers/gpu/drm/bridge/imx/Kconfig
> > > b/drivers/gpu/drm/bridge/imx/Kconfig
> > > index f1c91b6814a5..4d1f027d07f8 100644
> > > --- a/drivers/gpu/drm/bridge/imx/Kconfig
> > > +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> > > @@ -6,3 +6,11 @@ config DRM_IMX8QXP_PIXEL_COMBINER
> > >  	help
> > >  	  Choose this to enable pixel combiner found in
> > >  	  Freescale i.MX8qm/qxp processors.
> > > +
> > > +config DRM_IMX8QXP_PIXEL_LINK
> > > +	tristate "Freescale i.MX8QM/QXP display pixel link"
> > > +	depends on OF
> > > +	select DRM_KMS_HELPER
> > 
> > Should this depend on (or select) IMX_SCU ?
> 
> Will add 'depends on IMX_SCU'.
> 
> > > +	help
> > > +	  Choose this to enable display pixel link found in
> > > +	  Freescale i.MX8qm/qxp processors.
> > > diff --git a/drivers/gpu/drm/bridge/imx/Makefile
> > > b/drivers/gpu/drm/bridge/imx/Makefile
> > > index 7d7c8d674bf0..c15469fb5789 100644
> > > --- a/drivers/gpu/drm/bridge/imx/Makefile
> > > +++ b/drivers/gpu/drm/bridge/imx/Makefile
> > > @@ -1 +1,2 @@
> > >  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-
> > > combiner.o
> > > +obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
> > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > > new file mode 100644
> > > index 000000000000..52b9b96549e1
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
> > > @@ -0,0 +1,429 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +
> > > +/*
> > > + * Copyright 2020 NXP
> > > + */
> > > +
> > > +#include <linux/firmware/imx/svc/misc.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_graph.h>
> > > +#include <linux/platform_device.h>
> > > +
> > > +#include <drm/drm_atomic_state_helper.h>
> > > +#include <drm/drm_bridge.h>
> > > +#include <drm/drm_print.h>
> > > +
> > > +#include <dt-bindings/firmware/imx/rsrc.h>
> > > +
> > > +#define DRIVER_NAME		"imx8qxp-display-pixel-link"
> > > +#define PL_MAX_MST_ADDR		3
> > > +#define PL_MAX_NEXT_BRIDGES	2
> > > +
> > > +struct imx8qxp_pixel_link {
> > > +	struct drm_bridge bridge;
> > > +	struct drm_bridge *next_bridge;
> > > +	struct device *dev;
> > > +	struct imx_sc_ipc *ipc_handle;
> > > +	int id;
> > > +	int stream_id;
> > > +	int dc_id;
> > > +	u32 sink_rsc;
> > > +	u32 mst_addr;
> > > +	u8 mst_addr_ctrl;
> > > +	u8 mst_en_ctrl;
> > > +	u8 mst_vld_ctrl;
> > > +	u8 sync_ctrl;
> > > +};
> > > +
> > > +static void imx8qxp_pixel_link_enable_mst_en(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->mst_en_ctrl, true);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to enable DC%d stream%d pixel link mst_en: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +}
> > > +
> > > +static void imx8qxp_pixel_link_enable_mst_vld(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->mst_vld_ctrl, true);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to enable DC%d stream%d pixel link mst_vld: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +}
> > > +
> > > +static void imx8qxp_pixel_link_enable_sync(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->sync_ctrl, true);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to enable DC%d stream%d pixel link sync: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +}
> > > +
> > > +static int imx8qxp_pixel_link_disable_mst_en(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->mst_en_ctrl, false);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to disable DC%d stream%d pixel link mst_en: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int imx8qxp_pixel_link_disable_mst_vld(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->mst_vld_ctrl, false);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to disable DC%d stream%d pixel link mst_vld: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int imx8qxp_pixel_link_disable_sync(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
> > > +				      pl->sync_ctrl, false);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to disable DC%d stream%d pixel link sync: %d\n",
> > > +			      pl->dc_id, pl->stream_id, ret);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static void imx8qxp_pixel_link_set_mst_addr(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx_sc_misc_set_control(pl->ipc_handle,
> > > +				      pl->sink_rsc, pl->mst_addr_ctrl,
> > > +				      pl->mst_addr);
> > > +	if (ret)
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "failed to set DC%d stream%d pixel link mst addr(%u): %d\n",
> > > +			      pl->dc_id, pl->stream_id, pl->mst_addr, ret);
> > > +}
> > > +
> > > +static int imx8qxp_pixel_link_bridge_attach(struct drm_bridge *bridge,
> > > +					    enum drm_bridge_attach_flags flags)
> > > +{
> > > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > > +
> > > +	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> > > +		DRM_DEV_ERROR(pl->dev,
> > > +			      "do not support creating a drm_connector\n");
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	if (!bridge->encoder) {
> > > +		DRM_DEV_ERROR(pl->dev, "missing encoder\n");
> > > +		return -ENODEV;
> > > +	}
> > > +
> > > +	return drm_bridge_attach(bridge->encoder,
> > > +				 pl->next_bridge, bridge,
> > > +				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > > +}
> > > +
> > > +static void
> > > +imx8qxp_pixel_link_bridge_mode_set(struct drm_bridge *bridge,
> > > +				   const struct drm_display_mode *mode,
> > > +				   const struct drm_display_mode *adjusted_mode)
> > > +{
> > > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > > +
> > > +	imx8qxp_pixel_link_set_mst_addr(pl);
> > > +}
> > > +
> > > +static void
> > > +imx8qxp_pixel_link_bridge_atomic_enable(struct drm_bridge *bridge,
> > > +					struct drm_bridge_state
> > > *old_bridge_state)
> > > +{
> > > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > > +
> > > +	imx8qxp_pixel_link_enable_mst_en(pl);
> > > +	imx8qxp_pixel_link_enable_mst_vld(pl);
> > > +	imx8qxp_pixel_link_enable_sync(pl);
> > > +}
> > > +
> > > +static void
> > > +imx8qxp_pixel_link_bridge_atomic_disable(struct drm_bridge *bridge,
> > > +					 struct drm_bridge_state
> > > *old_bridge_state)
> > > +{
> > > +	struct imx8qxp_pixel_link *pl = bridge->driver_private;
> > > +
> > > +	imx8qxp_pixel_link_disable_mst_en(pl);
> > > +	imx8qxp_pixel_link_disable_mst_vld(pl);
> > > +	imx8qxp_pixel_link_disable_sync(pl);
> > > +}
> > > +
> > > +static const u32 imx8qxp_pixel_link_bus_output_fmts[] = {
> > > +	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
> > > +	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
> > > +};
> > > +
> > > +static bool imx8qxp_pixel_link_bus_output_fmt_supported(u32 fmt)
> > > +{
> > > +	int i;
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(imx8qxp_pixel_link_bus_output_fmts); i++) {
> > > +		if (imx8qxp_pixel_link_bus_output_fmts[i] == fmt)
> > > +			return true;
> > > +	}
> > > +
> > > +	return false;
> > > +}
> > > +
> > > +static u32 *
> > > +imx8qxp_pixel_link_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_pixel_link_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;
> > > +
> > > +	input_fmts[0] = output_fmt;
> > > +
> > > +	return input_fmts;
> > > +}
> > > +
> > > +static u32 *
> > > +imx8qxp_pixel_link_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_pixel_link_bus_output_fmts);
> > > +	return kmemdup(imx8qxp_pixel_link_bus_output_fmts,
> > > +			sizeof(imx8qxp_pixel_link_bus_output_fmts), GFP_KERNEL);
> > > +}
> > > +
> > > +static const struct drm_bridge_funcs imx8qxp_pixel_link_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,
> > > +	.attach			= imx8qxp_pixel_link_bridge_attach,
> > > +	.mode_set		= imx8qxp_pixel_link_bridge_mode_set,
> > > +	.atomic_enable		= imx8qxp_pixel_link_bridge_atomic_enable,
> > > +	.atomic_disable		= imx8qxp_pixel_link_bridge_atomic_disable,
> > > +	.atomic_get_input_bus_fmts =
> > > +			imx8qxp_pixel_link_bridge_atomic_get_input_bus_fmts,
> > > +	.atomic_get_output_bus_fmts =
> > > +			imx8qxp_pixel_link_bridge_atomic_get_output_bus_fmts,
> > > +};
> > > +
> > > +static int imx8qxp_pixel_link_disable_all_controls(struct
> > > imx8qxp_pixel_link *pl)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = imx8qxp_pixel_link_disable_mst_en(pl);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	ret = imx8qxp_pixel_link_disable_mst_vld(pl);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	return imx8qxp_pixel_link_disable_sync(pl);
> > > +}
> > > +
> > > +static struct drm_bridge *
> > > +imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
> > > +{
> > > +	struct device_node *np = pl->dev->of_node;
> > > +	struct device_node *port, *remote;
> > > +	struct drm_bridge *next_bridge[PL_MAX_NEXT_BRIDGES];
> > > +	u32 port_id;
> > > +	bool found_port = false;
> > > +	int reg, ep_cnt = 0;
> > > +	/* select the first next bridge by default */
> > > +	int bridge_sel = 0;
> > > +
> > > +	for (port_id = 1; port_id <= PL_MAX_MST_ADDR + 1; port_id++) {
> > > +		port = of_graph_get_port_by_id(np, port_id);
> > > +		if (!port)
> > > +			continue;
> > > +
> > > +		if (of_device_is_available(port)) {
> > > +			found_port = true;
> > > +			of_node_put(port);
> > > +			break;
> > > +		}
> > > +
> > > +		of_node_put(port);
> > > +	}
> > > +
> > > +	if (!found_port) {
> > > +		DRM_DEV_ERROR(pl->dev, "no available output port\n");
> > > +		return ERR_PTR(-ENODEV);
> > > +	}
> > > +
> > > +	for (reg = 0; reg < PL_MAX_NEXT_BRIDGES; reg++) {
> > > +		remote = of_graph_get_remote_node(np, port_id, reg);
> > > +		if (!remote)
> > > +			continue;
> > > +
> > > +		if (!of_device_is_available(remote->parent)) {
> > > +			DRM_DEV_DEBUG(pl->dev,
> > > +				      "port%u endpoint%u remote parent is not available\n",
> > > +				      port_id, reg);
> > > +			of_node_put(remote);
> > > +			continue;
> > > +		}
> > > +
> > > +		next_bridge[ep_cnt] = of_drm_find_bridge(remote);
> > > +		if (!next_bridge[ep_cnt]) {
> > > +			of_node_put(remote);
> > > +			return ERR_PTR(-EPROBE_DEFER);
> > > +		}
> > > +
> > > +		/* specially select the next bridge with companion PXL2DPI */
> > > +		if (of_find_property(remote, "fsl,companion-pxl2dpi", NULL))
> > > +			bridge_sel = ep_cnt;
> > > +
> > > +		ep_cnt++;
> > > +
> > > +		of_node_put(remote);
> > > +	}
> > > +
> > > +	pl->mst_addr = port_id - 1;
> > > +
> > > +	return next_bridge[bridge_sel];
> > > +}
> > > +
> > > +static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
> > > +{
> > > +	struct imx8qxp_pixel_link *pl;
> > > +	struct device *dev = &pdev->dev;
> > > +	struct device_node *np = dev->of_node;
> > > +	int ret;
> > > +
> > > +	pl = devm_kzalloc(dev, sizeof(*pl), GFP_KERNEL);
> > > +	if (!pl)
> > > +		return -ENOMEM;
> > > +
> > > +	ret = imx_scu_get_handle(&pl->ipc_handle);
> > > +	if (ret) {
> > > +		if (ret != -EPROBE_DEFER)
> > > +			DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
> > > +				      ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	pl->id = of_alias_get_id(np, "dc_pl");
> > 
> > Could we avoid relying on aliases ? I'd add an id property to the DT
> > node instead, or possibly even better a dc id and a stream id.
> 
> Will add two properties for dc id and stream id.
> Do 'fsl,dc-id' and 'fsl,dc-stream-id' look ok?

Looks good to me.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
index f1c91b6814a5..4d1f027d07f8 100644
--- a/drivers/gpu/drm/bridge/imx/Kconfig
+++ b/drivers/gpu/drm/bridge/imx/Kconfig
@@ -6,3 +6,11 @@  config DRM_IMX8QXP_PIXEL_COMBINER
 	help
 	  Choose this to enable pixel combiner found in
 	  Freescale i.MX8qm/qxp processors.
+
+config DRM_IMX8QXP_PIXEL_LINK
+	tristate "Freescale i.MX8QM/QXP display pixel link"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  Choose this to enable display pixel link found in
+	  Freescale i.MX8qm/qxp processors.
diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
index 7d7c8d674bf0..c15469fb5789 100644
--- a/drivers/gpu/drm/bridge/imx/Makefile
+++ b/drivers/gpu/drm/bridge/imx/Makefile
@@ -1 +1,2 @@ 
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
+obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
new file mode 100644
index 000000000000..52b9b96549e1
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
@@ -0,0 +1,429 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2020 NXP
+ */
+
+#include <linux/firmware/imx/svc/misc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_print.h>
+
+#include <dt-bindings/firmware/imx/rsrc.h>
+
+#define DRIVER_NAME		"imx8qxp-display-pixel-link"
+#define PL_MAX_MST_ADDR		3
+#define PL_MAX_NEXT_BRIDGES	2
+
+struct imx8qxp_pixel_link {
+	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
+	struct device *dev;
+	struct imx_sc_ipc *ipc_handle;
+	int id;
+	int stream_id;
+	int dc_id;
+	u32 sink_rsc;
+	u32 mst_addr;
+	u8 mst_addr_ctrl;
+	u8 mst_en_ctrl;
+	u8 mst_vld_ctrl;
+	u8 sync_ctrl;
+};
+
+static void imx8qxp_pixel_link_enable_mst_en(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->mst_en_ctrl, true);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to enable DC%d stream%d pixel link mst_en: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+}
+
+static void imx8qxp_pixel_link_enable_mst_vld(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->mst_vld_ctrl, true);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to enable DC%d stream%d pixel link mst_vld: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+}
+
+static void imx8qxp_pixel_link_enable_sync(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->sync_ctrl, true);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to enable DC%d stream%d pixel link sync: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+}
+
+static int imx8qxp_pixel_link_disable_mst_en(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->mst_en_ctrl, false);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to disable DC%d stream%d pixel link mst_en: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+
+	return ret;
+}
+
+static int imx8qxp_pixel_link_disable_mst_vld(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->mst_vld_ctrl, false);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to disable DC%d stream%d pixel link mst_vld: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+
+	return ret;
+}
+
+static int imx8qxp_pixel_link_disable_sync(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc,
+				      pl->sync_ctrl, false);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to disable DC%d stream%d pixel link sync: %d\n",
+			      pl->dc_id, pl->stream_id, ret);
+
+	return ret;
+}
+
+static void imx8qxp_pixel_link_set_mst_addr(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx_sc_misc_set_control(pl->ipc_handle,
+				      pl->sink_rsc, pl->mst_addr_ctrl,
+				      pl->mst_addr);
+	if (ret)
+		DRM_DEV_ERROR(pl->dev,
+			      "failed to set DC%d stream%d pixel link mst addr(%u): %d\n",
+			      pl->dc_id, pl->stream_id, pl->mst_addr, ret);
+}
+
+static int imx8qxp_pixel_link_bridge_attach(struct drm_bridge *bridge,
+					    enum drm_bridge_attach_flags flags)
+{
+	struct imx8qxp_pixel_link *pl = bridge->driver_private;
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+		DRM_DEV_ERROR(pl->dev,
+			      "do not support creating a drm_connector\n");
+		return -EINVAL;
+	}
+
+	if (!bridge->encoder) {
+		DRM_DEV_ERROR(pl->dev, "missing encoder\n");
+		return -ENODEV;
+	}
+
+	return drm_bridge_attach(bridge->encoder,
+				 pl->next_bridge, bridge,
+				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+static void
+imx8qxp_pixel_link_bridge_mode_set(struct drm_bridge *bridge,
+				   const struct drm_display_mode *mode,
+				   const struct drm_display_mode *adjusted_mode)
+{
+	struct imx8qxp_pixel_link *pl = bridge->driver_private;
+
+	imx8qxp_pixel_link_set_mst_addr(pl);
+}
+
+static void
+imx8qxp_pixel_link_bridge_atomic_enable(struct drm_bridge *bridge,
+					struct drm_bridge_state *old_bridge_state)
+{
+	struct imx8qxp_pixel_link *pl = bridge->driver_private;
+
+	imx8qxp_pixel_link_enable_mst_en(pl);
+	imx8qxp_pixel_link_enable_mst_vld(pl);
+	imx8qxp_pixel_link_enable_sync(pl);
+}
+
+static void
+imx8qxp_pixel_link_bridge_atomic_disable(struct drm_bridge *bridge,
+					 struct drm_bridge_state *old_bridge_state)
+{
+	struct imx8qxp_pixel_link *pl = bridge->driver_private;
+
+	imx8qxp_pixel_link_disable_mst_en(pl);
+	imx8qxp_pixel_link_disable_mst_vld(pl);
+	imx8qxp_pixel_link_disable_sync(pl);
+}
+
+static const u32 imx8qxp_pixel_link_bus_output_fmts[] = {
+	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
+	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
+};
+
+static bool imx8qxp_pixel_link_bus_output_fmt_supported(u32 fmt)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(imx8qxp_pixel_link_bus_output_fmts); i++) {
+		if (imx8qxp_pixel_link_bus_output_fmts[i] == fmt)
+			return true;
+	}
+
+	return false;
+}
+
+static u32 *
+imx8qxp_pixel_link_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_pixel_link_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;
+
+	input_fmts[0] = output_fmt;
+
+	return input_fmts;
+}
+
+static u32 *
+imx8qxp_pixel_link_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_pixel_link_bus_output_fmts);
+	return kmemdup(imx8qxp_pixel_link_bus_output_fmts,
+			sizeof(imx8qxp_pixel_link_bus_output_fmts), GFP_KERNEL);
+}
+
+static const struct drm_bridge_funcs imx8qxp_pixel_link_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,
+	.attach			= imx8qxp_pixel_link_bridge_attach,
+	.mode_set		= imx8qxp_pixel_link_bridge_mode_set,
+	.atomic_enable		= imx8qxp_pixel_link_bridge_atomic_enable,
+	.atomic_disable		= imx8qxp_pixel_link_bridge_atomic_disable,
+	.atomic_get_input_bus_fmts =
+			imx8qxp_pixel_link_bridge_atomic_get_input_bus_fmts,
+	.atomic_get_output_bus_fmts =
+			imx8qxp_pixel_link_bridge_atomic_get_output_bus_fmts,
+};
+
+static int imx8qxp_pixel_link_disable_all_controls(struct imx8qxp_pixel_link *pl)
+{
+	int ret;
+
+	ret = imx8qxp_pixel_link_disable_mst_en(pl);
+	if (ret)
+		return ret;
+
+	ret = imx8qxp_pixel_link_disable_mst_vld(pl);
+	if (ret)
+		return ret;
+
+	return imx8qxp_pixel_link_disable_sync(pl);
+}
+
+static struct drm_bridge *
+imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
+{
+	struct device_node *np = pl->dev->of_node;
+	struct device_node *port, *remote;
+	struct drm_bridge *next_bridge[PL_MAX_NEXT_BRIDGES];
+	u32 port_id;
+	bool found_port = false;
+	int reg, ep_cnt = 0;
+	/* select the first next bridge by default */
+	int bridge_sel = 0;
+
+	for (port_id = 1; port_id <= PL_MAX_MST_ADDR + 1; port_id++) {
+		port = of_graph_get_port_by_id(np, port_id);
+		if (!port)
+			continue;
+
+		if (of_device_is_available(port)) {
+			found_port = true;
+			of_node_put(port);
+			break;
+		}
+
+		of_node_put(port);
+	}
+
+	if (!found_port) {
+		DRM_DEV_ERROR(pl->dev, "no available output port\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	for (reg = 0; reg < PL_MAX_NEXT_BRIDGES; reg++) {
+		remote = of_graph_get_remote_node(np, port_id, reg);
+		if (!remote)
+			continue;
+
+		if (!of_device_is_available(remote->parent)) {
+			DRM_DEV_DEBUG(pl->dev,
+				      "port%u endpoint%u remote parent is not available\n",
+				      port_id, reg);
+			of_node_put(remote);
+			continue;
+		}
+
+		next_bridge[ep_cnt] = of_drm_find_bridge(remote);
+		if (!next_bridge[ep_cnt]) {
+			of_node_put(remote);
+			return ERR_PTR(-EPROBE_DEFER);
+		}
+
+		/* specially select the next bridge with companion PXL2DPI */
+		if (of_find_property(remote, "fsl,companion-pxl2dpi", NULL))
+			bridge_sel = ep_cnt;
+
+		ep_cnt++;
+
+		of_node_put(remote);
+	}
+
+	pl->mst_addr = port_id - 1;
+
+	return next_bridge[bridge_sel];
+}
+
+static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
+{
+	struct imx8qxp_pixel_link *pl;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int ret;
+
+	pl = devm_kzalloc(dev, sizeof(*pl), GFP_KERNEL);
+	if (!pl)
+		return -ENOMEM;
+
+	ret = imx_scu_get_handle(&pl->ipc_handle);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
+				      ret);
+		return ret;
+	}
+
+	pl->id = of_alias_get_id(np, "dc_pl");
+	if (pl->id < 0) {
+		DRM_DEV_ERROR(dev,
+			      "failed to get pixel link node alias id: %d\n",
+			      pl->id);
+		return pl->id;
+	}
+
+	pl->dev = dev;
+
+	pl->dc_id = pl->id / 2;
+	pl->stream_id = pl->id % 2;
+
+	pl->sink_rsc = pl->dc_id ? IMX_SC_R_DC_1 : IMX_SC_R_DC_0;
+
+	if (pl->stream_id == 0) {
+		pl->mst_addr_ctrl = IMX_SC_C_PXL_LINK_MST1_ADDR;
+		pl->mst_en_ctrl   = IMX_SC_C_PXL_LINK_MST1_ENB;
+		pl->mst_vld_ctrl  = IMX_SC_C_PXL_LINK_MST1_VLD;
+		pl->sync_ctrl     = IMX_SC_C_SYNC_CTRL0;
+	} else {
+		pl->mst_addr_ctrl = IMX_SC_C_PXL_LINK_MST2_ADDR;
+		pl->mst_en_ctrl   = IMX_SC_C_PXL_LINK_MST2_ENB;
+		pl->mst_vld_ctrl  = IMX_SC_C_PXL_LINK_MST2_VLD;
+		pl->sync_ctrl     = IMX_SC_C_SYNC_CTRL1;
+	}
+
+	/* disable all controls to POR default */
+	ret = imx8qxp_pixel_link_disable_all_controls(pl);
+	if (ret)
+		return ret;
+
+	pl->next_bridge = imx8qxp_pixel_link_find_next_bridge(pl);
+	if (IS_ERR(pl->next_bridge)) {
+		ret = PTR_ERR(pl->next_bridge);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "failed to find next bridge: %d\n",
+				      ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pl);
+
+	pl->bridge.driver_private = pl;
+	pl->bridge.funcs = &imx8qxp_pixel_link_bridge_funcs;
+	pl->bridge.of_node = np;
+
+	drm_bridge_add(&pl->bridge);
+
+	return ret;
+}
+
+static int imx8qxp_pixel_link_bridge_remove(struct platform_device *pdev)
+{
+	struct imx8qxp_pixel_link *pl = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&pl->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id imx8qxp_pixel_link_dt_ids[] = {
+	{ .compatible = "fsl,imx8qm-dc-pixel-link", },
+	{ .compatible = "fsl,imx8qxp-dc-pixel-link", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx8qxp_pixel_link_dt_ids);
+
+static struct platform_driver imx8qxp_pixel_link_bridge_driver = {
+	.probe	= imx8qxp_pixel_link_bridge_probe,
+	.remove = imx8qxp_pixel_link_bridge_remove,
+	.driver	= {
+		.of_match_table = imx8qxp_pixel_link_dt_ids,
+		.name = DRIVER_NAME,
+	},
+};
+module_platform_driver(imx8qxp_pixel_link_bridge_driver);
+
+MODULE_DESCRIPTION("i.MX8QXP/QM display pixel link bridge driver");
+MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);