Re: [PATCH 07/14] drm/bridge: imx: Add i.MX8qm/qxp display pixel link support

On Thu, Dec 17, 2020 at 05:59:26PM +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.

Signed-off-by: Liu Ying victor.liu@nxp.com

drivers/gpu/drm/bridge/imx/Kconfig | 8 + drivers/gpu/drm/bridge/imx/Makefile | 1 + drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c | 411 ++++++++++++++++++++++++ 3 files changed, 420 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 f1c91b6..4d1f027 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 7d7c8d6..c15469f 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 00000000..1af7467 --- /dev/null +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c @@ -0,0 +1,411 @@ +// 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

+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;

+};

+#define DEFINE_IMX8QXP_PIXEL_LINK_ENABLE_CTRL(name) \ +static void \ +imx8qxp_pixel_link_enable_##name(struct imx8qxp_pixel_link *pl) \ +{ \

• int ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc, \

• 			  pl->name##_ctrl, true);	\
  

• if (ret) \

• DRM_DEV_ERROR(pl->dev,					\
  

• 	"failed to enable DC%d stream%d pixel link "	\
  

• 	#name ": %d\n",	pl->dc_id, pl->stream_id, ret);	\
  

+}

+DEFINE_IMX8QXP_PIXEL_LINK_ENABLE_CTRL(mst_en) +DEFINE_IMX8QXP_PIXEL_LINK_ENABLE_CTRL(mst_vld) +DEFINE_IMX8QXP_PIXEL_LINK_ENABLE_CTRL(sync)

+#define DEFINE_IMX8QXP_PIXEL_LINK_DISABLE_CTRL(name) \ +static int \ +imx8qxp_pixel_link_disable_##name(struct imx8qxp_pixel_link *pl) \ +{ \

• int ret = imx_sc_misc_set_control(pl->ipc_handle, pl->sink_rsc, \

• 			  pl->name##_ctrl, false);	\
  

• if (ret) \

• DRM_DEV_ERROR(pl->dev,					\
  

• 	"failed to disable DC%d stream%d pixel link "	\
  

• 	#name ": %d\n",	pl->dc_id, pl->stream_id, ret);	\
  

• 							\
  

• return ret; \

+}

+DEFINE_IMX8QXP_PIXEL_LINK_DISABLE_CTRL(mst_en) +DEFINE_IMX8QXP_PIXEL_LINK_DISABLE_CTRL(mst_vld) +DEFINE_IMX8QXP_PIXEL_LINK_DISABLE_CTRL(sync)

+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 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, *ep, *remote;
• struct of_endpoint endpoint;
• struct drm_bridge *next_bridge[2], *err_bridge;
• u32 port_id, vld_port_id;
• int port_cnt = 0, ep_cnt = 0;
• int bridge_sel = 0; /* select the first next bridge by default */
• int ret;
• 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)) {
  

• 	port_cnt++;
  

• 	vld_port_id = port_id;
  

• }
  

• of_node_put(port);
  

• }
• /* check the number of available output ports */
• if (port_cnt == 0) {

• DRM_DEV_ERROR(pl->dev, "no available output port\n");
  

• return ERR_PTR(-ENODEV);
  

• } else if (port_cnt > 1) {

• DRM_DEV_ERROR(pl->dev, "invalid available output ports: %d\n",
  

• 						port_cnt);
  

• return ERR_PTR(-ENOTSUPP);
  

• }
• port = of_graph_get_port_by_id(np, vld_port_id);
• if (!port) {

• DRM_DEV_ERROR(pl->dev, "failed to get output port\n");
  

• return ERR_PTR(-ENODEV);
  

• }
• for_each_available_child_of_node(port, ep) {

for_each_endpoint_of_node

• /* 2 available endpoints at most */
  

• if (++ep_cnt > 2) {
  

• 	DRM_DEV_ERROR(pl->dev,
  

• 		      "invalid available endpoints: %d\n",
  

• 							ep_cnt);
  

Not really the kernel's job to validate the DT. Just get endpoints 0 and 1 if those are the 2 you want.

• 	err_bridge = ERR_PTR(-ENOTSUPP);
  

• 	of_node_put(ep);
  

• 	goto err;
  

• }
  

• ret = of_graph_parse_endpoint(ep, &endpoint);
  

• if (ret) {
  

• 	DRM_DEV_ERROR(pl->dev, "failed to parse endpoint: %d\n",
  

• 							ret);
  

• 	err_bridge = ERR_PTR(ret);
  

• 	of_node_put(ep);
  

• 	goto err;
  

• }
  

• remote = of_graph_get_remote_port_parent(ep);
  

• if (!remote || !of_device_is_available(remote)) {
  

• 	DRM_DEV_ERROR(pl->dev,
  

• 		      "endpoint%u has no available remote\n",
  

• 						endpoint.id);
  

• 	of_node_put(remote);
  

• 	of_node_put(ep);
  

• 	err_bridge = ERR_PTR(-ENODEV);
  

• 	goto err;
  

• } else if (!of_device_is_available(remote->parent)) {
  

• 	DRM_DEV_ERROR(pl->dev,
  

• 		"endpoint%u remote parent is not available\n",
  

• 						endpoint.id);
  

• 	of_node_put(remote);
  

• 	of_node_put(ep);
  

• 	err_bridge = ERR_PTR(-ENODEV);
  

• 	goto err;
  

• }
  

Rewrite all this in terms of of_graph_get_remote_node(). It takes care of of_device_is_available checking for you.

• next_bridge[ep_cnt - 1] = of_drm_find_bridge(remote);
  

• if (!next_bridge[ep_cnt - 1]) {
  

• 	of_node_put(remote);
  

• 	of_node_put(ep);
  

• 	err_bridge = ERR_PTR(-EPROBE_DEFER);
  

• 	goto err;
  

• }
  

• /* specially select the next bridge with companion PXL2DPI */
  

• if (of_find_property(remote, "fsl,companion-pxl2dpi", NULL))
  

• 	bridge_sel = ep_cnt - 1;
  

• of_node_put(remote);
  

• }
• pl->mst_addr = vld_port_id - 1;
• of_node_put(port);
• return next_bridge[bridge_sel];

+err:

• of_node_put(port);
• return err_bridge;

+}

+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");

What's this needed for? I doubt aliases is the right thing to use here.

Rob