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

Laurent Pinchart
2022-06-10T12:40:21Z

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.

--
Regards,

Laurent Pinchart