Hey Liu, Thanks for submitting this patch. I only have one comment below. With that addressed, feel free to add my r-b. Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx> On Thu, 18 Feb 2021 at 04:59, Liu Ying <victor.liu@xxxxxxx> 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@xxxxxxx> > --- > 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 + > drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c | 426 ++++++++++++++++++++++++ > 3 files changed, 435 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..2e5ba4a > --- /dev/null > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c > @@ -0,0 +1,426 @@ > +// 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; > + int bridge_sel = 0; /* select the first next bridge by default */ Is this comment on the wrong line? > + > + 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@xxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:" DRIVER_NAME); > -- > 2.7.4 >