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

Liu Ying
2022-06-09T06:49:08Z

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
+ 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);
--
2.25.1