--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2020 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_print.h>
+
+#define PC_CTRL_REG 0x0
+#define PC_COMBINE_ENABLE BIT(0)
+#define PC_DISP_BYPASS(n) BIT(1 + 21 * (n))
+#define PC_DISP_HSYNC_POLARITY(n) BIT(2 + 11 * (n))
+#define PC_DISP_HSYNC_POLARITY_POS(n) DISP_HSYNC_POLARITY(n)
+#define PC_DISP_VSYNC_POLARITY(n) BIT(3 + 11 * (n))
+#define PC_DISP_VSYNC_POLARITY_POS(n) DISP_VSYNC_POLARITY(n)
+#define PC_DISP_DVALID_POLARITY(n) BIT(4 + 11 * (n))
+#define PC_DISP_DVALID_POLARITY_POS(n) DISP_DVALID_POLARITY(n)
+#define PC_VSYNC_MASK_ENABLE BIT(5)
+#define PC_SKIP_MODE BIT(6)
+#define PC_SKIP_NUMBER_MASK GENMASK(12, 7)
+#define PC_SKIP_NUMBER(n) FIELD_PREP(PC_SKIP_NUMBER_MASK, (n))
+#define PC_DISP0_PIX_DATA_FORMAT_MASK GENMASK(18, 16)
+#define PC_DISP0_PIX_DATA_FORMAT(fmt) \
+ FIELD_PREP(PC_DISP0_PIX_DATA_FORMAT_MASK, (fmt))
+#define PC_DISP1_PIX_DATA_FORMAT_MASK GENMASK(21, 19)
+#define PC_DISP1_PIX_DATA_FORMAT(fmt) \
+ FIELD_PREP(PC_DISP1_PIX_DATA_FORMAT_MASK, (fmt))
+
+#define PC_SW_RESET_REG 0x20
+#define PC_SW_RESET_N BIT(0)
+#define PC_DISP_SW_RESET_N(n) BIT(1 + (n))
+#define PC_FULL_RESET_N (PC_SW_RESET_N | \
+ PC_DISP_SW_RESET_N(0) | \
+ PC_DISP_SW_RESET_N(1))
+
+#define PC_REG_SET 0x4
+#define PC_REG_CLR 0x8
+
+#define DRIVER_NAME "imx8qxp-pixel-combiner"
+
+enum imx8qxp_pc_pix_data_format {
+ RGB,
+ YUV444,
+ YUV422,
+ SPLIT_RGB,
+};
+
+struct imx8qxp_pc_channel {
+ struct drm_bridge bridge;
+ struct drm_bridge *next_bridge;
+ struct imx8qxp_pc *pc;
+ unsigned int stream_id;
+ bool is_available;
+};
+
+struct imx8qxp_pc {
+ struct device *dev;
+ struct imx8qxp_pc_channel ch[2];
+ struct clk *clk_apb;
+ void __iomem *base;
+};
+
+static inline u32 imx8qxp_pc_read(struct imx8qxp_pc *pc, unsigned int offset)
+{
+ return readl(pc->base + offset);
+}
+
+static inline void
+imx8qxp_pc_write(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+ writel(value, pc->base + offset);
+}
+
+static inline void
+imx8qxp_pc_write_set(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+ imx8qxp_pc_write(pc, offset + PC_REG_SET, value);
+}
+
+static inline void
+imx8qxp_pc_write_clr(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
+{
+ imx8qxp_pc_write(pc, offset + PC_REG_CLR, value);
+}
+
+static enum drm_mode_status
+imx8qxp_pc_bridge_mode_valid(struct drm_bridge *bridge,
+ const struct drm_display_info *info,
+ const struct drm_display_mode *mode)
+{
+ if (mode->hdisplay > 2560)
+ return MODE_BAD_HVALUE;
+
+ return MODE_OK;
+}
+
+static int imx8qxp_pc_bridge_attach(struct drm_bridge *bridge,
+ enum drm_bridge_attach_flags flags)
+{
+ struct imx8qxp_pc_channel *ch = bridge->driver_private;
+ struct imx8qxp_pc *pc = ch->pc;
+
+ if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+ DRM_DEV_ERROR(pc->dev,
+ "do not support creating a drm_connector\n");
+ return -EINVAL;
+ }
+
+ if (!bridge->encoder) {
+ DRM_DEV_ERROR(pc->dev, "missing encoder\n");
+ return -ENODEV;
+ }
+
+ return drm_bridge_attach(bridge->encoder,
+ ch->next_bridge, bridge,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+static void
+imx8qxp_pc_bridge_mode_set(struct drm_bridge *bridge,
+ const struct drm_display_mode *mode,
+ const struct drm_display_mode *adjusted_mode)
+{
+ struct imx8qxp_pc_channel *ch = bridge->driver_private;
+ struct imx8qxp_pc *pc = ch->pc;
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_get_sync(pc->dev);
+ if (ret < 0)
+ DRM_DEV_ERROR(pc->dev,
+ "failed to get runtime PM sync: %d\n", ret);
+
+ ret = clk_prepare_enable(pc->clk_apb);
+ if (ret)
+ DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+ __func__, ret);
+
+ /* HSYNC to pixel link is active low. */
+ imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
+ PC_DISP_HSYNC_POLARITY(ch->stream_id));
+
+ /* VSYNC to pixel link is active low. */
+ imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
+ PC_DISP_VSYNC_POLARITY(ch->stream_id));
+
+ /* Data enable to pixel link is active high. */
+ imx8qxp_pc_write_set(pc, PC_CTRL_REG,
+ PC_DISP_DVALID_POLARITY(ch->stream_id));
+
+ /* Mask the first frame output which may be incomplete. */
+ imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_VSYNC_MASK_ENABLE);
+
+ /* Only support RGB currently. */
+ val = imx8qxp_pc_read(pc, PC_CTRL_REG);
+ if (ch->stream_id == 0) {
+ val &= ~PC_DISP0_PIX_DATA_FORMAT_MASK;
+ val |= PC_DISP0_PIX_DATA_FORMAT(RGB);
+ } else {
+ val &= ~PC_DISP1_PIX_DATA_FORMAT_MASK;
+ val |= PC_DISP1_PIX_DATA_FORMAT(RGB);
+ }
+ imx8qxp_pc_write(pc, PC_CTRL_REG, val);
+
+ /* Only support bypass mode currently. */
+ imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_DISP_BYPASS(ch->stream_id));
+
+ clk_disable_unprepare(pc->clk_apb);
+}
+
+static void
+imx8qxp_pc_bridge_atomic_disable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_bridge_state)
+{
+ struct imx8qxp_pc_channel *ch = bridge->driver_private;
+ struct imx8qxp_pc *pc = ch->pc;
+ int ret;
+
+ ret = pm_runtime_put(pc->dev);
+ if (ret < 0)
+ DRM_DEV_ERROR(pc->dev, "failed to put runtime PM: %d\n", ret);
+}
+
+static const u32 imx8qxp_pc_bus_output_fmts[] = {
+ MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
+ MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
+};
+
+static bool imx8qxp_pc_bus_output_fmt_supported(u32 fmt)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(imx8qxp_pc_bus_output_fmts); i++) {
+ if (imx8qxp_pc_bus_output_fmts[i] == fmt)
+ return true;
+ }
+
+ return false;
+}
+
+static u32 *
+imx8qxp_pc_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_pc_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;
+
+ switch (output_fmt) {
+ case MEDIA_BUS_FMT_RGB888_1X36_CPADLO:
+ input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X30_CPADLO;
+ break;
+ case MEDIA_BUS_FMT_RGB666_1X36_CPADLO:
+ input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X30_CPADLO;
+ break;
+ default:
+ kfree(input_fmts);
+ input_fmts = NULL;
+ break;
+ }
+
+ return input_fmts;
+}
+
+static u32 *
+imx8qxp_pc_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_pc_bus_output_fmts);
+ return kmemdup(imx8qxp_pc_bus_output_fmts,
+ sizeof(imx8qxp_pc_bus_output_fmts), GFP_KERNEL);
+}
+
+static const struct drm_bridge_funcs imx8qxp_pc_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,
+ .mode_valid = imx8qxp_pc_bridge_mode_valid,
+ .attach = imx8qxp_pc_bridge_attach,
+ .mode_set = imx8qxp_pc_bridge_mode_set,
+ .atomic_disable = imx8qxp_pc_bridge_atomic_disable,
+ .atomic_get_input_bus_fmts =
+ imx8qxp_pc_bridge_atomic_get_input_bus_fmts,
+ .atomic_get_output_bus_fmts =
+ imx8qxp_pc_bridge_atomic_get_output_bus_fmts,
+};
+
+static int imx8qxp_pc_bridge_probe(struct platform_device *pdev)
+{
+ struct imx8qxp_pc *pc;
+ struct imx8qxp_pc_channel *ch;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *child, *remote;
+ u32 i;
+ int ret;
+
+ pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ pc->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pc->base))
+ return PTR_ERR(pc->base);
+
+ pc->dev = dev;
+
+ pc->clk_apb = devm_clk_get(dev, "apb");
+ if (IS_ERR(pc->clk_apb)) {
+ ret = PTR_ERR(pc->clk_apb);
+ if (ret != -EPROBE_DEFER)
+ DRM_DEV_ERROR(dev, "failed to get apb clock: %d\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, pc);
+ pm_runtime_enable(dev);
+
+ for_each_available_child_of_node(np, child) {
+ ret = of_property_read_u32(child, "reg", &i);
+ if (ret || i > 1) {
+ ret = -EINVAL;
+ DRM_DEV_ERROR(dev,
+ "invalid channel(%u) node address\n", i);
+ goto free_child;
+ }
+
+ ch = &pc->ch[i];
+ ch->pc = pc;
+ ch->stream_id = i;
+
+ remote = of_graph_get_remote_node(child, 1, 0);
+ if (!remote) {
+ ret = -ENODEV;
+ DRM_DEV_ERROR(dev,
+ "channel%u failed to get port1's remote node: %d\n",
+ i, ret);
+ goto free_child;
+ }
+
+ ch->next_bridge = of_drm_find_bridge(remote);
+ if (!ch->next_bridge) {
+ of_node_put(remote);
+ ret = -EPROBE_DEFER;
+ DRM_DEV_DEBUG_DRIVER(dev,
+ "channel%u failed to find next bridge: %d\n",
+ i, ret);
+ goto free_child;
+ }
+
+ of_node_put(remote);
+
+ ch->bridge.driver_private = ch;
+ ch->bridge.funcs = &imx8qxp_pc_bridge_funcs;
+ ch->bridge.of_node = child;
+ ch->is_available = true;
+
+ drm_bridge_add(&ch->bridge);
+ }
+
+ return 0;
+
+free_child:
+ of_node_put(child);
+
+ if (i == 1 && pc->ch[0].next_bridge)
+ drm_bridge_remove(&pc->ch[0].bridge);
+
+ pm_runtime_disable(dev);
+ return ret;
+}
+
+static int imx8qxp_pc_bridge_remove(struct platform_device *pdev)
+{
+ struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+ struct imx8qxp_pc_channel *ch;
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ ch = &pc->ch[i];
+
+ if (!ch->is_available)
+ continue;
+
+ drm_bridge_remove(&ch->bridge);
+ ch->is_available = false;
+ }
+
+ pm_runtime_disable(&pdev->dev);
+
+ return 0;
+}
+
+static int __maybe_unused imx8qxp_pc_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = clk_prepare_enable(pc->clk_apb);
+ if (ret)
+ DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+ __func__, ret);
+
+ /* Disable pixel combiner by full reset. */
+ imx8qxp_pc_write_clr(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
+
+ clk_disable_unprepare(pc->clk_apb);
+
+ /* Ensure the reset takes effect. */
+ usleep_range(10, 20);
+
+ return ret;
+}
+
+static int __maybe_unused imx8qxp_pc_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = clk_prepare_enable(pc->clk_apb);
+ if (ret) {
+ DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ /* out of reset */
+ imx8qxp_pc_write_set(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
+
+ clk_disable_unprepare(pc->clk_apb);
+
+ return ret;
+}
+
+static const struct dev_pm_ops imx8qxp_pc_pm_ops = {
+ SET_RUNTIME_PM_OPS(imx8qxp_pc_runtime_suspend,
+ imx8qxp_pc_runtime_resume, NULL)
+};
+
+static const struct of_device_id imx8qxp_pc_dt_ids[] = {
+ { .compatible = "fsl,imx8qm-pixel-combiner", },
+ { .compatible = "fsl,imx8qxp-pixel-combiner", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx8qxp_pc_dt_ids);
+
+static struct platform_driver imx8qxp_pc_bridge_driver = {
+ .probe = imx8qxp_pc_bridge_probe,
+ .remove = imx8qxp_pc_bridge_remove,
+ .driver = {
+ .pm = &imx8qxp_pc_pm_ops,
+ .name = DRIVER_NAME,
+ .of_match_table = imx8qxp_pc_dt_ids,
+ },
+};
+module_platform_driver(imx8qxp_pc_bridge_driver);
+
+MODULE_DESCRIPTION("i.MX8QM/QXP pixel combiner bridge driver");
+MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);