Waveshare touchscreen consists of a DPI panel and a driver board.
The waveshare driver board consists of ICN6211 and a MCU to
convert DSI to DPI and control the backlight.
This driver treats the MCU and ICN6211 board as a whole unit.
It can support all resolution waveshare DSI2DPI based panel,
the timing table should come from 'panel-dpi' panel in the device tree.
Signed-off-by: Joseph Guo <qijian....@nxp.com>
---
drivers/gpu/drm/bridge/Kconfig | 11 ++
drivers/gpu/drm/bridge/Makefile | 1 +
drivers/gpu/drm/bridge/waveshare-dsi.c | 210 +++++++++++++++++++++++++++++++++
3 files changed, 222 insertions(+)
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index
cb3b797fcea1c73e83c9187fef6582296b340305..26fec25c61ed7d950c094e0224f1196946079485
100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -472,4 +472,15 @@ config DRM_ITE_IT6161
help
ITE IT6161 bridge chip driver.
+config DRM_WAVESHARE_BRIDGE
+ tristate "Waveshare DSI bridge"
+ depends on OF
+ select DRM_PANEL_BRIDGE
+ select DRM_KMS_HELPER
+ select DRM_MIPI_DSI
+ select REGMAP_I2C
+ help
+ Driver for waveshare DSI to DPI bridge board.
+ Please say Y if you have such hardware
+
endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index
d1db90688a150fdc3a5fd40acebe740798c452b0..3caa4d8f71675804328aa5a51ec67b2587938621
100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -48,3 +48,4 @@ obj-$(CONFIG_DRM_ITE_IT6263) += it6263.o
obj-$(CONFIG_DRM_ITE_IT6161) += it6161.o
obj-$(CONFIG_DRM_SEC_MIPI_DSIM) += sec-dsim.o
obj-$(CONFIG_DRM_NXP_SEIKO_43WVFIG) += nxp-seiko-43wvfig.o
+obj-$(CONFIG_DRM_WAVESHARE_BRIDGE) += waveshare-dsi.o
diff --git a/drivers/gpu/drm/bridge/waveshare-dsi.c
b/drivers/gpu/drm/bridge/waveshare-dsi.c
new file mode 100644
index
0000000000000000000000000000000000000000..efb3a2fc501b5725b02f49862526d1704a3a4b7b
--- /dev/null
+++ b/drivers/gpu/drm/bridge/waveshare-dsi.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ * Based on panel-raspberrypi-touchscreen by Broadcom
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+struct ws_bridge {
+ struct drm_bridge bridge;
+ struct drm_bridge *next_bridge;
+ struct backlight_device *backlight;
+ struct device *dev;
+ struct regmap *reg_map;
+};
+
+static const struct regmap_config ws_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0xff,
+ .disable_debugfs = true,
+};
+
+static struct ws_bridge *bridge_to_ws_bridge(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct ws_bridge, bridge);
+}
+
+static int ws_bridge_attach_dsi(struct ws_bridge *ws)
+{
+ struct device_node *dsi_host_node;
+ struct mipi_dsi_host *host;
+ struct mipi_dsi_device *dsi;
+ const struct mipi_dsi_device_info info = {
+ .type = "ws-bridge",
+ .channel = 0,
+ .node = NULL,
+ };
+ struct device *dev = ws->dev;
+ int ret;
+
+ dsi_host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
+ if (!dsi_host_node) {
+ dev_err(dev, "Failed to get remote port\n");
+ return -ENODEV;
+ }
+
+ host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+
+ of_node_put(dsi_host_node);
+ if (!host)
+ return dev_err_probe(dev, -EPROBE_DEFER, "Failed to find
dsi_host\n");
+
+ dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
+
+ if (IS_ERR(dsi))
+ return dev_err_probe(dev, PTR_ERR(dsi), "Failed to create dsi
device\n");
+
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
+ MIPI_DSI_CLOCK_NON_CONTINUOUS;
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->lanes = 2;
+
+ ret = devm_mipi_dsi_attach(dev, dsi);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to attach dsi to
host\n");
+
+ return 0;
+}
+
+static int ws_bridge_bridge_attach(struct drm_bridge *bridge,
+ enum drm_bridge_attach_flags flags)
+{
+ struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+ int ret;
+
+ ret = ws_bridge_attach_dsi(ws);
+ if (ret)
+ return ret;
+
+ return drm_bridge_attach(ws->bridge.encoder, ws->next_bridge,
+ &ws->bridge, flags);
+}
+
+static void ws_bridge_bridge_enable(struct drm_bridge *bridge)
+{
+ struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+
+ regmap_write(ws->reg_map, 0xad, 0x01);
+ backlight_enable(ws->backlight);
+}
+
+static void ws_bridge_bridge_disable(struct drm_bridge *bridge)
+{
+ struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+
+ backlight_disable(ws->backlight);
+ regmap_write(ws->reg_map, 0xad, 0x00);
+}
+
+static const struct drm_bridge_funcs ws_bridge_bridge_funcs = {
+ .enable = ws_bridge_bridge_enable,
+ .disable = ws_bridge_bridge_disable,
+ .attach = ws_bridge_bridge_attach,
+};
+
+static int ws_bridge_bl_update_status(struct backlight_device *bl)
+{
+ struct ws_bridge *ws = bl_get_data(bl);
+
+ regmap_write(ws->reg_map, 0xab, 0xff - backlight_get_brightness(bl));
+ regmap_write(ws->reg_map, 0xaa, 0x01);
+
+ return 0;
+}
+
+static const struct backlight_ops ws_bridge_bl_ops = {
+ .update_status = ws_bridge_bl_update_status,
+};
+
+static struct backlight_device *ws_bridge_create_backlight(struct ws_bridge
*ws)
+{
+ struct device *dev = ws->dev;
+ const struct backlight_properties props = {
+ .type = BACKLIGHT_RAW,
+ .brightness = 255,
+ .max_brightness = 255,
+ };
+
+ return devm_backlight_device_register(dev, dev_name(dev), dev, ws,
+ &ws_bridge_bl_ops, &props);
+}
+
+static int ws_bridge_probe(struct i2c_client *i2c)
+{
+ struct device *dev = &i2c->dev;
+ struct ws_bridge *ws;
+ struct drm_panel *panel;
+ int ret;
+ struct backlight_device *backlight;
+
+ ws = devm_kzalloc(dev, sizeof(*ws), GFP_KERNEL);
+ if (!ws)
+ return -ENOMEM;
+
+ ws->dev = dev;
+
+ ws->reg_map = devm_regmap_init_i2c(i2c, &ws_regmap_config);
+ if (IS_ERR(ws->reg_map))
+ return dev_err_probe(dev, PTR_ERR(ws->reg_map), "Failed to
allocate regmap\n");
+
+ ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, &panel, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to find remote panel\n");
+
+ ws->next_bridge = devm_drm_panel_bridge_add(dev, panel);
+ if (IS_ERR(ws->next_bridge))
+ return PTR_ERR(ws->next_bridge);
+
+ ws->backlight = ws_bridge_create_backlight(ws);
+ if (IS_ERR(backlight)) {
+ ret = PTR_ERR(backlight);
+ dev_err(dev, "Failed to create backlight: %d\n", ret);
+ return ret;
+ }
+
+ regmap_write(ws->reg_map, 0xc0, 0x01);
+ regmap_write(ws->reg_map, 0xc2, 0x01);
+ regmap_write(ws->reg_map, 0xac, 0x01);
+
+ ws->bridge.funcs = &ws_bridge_bridge_funcs;
+ ws->bridge.type = DRM_MODE_CONNECTOR_DPI;
+ ws->bridge.of_node = dev->of_node;
+ devm_drm_bridge_add(dev, &ws->bridge);
+
+ return 0;
+}
+
+static const struct of_device_id ws_bridge_of_ids[] = {
+ {.compatible = "waveshare,dsi2dpi",},
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, ws_bridge_of_ids);
+
+static struct i2c_driver ws_bridge_driver = {
+ .driver = {
+ .name = "ws_dsi2dpi",
+ .of_match_table = ws_bridge_of_ids,
+ },
+ .probe = ws_bridge_probe,
+};
+module_i2c_driver(ws_bridge_driver);
+
+MODULE_AUTHOR("Joseph Guo <qijian....@nxp.com>");
+MODULE_DESCRIPTION("Waveshare DSI2DPI bridge driver");
+MODULE_LICENSE("GPL");
--
2.34.1
