1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2025 NXP 4 * Based on panel-raspberrypi-touchscreen by Broadcom 5 */ 6 7 #include <linux/backlight.h> 8 #include <linux/err.h> 9 #include <linux/i2c.h> 10 #include <linux/module.h> 11 #include <linux/of.h> 12 #include <linux/of_graph.h> 13 #include <linux/regmap.h> 14 15 #include <drm/drm_bridge.h> 16 #include <drm/drm_mipi_dsi.h> 17 #include <drm/drm_of.h> 18 #include <drm/drm_panel.h> 19 20 struct ws_bridge { 21 struct drm_bridge bridge; 22 struct drm_bridge *next_bridge; 23 struct backlight_device *backlight; 24 struct device *dev; 25 struct regmap *reg_map; 26 }; 27 28 static const struct regmap_config ws_regmap_config = { 29 .reg_bits = 8, 30 .val_bits = 8, 31 .max_register = 0xff, 32 }; 33 34 static struct ws_bridge *bridge_to_ws_bridge(struct drm_bridge *bridge) 35 { 36 return container_of(bridge, struct ws_bridge, bridge); 37 } 38 39 static int ws_bridge_attach_dsi(struct ws_bridge *ws) 40 { 41 const struct mipi_dsi_device_info info = { 42 .type = "ws-bridge", 43 .channel = 0, 44 .node = NULL, 45 }; 46 struct device_node *dsi_host_node; 47 struct device *dev = ws->dev; 48 struct mipi_dsi_device *dsi; 49 struct mipi_dsi_host *host; 50 int ret; 51 52 dsi_host_node = of_graph_get_remote_node(dev->of_node, 0, 0); 53 if (!dsi_host_node) { 54 dev_err(dev, "Failed to get remote port\n"); 55 return -ENODEV; 56 } 57 host = of_find_mipi_dsi_host_by_node(dsi_host_node); 58 of_node_put(dsi_host_node); 59 if (!host) 60 return dev_err_probe(dev, -EPROBE_DEFER, "Failed to find dsi_host\n"); 61 62 dsi = devm_mipi_dsi_device_register_full(dev, host, &info); 63 if (IS_ERR(dsi)) 64 return dev_err_probe(dev, PTR_ERR(dsi), "Failed to create dsi device\n"); 65 66 dsi->mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | 67 MIPI_DSI_CLOCK_NON_CONTINUOUS; 68 dsi->format = MIPI_DSI_FMT_RGB888; 69 dsi->lanes = 2; 70 71 ret = devm_mipi_dsi_attach(dev, dsi); 72 if (ret < 0) 73 return dev_err_probe(dev, ret, "Failed to attach dsi to host\n"); 74 75 return 0; 76 } 77 78 static int ws_bridge_bridge_attach(struct drm_bridge *bridge, 79 struct drm_encoder *encoder, 80 enum drm_bridge_attach_flags flags) 81 { 82 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 83 int ret; 84 85 ret = ws_bridge_attach_dsi(ws); 86 if (ret) 87 return ret; 88 89 return drm_bridge_attach(encoder, ws->next_bridge, 90 &ws->bridge, flags); 91 } 92 93 static void ws_bridge_bridge_enable(struct drm_bridge *bridge) 94 { 95 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 96 97 regmap_write(ws->reg_map, 0xad, 0x01); 98 backlight_enable(ws->backlight); 99 } 100 101 static void ws_bridge_bridge_disable(struct drm_bridge *bridge) 102 { 103 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 104 105 backlight_disable(ws->backlight); 106 regmap_write(ws->reg_map, 0xad, 0x00); 107 } 108 109 static const struct drm_bridge_funcs ws_bridge_bridge_funcs = { 110 .enable = ws_bridge_bridge_enable, 111 .disable = ws_bridge_bridge_disable, 112 .attach = ws_bridge_bridge_attach, 113 }; 114 115 static int ws_bridge_bl_update_status(struct backlight_device *bl) 116 { 117 struct ws_bridge *ws = bl_get_data(bl); 118 119 regmap_write(ws->reg_map, 0xab, 0xff - backlight_get_brightness(bl)); 120 regmap_write(ws->reg_map, 0xaa, 0x01); 121 122 return 0; 123 } 124 125 static const struct backlight_ops ws_bridge_bl_ops = { 126 .update_status = ws_bridge_bl_update_status, 127 }; 128 129 static struct backlight_device *ws_bridge_create_backlight(struct ws_bridge *ws) 130 { 131 const struct backlight_properties props = { 132 .type = BACKLIGHT_RAW, 133 .brightness = 255, 134 .max_brightness = 255, 135 }; 136 struct device *dev = ws->dev; 137 138 return devm_backlight_device_register(dev, dev_name(dev), dev, ws, 139 &ws_bridge_bl_ops, &props); 140 } 141 142 static int ws_bridge_probe(struct i2c_client *i2c) 143 { 144 struct device *dev = &i2c->dev; 145 struct drm_panel *panel; 146 struct ws_bridge *ws; 147 int ret; 148 149 ws = devm_drm_bridge_alloc(dev, struct ws_bridge, bridge, &ws_bridge_bridge_funcs); 150 if (IS_ERR(ws)) 151 return PTR_ERR(ws); 152 153 ws->dev = dev; 154 155 ws->reg_map = devm_regmap_init_i2c(i2c, &ws_regmap_config); 156 if (IS_ERR(ws->reg_map)) 157 return dev_err_probe(dev, PTR_ERR(ws->reg_map), "Failed to allocate regmap\n"); 158 159 ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, &panel, NULL); 160 if (ret) 161 return dev_err_probe(dev, ret, "Failed to find remote panel\n"); 162 163 ws->next_bridge = devm_drm_panel_bridge_add(dev, panel); 164 if (IS_ERR(ws->next_bridge)) 165 return PTR_ERR(ws->next_bridge); 166 167 ws->backlight = ws_bridge_create_backlight(ws); 168 if (IS_ERR(ws->backlight)) { 169 ret = PTR_ERR(ws->backlight); 170 dev_err(dev, "Failed to create backlight: %d\n", ret); 171 return ret; 172 } 173 174 regmap_write(ws->reg_map, 0xc0, 0x01); 175 regmap_write(ws->reg_map, 0xc2, 0x01); 176 regmap_write(ws->reg_map, 0xac, 0x01); 177 178 ws->bridge.type = DRM_MODE_CONNECTOR_DPI; 179 ws->bridge.of_node = dev->of_node; 180 devm_drm_bridge_add(dev, &ws->bridge); 181 182 return 0; 183 } 184 185 static const struct of_device_id ws_bridge_of_ids[] = { 186 {.compatible = "waveshare,dsi2dpi",}, 187 { } 188 }; 189 190 MODULE_DEVICE_TABLE(of, ws_bridge_of_ids); 191 192 static struct i2c_driver ws_bridge_driver = { 193 .driver = { 194 .name = "ws_dsi2dpi", 195 .of_match_table = ws_bridge_of_ids, 196 }, 197 .probe = ws_bridge_probe, 198 }; 199 module_i2c_driver(ws_bridge_driver); 200 201 MODULE_AUTHOR("Joseph Guo <qijian.guo@nxp.com>"); 202 MODULE_DESCRIPTION("Waveshare DSI2DPI bridge driver"); 203 MODULE_LICENSE("GPL"); 204