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 ret = drm_of_get_data_lanes_count_ep(dev->of_node, 0, 0, 1, 4); 70 if (ret < 0) { 71 dev_warn(dev, "Invalid or missing DSI lane count %d, falling back to 2 lanes\n", 72 ret); 73 dsi->lanes = 2; /* Old DT backward compatibility */ 74 } else { 75 dsi->lanes = ret; 76 } 77 78 ret = devm_mipi_dsi_attach(dev, dsi); 79 if (ret < 0) 80 return dev_err_probe(dev, ret, "Failed to attach dsi to host\n"); 81 82 return 0; 83 } 84 85 static int ws_bridge_bridge_attach(struct drm_bridge *bridge, 86 struct drm_encoder *encoder, 87 enum drm_bridge_attach_flags flags) 88 { 89 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 90 91 return drm_bridge_attach(encoder, ws->next_bridge, 92 &ws->bridge, flags); 93 } 94 95 static void ws_bridge_bridge_enable(struct drm_bridge *bridge) 96 { 97 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 98 99 regmap_write(ws->reg_map, 0xad, 0x01); 100 backlight_enable(ws->backlight); 101 } 102 103 static void ws_bridge_bridge_disable(struct drm_bridge *bridge) 104 { 105 struct ws_bridge *ws = bridge_to_ws_bridge(bridge); 106 107 backlight_disable(ws->backlight); 108 regmap_write(ws->reg_map, 0xad, 0x00); 109 } 110 111 static const struct drm_bridge_funcs ws_bridge_bridge_funcs = { 112 .enable = ws_bridge_bridge_enable, 113 .disable = ws_bridge_bridge_disable, 114 .attach = ws_bridge_bridge_attach, 115 }; 116 117 static int ws_bridge_bl_update_status(struct backlight_device *bl) 118 { 119 struct ws_bridge *ws = bl_get_data(bl); 120 121 regmap_write(ws->reg_map, 0xab, 0xff - backlight_get_brightness(bl)); 122 regmap_write(ws->reg_map, 0xaa, 0x01); 123 124 return 0; 125 } 126 127 static const struct backlight_ops ws_bridge_bl_ops = { 128 .update_status = ws_bridge_bl_update_status, 129 }; 130 131 static struct backlight_device *ws_bridge_create_backlight(struct ws_bridge *ws) 132 { 133 const struct backlight_properties props = { 134 .type = BACKLIGHT_RAW, 135 .brightness = 255, 136 .max_brightness = 255, 137 }; 138 struct device *dev = ws->dev; 139 140 return devm_backlight_device_register(dev, dev_name(dev), dev, ws, 141 &ws_bridge_bl_ops, &props); 142 } 143 144 static int ws_bridge_probe(struct i2c_client *i2c) 145 { 146 struct device *dev = &i2c->dev; 147 struct drm_panel *panel; 148 struct ws_bridge *ws; 149 int ret; 150 151 ws = devm_drm_bridge_alloc(dev, struct ws_bridge, bridge, &ws_bridge_bridge_funcs); 152 if (IS_ERR(ws)) 153 return PTR_ERR(ws); 154 155 ws->dev = dev; 156 157 ws->reg_map = devm_regmap_init_i2c(i2c, &ws_regmap_config); 158 if (IS_ERR(ws->reg_map)) 159 return dev_err_probe(dev, PTR_ERR(ws->reg_map), "Failed to allocate regmap\n"); 160 161 ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, &panel, NULL); 162 if (ret) 163 return dev_err_probe(dev, ret, "Failed to find remote panel\n"); 164 165 ws->next_bridge = devm_drm_panel_bridge_add(dev, panel); 166 if (IS_ERR(ws->next_bridge)) 167 return PTR_ERR(ws->next_bridge); 168 169 ws->backlight = ws_bridge_create_backlight(ws); 170 if (IS_ERR(ws->backlight)) { 171 ret = PTR_ERR(ws->backlight); 172 dev_err(dev, "Failed to create backlight: %d\n", ret); 173 return ret; 174 } 175 176 regmap_write(ws->reg_map, 0xc0, 0x01); 177 regmap_write(ws->reg_map, 0xc2, 0x01); 178 regmap_write(ws->reg_map, 0xac, 0x01); 179 180 ws->bridge.type = DRM_MODE_CONNECTOR_DPI; 181 ws->bridge.of_node = dev->of_node; 182 devm_drm_bridge_add(dev, &ws->bridge); 183 184 return ws_bridge_attach_dsi(ws); 185 } 186 187 static const struct of_device_id ws_bridge_of_ids[] = { 188 {.compatible = "waveshare,dsi2dpi",}, 189 { } 190 }; 191 192 MODULE_DEVICE_TABLE(of, ws_bridge_of_ids); 193 194 static struct i2c_driver ws_bridge_driver = { 195 .driver = { 196 .name = "ws_dsi2dpi", 197 .of_match_table = ws_bridge_of_ids, 198 }, 199 .probe = ws_bridge_probe, 200 }; 201 module_i2c_driver(ws_bridge_driver); 202 203 MODULE_AUTHOR("Joseph Guo <qijian.guo@nxp.com>"); 204 MODULE_DESCRIPTION("Waveshare DSI2DPI bridge driver"); 205 MODULE_LICENSE("GPL"); 206