1 /* 2 * Generic LVDS panel driver 3 * 4 * Copyright (C) 2016 Laurent Pinchart 5 * Copyright (C) 2016 Renesas Electronics Corporation 6 * 7 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com) 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 */ 14 15 #include <linux/backlight.h> 16 #include <linux/gpio/consumer.h> 17 #include <linux/module.h> 18 #include <linux/of_platform.h> 19 #include <linux/platform_device.h> 20 #include <linux/regulator/consumer.h> 21 #include <linux/slab.h> 22 23 #include <drm/drmP.h> 24 #include <drm/drm_crtc.h> 25 #include <drm/drm_panel.h> 26 27 #include <video/display_timing.h> 28 #include <video/of_display_timing.h> 29 #include <video/videomode.h> 30 31 struct panel_lvds { 32 struct drm_panel panel; 33 struct device *dev; 34 35 const char *label; 36 unsigned int width; 37 unsigned int height; 38 struct videomode video_mode; 39 unsigned int bus_format; 40 bool data_mirror; 41 42 struct backlight_device *backlight; 43 struct regulator *supply; 44 45 struct gpio_desc *enable_gpio; 46 struct gpio_desc *reset_gpio; 47 }; 48 49 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel) 50 { 51 return container_of(panel, struct panel_lvds, panel); 52 } 53 54 static int panel_lvds_disable(struct drm_panel *panel) 55 { 56 struct panel_lvds *lvds = to_panel_lvds(panel); 57 58 if (lvds->backlight) { 59 lvds->backlight->props.power = FB_BLANK_POWERDOWN; 60 lvds->backlight->props.state |= BL_CORE_FBBLANK; 61 backlight_update_status(lvds->backlight); 62 } 63 64 return 0; 65 } 66 67 static int panel_lvds_unprepare(struct drm_panel *panel) 68 { 69 struct panel_lvds *lvds = to_panel_lvds(panel); 70 71 if (lvds->enable_gpio) 72 gpiod_set_value_cansleep(lvds->enable_gpio, 0); 73 74 if (lvds->supply) 75 regulator_disable(lvds->supply); 76 77 return 0; 78 } 79 80 static int panel_lvds_prepare(struct drm_panel *panel) 81 { 82 struct panel_lvds *lvds = to_panel_lvds(panel); 83 84 if (lvds->supply) { 85 int err; 86 87 err = regulator_enable(lvds->supply); 88 if (err < 0) { 89 dev_err(lvds->dev, "failed to enable supply: %d\n", 90 err); 91 return err; 92 } 93 } 94 95 if (lvds->enable_gpio) 96 gpiod_set_value_cansleep(lvds->enable_gpio, 1); 97 98 return 0; 99 } 100 101 static int panel_lvds_enable(struct drm_panel *panel) 102 { 103 struct panel_lvds *lvds = to_panel_lvds(panel); 104 105 if (lvds->backlight) { 106 lvds->backlight->props.state &= ~BL_CORE_FBBLANK; 107 lvds->backlight->props.power = FB_BLANK_UNBLANK; 108 backlight_update_status(lvds->backlight); 109 } 110 111 return 0; 112 } 113 114 static int panel_lvds_get_modes(struct drm_panel *panel) 115 { 116 struct panel_lvds *lvds = to_panel_lvds(panel); 117 struct drm_connector *connector = lvds->panel.connector; 118 struct drm_display_mode *mode; 119 120 mode = drm_mode_create(lvds->panel.drm); 121 if (!mode) 122 return 0; 123 124 drm_display_mode_from_videomode(&lvds->video_mode, mode); 125 mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; 126 drm_mode_probed_add(connector, mode); 127 128 connector->display_info.width_mm = lvds->width; 129 connector->display_info.height_mm = lvds->height; 130 drm_display_info_set_bus_formats(&connector->display_info, 131 &lvds->bus_format, 1); 132 connector->display_info.bus_flags = lvds->data_mirror 133 ? DRM_BUS_FLAG_DATA_LSB_TO_MSB 134 : DRM_BUS_FLAG_DATA_MSB_TO_LSB; 135 136 return 1; 137 } 138 139 static const struct drm_panel_funcs panel_lvds_funcs = { 140 .disable = panel_lvds_disable, 141 .unprepare = panel_lvds_unprepare, 142 .prepare = panel_lvds_prepare, 143 .enable = panel_lvds_enable, 144 .get_modes = panel_lvds_get_modes, 145 }; 146 147 static int panel_lvds_parse_dt(struct panel_lvds *lvds) 148 { 149 struct device_node *np = lvds->dev->of_node; 150 struct display_timing timing; 151 const char *mapping; 152 int ret; 153 154 ret = of_get_display_timing(np, "panel-timing", &timing); 155 if (ret < 0) 156 return ret; 157 158 videomode_from_timing(&timing, &lvds->video_mode); 159 160 ret = of_property_read_u32(np, "width-mm", &lvds->width); 161 if (ret < 0) { 162 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 163 np, "width-mm"); 164 return -ENODEV; 165 } 166 ret = of_property_read_u32(np, "height-mm", &lvds->height); 167 if (ret < 0) { 168 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 169 np, "height-mm"); 170 return -ENODEV; 171 } 172 173 of_property_read_string(np, "label", &lvds->label); 174 175 ret = of_property_read_string(np, "data-mapping", &mapping); 176 if (ret < 0) { 177 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 178 np, "data-mapping"); 179 return -ENODEV; 180 } 181 182 if (!strcmp(mapping, "jeida-18")) { 183 lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG; 184 } else if (!strcmp(mapping, "jeida-24")) { 185 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA; 186 } else if (!strcmp(mapping, "vesa-24")) { 187 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG; 188 } else { 189 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 190 np, "data-mapping"); 191 return -EINVAL; 192 } 193 194 lvds->data_mirror = of_property_read_bool(np, "data-mirror"); 195 196 return 0; 197 } 198 199 static int panel_lvds_probe(struct platform_device *pdev) 200 { 201 struct panel_lvds *lvds; 202 struct device_node *np; 203 int ret; 204 205 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); 206 if (!lvds) 207 return -ENOMEM; 208 209 lvds->dev = &pdev->dev; 210 211 ret = panel_lvds_parse_dt(lvds); 212 if (ret < 0) 213 return ret; 214 215 lvds->supply = devm_regulator_get_optional(lvds->dev, "power"); 216 if (IS_ERR(lvds->supply)) { 217 ret = PTR_ERR(lvds->supply); 218 219 if (ret != -ENODEV) { 220 if (ret != -EPROBE_DEFER) 221 dev_err(lvds->dev, "failed to request regulator: %d\n", 222 ret); 223 return ret; 224 } 225 226 lvds->supply = NULL; 227 } 228 229 /* Get GPIOs and backlight controller. */ 230 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable", 231 GPIOD_OUT_LOW); 232 if (IS_ERR(lvds->enable_gpio)) { 233 ret = PTR_ERR(lvds->enable_gpio); 234 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 235 "enable", ret); 236 return ret; 237 } 238 239 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset", 240 GPIOD_OUT_HIGH); 241 if (IS_ERR(lvds->reset_gpio)) { 242 ret = PTR_ERR(lvds->reset_gpio); 243 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 244 "reset", ret); 245 return ret; 246 } 247 248 np = of_parse_phandle(lvds->dev->of_node, "backlight", 0); 249 if (np) { 250 lvds->backlight = of_find_backlight_by_node(np); 251 of_node_put(np); 252 253 if (!lvds->backlight) 254 return -EPROBE_DEFER; 255 } 256 257 /* 258 * TODO: Handle all power supplies specified in the DT node in a generic 259 * way for panels that don't care about power supply ordering. LVDS 260 * panels that require a specific power sequence will need a dedicated 261 * driver. 262 */ 263 264 /* Register the panel. */ 265 drm_panel_init(&lvds->panel); 266 lvds->panel.dev = lvds->dev; 267 lvds->panel.funcs = &panel_lvds_funcs; 268 269 ret = drm_panel_add(&lvds->panel); 270 if (ret < 0) 271 goto error; 272 273 dev_set_drvdata(lvds->dev, lvds); 274 return 0; 275 276 error: 277 put_device(&lvds->backlight->dev); 278 return ret; 279 } 280 281 static int panel_lvds_remove(struct platform_device *pdev) 282 { 283 struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev); 284 285 drm_panel_detach(&lvds->panel); 286 drm_panel_remove(&lvds->panel); 287 288 panel_lvds_disable(&lvds->panel); 289 290 if (lvds->backlight) 291 put_device(&lvds->backlight->dev); 292 293 return 0; 294 } 295 296 static const struct of_device_id panel_lvds_of_table[] = { 297 { .compatible = "panel-lvds", }, 298 { /* Sentinel */ }, 299 }; 300 301 MODULE_DEVICE_TABLE(of, panel_lvds_of_table); 302 303 static struct platform_driver panel_lvds_driver = { 304 .probe = panel_lvds_probe, 305 .remove = panel_lvds_remove, 306 .driver = { 307 .name = "panel-lvds", 308 .of_match_table = panel_lvds_of_table, 309 }, 310 }; 311 312 module_platform_driver(panel_lvds_driver); 313 314 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 315 MODULE_DESCRIPTION("LVDS Panel Driver"); 316 MODULE_LICENSE("GPL"); 317