drivers/gpu/drm/panel/panel-lvds.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Generic LVDS panel driver
   4  *
   5  * Copyright (C) 2016 Laurent Pinchart
   6  * Copyright (C) 2016 Renesas Electronics Corporation
   7  *
   8  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   9  */
  10
  11 #include <linux/backlight.h>
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/module.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regulator/consumer.h>
  17 #include <linux/slab.h>
  18
  19 #include <video/display_timing.h>
  20 #include <video/of_display_timing.h>
  21 #include <video/videomode.h>
  22
  23 #include <drm/drm_crtc.h>
  24 #include <drm/drm_panel.h>
  25
  26 struct panel_lvds {
  27         struct drm_panel panel;
  28         struct device *dev;
  29
  30         const char *label;
  31         unsigned int width;
  32         unsigned int height;
  33         struct videomode video_mode;
  34         unsigned int bus_format;
  35         bool data_mirror;
  36
  37         struct backlight_device *backlight;
  38         struct regulator *supply;
  39
  40         struct gpio_desc *enable_gpio;
  41         struct gpio_desc *reset_gpio;
  42 };
  43
  44 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
  45 {
  46         return container_of(panel, struct panel_lvds, panel);
  47 }
  48
  49 static int panel_lvds_disable(struct drm_panel *panel)
  50 {
  51         struct panel_lvds *lvds = to_panel_lvds(panel);
  52
  53         if (lvds->backlight) {
  54                 lvds->backlight->props.power = FB_BLANK_POWERDOWN;
  55                 lvds->backlight->props.state |= BL_CORE_FBBLANK;
  56                 backlight_update_status(lvds->backlight);
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int panel_lvds_unprepare(struct drm_panel *panel)
  63 {
  64         struct panel_lvds *lvds = to_panel_lvds(panel);
  65
  66         if (lvds->enable_gpio)
  67                 gpiod_set_value_cansleep(lvds->enable_gpio, 0);
  68
  69         if (lvds->supply)
  70                 regulator_disable(lvds->supply);
  71
  72         return 0;
  73 }
  74
  75 static int panel_lvds_prepare(struct drm_panel *panel)
  76 {
  77         struct panel_lvds *lvds = to_panel_lvds(panel);
  78
  79         if (lvds->supply) {
  80                 int err;
  81
  82                 err = regulator_enable(lvds->supply);
  83                 if (err < 0) {
  84                         dev_err(lvds->dev, "failed to enable supply: %d\n",
  85                                 err);
  86                         return err;
  87                 }
  88         }
  89
  90         if (lvds->enable_gpio)
  91                 gpiod_set_value_cansleep(lvds->enable_gpio, 1);
  92
  93         return 0;
  94 }
  95
  96 static int panel_lvds_enable(struct drm_panel *panel)
  97 {
  98         struct panel_lvds *lvds = to_panel_lvds(panel);
  99
 100         if (lvds->backlight) {
 101                 lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
 102                 lvds->backlight->props.power = FB_BLANK_UNBLANK;
 103                 backlight_update_status(lvds->backlight);
 104         }
 105
 106         return 0;
 107 }
 108
 109 static int panel_lvds_get_modes(struct drm_panel *panel)
 110 {
 111         struct panel_lvds *lvds = to_panel_lvds(panel);
 112         struct drm_connector *connector = lvds->panel.connector;
 113         struct drm_display_mode *mode;
 114
 115         mode = drm_mode_create(lvds->panel.drm);
 116         if (!mode)
 117                 return 0;
 118
 119         drm_display_mode_from_videomode(&lvds->video_mode, mode);
 120         mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
 121         drm_mode_probed_add(connector, mode);
 122
 123         connector->display_info.width_mm = lvds->width;
 124         connector->display_info.height_mm = lvds->height;
 125         drm_display_info_set_bus_formats(&connector->display_info,
 126                                          &lvds->bus_format, 1);
 127         connector->display_info.bus_flags = lvds->data_mirror
 128                                           ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
 129                                           : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
 130
 131         return 1;
 132 }
 133
 134 static const struct drm_panel_funcs panel_lvds_funcs = {
 135         .disable = panel_lvds_disable,
 136         .unprepare = panel_lvds_unprepare,
 137         .prepare = panel_lvds_prepare,
 138         .enable = panel_lvds_enable,
 139         .get_modes = panel_lvds_get_modes,
 140 };
 141
 142 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
 143 {
 144         struct device_node *np = lvds->dev->of_node;
 145         struct display_timing timing;
 146         const char *mapping;
 147         int ret;
 148
 149         ret = of_get_display_timing(np, "panel-timing", &timing);
 150         if (ret < 0) {
 151                 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
 152                         np, ret);
 153                 return ret;
 154         }
 155
 156         videomode_from_timing(&timing, &lvds->video_mode);
 157
 158         ret = of_property_read_u32(np, "width-mm", &lvds->width);
 159         if (ret < 0) {
 160                 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
 161                         np, "width-mm");
 162                 return -ENODEV;
 163         }
 164         ret = of_property_read_u32(np, "height-mm", &lvds->height);
 165         if (ret < 0) {
 166                 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
 167                         np, "height-mm");
 168                 return -ENODEV;
 169         }
 170
 171         of_property_read_string(np, "label", &lvds->label);
 172
 173         ret = of_property_read_string(np, "data-mapping", &mapping);
 174         if (ret < 0) {
 175                 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
 176                         np, "data-mapping");
 177                 return -ENODEV;
 178         }
 179
 180         if (!strcmp(mapping, "jeida-18")) {
 181                 lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
 182         } else if (!strcmp(mapping, "jeida-24")) {
 183                 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
 184         } else if (!strcmp(mapping, "vesa-24")) {
 185                 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
 186         } else {
 187                 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
 188                         np, "data-mapping");
 189                 return -EINVAL;
 190         }
 191
 192         lvds->data_mirror = of_property_read_bool(np, "data-mirror");
 193
 194         return 0;
 195 }
 196
 197 static int panel_lvds_probe(struct platform_device *pdev)
 198 {
 199         struct panel_lvds *lvds;
 200         int ret;
 201
 202         lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
 203         if (!lvds)
 204                 return -ENOMEM;
 205
 206         lvds->dev = &pdev->dev;
 207
 208         ret = panel_lvds_parse_dt(lvds);
 209         if (ret < 0)
 210                 return ret;
 211
 212         lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
 213         if (IS_ERR(lvds->supply)) {
 214                 ret = PTR_ERR(lvds->supply);
 215
 216                 if (ret != -ENODEV) {
 217                         if (ret != -EPROBE_DEFER)
 218                                 dev_err(lvds->dev, "failed to request regulator: %d\n",
 219                                         ret);
 220                         return ret;
 221                 }
 222
 223                 lvds->supply = NULL;
 224         }
 225
 226         /* Get GPIOs and backlight controller. */
 227         lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
 228                                                      GPIOD_OUT_LOW);
 229         if (IS_ERR(lvds->enable_gpio)) {
 230                 ret = PTR_ERR(lvds->enable_gpio);
 231                 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
 232                         "enable", ret);
 233                 return ret;
 234         }
 235
 236         lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
 237                                                      GPIOD_OUT_HIGH);
 238         if (IS_ERR(lvds->reset_gpio)) {
 239                 ret = PTR_ERR(lvds->reset_gpio);
 240                 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
 241                         "reset", ret);
 242                 return ret;
 243         }
 244
 245         lvds->backlight = devm_of_find_backlight(lvds->dev);
 246         if (IS_ERR(lvds->backlight))
 247                 return PTR_ERR(lvds->backlight);
 248
 249         /*
 250          * TODO: Handle all power supplies specified in the DT node in a generic
 251          * way for panels that don't care about power supply ordering. LVDS
 252          * panels that require a specific power sequence will need a dedicated
 253          * driver.
 254          */
 255
 256         /* Register the panel. */
 257         drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
 258                        DRM_MODE_CONNECTOR_LVDS);
 259
 260         ret = drm_panel_add(&lvds->panel);
 261         if (ret < 0)
 262                 return ret;
 263
 264         dev_set_drvdata(lvds->dev, lvds);
 265         return 0;
 266 }
 267
 268 static int panel_lvds_remove(struct platform_device *pdev)
 269 {
 270         struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);
 271
 272         drm_panel_remove(&lvds->panel);
 273
 274         panel_lvds_disable(&lvds->panel);
 275
 276         return 0;
 277 }
 278
 279 static const struct of_device_id panel_lvds_of_table[] = {
 280         { .compatible = "panel-lvds", },
 281         { /* Sentinel */ },
 282 };
 283
 284 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
 285
 286 static struct platform_driver panel_lvds_driver = {
 287         .probe          = panel_lvds_probe,
 288         .remove         = panel_lvds_remove,
 289         .driver         = {
 290                 .name   = "panel-lvds",
 291                 .of_match_table = panel_lvds_of_table,
 292         },
 293 };
 294
 295 module_platform_driver(panel_lvds_driver);
 296
 297 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 298 MODULE_DESCRIPTION("LVDS Panel Driver");
 299 MODULE_LICENSE("GPL");