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

   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_remove(&lvds->panel);
 286
 287         panel_lvds_disable(&lvds->panel);
 288
 289         if (lvds->backlight)
 290                 put_device(&lvds->backlight->dev);
 291
 292         return 0;
 293 }
 294
 295 static const struct of_device_id panel_lvds_of_table[] = {
 296         { .compatible = "panel-lvds", },
 297         { /* Sentinel */ },
 298 };
 299
 300 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
 301
 302 static struct platform_driver panel_lvds_driver = {
 303         .probe          = panel_lvds_probe,
 304         .remove         = panel_lvds_remove,
 305         .driver         = {
 306                 .name   = "panel-lvds",
 307                 .of_match_table = panel_lvds_of_table,
 308         },
 309 };
 310
 311 module_platform_driver(panel_lvds_driver);
 312
 313 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 314 MODULE_DESCRIPTION("LVDS Panel Driver");
 315 MODULE_LICENSE("GPL");