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

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