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