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