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