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