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.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 drm_display_mode dmode;
  34         u32 bus_flags;
  35         unsigned int bus_format;
  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_duplicate(connector->dev, &lvds->dmode);
  91         if (!mode)
  92                 return 0;
  93
  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->dmode.width_mm;
  98         connector->display_info.height_mm = lvds->dmode.height_mm;
  99         drm_display_info_set_bus_formats(&connector->display_info,
 100                                          &lvds->bus_format, 1);
 101         connector->display_info.bus_flags = lvds->bus_flags;
 102
 103         /*
 104          * TODO: Remove once all drm drivers call
 105          * drm_connector_set_orientation_from_panel()
 106          */
 107         drm_connector_set_panel_orientation(connector, lvds->orientation);
 108
 109         return 1;
 110 }
 111
 112 static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel)
 113 {
 114         struct panel_lvds *lvds = to_panel_lvds(panel);
 115
 116         return lvds->orientation;
 117 }
 118
 119 static const struct drm_panel_funcs panel_lvds_funcs = {
 120         .unprepare = panel_lvds_unprepare,
 121         .prepare = panel_lvds_prepare,
 122         .get_modes = panel_lvds_get_modes,
 123         .get_orientation = panel_lvds_get_orientation,
 124 };
 125
 126 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
 127 {
 128         struct device_node *np = lvds->dev->of_node;
 129         int ret;
 130
 131         ret = of_drm_get_panel_orientation(np, &lvds->orientation);
 132         if (ret < 0) {
 133                 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
 134                 return ret;
 135         }
 136
 137         ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags);
 138         if (ret < 0) {
 139                 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
 140                         np, ret);
 141                 return ret;
 142         }
 143
 144         of_property_read_string(np, "label", &lvds->label);
 145
 146         ret = drm_of_lvds_get_data_mapping(np);
 147         if (ret < 0) {
 148                 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
 149                         np, "data-mapping");
 150                 return ret;
 151         }
 152
 153         lvds->bus_format = ret;
 154
 155         lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ?
 156                            DRM_BUS_FLAG_DATA_LSB_TO_MSB :
 157                            DRM_BUS_FLAG_DATA_MSB_TO_LSB;
 158
 159         return 0;
 160 }
 161
 162 static int panel_lvds_probe(struct platform_device *pdev)
 163 {
 164         struct panel_lvds *lvds;
 165         int ret;
 166
 167         lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
 168         if (!lvds)
 169                 return -ENOMEM;
 170
 171         lvds->dev = &pdev->dev;
 172
 173         ret = panel_lvds_parse_dt(lvds);
 174         if (ret < 0)
 175                 return ret;
 176
 177         lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
 178         if (IS_ERR(lvds->supply)) {
 179                 ret = PTR_ERR(lvds->supply);
 180
 181                 if (ret != -ENODEV) {
 182                         if (ret != -EPROBE_DEFER)
 183                                 dev_err(lvds->dev, "failed to request regulator: %d\n",
 184                                         ret);
 185                         return ret;
 186                 }
 187
 188                 lvds->supply = NULL;
 189         }
 190
 191         /* Get GPIOs and backlight controller. */
 192         lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
 193                                                      GPIOD_OUT_LOW);
 194         if (IS_ERR(lvds->enable_gpio)) {
 195                 ret = PTR_ERR(lvds->enable_gpio);
 196                 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
 197                         "enable", ret);
 198                 return ret;
 199         }
 200
 201         lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
 202                                                      GPIOD_OUT_HIGH);
 203         if (IS_ERR(lvds->reset_gpio)) {
 204                 ret = PTR_ERR(lvds->reset_gpio);
 205                 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
 206                         "reset", ret);
 207                 return ret;
 208         }
 209
 210         /*
 211          * TODO: Handle all power supplies specified in the DT node in a generic
 212          * way for panels that don't care about power supply ordering. LVDS
 213          * panels that require a specific power sequence will need a dedicated
 214          * driver.
 215          */
 216
 217         /* Register the panel. */
 218         drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
 219                        DRM_MODE_CONNECTOR_LVDS);
 220
 221         ret = drm_panel_of_backlight(&lvds->panel);
 222         if (ret)
 223                 return ret;
 224
 225         drm_panel_add(&lvds->panel);
 226
 227         dev_set_drvdata(lvds->dev, lvds);
 228         return 0;
 229 }
 230
 231 static void panel_lvds_remove(struct platform_device *pdev)
 232 {
 233         struct panel_lvds *lvds = platform_get_drvdata(pdev);
 234
 235         drm_panel_remove(&lvds->panel);
 236
 237         drm_panel_disable(&lvds->panel);
 238 }
 239
 240 static const struct of_device_id panel_lvds_of_table[] = {
 241         { .compatible = "panel-lvds", },
 242         { /* Sentinel */ },
 243 };
 244
 245 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
 246
 247 static struct platform_driver panel_lvds_driver = {
 248         .probe          = panel_lvds_probe,
 249         .remove         = panel_lvds_remove,
 250         .driver         = {
 251                 .name   = "panel-lvds",
 252                 .of_match_table = panel_lvds_of_table,
 253         },
 254 };
 255
 256 module_platform_driver(panel_lvds_driver);
 257
 258 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 259 MODULE_DESCRIPTION("LVDS Panel Driver");
 260 MODULE_LICENSE("GPL");