drivers/gpu/drm/bridge/lvds-codec.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2019 Renesas Electronics Corporation
   4  * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   5  */
   6
   7 #include <linux/gpio/consumer.h>
   8 #include <linux/module.h>
   9 #include <linux/of.h>
  10 #include <linux/of_device.h>
  11 #include <linux/of_graph.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regulator/consumer.h>
  14
  15 #include <drm/drm_bridge.h>
  16 #include <drm/drm_panel.h>
  17
  18 struct lvds_codec {
  19         struct device *dev;
  20         struct drm_bridge bridge;
  21         struct drm_bridge *panel_bridge;
  22         struct regulator *vcc;
  23         struct gpio_desc *powerdown_gpio;
  24         u32 connector_type;
  25 };
  26
  27 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
  28 {
  29         return container_of(bridge, struct lvds_codec, bridge);
  30 }
  31
  32 static int lvds_codec_attach(struct drm_bridge *bridge,
  33                              enum drm_bridge_attach_flags flags)
  34 {
  35         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  36
  37         return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
  38                                  bridge, flags);
  39 }
  40
  41 static void lvds_codec_enable(struct drm_bridge *bridge)
  42 {
  43         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  44         int ret;
  45
  46         ret = regulator_enable(lvds_codec->vcc);
  47         if (ret) {
  48                 dev_err(lvds_codec->dev,
  49                         "Failed to enable regulator \"vcc\": %d\n", ret);
  50                 return;
  51         }
  52
  53         if (lvds_codec->powerdown_gpio)
  54                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
  55 }
  56
  57 static void lvds_codec_disable(struct drm_bridge *bridge)
  58 {
  59         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  60         int ret;
  61
  62         if (lvds_codec->powerdown_gpio)
  63                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
  64
  65         ret = regulator_disable(lvds_codec->vcc);
  66         if (ret)
  67                 dev_err(lvds_codec->dev,
  68                         "Failed to disable regulator \"vcc\": %d\n", ret);
  69 }
  70
  71 static const struct drm_bridge_funcs funcs = {
  72         .attach = lvds_codec_attach,
  73         .enable = lvds_codec_enable,
  74         .disable = lvds_codec_disable,
  75 };
  76
  77 static int lvds_codec_probe(struct platform_device *pdev)
  78 {
  79         struct device *dev = &pdev->dev;
  80         struct device_node *panel_node;
  81         struct drm_panel *panel;
  82         struct lvds_codec *lvds_codec;
  83
  84         lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
  85         if (!lvds_codec)
  86                 return -ENOMEM;
  87
  88         lvds_codec->dev = &pdev->dev;
  89         lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
  90
  91         lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
  92         if (IS_ERR(lvds_codec->vcc))
  93                 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
  94                                      "Unable to get \"vcc\" supply\n");
  95
  96         lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
  97                                                              GPIOD_OUT_HIGH);
  98         if (IS_ERR(lvds_codec->powerdown_gpio))
  99                 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
 100                                      "powerdown GPIO failure\n");
 101
 102         /* Locate the panel DT node. */
 103         panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
 104         if (!panel_node) {
 105                 dev_dbg(dev, "panel DT node not found\n");
 106                 return -ENXIO;
 107         }
 108
 109         panel = of_drm_find_panel(panel_node);
 110         of_node_put(panel_node);
 111         if (IS_ERR(panel)) {
 112                 dev_dbg(dev, "panel not found, deferring probe\n");
 113                 return PTR_ERR(panel);
 114         }
 115
 116         lvds_codec->panel_bridge =
 117                 devm_drm_panel_bridge_add_typed(dev, panel,
 118                                                 lvds_codec->connector_type);
 119         if (IS_ERR(lvds_codec->panel_bridge))
 120                 return PTR_ERR(lvds_codec->panel_bridge);
 121
 122         /*
 123          * The panel_bridge bridge is attached to the panel's of_node,
 124          * but we need a bridge attached to our of_node for our user
 125          * to look up.
 126          */
 127         lvds_codec->bridge.of_node = dev->of_node;
 128         lvds_codec->bridge.funcs = &funcs;
 129         drm_bridge_add(&lvds_codec->bridge);
 130
 131         platform_set_drvdata(pdev, lvds_codec);
 132
 133         return 0;
 134 }
 135
 136 static int lvds_codec_remove(struct platform_device *pdev)
 137 {
 138         struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
 139
 140         drm_bridge_remove(&lvds_codec->bridge);
 141
 142         return 0;
 143 }
 144
 145 static const struct of_device_id lvds_codec_match[] = {
 146         {
 147                 .compatible = "lvds-decoder",
 148                 .data = (void *)DRM_MODE_CONNECTOR_DPI,
 149         },
 150         {
 151                 .compatible = "lvds-encoder",
 152                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 153         },
 154         {
 155                 .compatible = "thine,thc63lvdm83d",
 156                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 157         },
 158         {},
 159 };
 160 MODULE_DEVICE_TABLE(of, lvds_codec_match);
 161
 162 static struct platform_driver lvds_codec_driver = {
 163         .probe  = lvds_codec_probe,
 164         .remove = lvds_codec_remove,
 165         .driver         = {
 166                 .name           = "lvds-codec",
 167                 .of_match_table = lvds_codec_match,
 168         },
 169 };
 170 module_platform_driver(lvds_codec_driver);
 171
 172 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 173 MODULE_DESCRIPTION("LVDS encoders and decoders");
 174 MODULE_LICENSE("GPL");