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
  14 #include <drm/drm_bridge.h>
  15 #include <drm/drm_panel.h>
  16
  17 struct lvds_codec {
  18         struct drm_bridge bridge;
  19         struct drm_bridge *panel_bridge;
  20         struct gpio_desc *powerdown_gpio;
  21         u32 connector_type;
  22 };
  23
  24 static int lvds_codec_attach(struct drm_bridge *bridge)
  25 {
  26         struct lvds_codec *lvds_codec = container_of(bridge,
  27                                                      struct lvds_codec, bridge);
  28
  29         return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
  30                                  bridge);
  31 }
  32
  33 static void lvds_codec_enable(struct drm_bridge *bridge)
  34 {
  35         struct lvds_codec *lvds_codec = container_of(bridge,
  36                                                      struct lvds_codec, bridge);
  37
  38         if (lvds_codec->powerdown_gpio)
  39                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
  40 }
  41
  42 static void lvds_codec_disable(struct drm_bridge *bridge)
  43 {
  44         struct lvds_codec *lvds_codec = container_of(bridge,
  45                                                      struct lvds_codec, bridge);
  46
  47         if (lvds_codec->powerdown_gpio)
  48                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
  49 }
  50
  51 static struct drm_bridge_funcs funcs = {
  52         .attach = lvds_codec_attach,
  53         .enable = lvds_codec_enable,
  54         .disable = lvds_codec_disable,
  55 };
  56
  57 static int lvds_codec_probe(struct platform_device *pdev)
  58 {
  59         struct device *dev = &pdev->dev;
  60         struct device_node *panel_node;
  61         struct drm_panel *panel;
  62         struct lvds_codec *lvds_codec;
  63
  64         lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
  65         if (!lvds_codec)
  66                 return -ENOMEM;
  67
  68         lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
  69         lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
  70                                                              GPIOD_OUT_HIGH);
  71         if (IS_ERR(lvds_codec->powerdown_gpio)) {
  72                 int err = PTR_ERR(lvds_codec->powerdown_gpio);
  73
  74                 if (err != -EPROBE_DEFER)
  75                         dev_err(dev, "powerdown GPIO failure: %d\n", err);
  76                 return err;
  77         }
  78
  79         /* Locate the panel DT node. */
  80         panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
  81         if (!panel_node) {
  82                 dev_dbg(dev, "panel DT node not found\n");
  83                 return -ENXIO;
  84         }
  85
  86         panel = of_drm_find_panel(panel_node);
  87         of_node_put(panel_node);
  88         if (IS_ERR(panel)) {
  89                 dev_dbg(dev, "panel not found, deferring probe\n");
  90                 return PTR_ERR(panel);
  91         }
  92
  93         lvds_codec->panel_bridge =
  94                 devm_drm_panel_bridge_add_typed(dev, panel,
  95                                                 lvds_codec->connector_type);
  96         if (IS_ERR(lvds_codec->panel_bridge))
  97                 return PTR_ERR(lvds_codec->panel_bridge);
  98
  99         /*
 100          * The panel_bridge bridge is attached to the panel's of_node,
 101          * but we need a bridge attached to our of_node for our user
 102          * to look up.
 103          */
 104         lvds_codec->bridge.of_node = dev->of_node;
 105         lvds_codec->bridge.funcs = &funcs;
 106         drm_bridge_add(&lvds_codec->bridge);
 107
 108         platform_set_drvdata(pdev, lvds_codec);
 109
 110         return 0;
 111 }
 112
 113 static int lvds_codec_remove(struct platform_device *pdev)
 114 {
 115         struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
 116
 117         drm_bridge_remove(&lvds_codec->bridge);
 118
 119         return 0;
 120 }
 121
 122 static const struct of_device_id lvds_codec_match[] = {
 123         {
 124                 .compatible = "lvds-decoder",
 125                 .data = (void *)DRM_MODE_CONNECTOR_DPI,
 126         },
 127         {
 128                 .compatible = "lvds-encoder",
 129                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 130         },
 131         {
 132                 .compatible = "thine,thc63lvdm83d",
 133                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 134         },
 135         {},
 136 };
 137 MODULE_DEVICE_TABLE(of, lvds_codec_match);
 138
 139 static struct platform_driver lvds_codec_driver = {
 140         .probe  = lvds_codec_probe,
 141         .remove = lvds_codec_remove,
 142         .driver         = {
 143                 .name           = "lvds-codec",
 144                 .of_match_table = lvds_codec_match,
 145         },
 146 };
 147 module_platform_driver(lvds_codec_driver);
 148
 149 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 150 MODULE_DESCRIPTION("LVDS encoders and decoders");
 151 MODULE_LICENSE("GPL");