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