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_graph.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regulator/consumer.h>
  13
  14 #include <drm/drm_atomic_helper.h>
  15 #include <drm/drm_bridge.h>
  16 #include <drm/drm_of.h>
  17 #include <drm/drm_panel.h>
  18
  19 struct lvds_codec {
  20         struct device *dev;
  21         struct drm_bridge bridge;
  22         struct drm_bridge *panel_bridge;
  23         struct drm_bridge_timings timings;
  24         struct regulator *vcc;
  25         struct gpio_desc *powerdown_gpio;
  26         u32 connector_type;
  27         unsigned int bus_format;
  28 };
  29
  30 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
  31 {
  32         return container_of(bridge, struct lvds_codec, bridge);
  33 }
  34
  35 static int lvds_codec_attach(struct drm_bridge *bridge,
  36                              enum drm_bridge_attach_flags flags)
  37 {
  38         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  39
  40         return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
  41                                  bridge, flags);
  42 }
  43
  44 static void lvds_codec_enable(struct drm_bridge *bridge)
  45 {
  46         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  47         int ret;
  48
  49         ret = regulator_enable(lvds_codec->vcc);
  50         if (ret) {
  51                 dev_err(lvds_codec->dev,
  52                         "Failed to enable regulator \"vcc\": %d\n", ret);
  53                 return;
  54         }
  55
  56         if (lvds_codec->powerdown_gpio)
  57                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
  58 }
  59
  60 static void lvds_codec_disable(struct drm_bridge *bridge)
  61 {
  62         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  63         int ret;
  64
  65         if (lvds_codec->powerdown_gpio)
  66                 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
  67
  68         ret = regulator_disable(lvds_codec->vcc);
  69         if (ret)
  70                 dev_err(lvds_codec->dev,
  71                         "Failed to disable regulator \"vcc\": %d\n", ret);
  72 }
  73
  74 static const struct drm_bridge_funcs funcs = {
  75         .attach = lvds_codec_attach,
  76         .enable = lvds_codec_enable,
  77         .disable = lvds_codec_disable,
  78 };
  79
  80 #define MAX_INPUT_SEL_FORMATS 1
  81 static u32 *
  82 lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
  83                                      struct drm_bridge_state *bridge_state,
  84                                      struct drm_crtc_state *crtc_state,
  85                                      struct drm_connector_state *conn_state,
  86                                      u32 output_fmt,
  87                                      unsigned int *num_input_fmts)
  88 {
  89         struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
  90         u32 *input_fmts;
  91
  92         *num_input_fmts = 0;
  93
  94         input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
  95                              GFP_KERNEL);
  96         if (!input_fmts)
  97                 return NULL;
  98
  99         input_fmts[0] = lvds_codec->bus_format;
 100         *num_input_fmts = MAX_INPUT_SEL_FORMATS;
 101
 102         return input_fmts;
 103 }
 104
 105 static const struct drm_bridge_funcs funcs_decoder = {
 106         .attach = lvds_codec_attach,
 107         .enable = lvds_codec_enable,
 108         .disable = lvds_codec_disable,
 109         .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 110         .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 111         .atomic_reset = drm_atomic_helper_bridge_reset,
 112         .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
 113 };
 114
 115 static int lvds_codec_probe(struct platform_device *pdev)
 116 {
 117         struct device *dev = &pdev->dev;
 118         struct device_node *panel_node;
 119         struct device_node *bus_node;
 120         struct drm_panel *panel;
 121         struct lvds_codec *lvds_codec;
 122         u32 val;
 123         int ret;
 124
 125         lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
 126         if (!lvds_codec)
 127                 return -ENOMEM;
 128
 129         lvds_codec->dev = &pdev->dev;
 130         lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
 131
 132         lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
 133         if (IS_ERR(lvds_codec->vcc))
 134                 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
 135                                      "Unable to get \"vcc\" supply\n");
 136
 137         lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
 138                                                              GPIOD_OUT_HIGH);
 139         if (IS_ERR(lvds_codec->powerdown_gpio))
 140                 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
 141                                      "powerdown GPIO failure\n");
 142
 143         /* Locate the panel DT node. */
 144         panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
 145         if (!panel_node) {
 146                 dev_dbg(dev, "panel DT node not found\n");
 147                 return -ENXIO;
 148         }
 149
 150         panel = of_drm_find_panel(panel_node);
 151         of_node_put(panel_node);
 152         if (IS_ERR(panel)) {
 153                 dev_dbg(dev, "panel not found, deferring probe\n");
 154                 return PTR_ERR(panel);
 155         }
 156
 157         lvds_codec->panel_bridge =
 158                 devm_drm_panel_bridge_add_typed(dev, panel,
 159                                                 lvds_codec->connector_type);
 160         if (IS_ERR(lvds_codec->panel_bridge))
 161                 return PTR_ERR(lvds_codec->panel_bridge);
 162
 163         lvds_codec->bridge.funcs = &funcs;
 164
 165         /*
 166          * Decoder input LVDS format is a property of the decoder chip or even
 167          * its strapping. Handle data-mapping the same way lvds-panel does. In
 168          * case data-mapping is not present, do nothing, since there are still
 169          * legacy bindings which do not specify this property.
 170          */
 171         if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
 172                 bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
 173                 if (!bus_node) {
 174                         dev_dbg(dev, "bus DT node not found\n");
 175                         return -ENXIO;
 176                 }
 177
 178                 ret = drm_of_lvds_get_data_mapping(bus_node);
 179                 of_node_put(bus_node);
 180                 if (ret == -ENODEV) {
 181                         dev_warn(dev, "missing 'data-mapping' DT property\n");
 182                 } else if (ret < 0) {
 183                         dev_err(dev, "invalid 'data-mapping' DT property\n");
 184                         return ret;
 185                 } else {
 186                         lvds_codec->bus_format = ret;
 187                         lvds_codec->bridge.funcs = &funcs_decoder;
 188                 }
 189         }
 190
 191         /*
 192          * Encoder might sample data on different clock edge than the display,
 193          * for example OnSemi FIN3385 has a dedicated strapping pin to select
 194          * the sampling edge.
 195          */
 196         if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
 197             !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
 198                 lvds_codec->timings.input_bus_flags = val ?
 199                         DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
 200                         DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
 201         }
 202
 203         /*
 204          * The panel_bridge bridge is attached to the panel's of_node,
 205          * but we need a bridge attached to our of_node for our user
 206          * to look up.
 207          */
 208         lvds_codec->bridge.of_node = dev->of_node;
 209         lvds_codec->bridge.timings = &lvds_codec->timings;
 210         drm_bridge_add(&lvds_codec->bridge);
 211
 212         platform_set_drvdata(pdev, lvds_codec);
 213
 214         return 0;
 215 }
 216
 217 static void lvds_codec_remove(struct platform_device *pdev)
 218 {
 219         struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
 220
 221         drm_bridge_remove(&lvds_codec->bridge);
 222 }
 223
 224 static const struct of_device_id lvds_codec_match[] = {
 225         {
 226                 .compatible = "lvds-decoder",
 227                 .data = (void *)DRM_MODE_CONNECTOR_DPI,
 228         },
 229         {
 230                 .compatible = "lvds-encoder",
 231                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 232         },
 233         {
 234                 .compatible = "thine,thc63lvdm83d",
 235                 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
 236         },
 237         {},
 238 };
 239 MODULE_DEVICE_TABLE(of, lvds_codec_match);
 240
 241 static struct platform_driver lvds_codec_driver = {
 242         .probe  = lvds_codec_probe,
 243         .remove_new = lvds_codec_remove,
 244         .driver         = {
 245                 .name           = "lvds-codec",
 246                 .of_match_table = lvds_codec_match,
 247         },
 248 };
 249 module_platform_driver(lvds_codec_driver);
 250
 251 MODULE_AUTHOR("Laurent Pinchart <[email protected]>");
 252 MODULE_DESCRIPTION("LVDS encoders and decoders");
 253 MODULE_LICENSE("GPL");