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