drm/bridge/lvds-codec.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright (C) 2019 Renesas Electronics Corporation
0004  * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
0005  */
0006
0007 #include <linux/gpio/consumer.h>
0008 #include <linux/module.h>
0009 #include <linux/of.h>
0010 #include <linux/of_device.h>
0011 #include <linux/of_graph.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/regulator/consumer.h>
0014
0015 #include <drm/drm_atomic_helper.h>
0016 #include <drm/drm_bridge.h>
0017 #include <drm/drm_of.h>
0018 #include <drm/drm_panel.h>
0019
0020 struct lvds_codec {
0021     struct device *dev;
0022     struct drm_bridge bridge;
0023     struct drm_bridge *panel_bridge;
0024     struct drm_bridge_timings timings;
0025     struct regulator *vcc;
0026     struct gpio_desc *powerdown_gpio;
0027     u32 connector_type;
0028     unsigned int bus_format;
0029 };
0030
0031 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
0032 {
0033     return container_of(bridge, struct lvds_codec, bridge);
0034 }
0035
0036 static int lvds_codec_attach(struct drm_bridge *bridge,
0037                  enum drm_bridge_attach_flags flags)
0038 {
0039     struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
0040
0041     return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
0042                  bridge, flags);
0043 }
0044
0045 static void lvds_codec_enable(struct drm_bridge *bridge)
0046 {
0047     struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
0048     int ret;
0049
0050     ret = regulator_enable(lvds_codec->vcc);
0051     if (ret) {
0052         dev_err(lvds_codec->dev,
0053             "Failed to enable regulator \"vcc\": %d\n", ret);
0054         return;
0055     }
0056
0057     if (lvds_codec->powerdown_gpio)
0058         gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
0059 }
0060
0061 static void lvds_codec_disable(struct drm_bridge *bridge)
0062 {
0063     struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
0064     int ret;
0065
0066     if (lvds_codec->powerdown_gpio)
0067         gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
0068
0069     ret = regulator_disable(lvds_codec->vcc);
0070     if (ret)
0071         dev_err(lvds_codec->dev,
0072             "Failed to disable regulator \"vcc\": %d\n", ret);
0073 }
0074
0075 static const struct drm_bridge_funcs funcs = {
0076     .attach = lvds_codec_attach,
0077     .enable = lvds_codec_enable,
0078     .disable = lvds_codec_disable,
0079 };
0080
0081 #define MAX_INPUT_SEL_FORMATS 1
0082 static u32 *
0083 lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
0084                      struct drm_bridge_state *bridge_state,
0085                      struct drm_crtc_state *crtc_state,
0086                      struct drm_connector_state *conn_state,
0087                      u32 output_fmt,
0088                      unsigned int *num_input_fmts)
0089 {
0090     struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
0091     u32 *input_fmts;
0092
0093     *num_input_fmts = 0;
0094
0095     input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
0096                  GFP_KERNEL);
0097     if (!input_fmts)
0098         return NULL;
0099
0100     input_fmts[0] = lvds_codec->bus_format;
0101     *num_input_fmts = MAX_INPUT_SEL_FORMATS;
0102
0103     return input_fmts;
0104 }
0105
0106 static const struct drm_bridge_funcs funcs_decoder = {
0107     .attach = lvds_codec_attach,
0108     .enable = lvds_codec_enable,
0109     .disable = lvds_codec_disable,
0110     .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
0111     .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
0112     .atomic_reset = drm_atomic_helper_bridge_reset,
0113     .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
0114 };
0115
0116 static int lvds_codec_probe(struct platform_device *pdev)
0117 {
0118     struct device *dev = &pdev->dev;
0119     struct device_node *panel_node;
0120     struct device_node *bus_node;
0121     struct drm_panel *panel;
0122     struct lvds_codec *lvds_codec;
0123     u32 val;
0124     int ret;
0125
0126     lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
0127     if (!lvds_codec)
0128         return -ENOMEM;
0129
0130     lvds_codec->dev = &pdev->dev;
0131     lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
0132
0133     lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
0134     if (IS_ERR(lvds_codec->vcc))
0135         return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
0136                      "Unable to get \"vcc\" supply\n");
0137
0138     lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
0139                                  GPIOD_OUT_HIGH);
0140     if (IS_ERR(lvds_codec->powerdown_gpio))
0141         return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
0142                      "powerdown GPIO failure\n");
0143
0144     /* Locate the panel DT node. */
0145     panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
0146     if (!panel_node) {
0147         dev_dbg(dev, "panel DT node not found\n");
0148         return -ENXIO;
0149     }
0150
0151     panel = of_drm_find_panel(panel_node);
0152     of_node_put(panel_node);
0153     if (IS_ERR(panel)) {
0154         dev_dbg(dev, "panel not found, deferring probe\n");
0155         return PTR_ERR(panel);
0156     }
0157
0158     lvds_codec->panel_bridge =
0159         devm_drm_panel_bridge_add_typed(dev, panel,
0160                         lvds_codec->connector_type);
0161     if (IS_ERR(lvds_codec->panel_bridge))
0162         return PTR_ERR(lvds_codec->panel_bridge);
0163
0164     lvds_codec->bridge.funcs = &funcs;
0165
0166     /*
0167      * Decoder input LVDS format is a property of the decoder chip or even
0168      * its strapping. Handle data-mapping the same way lvds-panel does. In
0169      * case data-mapping is not present, do nothing, since there are still
0170      * legacy bindings which do not specify this property.
0171      */
0172     if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
0173         bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
0174         if (!bus_node) {
0175             dev_dbg(dev, "bus DT node not found\n");
0176             return -ENXIO;
0177         }
0178
0179         ret = drm_of_lvds_get_data_mapping(bus_node);
0180         of_node_put(bus_node);
0181         if (ret == -ENODEV) {
0182             dev_warn(dev, "missing 'data-mapping' DT property\n");
0183         } else if (ret < 0) {
0184             dev_err(dev, "invalid 'data-mapping' DT property\n");
0185             return ret;
0186         } else {
0187             lvds_codec->bus_format = ret;
0188             lvds_codec->bridge.funcs = &funcs_decoder;
0189         }
0190     }
0191
0192     /*
0193      * Encoder might sample data on different clock edge than the display,
0194      * for example OnSemi FIN3385 has a dedicated strapping pin to select
0195      * the sampling edge.
0196      */
0197     if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
0198         !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
0199         lvds_codec->timings.input_bus_flags = val ?
0200             DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
0201             DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
0202     }
0203
0204     /*
0205      * The panel_bridge bridge is attached to the panel's of_node,
0206      * but we need a bridge attached to our of_node for our user
0207      * to look up.
0208      */
0209     lvds_codec->bridge.of_node = dev->of_node;
0210     lvds_codec->bridge.timings = &lvds_codec->timings;
0211     drm_bridge_add(&lvds_codec->bridge);
0212
0213     platform_set_drvdata(pdev, lvds_codec);
0214
0215     return 0;
0216 }
0217
0218 static int lvds_codec_remove(struct platform_device *pdev)
0219 {
0220     struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
0221
0222     drm_bridge_remove(&lvds_codec->bridge);
0223
0224     return 0;
0225 }
0226
0227 static const struct of_device_id lvds_codec_match[] = {
0228     {
0229         .compatible = "lvds-decoder",
0230         .data = (void *)DRM_MODE_CONNECTOR_DPI,
0231     },
0232     {
0233         .compatible = "lvds-encoder",
0234         .data = (void *)DRM_MODE_CONNECTOR_LVDS,
0235     },
0236     {
0237         .compatible = "thine,thc63lvdm83d",
0238         .data = (void *)DRM_MODE_CONNECTOR_LVDS,
0239     },
0240     {},
0241 };
0242 MODULE_DEVICE_TABLE(of, lvds_codec_match);
0243
0244 static struct platform_driver lvds_codec_driver = {
0245     .probe  = lvds_codec_probe,
0246     .remove = lvds_codec_remove,
0247     .driver     = {
0248         .name       = "lvds-codec",
0249         .of_match_table = lvds_codec_match,
0250     },
0251 };
0252 module_platform_driver(lvds_codec_driver);
0253
0254 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
0255 MODULE_DESCRIPTION("LVDS encoders and decoders");
0256 MODULE_LICENSE("GPL");