drivers/gpu/drm/bridge/thc63lvd1024.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * THC63LVD1024 LVDS to parallel data DRM bridge driver.
   4  *
   5  * Copyright (C) 2018 Jacopo Mondi <jacopo+renesas@jmondi.org>
   6  */
   7
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/of_graph.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regulator/consumer.h>
  14 #include <linux/slab.h>
  15
  16 #include <drm/drm_bridge.h>
  17 #include <drm/drm_panel.h>
  18
  19 enum thc63_ports {
  20         THC63_LVDS_IN0,
  21         THC63_LVDS_IN1,
  22         THC63_RGB_OUT0,
  23         THC63_RGB_OUT1,
  24 };
  25
  26 struct thc63_dev {
  27         struct device *dev;
  28
  29         struct regulator *vcc;
  30
  31         struct gpio_desc *pdwn;
  32         struct gpio_desc *oe;
  33
  34         struct drm_bridge bridge;
  35         struct drm_bridge *next;
  36
  37         struct drm_bridge_timings timings;
  38 };
  39
  40 static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge)
  41 {
  42         return container_of(bridge, struct thc63_dev, bridge);
  43 }
  44
  45 static int thc63_attach(struct drm_bridge *bridge,
  46                         enum drm_bridge_attach_flags flags)
  47 {
  48         struct thc63_dev *thc63 = to_thc63(bridge);
  49
  50         return drm_bridge_attach(bridge->encoder, thc63->next, bridge, flags);
  51 }
  52
  53 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge,
  54                                         const struct drm_display_info *info,
  55                                         const struct drm_display_mode *mode)
  56 {
  57         struct thc63_dev *thc63 = to_thc63(bridge);
  58         unsigned int min_freq;
  59         unsigned int max_freq;
  60
  61         /*
  62          * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but
  63          * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out
  64          * isn't supported by the driver yet, simply derive the limits from the
  65          * input mode.
  66          */
  67         if (thc63->timings.dual_link) {
  68                 min_freq = 40000;
  69                 max_freq = 150000;
  70         } else {
  71                 min_freq = 8000;
  72                 max_freq = 135000;
  73         }
  74
  75         if (mode->clock < min_freq)
  76                 return MODE_CLOCK_LOW;
  77
  78         if (mode->clock > max_freq)
  79                 return MODE_CLOCK_HIGH;
  80
  81         return MODE_OK;
  82 }
  83
  84 static void thc63_enable(struct drm_bridge *bridge)
  85 {
  86         struct thc63_dev *thc63 = to_thc63(bridge);
  87         int ret;
  88
  89         ret = regulator_enable(thc63->vcc);
  90         if (ret) {
  91                 dev_err(thc63->dev,
  92                         "Failed to enable regulator \"vcc\": %d\n", ret);
  93                 return;
  94         }
  95
  96         gpiod_set_value(thc63->pdwn, 0);
  97         gpiod_set_value(thc63->oe, 1);
  98 }
  99
 100 static void thc63_disable(struct drm_bridge *bridge)
 101 {
 102         struct thc63_dev *thc63 = to_thc63(bridge);
 103         int ret;
 104
 105         gpiod_set_value(thc63->oe, 0);
 106         gpiod_set_value(thc63->pdwn, 1);
 107
 108         ret = regulator_disable(thc63->vcc);
 109         if (ret)
 110                 dev_err(thc63->dev,
 111                         "Failed to disable regulator \"vcc\": %d\n", ret);
 112 }
 113
 114 static const struct drm_bridge_funcs thc63_bridge_func = {
 115         .attach = thc63_attach,
 116         .mode_valid = thc63_mode_valid,
 117         .enable = thc63_enable,
 118         .disable = thc63_disable,
 119 };
 120
 121 static int thc63_parse_dt(struct thc63_dev *thc63)
 122 {
 123         struct device_node *endpoint;
 124         struct device_node *remote;
 125
 126         remote = of_graph_get_remote_node(thc63->dev->of_node,
 127                                           THC63_RGB_OUT0, -1);
 128         if (!remote) {
 129                 dev_err(thc63->dev, "No remote endpoint for port@%u\n",
 130                         THC63_RGB_OUT0);
 131                 return -ENODEV;
 132         }
 133
 134         thc63->next = of_drm_find_bridge(remote);
 135         of_node_put(remote);
 136         if (!thc63->next)
 137                 return -EPROBE_DEFER;
 138
 139         endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
 140                                                  THC63_LVDS_IN1, -1);
 141         if (endpoint) {
 142                 remote = of_graph_get_remote_port_parent(endpoint);
 143                 of_node_put(endpoint);
 144
 145                 if (remote) {
 146                         if (of_device_is_available(remote))
 147                                 thc63->timings.dual_link = true;
 148                         of_node_put(remote);
 149                 }
 150         }
 151
 152         dev_dbg(thc63->dev, "operating in %s-link mode\n",
 153                 thc63->timings.dual_link ? "dual" : "single");
 154
 155         return 0;
 156 }
 157
 158 static int thc63_gpio_init(struct thc63_dev *thc63)
 159 {
 160         thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW);
 161         if (IS_ERR(thc63->oe)) {
 162                 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n",
 163                         PTR_ERR(thc63->oe));
 164                 return PTR_ERR(thc63->oe);
 165         }
 166
 167         thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown",
 168                                               GPIOD_OUT_HIGH);
 169         if (IS_ERR(thc63->pdwn)) {
 170                 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n",
 171                         PTR_ERR(thc63->pdwn));
 172                 return PTR_ERR(thc63->pdwn);
 173         }
 174
 175         return 0;
 176 }
 177
 178 static int thc63_probe(struct platform_device *pdev)
 179 {
 180         struct thc63_dev *thc63;
 181         int ret;
 182
 183         thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL);
 184         if (!thc63)
 185                 return -ENOMEM;
 186
 187         thc63->dev = &pdev->dev;
 188         platform_set_drvdata(pdev, thc63);
 189
 190         thc63->vcc = devm_regulator_get(thc63->dev, "vcc");
 191         if (IS_ERR(thc63->vcc)) {
 192                 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER)
 193                         return -EPROBE_DEFER;
 194
 195                 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n",
 196                         PTR_ERR(thc63->vcc));
 197                 return PTR_ERR(thc63->vcc);
 198         }
 199
 200         ret = thc63_gpio_init(thc63);
 201         if (ret)
 202                 return ret;
 203
 204         ret = thc63_parse_dt(thc63);
 205         if (ret)
 206                 return ret;
 207
 208         thc63->bridge.driver_private = thc63;
 209         thc63->bridge.of_node = pdev->dev.of_node;
 210         thc63->bridge.funcs = &thc63_bridge_func;
 211         thc63->bridge.timings = &thc63->timings;
 212
 213         drm_bridge_add(&thc63->bridge);
 214
 215         return 0;
 216 }
 217
 218 static void thc63_remove(struct platform_device *pdev)
 219 {
 220         struct thc63_dev *thc63 = platform_get_drvdata(pdev);
 221
 222         drm_bridge_remove(&thc63->bridge);
 223 }
 224
 225 static const struct of_device_id thc63_match[] = {
 226         { .compatible = "thine,thc63lvd1024", },
 227         { },
 228 };
 229 MODULE_DEVICE_TABLE(of, thc63_match);
 230
 231 static struct platform_driver thc63_driver = {
 232         .probe  = thc63_probe,
 233         .remove = thc63_remove,
 234         .driver = {
 235                 .name           = "thc63lvd1024",
 236                 .of_match_table = thc63_match,
 237         },
 238 };
 239 module_platform_driver(thc63_driver);
 240
 241 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
 242 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver");
 243 MODULE_LICENSE("GPL v2");