drivers/gpu/drm/bridge/ti-tfp410.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2016 Texas Instruments
   4  * Author: Jyri Sarha <jsarha@ti.com>
   5  */
   6
   7 #include <linux/gpio/consumer.h>
   8 #include <linux/i2c.h>
   9 #include <linux/module.h>
  10 #include <linux/of_graph.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/workqueue.h>
  13
  14 #include <drm/drm_atomic_helper.h>
  15 #include <drm/drm_bridge.h>
  16 #include <drm/drm_crtc.h>
  17 #include <drm/drm_print.h>
  18 #include <drm/drm_probe_helper.h>
  19
  20 #define HOTPLUG_DEBOUNCE_MS             1100
  21
  22 struct tfp410 {
  23         struct drm_bridge       bridge;
  24         struct drm_connector    connector;
  25
  26         u32                     bus_format;
  27         struct delayed_work     hpd_work;
  28         struct gpio_desc        *powerdown;
  29
  30         struct drm_bridge_timings timings;
  31         struct drm_bridge       *next_bridge;
  32
  33         struct device *dev;
  34 };
  35
  36 static inline struct tfp410 *
  37 drm_bridge_to_tfp410(struct drm_bridge *bridge)
  38 {
  39         return container_of(bridge, struct tfp410, bridge);
  40 }
  41
  42 static inline struct tfp410 *
  43 drm_connector_to_tfp410(struct drm_connector *connector)
  44 {
  45         return container_of(connector, struct tfp410, connector);
  46 }
  47
  48 static int tfp410_get_modes(struct drm_connector *connector)
  49 {
  50         struct tfp410 *dvi = drm_connector_to_tfp410(connector);
  51         struct edid *edid;
  52         int ret;
  53
  54         edid = drm_bridge_get_edid(dvi->next_bridge, connector);
  55         if (IS_ERR_OR_NULL(edid)) {
  56                 if (edid != ERR_PTR(-ENOTSUPP))
  57                         DRM_INFO("EDID read failed. Fallback to standard modes\n");
  58
  59                 /*
  60                  * No EDID, fallback on the XGA standard modes and prefer a mode
  61                  * pretty much anything can handle.
  62                  */
  63                 ret = drm_add_modes_noedid(connector, 1920, 1200);
  64                 drm_set_preferred_mode(connector, 1024, 768);
  65                 return ret;
  66         }
  67
  68         drm_connector_update_edid_property(connector, edid);
  69
  70         ret = drm_add_edid_modes(connector, edid);
  71
  72         kfree(edid);
  73
  74         return ret;
  75 }
  76
  77 static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
  78         .get_modes      = tfp410_get_modes,
  79 };
  80
  81 static enum drm_connector_status
  82 tfp410_connector_detect(struct drm_connector *connector, bool force)
  83 {
  84         struct tfp410 *dvi = drm_connector_to_tfp410(connector);
  85
  86         return drm_bridge_detect(dvi->next_bridge);
  87 }
  88
  89 static const struct drm_connector_funcs tfp410_con_funcs = {
  90         .detect                 = tfp410_connector_detect,
  91         .fill_modes             = drm_helper_probe_single_connector_modes,
  92         .destroy                = drm_connector_cleanup,
  93         .reset                  = drm_atomic_helper_connector_reset,
  94         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
  95         .atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
  96 };
  97
  98 static void tfp410_hpd_work_func(struct work_struct *work)
  99 {
 100         struct tfp410 *dvi;
 101
 102         dvi = container_of(work, struct tfp410, hpd_work.work);
 103
 104         if (dvi->bridge.dev)
 105                 drm_helper_hpd_irq_event(dvi->bridge.dev);
 106 }
 107
 108 static void tfp410_hpd_callback(void *arg, enum drm_connector_status status)
 109 {
 110         struct tfp410 *dvi = arg;
 111
 112         mod_delayed_work(system_wq, &dvi->hpd_work,
 113                          msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
 114 }
 115
 116 static int tfp410_attach(struct drm_bridge *bridge,
 117                          enum drm_bridge_attach_flags flags)
 118 {
 119         struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
 120         int ret;
 121
 122         ret = drm_bridge_attach(bridge->encoder, dvi->next_bridge, bridge,
 123                                 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 124         if (ret < 0)
 125                 return ret;
 126
 127         if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
 128                 return 0;
 129
 130         if (!bridge->encoder) {
 131                 dev_err(dvi->dev, "Missing encoder\n");
 132                 return -ENODEV;
 133         }
 134
 135         if (dvi->next_bridge->ops & DRM_BRIDGE_OP_DETECT)
 136                 dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
 137         else
 138                 dvi->connector.polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
 139
 140         if (dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
 141                 INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
 142                 drm_bridge_hpd_enable(dvi->next_bridge, tfp410_hpd_callback,
 143                                       dvi);
 144         }
 145
 146         drm_connector_helper_add(&dvi->connector,
 147                                  &tfp410_con_helper_funcs);
 148         ret = drm_connector_init_with_ddc(bridge->dev, &dvi->connector,
 149                                           &tfp410_con_funcs,
 150                                           dvi->next_bridge->type,
 151                                           dvi->next_bridge->ddc);
 152         if (ret) {
 153                 dev_err(dvi->dev, "drm_connector_init_with_ddc() failed: %d\n",
 154                         ret);
 155                 return ret;
 156         }
 157
 158         drm_display_info_set_bus_formats(&dvi->connector.display_info,
 159                                          &dvi->bus_format, 1);
 160
 161         drm_connector_attach_encoder(&dvi->connector, bridge->encoder);
 162
 163         return 0;
 164 }
 165
 166 static void tfp410_detach(struct drm_bridge *bridge)
 167 {
 168         struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
 169
 170         if (dvi->connector.dev && dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
 171                 drm_bridge_hpd_disable(dvi->next_bridge);
 172                 cancel_delayed_work_sync(&dvi->hpd_work);
 173         }
 174 }
 175
 176 static void tfp410_enable(struct drm_bridge *bridge)
 177 {
 178         struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
 179
 180         gpiod_set_value_cansleep(dvi->powerdown, 0);
 181 }
 182
 183 static void tfp410_disable(struct drm_bridge *bridge)
 184 {
 185         struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
 186
 187         gpiod_set_value_cansleep(dvi->powerdown, 1);
 188 }
 189
 190 static enum drm_mode_status tfp410_mode_valid(struct drm_bridge *bridge,
 191                                               const struct drm_display_mode *mode)
 192 {
 193         if (mode->clock < 25000)
 194                 return MODE_CLOCK_LOW;
 195
 196         if (mode->clock > 165000)
 197                 return MODE_CLOCK_HIGH;
 198
 199         return MODE_OK;
 200 }
 201
 202 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
 203         .attach         = tfp410_attach,
 204         .detach         = tfp410_detach,
 205         .enable         = tfp410_enable,
 206         .disable        = tfp410_disable,
 207         .mode_valid     = tfp410_mode_valid,
 208 };
 209
 210 static const struct drm_bridge_timings tfp410_default_timings = {
 211         .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
 212                          | DRM_BUS_FLAG_DE_HIGH,
 213         .setup_time_ps = 1200,
 214         .hold_time_ps = 1300,
 215 };
 216
 217 static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
 218 {
 219         struct drm_bridge_timings *timings = &dvi->timings;
 220         struct device_node *ep;
 221         u32 pclk_sample = 0;
 222         u32 bus_width = 24;
 223         s32 deskew = 0;
 224
 225         /* Start with defaults. */
 226         *timings = tfp410_default_timings;
 227
 228         if (i2c)
 229                 /*
 230                  * In I2C mode timings are configured through the I2C interface.
 231                  * As the driver doesn't support I2C configuration yet, we just
 232                  * go with the defaults (BSEL=1, DSEL=1, DKEN=0, EDGE=1).
 233                  */
 234                 return 0;
 235
 236         /*
 237          * In non-I2C mode, timings are configured through the BSEL, DSEL, DKEN
 238          * and EDGE pins. They are specified in DT through endpoint properties
 239          * and vendor-specific properties.
 240          */
 241         ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 0, 0);
 242         if (!ep)
 243                 return -EINVAL;
 244
 245         /* Get the sampling edge from the endpoint. */
 246         of_property_read_u32(ep, "pclk-sample", &pclk_sample);
 247         of_property_read_u32(ep, "bus-width", &bus_width);
 248         of_node_put(ep);
 249
 250         timings->input_bus_flags = DRM_BUS_FLAG_DE_HIGH;
 251
 252         switch (pclk_sample) {
 253         case 0:
 254                 timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE
 255                                          |  DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
 256                 break;
 257         case 1:
 258                 timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
 259                                          |  DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE;
 260                 break;
 261         default:
 262                 return -EINVAL;
 263         }
 264
 265         switch (bus_width) {
 266         case 12:
 267                 dvi->bus_format = MEDIA_BUS_FMT_RGB888_2X12_LE;
 268                 break;
 269         case 24:
 270                 dvi->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 271                 break;
 272         default:
 273                 return -EINVAL;
 274         }
 275
 276         /* Get the setup and hold time from vendor-specific properties. */
 277         of_property_read_u32(dvi->dev->of_node, "ti,deskew", (u32 *)&deskew);
 278         if (deskew < -4 || deskew > 3)
 279                 return -EINVAL;
 280
 281         timings->setup_time_ps = min(0, 1200 - 350 * deskew);
 282         timings->hold_time_ps = min(0, 1300 + 350 * deskew);
 283
 284         return 0;
 285 }
 286
 287 static int tfp410_init(struct device *dev, bool i2c)
 288 {
 289         struct device_node *node;
 290         struct tfp410 *dvi;
 291         int ret;
 292
 293         if (!dev->of_node) {
 294                 dev_err(dev, "device-tree data is missing\n");
 295                 return -ENXIO;
 296         }
 297
 298         dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
 299         if (!dvi)
 300                 return -ENOMEM;
 301
 302         dvi->dev = dev;
 303         dev_set_drvdata(dev, dvi);
 304
 305         dvi->bridge.funcs = &tfp410_bridge_funcs;
 306         dvi->bridge.of_node = dev->of_node;
 307         dvi->bridge.timings = &dvi->timings;
 308         dvi->bridge.type = DRM_MODE_CONNECTOR_DVID;
 309
 310         ret = tfp410_parse_timings(dvi, i2c);
 311         if (ret)
 312                 return ret;
 313
 314         /* Get the next bridge, connected to port@1. */
 315         node = of_graph_get_remote_node(dev->of_node, 1, -1);
 316         if (!node)
 317                 return -ENODEV;
 318
 319         dvi->next_bridge = of_drm_find_bridge(node);
 320         of_node_put(node);
 321
 322         if (!dvi->next_bridge)
 323                 return -EPROBE_DEFER;
 324
 325         /* Get the powerdown GPIO. */
 326         dvi->powerdown = devm_gpiod_get_optional(dev, "powerdown",
 327                                                  GPIOD_OUT_HIGH);
 328         if (IS_ERR(dvi->powerdown)) {
 329                 dev_err(dev, "failed to parse powerdown gpio\n");
 330                 return PTR_ERR(dvi->powerdown);
 331         }
 332
 333         /*  Register the DRM bridge. */
 334         drm_bridge_add(&dvi->bridge);
 335
 336         return 0;
 337 }
 338
 339 static int tfp410_fini(struct device *dev)
 340 {
 341         struct tfp410 *dvi = dev_get_drvdata(dev);
 342
 343         drm_bridge_remove(&dvi->bridge);
 344
 345         return 0;
 346 }
 347
 348 static int tfp410_probe(struct platform_device *pdev)
 349 {
 350         return tfp410_init(&pdev->dev, false);
 351 }
 352
 353 static int tfp410_remove(struct platform_device *pdev)
 354 {
 355         return tfp410_fini(&pdev->dev);
 356 }
 357
 358 static const struct of_device_id tfp410_match[] = {
 359         { .compatible = "ti,tfp410" },
 360         {},
 361 };
 362 MODULE_DEVICE_TABLE(of, tfp410_match);
 363
 364 static struct platform_driver tfp410_platform_driver = {
 365         .probe  = tfp410_probe,
 366         .remove = tfp410_remove,
 367         .driver = {
 368                 .name           = "tfp410-bridge",
 369                 .of_match_table = tfp410_match,
 370         },
 371 };
 372
 373 #if IS_ENABLED(CONFIG_I2C)
 374 /* There is currently no i2c functionality. */
 375 static int tfp410_i2c_probe(struct i2c_client *client,
 376                             const struct i2c_device_id *id)
 377 {
 378         int reg;
 379
 380         if (!client->dev.of_node ||
 381             of_property_read_u32(client->dev.of_node, "reg", &reg)) {
 382                 dev_err(&client->dev,
 383                         "Can't get i2c reg property from device-tree\n");
 384                 return -ENXIO;
 385         }
 386
 387         return tfp410_init(&client->dev, true);
 388 }
 389
 390 static int tfp410_i2c_remove(struct i2c_client *client)
 391 {
 392         return tfp410_fini(&client->dev);
 393 }
 394
 395 static const struct i2c_device_id tfp410_i2c_ids[] = {
 396         { "tfp410", 0 },
 397         { }
 398 };
 399 MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
 400
 401 static struct i2c_driver tfp410_i2c_driver = {
 402         .driver = {
 403                 .name   = "tfp410",
 404                 .of_match_table = of_match_ptr(tfp410_match),
 405         },
 406         .id_table       = tfp410_i2c_ids,
 407         .probe          = tfp410_i2c_probe,
 408         .remove         = tfp410_i2c_remove,
 409 };
 410 #endif /* IS_ENABLED(CONFIG_I2C) */
 411
 412 static struct {
 413         uint i2c:1;
 414         uint platform:1;
 415 }  tfp410_registered_driver;
 416
 417 static int __init tfp410_module_init(void)
 418 {
 419         int ret;
 420
 421 #if IS_ENABLED(CONFIG_I2C)
 422         ret = i2c_add_driver(&tfp410_i2c_driver);
 423         if (ret)
 424                 pr_err("%s: registering i2c driver failed: %d",
 425                        __func__, ret);
 426         else
 427                 tfp410_registered_driver.i2c = 1;
 428 #endif
 429
 430         ret = platform_driver_register(&tfp410_platform_driver);
 431         if (ret)
 432                 pr_err("%s: registering platform driver failed: %d",
 433                        __func__, ret);
 434         else
 435                 tfp410_registered_driver.platform = 1;
 436
 437         if (tfp410_registered_driver.i2c ||
 438             tfp410_registered_driver.platform)
 439                 return 0;
 440
 441         return ret;
 442 }
 443 module_init(tfp410_module_init);
 444
 445 static void __exit tfp410_module_exit(void)
 446 {
 447 #if IS_ENABLED(CONFIG_I2C)
 448         if (tfp410_registered_driver.i2c)
 449                 i2c_del_driver(&tfp410_i2c_driver);
 450 #endif
 451         if (tfp410_registered_driver.platform)
 452                 platform_driver_unregister(&tfp410_platform_driver);
 453 }
 454 module_exit(tfp410_module_exit);
 455
 456 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
 457 MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
 458 MODULE_LICENSE("GPL");