drivers/gpu/drm/bridge/display-connector.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   4  */
   5
   6 #include <linux/gpio/consumer.h>
   7 #include <linux/i2c.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/module.h>
  10 #include <linux/mutex.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regulator/consumer.h>
  15
  16 #include <drm/drm_atomic_helper.h>
  17 #include <drm/drm_bridge.h>
  18 #include <drm/drm_edid.h>
  19
  20 struct display_connector {
  21         struct drm_bridge       bridge;
  22
  23         struct gpio_desc        *hpd_gpio;
  24         int                     hpd_irq;
  25
  26         struct regulator        *dp_pwr;
  27         struct gpio_desc        *ddc_en;
  28 };
  29
  30 static inline struct display_connector *
  31 to_display_connector(struct drm_bridge *bridge)
  32 {
  33         return container_of(bridge, struct display_connector, bridge);
  34 }
  35
  36 static int display_connector_attach(struct drm_bridge *bridge,
  37                                     enum drm_bridge_attach_flags flags)
  38 {
  39         return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
  40 }
  41
  42 static enum drm_connector_status
  43 display_connector_detect(struct drm_bridge *bridge)
  44 {
  45         struct display_connector *conn = to_display_connector(bridge);
  46
  47         if (conn->hpd_gpio) {
  48                 if (gpiod_get_value_cansleep(conn->hpd_gpio))
  49                         return connector_status_connected;
  50                 else
  51                         return connector_status_disconnected;
  52         }
  53
  54         if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc))
  55                 return connector_status_connected;
  56
  57         switch (conn->bridge.type) {
  58         case DRM_MODE_CONNECTOR_DVIA:
  59         case DRM_MODE_CONNECTOR_DVID:
  60         case DRM_MODE_CONNECTOR_DVII:
  61         case DRM_MODE_CONNECTOR_HDMIA:
  62         case DRM_MODE_CONNECTOR_HDMIB:
  63                 /*
  64                  * For DVI and HDMI connectors a DDC probe failure indicates
  65                  * that no cable is connected.
  66                  */
  67                 return connector_status_disconnected;
  68
  69         case DRM_MODE_CONNECTOR_Composite:
  70         case DRM_MODE_CONNECTOR_SVIDEO:
  71         case DRM_MODE_CONNECTOR_VGA:
  72         default:
  73                 /*
  74                  * Composite and S-Video connectors have no other detection
  75                  * mean than the HPD GPIO. For VGA connectors, even if we have
  76                  * an I2C bus, we can't assume that the cable is disconnected
  77                  * if drm_probe_ddc fails, as some cables don't wire the DDC
  78                  * pins.
  79                  */
  80                 return connector_status_unknown;
  81         }
  82 }
  83
  84 static struct edid *display_connector_get_edid(struct drm_bridge *bridge,
  85                                                struct drm_connector *connector)
  86 {
  87         struct display_connector *conn = to_display_connector(bridge);
  88
  89         return drm_get_edid(connector, conn->bridge.ddc);
  90 }
  91
  92 /*
  93  * Since this bridge is tied to the connector, it acts like a passthrough,
  94  * so concerning the output bus formats, either pass the bus formats from the
  95  * previous bridge or return fallback data like done in the bridge function:
  96  * drm_atomic_bridge_chain_select_bus_fmts().
  97  * This supports negotiation if the bridge chain has all bits in place.
  98  */
  99 static u32 *display_connector_get_output_bus_fmts(struct drm_bridge *bridge,
 100                                         struct drm_bridge_state *bridge_state,
 101                                         struct drm_crtc_state *crtc_state,
 102                                         struct drm_connector_state *conn_state,
 103                                         unsigned int *num_output_fmts)
 104 {
 105         struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
 106         struct drm_bridge_state *prev_bridge_state;
 107
 108         if (!prev_bridge || !prev_bridge->funcs->atomic_get_output_bus_fmts) {
 109                 struct drm_connector *conn = conn_state->connector;
 110                 u32 *out_bus_fmts;
 111
 112                 *num_output_fmts = 1;
 113                 out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
 114                 if (!out_bus_fmts)
 115                         return NULL;
 116
 117                 if (conn->display_info.num_bus_formats &&
 118                     conn->display_info.bus_formats)
 119                         out_bus_fmts[0] = conn->display_info.bus_formats[0];
 120                 else
 121                         out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
 122
 123                 return out_bus_fmts;
 124         }
 125
 126         prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
 127                                                             prev_bridge);
 128
 129         return prev_bridge->funcs->atomic_get_output_bus_fmts(prev_bridge, prev_bridge_state,
 130                                                               crtc_state, conn_state,
 131                                                               num_output_fmts);
 132 }
 133
 134 /*
 135  * Since this bridge is tied to the connector, it acts like a passthrough,
 136  * so concerning the input bus formats, either pass the bus formats from the
 137  * previous bridge or MEDIA_BUS_FMT_FIXED (like select_bus_fmt_recursive())
 138  * when atomic_get_input_bus_fmts is not supported.
 139  * This supports negotiation if the bridge chain has all bits in place.
 140  */
 141 static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge,
 142                                         struct drm_bridge_state *bridge_state,
 143                                         struct drm_crtc_state *crtc_state,
 144                                         struct drm_connector_state *conn_state,
 145                                         u32 output_fmt,
 146                                         unsigned int *num_input_fmts)
 147 {
 148         struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
 149         struct drm_bridge_state *prev_bridge_state;
 150
 151         if (!prev_bridge || !prev_bridge->funcs->atomic_get_input_bus_fmts) {
 152                 u32 *in_bus_fmts;
 153
 154                 *num_input_fmts = 1;
 155                 in_bus_fmts = kmalloc(sizeof(*in_bus_fmts), GFP_KERNEL);
 156                 if (!in_bus_fmts)
 157                         return NULL;
 158
 159                 in_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
 160
 161                 return in_bus_fmts;
 162         }
 163
 164         prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
 165                                                             prev_bridge);
 166
 167         return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state,
 168                                                              crtc_state, conn_state, output_fmt,
 169                                                              num_input_fmts);
 170 }
 171
 172 static const struct drm_bridge_funcs display_connector_bridge_funcs = {
 173         .attach = display_connector_attach,
 174         .detect = display_connector_detect,
 175         .get_edid = display_connector_get_edid,
 176         .atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
 177         .atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
 178         .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 179         .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 180         .atomic_reset = drm_atomic_helper_bridge_reset,
 181 };
 182
 183 static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
 184 {
 185         struct display_connector *conn = arg;
 186         struct drm_bridge *bridge = &conn->bridge;
 187
 188         drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));
 189
 190         return IRQ_HANDLED;
 191 }
 192
 193 static int display_connector_probe(struct platform_device *pdev)
 194 {
 195         struct display_connector *conn;
 196         unsigned int type;
 197         const char *label = NULL;
 198         int ret;
 199
 200         conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
 201         if (!conn)
 202                 return -ENOMEM;
 203
 204         platform_set_drvdata(pdev, conn);
 205
 206         type = (uintptr_t)of_device_get_match_data(&pdev->dev);
 207
 208         /* Get the exact connector type. */
 209         switch (type) {
 210         case DRM_MODE_CONNECTOR_DVII: {
 211                 bool analog, digital;
 212
 213                 analog = of_property_read_bool(pdev->dev.of_node, "analog");
 214                 digital = of_property_read_bool(pdev->dev.of_node, "digital");
 215                 if (analog && !digital) {
 216                         conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
 217                 } else if (!analog && digital) {
 218                         conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
 219                 } else if (analog && digital) {
 220                         conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
 221                 } else {
 222                         dev_err(&pdev->dev, "DVI connector with no type\n");
 223                         return -EINVAL;
 224                 }
 225                 break;
 226         }
 227
 228         case DRM_MODE_CONNECTOR_HDMIA: {
 229                 const char *hdmi_type;
 230
 231                 ret = of_property_read_string(pdev->dev.of_node, "type",
 232                                               &hdmi_type);
 233                 if (ret < 0) {
 234                         dev_err(&pdev->dev, "HDMI connector with no type\n");
 235                         return -EINVAL;
 236                 }
 237
 238                 if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") ||
 239                     !strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) {
 240                         conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 241                 } else if (!strcmp(hdmi_type, "b")) {
 242                         conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
 243                 } else {
 244                         dev_err(&pdev->dev,
 245                                 "Unsupported HDMI connector type '%s'\n",
 246                                 hdmi_type);
 247                         return -EINVAL;
 248                 }
 249
 250                 break;
 251         }
 252
 253         default:
 254                 conn->bridge.type = type;
 255                 break;
 256         }
 257
 258         /* All the supported connector types support interlaced modes. */
 259         conn->bridge.interlace_allowed = true;
 260
 261         /* Get the optional connector label. */
 262         of_property_read_string(pdev->dev.of_node, "label", &label);
 263
 264         /*
 265          * Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
 266          * edge interrupts, register an interrupt handler.
 267          */
 268         if (type == DRM_MODE_CONNECTOR_DVII ||
 269             type == DRM_MODE_CONNECTOR_HDMIA ||
 270             type == DRM_MODE_CONNECTOR_DisplayPort) {
 271                 conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
 272                                                          GPIOD_IN);
 273                 if (IS_ERR(conn->hpd_gpio)) {
 274                         if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER)
 275                                 dev_err(&pdev->dev,
 276                                         "Unable to retrieve HPD GPIO\n");
 277                         return PTR_ERR(conn->hpd_gpio);
 278                 }
 279
 280                 conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
 281         } else {
 282                 conn->hpd_irq = -EINVAL;
 283         }
 284
 285         if (conn->hpd_irq >= 0) {
 286                 ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
 287                                                 NULL, display_connector_hpd_irq,
 288                                                 IRQF_TRIGGER_RISING |
 289                                                 IRQF_TRIGGER_FALLING |
 290                                                 IRQF_ONESHOT,
 291                                                 "HPD", conn);
 292                 if (ret) {
 293                         dev_info(&pdev->dev,
 294                                  "Failed to request HPD edge interrupt, falling back to polling\n");
 295                         conn->hpd_irq = -EINVAL;
 296                 }
 297         }
 298
 299         /* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
 300         if (type == DRM_MODE_CONNECTOR_DVII ||
 301             type == DRM_MODE_CONNECTOR_HDMIA ||
 302             type == DRM_MODE_CONNECTOR_VGA) {
 303                 struct device_node *phandle;
 304
 305                 phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
 306                 if (phandle) {
 307                         conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
 308                         of_node_put(phandle);
 309                         if (!conn->bridge.ddc)
 310                                 return -EPROBE_DEFER;
 311                 } else {
 312                         dev_dbg(&pdev->dev,
 313                                 "No I2C bus specified, disabling EDID readout\n");
 314                 }
 315         }
 316
 317         /* Get the DP PWR for DP connector. */
 318         if (type == DRM_MODE_CONNECTOR_DisplayPort) {
 319                 int ret;
 320
 321                 conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr");
 322
 323                 if (IS_ERR(conn->dp_pwr)) {
 324                         ret = PTR_ERR(conn->dp_pwr);
 325
 326                         switch (ret) {
 327                         case -ENODEV:
 328                                 conn->dp_pwr = NULL;
 329                                 break;
 330
 331                         case -EPROBE_DEFER:
 332                                 return -EPROBE_DEFER;
 333
 334                         default:
 335                                 dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
 336                                 return ret;
 337                         }
 338                 }
 339
 340                 if (conn->dp_pwr) {
 341                         ret = regulator_enable(conn->dp_pwr);
 342                         if (ret) {
 343                                 dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
 344                                 return ret;
 345                         }
 346                 }
 347         }
 348
 349         /* enable DDC */
 350         if (type == DRM_MODE_CONNECTOR_HDMIA) {
 351                 conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
 352                                                        GPIOD_OUT_HIGH);
 353
 354                 if (IS_ERR(conn->ddc_en)) {
 355                         dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
 356                         return PTR_ERR(conn->ddc_en);
 357                 }
 358         }
 359
 360         conn->bridge.funcs = &display_connector_bridge_funcs;
 361         conn->bridge.of_node = pdev->dev.of_node;
 362
 363         if (conn->bridge.ddc)
 364                 conn->bridge.ops |= DRM_BRIDGE_OP_EDID
 365                                  |  DRM_BRIDGE_OP_DETECT;
 366         if (conn->hpd_gpio)
 367                 conn->bridge.ops |= DRM_BRIDGE_OP_DETECT;
 368         if (conn->hpd_irq >= 0)
 369                 conn->bridge.ops |= DRM_BRIDGE_OP_HPD;
 370
 371         dev_dbg(&pdev->dev,
 372                 "Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
 373                 drm_get_connector_type_name(conn->bridge.type),
 374                 label ? label : "<unlabelled>",
 375                 conn->bridge.ddc ? "with" : "without",
 376                 conn->hpd_gpio ? "with" : "without",
 377                 conn->bridge.ops);
 378
 379         drm_bridge_add(&conn->bridge);
 380
 381         return 0;
 382 }
 383
 384 static int display_connector_remove(struct platform_device *pdev)
 385 {
 386         struct display_connector *conn = platform_get_drvdata(pdev);
 387
 388         if (conn->ddc_en)
 389                 gpiod_set_value(conn->ddc_en, 0);
 390
 391         if (conn->dp_pwr)
 392                 regulator_disable(conn->dp_pwr);
 393
 394         drm_bridge_remove(&conn->bridge);
 395
 396         if (!IS_ERR(conn->bridge.ddc))
 397                 i2c_put_adapter(conn->bridge.ddc);
 398
 399         return 0;
 400 }
 401
 402 static const struct of_device_id display_connector_match[] = {
 403         {
 404                 .compatible = "composite-video-connector",
 405                 .data = (void *)DRM_MODE_CONNECTOR_Composite,
 406         }, {
 407                 .compatible = "dvi-connector",
 408                 .data = (void *)DRM_MODE_CONNECTOR_DVII,
 409         }, {
 410                 .compatible = "hdmi-connector",
 411                 .data = (void *)DRM_MODE_CONNECTOR_HDMIA,
 412         }, {
 413                 .compatible = "svideo-connector",
 414                 .data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
 415         }, {
 416                 .compatible = "vga-connector",
 417                 .data = (void *)DRM_MODE_CONNECTOR_VGA,
 418         }, {
 419                 .compatible = "dp-connector",
 420                 .data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
 421         },
 422         {},
 423 };
 424 MODULE_DEVICE_TABLE(of, display_connector_match);
 425
 426 static struct platform_driver display_connector_driver = {
 427         .probe  = display_connector_probe,
 428         .remove = display_connector_remove,
 429         .driver         = {
 430                 .name           = "display-connector",
 431                 .of_match_table = display_connector_match,
 432         },
 433 };
 434 module_platform_driver(display_connector_driver);
 435
 436 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 437 MODULE_DESCRIPTION("Display connector driver");
 438 MODULE_LICENSE("GPL");