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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2019 Laurent Pinchart <[email protected]>
   4  */
   5
   6 #include <linux/gpio/consumer.h>
   7 #include <linux/i2c.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/media-bus-format.h>
  10 #include <linux/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/of.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        *supply;
  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 const struct drm_edid *display_connector_edid_read(struct drm_bridge *bridge,
  85                                                           struct drm_connector *connector)
  86 {
  87         struct display_connector *conn = to_display_connector(bridge);
  88
  89         return drm_edid_read_ddc(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         .edid_read = display_connector_edid_read,
 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_get_supply(struct platform_device *pdev,
 194                                         struct display_connector *conn,
 195                                         const char *name)
 196 {
 197         conn->supply = devm_regulator_get_optional(&pdev->dev, name);
 198
 199         if (conn->supply == ERR_PTR(-ENODEV))
 200                 conn->supply = NULL;
 201
 202         return PTR_ERR_OR_ZERO(conn->supply);
 203 }
 204
 205 static int display_connector_probe(struct platform_device *pdev)
 206 {
 207         struct display_connector *conn;
 208         unsigned int type;
 209         const char *label = NULL;
 210         int ret;
 211
 212         conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
 213         if (!conn)
 214                 return -ENOMEM;
 215
 216         platform_set_drvdata(pdev, conn);
 217
 218         type = (uintptr_t)of_device_get_match_data(&pdev->dev);
 219
 220         /* Get the exact connector type. */
 221         switch (type) {
 222         case DRM_MODE_CONNECTOR_DVII: {
 223                 bool analog, digital;
 224
 225                 analog = of_property_read_bool(pdev->dev.of_node, "analog");
 226                 digital = of_property_read_bool(pdev->dev.of_node, "digital");
 227                 if (analog && !digital) {
 228                         conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
 229                 } else if (!analog && digital) {
 230                         conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
 231                 } else if (analog && digital) {
 232                         conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
 233                 } else {
 234                         dev_err(&pdev->dev, "DVI connector with no type\n");
 235                         return -EINVAL;
 236                 }
 237                 break;
 238         }
 239
 240         case DRM_MODE_CONNECTOR_HDMIA: {
 241                 const char *hdmi_type;
 242
 243                 ret = of_property_read_string(pdev->dev.of_node, "type",
 244                                               &hdmi_type);
 245                 if (ret < 0) {
 246                         dev_err(&pdev->dev, "HDMI connector with no type\n");
 247                         return -EINVAL;
 248                 }
 249
 250                 if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") ||
 251                     !strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) {
 252                         conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 253                 } else if (!strcmp(hdmi_type, "b")) {
 254                         conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
 255                 } else {
 256                         dev_err(&pdev->dev,
 257                                 "Unsupported HDMI connector type '%s'\n",
 258                                 hdmi_type);
 259                         return -EINVAL;
 260                 }
 261
 262                 break;
 263         }
 264
 265         default:
 266                 conn->bridge.type = type;
 267                 break;
 268         }
 269
 270         /* All the supported connector types support interlaced modes. */
 271         conn->bridge.interlace_allowed = true;
 272
 273         /* Get the optional connector label. */
 274         of_property_read_string(pdev->dev.of_node, "label", &label);
 275
 276         /*
 277          * Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
 278          * edge interrupts, register an interrupt handler.
 279          */
 280         if (type == DRM_MODE_CONNECTOR_DVII ||
 281             type == DRM_MODE_CONNECTOR_HDMIA ||
 282             type == DRM_MODE_CONNECTOR_DisplayPort) {
 283                 conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
 284                                                          GPIOD_IN);
 285                 if (IS_ERR(conn->hpd_gpio))
 286                         return dev_err_probe(&pdev->dev, PTR_ERR(conn->hpd_gpio),
 287                                              "Unable to retrieve HPD GPIO\n");
 288
 289                 conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
 290         } else {
 291                 conn->hpd_irq = -EINVAL;
 292         }
 293
 294         if (conn->hpd_irq >= 0) {
 295                 ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
 296                                                 NULL, display_connector_hpd_irq,
 297                                                 IRQF_TRIGGER_RISING |
 298                                                 IRQF_TRIGGER_FALLING |
 299                                                 IRQF_ONESHOT,
 300                                                 "HPD", conn);
 301                 if (ret) {
 302                         dev_info(&pdev->dev,
 303                                  "Failed to request HPD edge interrupt, falling back to polling\n");
 304                         conn->hpd_irq = -EINVAL;
 305                 }
 306         }
 307
 308         /* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
 309         if (type == DRM_MODE_CONNECTOR_DVII ||
 310             type == DRM_MODE_CONNECTOR_HDMIA ||
 311             type == DRM_MODE_CONNECTOR_VGA) {
 312                 struct device_node *phandle;
 313
 314                 phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
 315                 if (phandle) {
 316                         conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
 317                         of_node_put(phandle);
 318                         if (!conn->bridge.ddc)
 319                                 return -EPROBE_DEFER;
 320                 } else {
 321                         dev_dbg(&pdev->dev,
 322                                 "No I2C bus specified, disabling EDID readout\n");
 323                 }
 324         }
 325
 326         /* Get the DP PWR for DP connector. */
 327         if (type == DRM_MODE_CONNECTOR_DisplayPort) {
 328                 int ret;
 329
 330                 ret = display_connector_get_supply(pdev, conn, "dp-pwr");
 331                 if (ret < 0)
 332                         return dev_err_probe(&pdev->dev, ret, "failed to get DP PWR regulator\n");
 333         }
 334
 335         /* enable DDC */
 336         if (type == DRM_MODE_CONNECTOR_HDMIA) {
 337                 int ret;
 338
 339                 conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
 340                                                        GPIOD_OUT_HIGH);
 341
 342                 if (IS_ERR(conn->ddc_en)) {
 343                         dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
 344                         return PTR_ERR(conn->ddc_en);
 345                 }
 346
 347                 ret = display_connector_get_supply(pdev, conn, "hdmi-pwr");
 348                 if (ret < 0)
 349                         return dev_err_probe(&pdev->dev, ret, "failed to get HDMI +5V Power regulator\n");
 350         }
 351
 352         if (conn->supply) {
 353                 ret = regulator_enable(conn->supply);
 354                 if (ret) {
 355                         dev_err(&pdev->dev, "failed to enable PWR regulator: %d\n", ret);
 356                         return ret;
 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 void 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->supply)
 392                 regulator_disable(conn->supply);
 393
 394         drm_bridge_remove(&conn->bridge);
 395
 396         if (!IS_ERR(conn->bridge.ddc))
 397                 i2c_put_adapter(conn->bridge.ddc);
 398 }
 399
 400 static const struct of_device_id display_connector_match[] = {
 401         {
 402                 .compatible = "composite-video-connector",
 403                 .data = (void *)DRM_MODE_CONNECTOR_Composite,
 404         }, {
 405                 .compatible = "dvi-connector",
 406                 .data = (void *)DRM_MODE_CONNECTOR_DVII,
 407         }, {
 408                 .compatible = "hdmi-connector",
 409                 .data = (void *)DRM_MODE_CONNECTOR_HDMIA,
 410         }, {
 411                 .compatible = "svideo-connector",
 412                 .data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
 413         }, {
 414                 .compatible = "vga-connector",
 415                 .data = (void *)DRM_MODE_CONNECTOR_VGA,
 416         }, {
 417                 .compatible = "dp-connector",
 418                 .data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
 419         },
 420         {},
 421 };
 422 MODULE_DEVICE_TABLE(of, display_connector_match);
 423
 424 static struct platform_driver display_connector_driver = {
 425         .probe  = display_connector_probe,
 426         .remove_new = display_connector_remove,
 427         .driver         = {
 428                 .name           = "display-connector",
 429                 .of_match_table = display_connector_match,
 430         },
 431 };
 432 module_platform_driver(display_connector_driver);
 433
 434 MODULE_AUTHOR("Laurent Pinchart <[email protected]>");
 435 MODULE_DESCRIPTION("Display connector driver");
 436 MODULE_LICENSE("GPL");