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/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 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_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 <laurent.pinchart@ideasonboard.com>"); 435 MODULE_DESCRIPTION("Display connector driver"); 436 MODULE_LICENSE("GPL"); 437