1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for onboard USB hubs 4 * 5 * Copyright (c) 2022, Google LLC 6 */ 7 8 #include <linux/device.h> 9 #include <linux/export.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/list.h> 14 #include <linux/module.h> 15 #include <linux/mutex.h> 16 #include <linux/of.h> 17 #include <linux/of_platform.h> 18 #include <linux/platform_device.h> 19 #include <linux/regulator/consumer.h> 20 #include <linux/slab.h> 21 #include <linux/suspend.h> 22 #include <linux/sysfs.h> 23 #include <linux/usb.h> 24 #include <linux/usb/hcd.h> 25 #include <linux/usb/onboard_hub.h> 26 #include <linux/workqueue.h> 27 28 #include "onboard_usb_hub.h" 29 30 /* 31 * Use generic names, as the actual names might differ between hubs. If a new 32 * hub requires more than the currently supported supplies, add a new one here. 33 */ 34 static const char * const supply_names[] = { 35 "vdd", 36 "vdd2", 37 }; 38 39 #define MAX_SUPPLIES ARRAY_SIZE(supply_names) 40 41 static void onboard_hub_attach_usb_driver(struct work_struct *work); 42 43 static struct usb_device_driver onboard_hub_usbdev_driver; 44 static DECLARE_WORK(attach_usb_driver_work, onboard_hub_attach_usb_driver); 45 46 /************************** Platform driver **************************/ 47 48 struct usbdev_node { 49 struct usb_device *udev; 50 struct list_head list; 51 }; 52 53 struct onboard_hub { 54 struct regulator_bulk_data supplies[MAX_SUPPLIES]; 55 struct device *dev; 56 const struct onboard_hub_pdata *pdata; 57 struct gpio_desc *reset_gpio; 58 bool always_powered_in_suspend; 59 bool is_powered_on; 60 bool going_away; 61 struct list_head udev_list; 62 struct mutex lock; 63 }; 64 65 static int onboard_hub_power_on(struct onboard_hub *hub) 66 { 67 int err; 68 69 err = regulator_bulk_enable(hub->pdata->num_supplies, hub->supplies); 70 if (err) { 71 dev_err(hub->dev, "failed to enable supplies: %d\n", err); 72 return err; 73 } 74 75 fsleep(hub->pdata->reset_us); 76 gpiod_set_value_cansleep(hub->reset_gpio, 0); 77 78 hub->is_powered_on = true; 79 80 return 0; 81 } 82 83 static int onboard_hub_power_off(struct onboard_hub *hub) 84 { 85 int err; 86 87 gpiod_set_value_cansleep(hub->reset_gpio, 1); 88 89 err = regulator_bulk_disable(hub->pdata->num_supplies, hub->supplies); 90 if (err) { 91 dev_err(hub->dev, "failed to disable supplies: %d\n", err); 92 return err; 93 } 94 95 hub->is_powered_on = false; 96 97 return 0; 98 } 99 100 static int __maybe_unused onboard_hub_suspend(struct device *dev) 101 { 102 struct onboard_hub *hub = dev_get_drvdata(dev); 103 struct usbdev_node *node; 104 bool power_off = true; 105 106 if (hub->always_powered_in_suspend) 107 return 0; 108 109 mutex_lock(&hub->lock); 110 111 list_for_each_entry(node, &hub->udev_list, list) { 112 if (!device_may_wakeup(node->udev->bus->controller)) 113 continue; 114 115 if (usb_wakeup_enabled_descendants(node->udev)) { 116 power_off = false; 117 break; 118 } 119 } 120 121 mutex_unlock(&hub->lock); 122 123 if (!power_off) 124 return 0; 125 126 return onboard_hub_power_off(hub); 127 } 128 129 static int __maybe_unused onboard_hub_resume(struct device *dev) 130 { 131 struct onboard_hub *hub = dev_get_drvdata(dev); 132 133 if (hub->is_powered_on) 134 return 0; 135 136 return onboard_hub_power_on(hub); 137 } 138 139 static inline void get_udev_link_name(const struct usb_device *udev, char *buf, size_t size) 140 { 141 snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev)); 142 } 143 144 static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev) 145 { 146 struct usbdev_node *node; 147 char link_name[64]; 148 int err; 149 150 mutex_lock(&hub->lock); 151 152 if (hub->going_away) { 153 err = -EINVAL; 154 goto error; 155 } 156 157 node = kzalloc(sizeof(*node), GFP_KERNEL); 158 if (!node) { 159 err = -ENOMEM; 160 goto error; 161 } 162 163 node->udev = udev; 164 165 list_add(&node->list, &hub->udev_list); 166 167 mutex_unlock(&hub->lock); 168 169 get_udev_link_name(udev, link_name, sizeof(link_name)); 170 WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name)); 171 172 return 0; 173 174 error: 175 mutex_unlock(&hub->lock); 176 177 return err; 178 } 179 180 static void onboard_hub_remove_usbdev(struct onboard_hub *hub, const struct usb_device *udev) 181 { 182 struct usbdev_node *node; 183 char link_name[64]; 184 185 get_udev_link_name(udev, link_name, sizeof(link_name)); 186 sysfs_remove_link(&hub->dev->kobj, link_name); 187 188 mutex_lock(&hub->lock); 189 190 list_for_each_entry(node, &hub->udev_list, list) { 191 if (node->udev == udev) { 192 list_del(&node->list); 193 kfree(node); 194 break; 195 } 196 } 197 198 mutex_unlock(&hub->lock); 199 } 200 201 static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr, 202 char *buf) 203 { 204 const struct onboard_hub *hub = dev_get_drvdata(dev); 205 206 return sysfs_emit(buf, "%d\n", hub->always_powered_in_suspend); 207 } 208 209 static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr, 210 const char *buf, size_t count) 211 { 212 struct onboard_hub *hub = dev_get_drvdata(dev); 213 bool val; 214 int ret; 215 216 ret = kstrtobool(buf, &val); 217 if (ret < 0) 218 return ret; 219 220 hub->always_powered_in_suspend = val; 221 222 return count; 223 } 224 static DEVICE_ATTR_RW(always_powered_in_suspend); 225 226 static struct attribute *onboard_hub_attrs[] = { 227 &dev_attr_always_powered_in_suspend.attr, 228 NULL, 229 }; 230 ATTRIBUTE_GROUPS(onboard_hub); 231 232 static void onboard_hub_attach_usb_driver(struct work_struct *work) 233 { 234 int err; 235 236 err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver); 237 if (err) 238 pr_err("Failed to attach USB driver: %d\n", err); 239 } 240 241 static int onboard_hub_probe(struct platform_device *pdev) 242 { 243 struct device *dev = &pdev->dev; 244 struct onboard_hub *hub; 245 unsigned int i; 246 int err; 247 248 hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL); 249 if (!hub) 250 return -ENOMEM; 251 252 hub->pdata = device_get_match_data(&pdev->dev); 253 if (!hub->pdata) 254 return -EINVAL; 255 256 if (hub->pdata->num_supplies > MAX_SUPPLIES) 257 return dev_err_probe(dev, -EINVAL, "max %zu supplies supported!\n", 258 MAX_SUPPLIES); 259 260 for (i = 0; i < hub->pdata->num_supplies; i++) 261 hub->supplies[i].supply = supply_names[i]; 262 263 err = devm_regulator_bulk_get(dev, hub->pdata->num_supplies, hub->supplies); 264 if (err) { 265 dev_err(dev, "Failed to get regulator supplies: %d\n", err); 266 return err; 267 } 268 269 hub->reset_gpio = devm_gpiod_get_optional(dev, "reset", 270 GPIOD_OUT_HIGH); 271 if (IS_ERR(hub->reset_gpio)) 272 return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), "failed to get reset GPIO\n"); 273 274 hub->dev = dev; 275 mutex_init(&hub->lock); 276 INIT_LIST_HEAD(&hub->udev_list); 277 278 dev_set_drvdata(dev, hub); 279 280 err = onboard_hub_power_on(hub); 281 if (err) 282 return err; 283 284 /* 285 * The USB driver might have been detached from the USB devices by 286 * onboard_hub_remove() (e.g. through an 'unbind' by userspace), 287 * make sure to re-attach it if needed. 288 * 289 * This needs to be done deferred to avoid self-deadlocks on systems 290 * with nested onboard hubs. 291 */ 292 schedule_work(&attach_usb_driver_work); 293 294 return 0; 295 } 296 297 static void onboard_hub_remove(struct platform_device *pdev) 298 { 299 struct onboard_hub *hub = dev_get_drvdata(&pdev->dev); 300 struct usbdev_node *node; 301 struct usb_device *udev; 302 303 hub->going_away = true; 304 305 mutex_lock(&hub->lock); 306 307 /* unbind the USB devices to avoid dangling references to this device */ 308 while (!list_empty(&hub->udev_list)) { 309 node = list_first_entry(&hub->udev_list, struct usbdev_node, list); 310 udev = node->udev; 311 312 /* 313 * Unbinding the driver will call onboard_hub_remove_usbdev(), 314 * which acquires hub->lock. We must release the lock first. 315 */ 316 get_device(&udev->dev); 317 mutex_unlock(&hub->lock); 318 device_release_driver(&udev->dev); 319 put_device(&udev->dev); 320 mutex_lock(&hub->lock); 321 } 322 323 mutex_unlock(&hub->lock); 324 325 onboard_hub_power_off(hub); 326 } 327 328 MODULE_DEVICE_TABLE(of, onboard_hub_match); 329 330 static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = { 331 SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume) 332 }; 333 334 static struct platform_driver onboard_hub_driver = { 335 .probe = onboard_hub_probe, 336 .remove_new = onboard_hub_remove, 337 338 .driver = { 339 .name = "onboard-usb-hub", 340 .of_match_table = onboard_hub_match, 341 .pm = pm_ptr(&onboard_hub_pm_ops), 342 .dev_groups = onboard_hub_groups, 343 }, 344 }; 345 346 /************************** USB driver **************************/ 347 348 #define VENDOR_ID_CYPRESS 0x04b4 349 #define VENDOR_ID_GENESYS 0x05e3 350 #define VENDOR_ID_MICROCHIP 0x0424 351 #define VENDOR_ID_REALTEK 0x0bda 352 #define VENDOR_ID_TI 0x0451 353 #define VENDOR_ID_VIA 0x2109 354 355 /* 356 * Returns the onboard_hub platform device that is associated with the USB 357 * device passed as parameter. 358 */ 359 static struct onboard_hub *_find_onboard_hub(struct device *dev) 360 { 361 struct platform_device *pdev; 362 struct device_node *np; 363 struct onboard_hub *hub; 364 365 pdev = of_find_device_by_node(dev->of_node); 366 if (!pdev) { 367 np = of_parse_phandle(dev->of_node, "peer-hub", 0); 368 if (!np) { 369 dev_err(dev, "failed to find device node for peer hub\n"); 370 return ERR_PTR(-EINVAL); 371 } 372 373 pdev = of_find_device_by_node(np); 374 of_node_put(np); 375 376 if (!pdev) 377 return ERR_PTR(-ENODEV); 378 } 379 380 hub = dev_get_drvdata(&pdev->dev); 381 put_device(&pdev->dev); 382 383 /* 384 * The presence of drvdata ('hub') indicates that the platform driver 385 * finished probing. This handles the case where (conceivably) we could 386 * be running at the exact same time as the platform driver's probe. If 387 * we detect the race we request probe deferral and we'll come back and 388 * try again. 389 */ 390 if (!hub) 391 return ERR_PTR(-EPROBE_DEFER); 392 393 return hub; 394 } 395 396 static int onboard_hub_usbdev_probe(struct usb_device *udev) 397 { 398 struct device *dev = &udev->dev; 399 struct onboard_hub *hub; 400 int err; 401 402 /* ignore supported hubs without device tree node */ 403 if (!dev->of_node) 404 return -ENODEV; 405 406 hub = _find_onboard_hub(dev); 407 if (IS_ERR(hub)) 408 return PTR_ERR(hub); 409 410 dev_set_drvdata(dev, hub); 411 412 err = onboard_hub_add_usbdev(hub, udev); 413 if (err) 414 return err; 415 416 return 0; 417 } 418 419 static void onboard_hub_usbdev_disconnect(struct usb_device *udev) 420 { 421 struct onboard_hub *hub = dev_get_drvdata(&udev->dev); 422 423 onboard_hub_remove_usbdev(hub, udev); 424 } 425 426 static const struct usb_device_id onboard_hub_id_table[] = { 427 { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 */ 428 { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 */ 429 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 */ 430 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 */ 431 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 */ 432 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 */ 433 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 */ 434 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 */ 435 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 */ 436 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 */ 437 { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 */ 438 { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 */ 439 { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 */ 440 { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 */ 441 { USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 */ 442 { USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 */ 443 { USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 */ 444 { USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 */ 445 {} 446 }; 447 MODULE_DEVICE_TABLE(usb, onboard_hub_id_table); 448 449 static struct usb_device_driver onboard_hub_usbdev_driver = { 450 .name = "onboard-usb-hub", 451 .probe = onboard_hub_usbdev_probe, 452 .disconnect = onboard_hub_usbdev_disconnect, 453 .generic_subclass = 1, 454 .supports_autosuspend = 1, 455 .id_table = onboard_hub_id_table, 456 }; 457 458 static int __init onboard_hub_init(void) 459 { 460 int ret; 461 462 ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE); 463 if (ret) 464 return ret; 465 466 ret = platform_driver_register(&onboard_hub_driver); 467 if (ret) 468 usb_deregister_device_driver(&onboard_hub_usbdev_driver); 469 470 return ret; 471 } 472 module_init(onboard_hub_init); 473 474 static void __exit onboard_hub_exit(void) 475 { 476 usb_deregister_device_driver(&onboard_hub_usbdev_driver); 477 platform_driver_unregister(&onboard_hub_driver); 478 479 cancel_work_sync(&attach_usb_driver_work); 480 } 481 module_exit(onboard_hub_exit); 482 483 MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>"); 484 MODULE_DESCRIPTION("Driver for discrete onboard USB hubs"); 485 MODULE_LICENSE("GPL v2"); 486