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/clk.h> |
9 | #include <linux/device.h> |
10 | #include <linux/export.h> |
11 | #include <linux/err.h> |
12 | #include <linux/gpio/consumer.h> |
13 | #include <linux/init.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/list.h> |
16 | #include <linux/module.h> |
17 | #include <linux/mutex.h> |
18 | #include <linux/of.h> |
19 | #include <linux/of_platform.h> |
20 | #include <linux/platform_device.h> |
21 | #include <linux/regulator/consumer.h> |
22 | #include <linux/slab.h> |
23 | #include <linux/suspend.h> |
24 | #include <linux/sysfs.h> |
25 | #include <linux/usb.h> |
26 | #include <linux/usb/hcd.h> |
27 | #include <linux/usb/onboard_hub.h> |
28 | #include <linux/workqueue.h> |
29 | |
30 | #include "onboard_usb_hub.h" |
31 | |
32 | /* |
33 | * Use generic names, as the actual names might differ between hubs. If a new |
34 | * hub requires more than the currently supported supplies, add a new one here. |
35 | */ |
36 | static const char * const supply_names[] = { |
37 | "vdd" , |
38 | "vdd2" , |
39 | }; |
40 | |
41 | #define MAX_SUPPLIES ARRAY_SIZE(supply_names) |
42 | |
43 | static void onboard_hub_attach_usb_driver(struct work_struct *work); |
44 | |
45 | static struct usb_device_driver onboard_hub_usbdev_driver; |
46 | static DECLARE_WORK(attach_usb_driver_work, onboard_hub_attach_usb_driver); |
47 | |
48 | /************************** Platform driver **************************/ |
49 | |
50 | struct usbdev_node { |
51 | struct usb_device *udev; |
52 | struct list_head list; |
53 | }; |
54 | |
55 | struct onboard_hub { |
56 | struct regulator_bulk_data supplies[MAX_SUPPLIES]; |
57 | struct device *dev; |
58 | const struct onboard_hub_pdata *pdata; |
59 | struct gpio_desc *reset_gpio; |
60 | bool always_powered_in_suspend; |
61 | bool is_powered_on; |
62 | bool going_away; |
63 | struct list_head udev_list; |
64 | struct mutex lock; |
65 | struct clk *clk; |
66 | }; |
67 | |
68 | static int onboard_hub_power_on(struct onboard_hub *hub) |
69 | { |
70 | int err; |
71 | |
72 | err = clk_prepare_enable(clk: hub->clk); |
73 | if (err) { |
74 | dev_err(hub->dev, "failed to enable clock: %pe\n" , ERR_PTR(err)); |
75 | return err; |
76 | } |
77 | |
78 | err = regulator_bulk_enable(num_consumers: hub->pdata->num_supplies, consumers: hub->supplies); |
79 | if (err) { |
80 | dev_err(hub->dev, "failed to enable supplies: %pe\n" , ERR_PTR(err)); |
81 | goto disable_clk; |
82 | } |
83 | |
84 | fsleep(usecs: hub->pdata->reset_us); |
85 | gpiod_set_value_cansleep(desc: hub->reset_gpio, value: 0); |
86 | |
87 | hub->is_powered_on = true; |
88 | |
89 | return 0; |
90 | |
91 | disable_clk: |
92 | clk_disable_unprepare(clk: hub->clk); |
93 | return err; |
94 | } |
95 | |
96 | static int onboard_hub_power_off(struct onboard_hub *hub) |
97 | { |
98 | int err; |
99 | |
100 | gpiod_set_value_cansleep(desc: hub->reset_gpio, value: 1); |
101 | |
102 | err = regulator_bulk_disable(num_consumers: hub->pdata->num_supplies, consumers: hub->supplies); |
103 | if (err) { |
104 | dev_err(hub->dev, "failed to disable supplies: %pe\n" , ERR_PTR(err)); |
105 | return err; |
106 | } |
107 | |
108 | clk_disable_unprepare(clk: hub->clk); |
109 | |
110 | hub->is_powered_on = false; |
111 | |
112 | return 0; |
113 | } |
114 | |
115 | static int __maybe_unused onboard_hub_suspend(struct device *dev) |
116 | { |
117 | struct onboard_hub *hub = dev_get_drvdata(dev); |
118 | struct usbdev_node *node; |
119 | bool power_off = true; |
120 | |
121 | if (hub->always_powered_in_suspend) |
122 | return 0; |
123 | |
124 | mutex_lock(&hub->lock); |
125 | |
126 | list_for_each_entry(node, &hub->udev_list, list) { |
127 | if (!device_may_wakeup(dev: node->udev->bus->controller)) |
128 | continue; |
129 | |
130 | if (usb_wakeup_enabled_descendants(udev: node->udev)) { |
131 | power_off = false; |
132 | break; |
133 | } |
134 | } |
135 | |
136 | mutex_unlock(lock: &hub->lock); |
137 | |
138 | if (!power_off) |
139 | return 0; |
140 | |
141 | return onboard_hub_power_off(hub); |
142 | } |
143 | |
144 | static int __maybe_unused onboard_hub_resume(struct device *dev) |
145 | { |
146 | struct onboard_hub *hub = dev_get_drvdata(dev); |
147 | |
148 | if (hub->is_powered_on) |
149 | return 0; |
150 | |
151 | return onboard_hub_power_on(hub); |
152 | } |
153 | |
154 | static inline void get_udev_link_name(const struct usb_device *udev, char *buf, size_t size) |
155 | { |
156 | snprintf(buf, size, fmt: "usb_dev.%s" , dev_name(dev: &udev->dev)); |
157 | } |
158 | |
159 | static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev) |
160 | { |
161 | struct usbdev_node *node; |
162 | char link_name[64]; |
163 | int err; |
164 | |
165 | mutex_lock(&hub->lock); |
166 | |
167 | if (hub->going_away) { |
168 | err = -EINVAL; |
169 | goto error; |
170 | } |
171 | |
172 | node = kzalloc(size: sizeof(*node), GFP_KERNEL); |
173 | if (!node) { |
174 | err = -ENOMEM; |
175 | goto error; |
176 | } |
177 | |
178 | node->udev = udev; |
179 | |
180 | list_add(new: &node->list, head: &hub->udev_list); |
181 | |
182 | mutex_unlock(lock: &hub->lock); |
183 | |
184 | get_udev_link_name(udev, buf: link_name, size: sizeof(link_name)); |
185 | WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name)); |
186 | |
187 | return 0; |
188 | |
189 | error: |
190 | mutex_unlock(lock: &hub->lock); |
191 | |
192 | return err; |
193 | } |
194 | |
195 | static void onboard_hub_remove_usbdev(struct onboard_hub *hub, const struct usb_device *udev) |
196 | { |
197 | struct usbdev_node *node; |
198 | char link_name[64]; |
199 | |
200 | get_udev_link_name(udev, buf: link_name, size: sizeof(link_name)); |
201 | sysfs_remove_link(kobj: &hub->dev->kobj, name: link_name); |
202 | |
203 | mutex_lock(&hub->lock); |
204 | |
205 | list_for_each_entry(node, &hub->udev_list, list) { |
206 | if (node->udev == udev) { |
207 | list_del(entry: &node->list); |
208 | kfree(objp: node); |
209 | break; |
210 | } |
211 | } |
212 | |
213 | mutex_unlock(lock: &hub->lock); |
214 | } |
215 | |
216 | static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr, |
217 | char *buf) |
218 | { |
219 | const struct onboard_hub *hub = dev_get_drvdata(dev); |
220 | |
221 | return sysfs_emit(buf, fmt: "%d\n" , hub->always_powered_in_suspend); |
222 | } |
223 | |
224 | static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr, |
225 | const char *buf, size_t count) |
226 | { |
227 | struct onboard_hub *hub = dev_get_drvdata(dev); |
228 | bool val; |
229 | int ret; |
230 | |
231 | ret = kstrtobool(s: buf, res: &val); |
232 | if (ret < 0) |
233 | return ret; |
234 | |
235 | hub->always_powered_in_suspend = val; |
236 | |
237 | return count; |
238 | } |
239 | static DEVICE_ATTR_RW(always_powered_in_suspend); |
240 | |
241 | static struct attribute *onboard_hub_attrs[] = { |
242 | &dev_attr_always_powered_in_suspend.attr, |
243 | NULL, |
244 | }; |
245 | ATTRIBUTE_GROUPS(onboard_hub); |
246 | |
247 | static void onboard_hub_attach_usb_driver(struct work_struct *work) |
248 | { |
249 | int err; |
250 | |
251 | err = driver_attach(drv: &onboard_hub_usbdev_driver.driver); |
252 | if (err) |
253 | pr_err("Failed to attach USB driver: %pe\n" , ERR_PTR(err)); |
254 | } |
255 | |
256 | static int onboard_hub_probe(struct platform_device *pdev) |
257 | { |
258 | struct device *dev = &pdev->dev; |
259 | struct onboard_hub *hub; |
260 | unsigned int i; |
261 | int err; |
262 | |
263 | hub = devm_kzalloc(dev, size: sizeof(*hub), GFP_KERNEL); |
264 | if (!hub) |
265 | return -ENOMEM; |
266 | |
267 | hub->pdata = device_get_match_data(dev); |
268 | if (!hub->pdata) |
269 | return -EINVAL; |
270 | |
271 | if (hub->pdata->num_supplies > MAX_SUPPLIES) |
272 | return dev_err_probe(dev, err: -EINVAL, fmt: "max %zu supplies supported!\n" , |
273 | MAX_SUPPLIES); |
274 | |
275 | for (i = 0; i < hub->pdata->num_supplies; i++) |
276 | hub->supplies[i].supply = supply_names[i]; |
277 | |
278 | err = devm_regulator_bulk_get(dev, num_consumers: hub->pdata->num_supplies, consumers: hub->supplies); |
279 | if (err) { |
280 | dev_err(dev, "Failed to get regulator supplies: %pe\n" , ERR_PTR(err)); |
281 | return err; |
282 | } |
283 | |
284 | hub->clk = devm_clk_get_optional(dev, NULL); |
285 | if (IS_ERR(ptr: hub->clk)) |
286 | return dev_err_probe(dev, err: PTR_ERR(ptr: hub->clk), fmt: "failed to get clock\n" ); |
287 | |
288 | hub->reset_gpio = devm_gpiod_get_optional(dev, con_id: "reset" , |
289 | flags: GPIOD_OUT_HIGH); |
290 | if (IS_ERR(ptr: hub->reset_gpio)) |
291 | return dev_err_probe(dev, err: PTR_ERR(ptr: hub->reset_gpio), fmt: "failed to get reset GPIO\n" ); |
292 | |
293 | hub->dev = dev; |
294 | mutex_init(&hub->lock); |
295 | INIT_LIST_HEAD(list: &hub->udev_list); |
296 | |
297 | dev_set_drvdata(dev, data: hub); |
298 | |
299 | err = onboard_hub_power_on(hub); |
300 | if (err) |
301 | return err; |
302 | |
303 | /* |
304 | * The USB driver might have been detached from the USB devices by |
305 | * onboard_hub_remove() (e.g. through an 'unbind' by userspace), |
306 | * make sure to re-attach it if needed. |
307 | * |
308 | * This needs to be done deferred to avoid self-deadlocks on systems |
309 | * with nested onboard hubs. |
310 | */ |
311 | schedule_work(work: &attach_usb_driver_work); |
312 | |
313 | return 0; |
314 | } |
315 | |
316 | static void onboard_hub_remove(struct platform_device *pdev) |
317 | { |
318 | struct onboard_hub *hub = dev_get_drvdata(dev: &pdev->dev); |
319 | struct usbdev_node *node; |
320 | struct usb_device *udev; |
321 | |
322 | hub->going_away = true; |
323 | |
324 | mutex_lock(&hub->lock); |
325 | |
326 | /* unbind the USB devices to avoid dangling references to this device */ |
327 | while (!list_empty(head: &hub->udev_list)) { |
328 | node = list_first_entry(&hub->udev_list, struct usbdev_node, list); |
329 | udev = node->udev; |
330 | |
331 | /* |
332 | * Unbinding the driver will call onboard_hub_remove_usbdev(), |
333 | * which acquires hub->lock. We must release the lock first. |
334 | */ |
335 | get_device(dev: &udev->dev); |
336 | mutex_unlock(lock: &hub->lock); |
337 | device_release_driver(dev: &udev->dev); |
338 | put_device(dev: &udev->dev); |
339 | mutex_lock(&hub->lock); |
340 | } |
341 | |
342 | mutex_unlock(lock: &hub->lock); |
343 | |
344 | onboard_hub_power_off(hub); |
345 | } |
346 | |
347 | MODULE_DEVICE_TABLE(of, onboard_hub_match); |
348 | |
349 | static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = { |
350 | SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume) |
351 | }; |
352 | |
353 | static struct platform_driver onboard_hub_driver = { |
354 | .probe = onboard_hub_probe, |
355 | .remove_new = onboard_hub_remove, |
356 | |
357 | .driver = { |
358 | .name = "onboard-usb-hub" , |
359 | .of_match_table = onboard_hub_match, |
360 | .pm = pm_ptr(&onboard_hub_pm_ops), |
361 | .dev_groups = onboard_hub_groups, |
362 | }, |
363 | }; |
364 | |
365 | /************************** USB driver **************************/ |
366 | |
367 | #define VENDOR_ID_CYPRESS 0x04b4 |
368 | #define VENDOR_ID_GENESYS 0x05e3 |
369 | #define VENDOR_ID_MICROCHIP 0x0424 |
370 | #define VENDOR_ID_REALTEK 0x0bda |
371 | #define VENDOR_ID_TI 0x0451 |
372 | #define VENDOR_ID_VIA 0x2109 |
373 | |
374 | /* |
375 | * Returns the onboard_hub platform device that is associated with the USB |
376 | * device passed as parameter. |
377 | */ |
378 | static struct onboard_hub *_find_onboard_hub(struct device *dev) |
379 | { |
380 | struct platform_device *pdev; |
381 | struct device_node *np; |
382 | struct onboard_hub *hub; |
383 | |
384 | pdev = of_find_device_by_node(np: dev->of_node); |
385 | if (!pdev) { |
386 | np = of_parse_phandle(np: dev->of_node, phandle_name: "peer-hub" , index: 0); |
387 | if (!np) { |
388 | dev_err(dev, "failed to find device node for peer hub\n" ); |
389 | return ERR_PTR(error: -EINVAL); |
390 | } |
391 | |
392 | pdev = of_find_device_by_node(np); |
393 | of_node_put(node: np); |
394 | |
395 | if (!pdev) |
396 | return ERR_PTR(error: -ENODEV); |
397 | } |
398 | |
399 | hub = dev_get_drvdata(dev: &pdev->dev); |
400 | put_device(dev: &pdev->dev); |
401 | |
402 | /* |
403 | * The presence of drvdata ('hub') indicates that the platform driver |
404 | * finished probing. This handles the case where (conceivably) we could |
405 | * be running at the exact same time as the platform driver's probe. If |
406 | * we detect the race we request probe deferral and we'll come back and |
407 | * try again. |
408 | */ |
409 | if (!hub) |
410 | return ERR_PTR(error: -EPROBE_DEFER); |
411 | |
412 | return hub; |
413 | } |
414 | |
415 | static int onboard_hub_usbdev_probe(struct usb_device *udev) |
416 | { |
417 | struct device *dev = &udev->dev; |
418 | struct onboard_hub *hub; |
419 | int err; |
420 | |
421 | /* ignore supported hubs without device tree node */ |
422 | if (!dev->of_node) |
423 | return -ENODEV; |
424 | |
425 | hub = _find_onboard_hub(dev); |
426 | if (IS_ERR(ptr: hub)) |
427 | return PTR_ERR(ptr: hub); |
428 | |
429 | dev_set_drvdata(dev, data: hub); |
430 | |
431 | err = onboard_hub_add_usbdev(hub, udev); |
432 | if (err) |
433 | return err; |
434 | |
435 | return 0; |
436 | } |
437 | |
438 | static void onboard_hub_usbdev_disconnect(struct usb_device *udev) |
439 | { |
440 | struct onboard_hub *hub = dev_get_drvdata(dev: &udev->dev); |
441 | |
442 | onboard_hub_remove_usbdev(hub, udev); |
443 | } |
444 | |
445 | static const struct usb_device_id onboard_hub_id_table[] = { |
446 | { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 */ |
447 | { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 */ |
448 | { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 */ |
449 | { USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 */ |
450 | { USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 */ |
451 | { USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 */ |
452 | { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 */ |
453 | { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 */ |
454 | { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 */ |
455 | { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 */ |
456 | { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 */ |
457 | { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 */ |
458 | { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 */ |
459 | { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 */ |
460 | { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 */ |
461 | { USB_DEVICE(VENDOR_ID_TI, 0x8025) }, /* TI USB8020B 3.0 */ |
462 | { USB_DEVICE(VENDOR_ID_TI, 0x8027) }, /* TI USB8020B 2.0 */ |
463 | { USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 */ |
464 | { USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 */ |
465 | { USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 */ |
466 | { USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 */ |
467 | {} |
468 | }; |
469 | MODULE_DEVICE_TABLE(usb, onboard_hub_id_table); |
470 | |
471 | static struct usb_device_driver onboard_hub_usbdev_driver = { |
472 | .name = "onboard-usb-hub" , |
473 | .probe = onboard_hub_usbdev_probe, |
474 | .disconnect = onboard_hub_usbdev_disconnect, |
475 | .generic_subclass = 1, |
476 | .supports_autosuspend = 1, |
477 | .id_table = onboard_hub_id_table, |
478 | }; |
479 | |
480 | static int __init onboard_hub_init(void) |
481 | { |
482 | int ret; |
483 | |
484 | ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE); |
485 | if (ret) |
486 | return ret; |
487 | |
488 | ret = platform_driver_register(&onboard_hub_driver); |
489 | if (ret) |
490 | usb_deregister_device_driver(&onboard_hub_usbdev_driver); |
491 | |
492 | return ret; |
493 | } |
494 | module_init(onboard_hub_init); |
495 | |
496 | static void __exit onboard_hub_exit(void) |
497 | { |
498 | usb_deregister_device_driver(&onboard_hub_usbdev_driver); |
499 | platform_driver_unregister(&onboard_hub_driver); |
500 | |
501 | cancel_work_sync(work: &attach_usb_driver_work); |
502 | } |
503 | module_exit(onboard_hub_exit); |
504 | |
505 | MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>" ); |
506 | MODULE_DESCRIPTION("Driver for discrete onboard USB hubs" ); |
507 | MODULE_LICENSE("GPL v2" ); |
508 | |