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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for onboard USB devices
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/i2c.h>
15#include <linux/kernel.h>
16#include <linux/list.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/of.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/regulator/consumer.h>
23#include <linux/slab.h>
24#include <linux/suspend.h>
25#include <linux/sysfs.h>
26#include <linux/usb.h>
27#include <linux/usb/hcd.h>
28#include <linux/usb/onboard_dev.h>
29#include <linux/workqueue.h>
30
31#include "onboard_usb_dev.h"
32
33/* USB5744 register offset and mask */
34#define USB5744_CMD_ATTACH 0xAA
35#define USB5744_CMD_ATTACH_LSB 0x56
36#define USB5744_CMD_CREG_ACCESS 0x99
37#define USB5744_CMD_CREG_ACCESS_LSB 0x37
38#define USB5744_CREG_MEM_ADDR 0x00
39#define USB5744_CREG_WRITE 0x00
40#define USB5744_CREG_RUNTIMEFLAGS2 0x41
41#define USB5744_CREG_RUNTIMEFLAGS2_LSB 0x1D
42#define USB5744_CREG_BYPASS_UDC_SUSPEND BIT(3)
43
44static void onboard_dev_attach_usb_driver(struct work_struct *work);
45
46static struct usb_device_driver onboard_dev_usbdev_driver;
47static DECLARE_WORK(attach_usb_driver_work, onboard_dev_attach_usb_driver);
48
49/************************** Platform driver **************************/
50
51struct usbdev_node {
52 struct usb_device *udev;
53 struct list_head list;
54};
55
56struct onboard_dev {
57 struct regulator_bulk_data supplies[MAX_SUPPLIES];
58 struct device *dev;
59 const struct onboard_dev_pdata *pdata;
60 struct gpio_desc *reset_gpio;
61 bool always_powered_in_suspend;
62 bool is_powered_on;
63 bool going_away;
64 struct list_head udev_list;
65 struct mutex lock;
66 struct clk *clk;
67};
68
69static int onboard_dev_get_regulators(struct onboard_dev *onboard_dev)
70{
71 const char * const *supply_names = onboard_dev->pdata->supply_names;
72 unsigned int num_supplies = onboard_dev->pdata->num_supplies;
73 struct device *dev = onboard_dev->dev;
74 unsigned int i;
75 int err;
76
77 if (num_supplies > MAX_SUPPLIES)
78 return dev_err_probe(dev, -EINVAL, "max %d supplies supported!\n",
79 MAX_SUPPLIES);
80
81 for (i = 0; i < num_supplies; i++)
82 onboard_dev->supplies[i].supply = supply_names[i];
83
84 err = devm_regulator_bulk_get(dev, num_supplies, onboard_dev->supplies);
85 if (err)
86 dev_err(dev, "Failed to get regulator supplies: %pe\n",
87 ERR_PTR(err));
88
89 return err;
90}
91
92static int onboard_dev_power_on(struct onboard_dev *onboard_dev)
93{
94 int err;
95
96 err = clk_prepare_enable(onboard_dev->clk);
97 if (err) {
98 dev_err(onboard_dev->dev, "failed to enable clock: %pe\n",
99 ERR_PTR(err));
100 return err;
101 }
102
103 err = regulator_bulk_enable(onboard_dev->pdata->num_supplies,
104 onboard_dev->supplies);
105 if (err) {
106 dev_err(onboard_dev->dev, "failed to enable supplies: %pe\n",
107 ERR_PTR(err));
108 goto disable_clk;
109 }
110
111 fsleep(onboard_dev->pdata->reset_us);
112 gpiod_set_value_cansleep(onboard_dev->reset_gpio, 0);
113 fsleep(onboard_dev->pdata->power_on_delay_us);
114
115 onboard_dev->is_powered_on = true;
116
117 return 0;
118
119disable_clk:
120 clk_disable_unprepare(onboard_dev->clk);
121 return err;
122}
123
124static int onboard_dev_power_off(struct onboard_dev *onboard_dev)
125{
126 int err;
127
128 gpiod_set_value_cansleep(onboard_dev->reset_gpio, 1);
129
130 err = regulator_bulk_disable(onboard_dev->pdata->num_supplies,
131 onboard_dev->supplies);
132 if (err) {
133 dev_err(onboard_dev->dev, "failed to disable supplies: %pe\n",
134 ERR_PTR(err));
135 return err;
136 }
137
138 clk_disable_unprepare(onboard_dev->clk);
139
140 onboard_dev->is_powered_on = false;
141
142 return 0;
143}
144
145static int __maybe_unused onboard_dev_suspend(struct device *dev)
146{
147 struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
148 struct usbdev_node *node;
149 bool power_off = true;
150
151 if (onboard_dev->always_powered_in_suspend)
152 return 0;
153
154 mutex_lock(&onboard_dev->lock);
155
156 list_for_each_entry(node, &onboard_dev->udev_list, list) {
157 if (!device_may_wakeup(node->udev->bus->controller))
158 continue;
159
160 if (usb_wakeup_enabled_descendants(node->udev)) {
161 power_off = false;
162 break;
163 }
164 }
165
166 mutex_unlock(&onboard_dev->lock);
167
168 if (!power_off)
169 return 0;
170
171 return onboard_dev_power_off(onboard_dev);
172}
173
174static int __maybe_unused onboard_dev_resume(struct device *dev)
175{
176 struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
177
178 if (onboard_dev->is_powered_on)
179 return 0;
180
181 return onboard_dev_power_on(onboard_dev);
182}
183
184static inline void get_udev_link_name(const struct usb_device *udev, char *buf,
185 size_t size)
186{
187 snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev));
188}
189
190static int onboard_dev_add_usbdev(struct onboard_dev *onboard_dev,
191 struct usb_device *udev)
192{
193 struct usbdev_node *node;
194 char link_name[64];
195 int err;
196
197 mutex_lock(&onboard_dev->lock);
198
199 if (onboard_dev->going_away) {
200 err = -EINVAL;
201 goto error;
202 }
203
204 node = kzalloc(sizeof(*node), GFP_KERNEL);
205 if (!node) {
206 err = -ENOMEM;
207 goto error;
208 }
209
210 node->udev = udev;
211
212 list_add(&node->list, &onboard_dev->udev_list);
213
214 mutex_unlock(&onboard_dev->lock);
215
216 get_udev_link_name(udev, link_name, sizeof(link_name));
217 WARN_ON(sysfs_create_link(&onboard_dev->dev->kobj, &udev->dev.kobj,
218 link_name));
219
220 return 0;
221
222error:
223 mutex_unlock(&onboard_dev->lock);
224
225 return err;
226}
227
228static void onboard_dev_remove_usbdev(struct onboard_dev *onboard_dev,
229 const struct usb_device *udev)
230{
231 struct usbdev_node *node;
232 char link_name[64];
233
234 get_udev_link_name(udev, link_name, sizeof(link_name));
235 sysfs_remove_link(&onboard_dev->dev->kobj, link_name);
236
237 mutex_lock(&onboard_dev->lock);
238
239 list_for_each_entry(node, &onboard_dev->udev_list, list) {
240 if (node->udev == udev) {
241 list_del(&node->list);
242 kfree(node);
243 break;
244 }
245 }
246
247 mutex_unlock(&onboard_dev->lock);
248}
249
250static ssize_t always_powered_in_suspend_show(struct device *dev,
251 struct device_attribute *attr,
252 char *buf)
253{
254 const struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
255
256 return sysfs_emit(buf, "%d\n", onboard_dev->always_powered_in_suspend);
257}
258
259static ssize_t always_powered_in_suspend_store(struct device *dev,
260 struct device_attribute *attr,
261 const char *buf, size_t count)
262{
263 struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
264 bool val;
265 int ret;
266
267 ret = kstrtobool(buf, &val);
268 if (ret < 0)
269 return ret;
270
271 onboard_dev->always_powered_in_suspend = val;
272
273 return count;
274}
275static DEVICE_ATTR_RW(always_powered_in_suspend);
276
277static struct attribute *onboard_dev_attrs[] = {
278 &dev_attr_always_powered_in_suspend.attr,
279 NULL,
280};
281
282static umode_t onboard_dev_attrs_are_visible(struct kobject *kobj,
283 struct attribute *attr,
284 int n)
285{
286 struct device *dev = kobj_to_dev(kobj);
287 struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
288
289 if (attr == &dev_attr_always_powered_in_suspend.attr &&
290 !onboard_dev->pdata->is_hub)
291 return 0;
292
293 return attr->mode;
294}
295
296static const struct attribute_group onboard_dev_group = {
297 .is_visible = onboard_dev_attrs_are_visible,
298 .attrs = onboard_dev_attrs,
299};
300__ATTRIBUTE_GROUPS(onboard_dev);
301
302
303static void onboard_dev_attach_usb_driver(struct work_struct *work)
304{
305 int err;
306
307 err = driver_attach(&onboard_dev_usbdev_driver.driver);
308 if (err)
309 pr_err("Failed to attach USB driver: %pe\n", ERR_PTR(err));
310}
311
312static int onboard_dev_5744_i2c_init(struct i2c_client *client)
313{
314#if IS_ENABLED(CONFIG_USB_ONBOARD_DEV_USB5744)
315 struct device *dev = &client->dev;
316 int ret;
317
318 /*
319 * Set BYPASS_UDC_SUSPEND bit to ensure MCU is always enabled
320 * and ready to respond to SMBus runtime commands.
321 * The command writes 5 bytes to memory and single data byte in
322 * configuration register.
323 */
324 char wr_buf[7] = {USB5744_CREG_MEM_ADDR, 5,
325 USB5744_CREG_WRITE, 1,
326 USB5744_CREG_RUNTIMEFLAGS2,
327 USB5744_CREG_RUNTIMEFLAGS2_LSB,
328 USB5744_CREG_BYPASS_UDC_SUSPEND};
329
330 ret = i2c_smbus_write_block_data(client, 0, sizeof(wr_buf), wr_buf);
331 if (ret)
332 return dev_err_probe(dev, ret, "BYPASS_UDC_SUSPEND bit configuration failed\n");
333
334 ret = i2c_smbus_write_word_data(client, USB5744_CMD_CREG_ACCESS,
335 USB5744_CMD_CREG_ACCESS_LSB);
336 if (ret)
337 return dev_err_probe(dev, ret, "Configuration Register Access Command failed\n");
338
339 /* Send SMBus command to boot hub. */
340 ret = i2c_smbus_write_word_data(client, USB5744_CMD_ATTACH,
341 USB5744_CMD_ATTACH_LSB);
342 if (ret < 0)
343 return dev_err_probe(dev, ret, "USB Attach with SMBus command failed\n");
344
345 return ret;
346#else
347 return -ENODEV;
348#endif
349}
350
351static int onboard_dev_probe(struct platform_device *pdev)
352{
353 struct device *dev = &pdev->dev;
354 struct onboard_dev *onboard_dev;
355 struct device_node *i2c_node;
356 int err;
357
358 onboard_dev = devm_kzalloc(dev, sizeof(*onboard_dev), GFP_KERNEL);
359 if (!onboard_dev)
360 return -ENOMEM;
361
362 onboard_dev->pdata = device_get_match_data(dev);
363 if (!onboard_dev->pdata)
364 return -EINVAL;
365
366 if (!onboard_dev->pdata->is_hub)
367 onboard_dev->always_powered_in_suspend = true;
368
369 onboard_dev->dev = dev;
370
371 err = onboard_dev_get_regulators(onboard_dev);
372 if (err)
373 return err;
374
375 onboard_dev->clk = devm_clk_get_optional(dev, NULL);
376 if (IS_ERR(onboard_dev->clk))
377 return dev_err_probe(dev, PTR_ERR(onboard_dev->clk),
378 "failed to get clock\n");
379
380 onboard_dev->reset_gpio = devm_gpiod_get_optional(dev, "reset",
381 GPIOD_OUT_HIGH);
382 if (IS_ERR(onboard_dev->reset_gpio))
383 return dev_err_probe(dev, PTR_ERR(onboard_dev->reset_gpio),
384 "failed to get reset GPIO\n");
385
386 mutex_init(&onboard_dev->lock);
387 INIT_LIST_HEAD(&onboard_dev->udev_list);
388
389 dev_set_drvdata(dev, onboard_dev);
390
391 err = onboard_dev_power_on(onboard_dev);
392 if (err)
393 return err;
394
395 i2c_node = of_parse_phandle(pdev->dev.of_node, "i2c-bus", 0);
396 if (i2c_node) {
397 struct i2c_client *client = NULL;
398
399#if IS_ENABLED(CONFIG_USB_ONBOARD_DEV_USB5744)
400 client = of_find_i2c_device_by_node(i2c_node);
401#endif
402 of_node_put(i2c_node);
403
404 if (!client) {
405 err = -EPROBE_DEFER;
406 goto err_power_off;
407 }
408
409 if (of_device_is_compatible(pdev->dev.of_node, "usb424,2744") ||
410 of_device_is_compatible(pdev->dev.of_node, "usb424,5744")) {
411 err = onboard_dev_5744_i2c_init(client);
412 onboard_dev->always_powered_in_suspend = true;
413 }
414
415 put_device(&client->dev);
416 if (err < 0)
417 goto err_power_off;
418 }
419
420 /*
421 * The USB driver might have been detached from the USB devices by
422 * onboard_dev_remove() (e.g. through an 'unbind' by userspace),
423 * make sure to re-attach it if needed.
424 *
425 * This needs to be done deferred to avoid self-deadlocks on systems
426 * with nested onboard hubs.
427 */
428 schedule_work(&attach_usb_driver_work);
429
430 return 0;
431
432err_power_off:
433 onboard_dev_power_off(onboard_dev);
434 return err;
435}
436
437static void onboard_dev_remove(struct platform_device *pdev)
438{
439 struct onboard_dev *onboard_dev = dev_get_drvdata(&pdev->dev);
440 struct usbdev_node *node;
441 struct usb_device *udev;
442
443 onboard_dev->going_away = true;
444
445 mutex_lock(&onboard_dev->lock);
446
447 /* unbind the USB devices to avoid dangling references to this device */
448 while (!list_empty(&onboard_dev->udev_list)) {
449 node = list_first_entry(&onboard_dev->udev_list,
450 struct usbdev_node, list);
451 udev = node->udev;
452
453 /*
454 * Unbinding the driver will call onboard_dev_remove_usbdev(),
455 * which acquires onboard_dev->lock. We must release the lock
456 * first.
457 */
458 get_device(&udev->dev);
459 mutex_unlock(&onboard_dev->lock);
460 device_release_driver(&udev->dev);
461 put_device(&udev->dev);
462 mutex_lock(&onboard_dev->lock);
463 }
464
465 mutex_unlock(&onboard_dev->lock);
466
467 onboard_dev_power_off(onboard_dev);
468}
469
470MODULE_DEVICE_TABLE(of, onboard_dev_match);
471
472static const struct dev_pm_ops __maybe_unused onboard_dev_pm_ops = {
473 SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_dev_suspend, onboard_dev_resume)
474};
475
476static struct platform_driver onboard_dev_driver = {
477 .probe = onboard_dev_probe,
478 .remove = onboard_dev_remove,
479
480 .driver = {
481 .name = "onboard-usb-dev",
482 .of_match_table = onboard_dev_match,
483 .pm = pm_ptr(&onboard_dev_pm_ops),
484 .dev_groups = onboard_dev_groups,
485 },
486};
487
488/************************** USB driver **************************/
489
490#define VENDOR_ID_CYPRESS 0x04b4
491#define VENDOR_ID_GENESYS 0x05e3
492#define VENDOR_ID_MICROCHIP 0x0424
493#define VENDOR_ID_REALTEK 0x0bda
494#define VENDOR_ID_TI 0x0451
495#define VENDOR_ID_VIA 0x2109
496#define VENDOR_ID_XMOS 0x20B1
497
498/*
499 * Returns the onboard_dev platform device that is associated with the USB
500 * device passed as parameter.
501 */
502static struct onboard_dev *_find_onboard_dev(struct device *dev)
503{
504 struct platform_device *pdev;
505 struct device_node *np;
506 struct onboard_dev *onboard_dev;
507
508 pdev = of_find_device_by_node(dev->of_node);
509 if (!pdev) {
510 np = of_parse_phandle(dev->of_node, "peer-hub", 0);
511 if (!np) {
512 dev_err(dev, "failed to find device node for peer hub\n");
513 return ERR_PTR(-EINVAL);
514 }
515
516 pdev = of_find_device_by_node(np);
517 of_node_put(np);
518
519 if (!pdev)
520 return ERR_PTR(-ENODEV);
521 }
522
523 onboard_dev = dev_get_drvdata(&pdev->dev);
524 put_device(&pdev->dev);
525
526 /*
527 * The presence of drvdata indicates that the platform driver finished
528 * probing. This handles the case where (conceivably) we could be
529 * running at the exact same time as the platform driver's probe. If
530 * we detect the race we request probe deferral and we'll come back and
531 * try again.
532 */
533 if (!onboard_dev)
534 return ERR_PTR(-EPROBE_DEFER);
535
536 return onboard_dev;
537}
538
539static bool onboard_dev_usbdev_match(struct usb_device *udev)
540{
541 /* Onboard devices using this driver must have a device tree node */
542 return !!udev->dev.of_node;
543}
544
545static int onboard_dev_usbdev_probe(struct usb_device *udev)
546{
547 struct device *dev = &udev->dev;
548 struct onboard_dev *onboard_dev;
549 int err;
550
551 onboard_dev = _find_onboard_dev(dev);
552 if (IS_ERR(onboard_dev))
553 return PTR_ERR(onboard_dev);
554
555 dev_set_drvdata(dev, onboard_dev);
556
557 err = onboard_dev_add_usbdev(onboard_dev, udev);
558 if (err)
559 return err;
560
561 return 0;
562}
563
564static void onboard_dev_usbdev_disconnect(struct usb_device *udev)
565{
566 struct onboard_dev *onboard_dev = dev_get_drvdata(&udev->dev);
567
568 onboard_dev_remove_usbdev(onboard_dev, udev);
569}
570
571static const struct usb_device_id onboard_dev_id_table[] = {
572 { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 HUB */
573 { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 HUB */
574 { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 HUB */
575 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 HUB */
576 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 HUB */
577 { USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 HUB */
578 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 HUB */
579 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 HUB */
580 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 HUB */
581 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 HUB */
582 { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 HUB */
583 { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 HUB */
584 { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 HUB */
585 { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 HUB */
586 { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 HUB */
587 { USB_DEVICE(VENDOR_ID_TI, 0x8025) }, /* TI USB8020B 3.0 HUB */
588 { USB_DEVICE(VENDOR_ID_TI, 0x8027) }, /* TI USB8020B 2.0 HUB */
589 { USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 HUB */
590 { USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 HUB */
591 { USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 HUB */
592 { USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 HUB */
593 { USB_DEVICE(VENDOR_ID_XMOS, 0x0013) }, /* XMOS XVF3500 Voice Processor */
594 {}
595};
596MODULE_DEVICE_TABLE(usb, onboard_dev_id_table);
597
598static struct usb_device_driver onboard_dev_usbdev_driver = {
599 .name = "onboard-usb-dev",
600 .match = onboard_dev_usbdev_match,
601 .probe = onboard_dev_usbdev_probe,
602 .disconnect = onboard_dev_usbdev_disconnect,
603 .generic_subclass = 1,
604 .supports_autosuspend = 1,
605 .id_table = onboard_dev_id_table,
606};
607
608static int __init onboard_dev_init(void)
609{
610 int ret;
611
612 ret = usb_register_device_driver(&onboard_dev_usbdev_driver, THIS_MODULE);
613 if (ret)
614 return ret;
615
616 ret = platform_driver_register(&onboard_dev_driver);
617 if (ret)
618 usb_deregister_device_driver(&onboard_dev_usbdev_driver);
619
620 return ret;
621}
622module_init(onboard_dev_init);
623
624static void __exit onboard_dev_exit(void)
625{
626 usb_deregister_device_driver(&onboard_dev_usbdev_driver);
627 platform_driver_unregister(&onboard_dev_driver);
628
629 cancel_work_sync(&attach_usb_driver_work);
630}
631module_exit(onboard_dev_exit);
632
633MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
634MODULE_DESCRIPTION("Driver for discrete onboard USB devices");
635MODULE_LICENSE("GPL v2");