summaryrefslogtreecommitdiff
path: root/drivers/usb/misc/onboard_usb_hub.c
blob: 2b45404e9732cefca8b6a8cd93fa4f08a015cc76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for onboard USB hubs
 *
 * Copyright (c) 2022, Google LLC
 */

#include <linux/device.h>
#include <linux/export.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/sysfs.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/onboard_hub.h>
#include <linux/workqueue.h>

#include "onboard_usb_hub.h"

/*
 * Use generic names, as the actual names might differ between hubs. If a new
 * hub requires more than the currently supported supplies, add a new one here.
 */
static const char * const supply_names[] = {
	"vdd",
	"vdd2",
};

#define MAX_SUPPLIES ARRAY_SIZE(supply_names)

static void onboard_hub_attach_usb_driver(struct work_struct *work);

static struct usb_device_driver onboard_hub_usbdev_driver;
static DECLARE_WORK(attach_usb_driver_work, onboard_hub_attach_usb_driver);

/************************** Platform driver **************************/

struct usbdev_node {
	struct usb_device *udev;
	struct list_head list;
};

struct onboard_hub {
	struct regulator_bulk_data supplies[MAX_SUPPLIES];
	struct device *dev;
	const struct onboard_hub_pdata *pdata;
	struct gpio_desc *reset_gpio;
	bool always_powered_in_suspend;
	bool is_powered_on;
	bool going_away;
	struct list_head udev_list;
	struct mutex lock;
};

static int onboard_hub_power_on(struct onboard_hub *hub)
{
	int err;

	err = regulator_bulk_enable(hub->pdata->num_supplies, hub->supplies);
	if (err) {
		dev_err(hub->dev, "failed to enable supplies: %d\n", err);
		return err;
	}

	fsleep(hub->pdata->reset_us);
	gpiod_set_value_cansleep(hub->reset_gpio, 0);

	hub->is_powered_on = true;

	return 0;
}

static int onboard_hub_power_off(struct onboard_hub *hub)
{
	int err;

	gpiod_set_value_cansleep(hub->reset_gpio, 1);

	err = regulator_bulk_disable(hub->pdata->num_supplies, hub->supplies);
	if (err) {
		dev_err(hub->dev, "failed to disable supplies: %d\n", err);
		return err;
	}

	hub->is_powered_on = false;

	return 0;
}

static int __maybe_unused onboard_hub_suspend(struct device *dev)
{
	struct onboard_hub *hub = dev_get_drvdata(dev);
	struct usbdev_node *node;
	bool power_off = true;

	if (hub->always_powered_in_suspend)
		return 0;

	mutex_lock(&hub->lock);

	list_for_each_entry(node, &hub->udev_list, list) {
		if (!device_may_wakeup(node->udev->bus->controller))
			continue;

		if (usb_wakeup_enabled_descendants(node->udev)) {
			power_off = false;
			break;
		}
	}

	mutex_unlock(&hub->lock);

	if (!power_off)
		return 0;

	return onboard_hub_power_off(hub);
}

static int __maybe_unused onboard_hub_resume(struct device *dev)
{
	struct onboard_hub *hub = dev_get_drvdata(dev);

	if (hub->is_powered_on)
		return 0;

	return onboard_hub_power_on(hub);
}

static inline void get_udev_link_name(const struct usb_device *udev, char *buf, size_t size)
{
	snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev));
}

static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
{
	struct usbdev_node *node;
	char link_name[64];
	int err;

	mutex_lock(&hub->lock);

	if (hub->going_away) {
		err = -EINVAL;
		goto error;
	}

	node = kzalloc(sizeof(*node), GFP_KERNEL);
	if (!node) {
		err = -ENOMEM;
		goto error;
	}

	node->udev = udev;

	list_add(&node->list, &hub->udev_list);

	mutex_unlock(&hub->lock);

	get_udev_link_name(udev, link_name, sizeof(link_name));
	WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));

	return 0;

error:
	mutex_unlock(&hub->lock);

	return err;
}

static void onboard_hub_remove_usbdev(struct onboard_hub *hub, const struct usb_device *udev)
{
	struct usbdev_node *node;
	char link_name[64];

	get_udev_link_name(udev, link_name, sizeof(link_name));
	sysfs_remove_link(&hub->dev->kobj, link_name);

	mutex_lock(&hub->lock);

	list_for_each_entry(node, &hub->udev_list, list) {
		if (node->udev == udev) {
			list_del(&node->list);
			kfree(node);
			break;
		}
	}

	mutex_unlock(&hub->lock);
}

static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	const struct onboard_hub *hub = dev_get_drvdata(dev);

	return sysfs_emit(buf, "%d\n", hub->always_powered_in_suspend);
}

static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct onboard_hub *hub = dev_get_drvdata(dev);
	bool val;
	int ret;

	ret = kstrtobool(buf, &val);
	if (ret < 0)
		return ret;

	hub->always_powered_in_suspend = val;

	return count;
}
static DEVICE_ATTR_RW(always_powered_in_suspend);

static struct attribute *onboard_hub_attrs[] = {
	&dev_attr_always_powered_in_suspend.attr,
	NULL,
};
ATTRIBUTE_GROUPS(onboard_hub);

static void onboard_hub_attach_usb_driver(struct work_struct *work)
{
	int err;

	err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
	if (err)
		pr_err("Failed to attach USB driver: %d\n", err);
}

static int onboard_hub_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct onboard_hub *hub;
	unsigned int i;
	int err;

	hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
	if (!hub)
		return -ENOMEM;

	hub->pdata = device_get_match_data(&pdev->dev);
	if (!hub->pdata)
		return -EINVAL;

	if (hub->pdata->num_supplies > MAX_SUPPLIES)
		return dev_err_probe(dev, -EINVAL, "max %zu supplies supported!\n",
				     MAX_SUPPLIES);

	for (i = 0; i < hub->pdata->num_supplies; i++)
		hub->supplies[i].supply = supply_names[i];

	err = devm_regulator_bulk_get(dev, hub->pdata->num_supplies, hub->supplies);
	if (err) {
		dev_err(dev, "Failed to get regulator supplies: %d\n", err);
		return err;
	}

	hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
						  GPIOD_OUT_HIGH);
	if (IS_ERR(hub->reset_gpio))
		return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), "failed to get reset GPIO\n");

	hub->dev = dev;
	mutex_init(&hub->lock);
	INIT_LIST_HEAD(&hub->udev_list);

	dev_set_drvdata(dev, hub);

	err = onboard_hub_power_on(hub);
	if (err)
		return err;

	/*
	 * The USB driver might have been detached from the USB devices by
	 * onboard_hub_remove() (e.g. through an 'unbind' by userspace),
	 * make sure to re-attach it if needed.
	 *
	 * This needs to be done deferred to avoid self-deadlocks on systems
	 * with nested onboard hubs.
	 */
	schedule_work(&attach_usb_driver_work);

	return 0;
}

static void onboard_hub_remove(struct platform_device *pdev)
{
	struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
	struct usbdev_node *node;
	struct usb_device *udev;

	hub->going_away = true;

	mutex_lock(&hub->lock);

	/* unbind the USB devices to avoid dangling references to this device */
	while (!list_empty(&hub->udev_list)) {
		node = list_first_entry(&hub->udev_list, struct usbdev_node, list);
		udev = node->udev;

		/*
		 * Unbinding the driver will call onboard_hub_remove_usbdev(),
		 * which acquires hub->lock.  We must release the lock first.
		 */
		get_device(&udev->dev);
		mutex_unlock(&hub->lock);
		device_release_driver(&udev->dev);
		put_device(&udev->dev);
		mutex_lock(&hub->lock);
	}

	mutex_unlock(&hub->lock);

	onboard_hub_power_off(hub);
}

MODULE_DEVICE_TABLE(of, onboard_hub_match);

static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = {
	SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume)
};

static struct platform_driver onboard_hub_driver = {
	.probe = onboard_hub_probe,
	.remove_new = onboard_hub_remove,

	.driver = {
		.name = "onboard-usb-hub",
		.of_match_table = onboard_hub_match,
		.pm = pm_ptr(&onboard_hub_pm_ops),
		.dev_groups = onboard_hub_groups,
	},
};

/************************** USB driver **************************/

#define VENDOR_ID_CYPRESS	0x04b4
#define VENDOR_ID_GENESYS	0x05e3
#define VENDOR_ID_MICROCHIP	0x0424
#define VENDOR_ID_REALTEK	0x0bda
#define VENDOR_ID_TI		0x0451
#define VENDOR_ID_VIA		0x2109

/*
 * Returns the onboard_hub platform device that is associated with the USB
 * device passed as parameter.
 */
static struct onboard_hub *_find_onboard_hub(struct device *dev)
{
	struct platform_device *pdev;
	struct device_node *np;
	struct onboard_hub *hub;

	pdev = of_find_device_by_node(dev->of_node);
	if (!pdev) {
		np = of_parse_phandle(dev->of_node, "peer-hub", 0);
		if (!np) {
			dev_err(dev, "failed to find device node for peer hub\n");
			return ERR_PTR(-EINVAL);
		}

		pdev = of_find_device_by_node(np);
		of_node_put(np);

		if (!pdev)
			return ERR_PTR(-ENODEV);
	}

	hub = dev_get_drvdata(&pdev->dev);
	put_device(&pdev->dev);

	/*
	 * The presence of drvdata ('hub') indicates that the platform driver
	 * finished probing. This handles the case where (conceivably) we could
	 * be running at the exact same time as the platform driver's probe. If
	 * we detect the race we request probe deferral and we'll come back and
	 * try again.
	 */
	if (!hub)
		return ERR_PTR(-EPROBE_DEFER);

	return hub;
}

static int onboard_hub_usbdev_probe(struct usb_device *udev)
{
	struct device *dev = &udev->dev;
	struct onboard_hub *hub;
	int err;

	/* ignore supported hubs without device tree node */
	if (!dev->of_node)
		return -ENODEV;

	hub = _find_onboard_hub(dev);
	if (IS_ERR(hub))
		return PTR_ERR(hub);

	dev_set_drvdata(dev, hub);

	err = onboard_hub_add_usbdev(hub, udev);
	if (err)
		return err;

	return 0;
}

static void onboard_hub_usbdev_disconnect(struct usb_device *udev)
{
	struct onboard_hub *hub = dev_get_drvdata(&udev->dev);

	onboard_hub_remove_usbdev(hub, udev);
}

static const struct usb_device_id onboard_hub_id_table[] = {
	{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 */
	{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 */
	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 */
	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 */
	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 */
	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 */
	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 */
	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 */
	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 */
	{ USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 */
	{ USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 */
	{ USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 */
	{ USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 */
	{}
};
MODULE_DEVICE_TABLE(usb, onboard_hub_id_table);

static struct usb_device_driver onboard_hub_usbdev_driver = {
	.name = "onboard-usb-hub",
	.probe = onboard_hub_usbdev_probe,
	.disconnect = onboard_hub_usbdev_disconnect,
	.generic_subclass = 1,
	.supports_autosuspend =	1,
	.id_table = onboard_hub_id_table,
};

static int __init onboard_hub_init(void)
{
	int ret;

	ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
	if (ret)
		return ret;

	ret = platform_driver_register(&onboard_hub_driver);
	if (ret)
		usb_deregister_device_driver(&onboard_hub_usbdev_driver);

	return ret;
}
module_init(onboard_hub_init);

static void __exit onboard_hub_exit(void)
{
	usb_deregister_device_driver(&onboard_hub_usbdev_driver);
	platform_driver_unregister(&onboard_hub_driver);

	cancel_work_sync(&attach_usb_driver_work);
}
module_exit(onboard_hub_exit);

MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
MODULE_LICENSE("GPL v2");