1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for SMSC USB3503 USB 2.0 hub controller driver
4 *
5 * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
6 */
7
8#include <linux/clk.h>
9#include <linux/i2c.h>
10#include <linux/gpio/consumer.h>
11#include <linux/delay.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/platform_data/usb3503.h>
16#include <linux/regmap.h>
17
18#define USB3503_VIDL		0x00
19#define USB3503_VIDM		0x01
20#define USB3503_PIDL		0x02
21#define USB3503_PIDM		0x03
22#define USB3503_DIDL		0x04
23#define USB3503_DIDM		0x05
24
25#define USB3503_CFG1		0x06
26#define USB3503_SELF_BUS_PWR	(1 << 7)
27
28#define USB3503_CFG2		0x07
29#define USB3503_CFG3		0x08
30#define USB3503_NRD		0x09
31
32#define USB3503_PDS		0x0a
33
34#define USB3503_SP_ILOCK	0xe7
35#define USB3503_SPILOCK_CONNECT	(1 << 1)
36#define USB3503_SPILOCK_CONFIG	(1 << 0)
37
38#define USB3503_CFGP		0xee
39#define USB3503_CLKSUSP		(1 << 7)
40
41#define USB3503_RESET		0xff
42
43struct usb3503 {
44	enum usb3503_mode	mode;
45	struct regmap		*regmap;
46	struct device		*dev;
47	struct clk		*clk;
48	u8	port_off_mask;
49	struct gpio_desc	*bypass;
50	struct gpio_desc	*intn;
51	struct gpio_desc 	*reset;
52	struct gpio_desc 	*connect;
53	bool	secondary_ref_clk;
54};
55
56static int usb3503_connect(struct usb3503 *hub)
57{
58	struct device *dev = hub->dev;
59	int err;
60
61	if (hub->regmap) {
62		/* SP_ILOCK: set connect_n, config_n for config */
63		err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
64			   (USB3503_SPILOCK_CONNECT
65				 | USB3503_SPILOCK_CONFIG));
66		if (err < 0) {
67			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
68			return err;
69		}
70
71		/* PDS : Set the ports which are disabled in self-powered mode. */
72		if (hub->port_off_mask) {
73			err = regmap_update_bits(hub->regmap, USB3503_PDS,
74					hub->port_off_mask,
75					hub->port_off_mask);
76			if (err < 0) {
77				dev_err(dev, "PDS failed (%d)\n", err);
78				return err;
79			}
80		}
81
82		/* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
83		err = regmap_update_bits(hub->regmap, USB3503_CFG1,
84					 USB3503_SELF_BUS_PWR,
85					 USB3503_SELF_BUS_PWR);
86		if (err < 0) {
87			dev_err(dev, "CFG1 failed (%d)\n", err);
88			return err;
89		}
90
91		/* SP_LOCK: clear connect_n, config_n for hub connect */
92		err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
93					 (USB3503_SPILOCK_CONNECT
94					  | USB3503_SPILOCK_CONFIG), 0);
95		if (err < 0) {
96			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
97			return err;
98		}
99	}
100
101	if (hub->connect)
102		gpiod_set_value_cansleep(hub->connect, 1);
103
104	hub->mode = USB3503_MODE_HUB;
105	dev_info(dev, "switched to HUB mode\n");
106
107	return 0;
108}
109
110static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
111{
112	struct device *dev = hub->dev;
113	int rst, bypass, conn;
114
115	switch (mode) {
116	case USB3503_MODE_HUB:
117		conn = 1;
118		rst = 0;
119		bypass = 0;
120		break;
121	case USB3503_MODE_STANDBY:
122		conn = 0;
123		rst = 1;
124		bypass = 1;
125		dev_info(dev, "switched to STANDBY mode\n");
126		break;
127	case USB3503_MODE_BYPASS:
128		conn = 0;
129		rst = 0;
130		bypass = 1;
131		break;
132	default:
133		dev_err(dev, "unknown mode is requested\n");
134		return -EINVAL;
135	}
136
137	if (!conn && hub->connect)
138		gpiod_set_value_cansleep(hub->connect, 0);
139
140	if (hub->reset)
141		gpiod_set_value_cansleep(hub->reset, rst);
142
143	if (hub->bypass)
144		gpiod_set_value_cansleep(hub->bypass, bypass);
145
146	if (conn) {
147		/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
148		usleep_range(4000, 10000);
149		return usb3503_connect(hub);
150	}
151
152	return 0;
153}
154
155static const struct regmap_config usb3503_regmap_config = {
156	.reg_bits = 8,
157	.val_bits = 8,
158
159	.max_register = USB3503_RESET,
160};
161
162static int usb3503_probe(struct usb3503 *hub)
163{
164	struct device *dev = hub->dev;
165	struct usb3503_platform_data *pdata = dev_get_platdata(dev);
166	struct device_node *np = dev->of_node;
167	int err;
168	bool is_clk_enabled = false;
169	u32 mode = USB3503_MODE_HUB;
170	const u32 *property;
171	enum gpiod_flags flags;
172	int len;
173
174	if (pdata) {
175		hub->port_off_mask	= pdata->port_off_mask;
176		hub->mode		= pdata->initial_mode;
177	} else if (np) {
178		u32 rate = 0;
179		hub->port_off_mask = 0;
180
181		if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
182			switch (rate) {
183			case 38400000:
184			case 26000000:
185			case 19200000:
186			case 12000000:
187				hub->secondary_ref_clk = 0;
188				break;
189			case 24000000:
190			case 27000000:
191			case 25000000:
192			case 50000000:
193				hub->secondary_ref_clk = 1;
194				break;
195			default:
196				dev_err(dev,
197					"unsupported reference clock rate (%d)\n",
198					(int) rate);
199				return -EINVAL;
200			}
201		}
202
203		hub->clk = devm_clk_get_optional(dev, "refclk");
204		if (IS_ERR(hub->clk)) {
205			dev_err(dev, "unable to request refclk (%ld)\n",
206					PTR_ERR(hub->clk));
207			return PTR_ERR(hub->clk);
208		}
209
210		if (rate != 0) {
211			err = clk_set_rate(hub->clk, rate);
212			if (err) {
213				dev_err(dev,
214					"unable to set reference clock rate to %d\n",
215					(int)rate);
216				return err;
217			}
218		}
219
220		err = clk_prepare_enable(hub->clk);
221		if (err) {
222			dev_err(dev, "unable to enable reference clock\n");
223			return err;
224		}
225
226		is_clk_enabled = true;
227		property = of_get_property(np, "disabled-ports", &len);
228		if (property && (len / sizeof(u32)) > 0) {
229			int i;
230			for (i = 0; i < len / sizeof(u32); i++) {
231				u32 port = be32_to_cpu(property[i]);
232				if ((1 <= port) && (port <= 3))
233					hub->port_off_mask |= (1 << port);
234			}
235		}
236
237		of_property_read_u32(np, "initial-mode", &mode);
238		hub->mode = mode;
239	}
240
241	if (hub->secondary_ref_clk)
242		flags = GPIOD_OUT_LOW;
243	else
244		flags = GPIOD_OUT_HIGH;
245	hub->intn = devm_gpiod_get_optional(dev, "intn", flags);
246	if (IS_ERR(hub->intn)) {
247		err = PTR_ERR(hub->intn);
248		goto err_clk;
249	}
250	if (hub->intn)
251		gpiod_set_consumer_name(hub->intn, "usb3503 intn");
252
253	hub->connect = devm_gpiod_get_optional(dev, "connect", GPIOD_OUT_LOW);
254	if (IS_ERR(hub->connect)) {
255		err = PTR_ERR(hub->connect);
256		goto err_clk;
257	}
258	if (hub->connect)
259		gpiod_set_consumer_name(hub->connect, "usb3503 connect");
260
261	hub->bypass = devm_gpiod_get_optional(dev, "bypass", GPIOD_OUT_HIGH);
262	if (IS_ERR(hub->bypass)) {
263		err = PTR_ERR(hub->bypass);
264		goto err_clk;
265	}
266	if (hub->bypass)
267		gpiod_set_consumer_name(hub->bypass, "usb3503 bypass");
268
269	hub->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
270	if (IS_ERR(hub->reset)) {
271		err = PTR_ERR(hub->reset);
272		goto err_clk;
273	}
274	if (hub->reset) {
275		/* Datasheet defines a hardware reset to be at least 100us */
276		usleep_range(100, 10000);
277		gpiod_set_consumer_name(hub->reset, "usb3503 reset");
278	}
279
280	if (hub->port_off_mask && !hub->regmap)
281		dev_err(dev, "Ports disabled with no control interface\n");
282
283	usb3503_switch_mode(hub, hub->mode);
284
285	dev_info(dev, "%s: probed in %s mode\n", __func__,
286			(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
287
288	return 0;
289
290err_clk:
291	if (is_clk_enabled)
292		clk_disable_unprepare(hub->clk);
293	return err;
294}
295
296static int usb3503_i2c_probe(struct i2c_client *i2c)
297{
298	struct usb3503 *hub;
299	int err;
300
301	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
302	if (!hub)
303		return -ENOMEM;
304
305	i2c_set_clientdata(i2c, hub);
306	hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
307	if (IS_ERR(hub->regmap)) {
308		err = PTR_ERR(hub->regmap);
309		dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
310		return err;
311	}
312	hub->dev = &i2c->dev;
313
314	return usb3503_probe(hub);
315}
316
317static void usb3503_i2c_remove(struct i2c_client *i2c)
318{
319	struct usb3503 *hub;
320
321	hub = i2c_get_clientdata(i2c);
322	clk_disable_unprepare(hub->clk);
323}
324
325static int usb3503_platform_probe(struct platform_device *pdev)
326{
327	struct usb3503 *hub;
328
329	hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
330	if (!hub)
331		return -ENOMEM;
332	hub->dev = &pdev->dev;
333	platform_set_drvdata(pdev, hub);
334
335	return usb3503_probe(hub);
336}
337
338static void usb3503_platform_remove(struct platform_device *pdev)
339{
340	struct usb3503 *hub;
341
342	hub = platform_get_drvdata(pdev);
343	clk_disable_unprepare(hub->clk);
344}
345
346static int __maybe_unused usb3503_suspend(struct usb3503 *hub)
347{
348	usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
349	clk_disable_unprepare(hub->clk);
350
351	return 0;
352}
353
354static int __maybe_unused usb3503_resume(struct usb3503 *hub)
355{
356	clk_prepare_enable(hub->clk);
357	usb3503_switch_mode(hub, hub->mode);
358
359	return 0;
360}
361
362static int __maybe_unused usb3503_i2c_suspend(struct device *dev)
363{
364	struct i2c_client *client = to_i2c_client(dev);
365
366	return usb3503_suspend(i2c_get_clientdata(client));
367}
368
369static int __maybe_unused usb3503_i2c_resume(struct device *dev)
370{
371	struct i2c_client *client = to_i2c_client(dev);
372
373	return usb3503_resume(i2c_get_clientdata(client));
374}
375
376static int __maybe_unused usb3503_platform_suspend(struct device *dev)
377{
378	return usb3503_suspend(dev_get_drvdata(dev));
379}
380
381static int __maybe_unused usb3503_platform_resume(struct device *dev)
382{
383	return usb3503_resume(dev_get_drvdata(dev));
384}
385
386static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
387		usb3503_i2c_resume);
388
389static SIMPLE_DEV_PM_OPS(usb3503_platform_pm_ops, usb3503_platform_suspend,
390		usb3503_platform_resume);
391
392static const struct i2c_device_id usb3503_id[] = {
393	{ USB3503_I2C_NAME, 0 },
394	{ }
395};
396MODULE_DEVICE_TABLE(i2c, usb3503_id);
397
398#ifdef CONFIG_OF
399static const struct of_device_id usb3503_of_match[] = {
400	{ .compatible = "smsc,usb3503", },
401	{ .compatible = "smsc,usb3503a", },
402	{ .compatible = "smsc,usb3803", },
403	{},
404};
405MODULE_DEVICE_TABLE(of, usb3503_of_match);
406#endif
407
408static struct i2c_driver usb3503_i2c_driver = {
409	.driver = {
410		.name = USB3503_I2C_NAME,
411		.pm = pm_ptr(&usb3503_i2c_pm_ops),
412		.of_match_table = of_match_ptr(usb3503_of_match),
413	},
414	.probe		= usb3503_i2c_probe,
415	.remove		= usb3503_i2c_remove,
416	.id_table	= usb3503_id,
417};
418
419static struct platform_driver usb3503_platform_driver = {
420	.driver = {
421		.name = USB3503_I2C_NAME,
422		.of_match_table = of_match_ptr(usb3503_of_match),
423		.pm = pm_ptr(&usb3503_platform_pm_ops),
424	},
425	.probe		= usb3503_platform_probe,
426	.remove_new	= usb3503_platform_remove,
427};
428
429static int __init usb3503_init(void)
430{
431	int err;
432
433	err = i2c_add_driver(&usb3503_i2c_driver);
434	if (err) {
435		pr_err("usb3503: Failed to register I2C driver: %d\n", err);
436		return err;
437	}
438
439	err = platform_driver_register(&usb3503_platform_driver);
440	if (err) {
441		pr_err("usb3503: Failed to register platform driver: %d\n",
442		       err);
443		i2c_del_driver(&usb3503_i2c_driver);
444		return err;
445	}
446
447	return 0;
448}
449module_init(usb3503_init);
450
451static void __exit usb3503_exit(void)
452{
453	platform_driver_unregister(&usb3503_platform_driver);
454	i2c_del_driver(&usb3503_i2c_driver);
455}
456module_exit(usb3503_exit);
457
458MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
459MODULE_DESCRIPTION("USB3503 USB HUB driver");
460MODULE_LICENSE("GPL");
461