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
43 struct 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 *intn;
50 struct gpio_desc *reset;
51 struct gpio_desc *connect;
52 bool secondary_ref_clk;
53 };
54
usb3503_reset(struct usb3503 * hub,int state)55 static int usb3503_reset(struct usb3503 *hub, int state)
56 {
57 if (!state && hub->connect)
58 gpiod_set_value_cansleep(hub->connect, 0);
59
60 if (hub->reset)
61 gpiod_set_value_cansleep(hub->reset, !state);
62
63 /* Wait T_HUBINIT == 4ms for hub logic to stabilize */
64 if (state)
65 usleep_range(4000, 10000);
66
67 return 0;
68 }
69
usb3503_connect(struct usb3503 * hub)70 static int usb3503_connect(struct usb3503 *hub)
71 {
72 struct device *dev = hub->dev;
73 int err;
74
75 usb3503_reset(hub, 1);
76
77 if (hub->regmap) {
78 /* SP_ILOCK: set connect_n, config_n for config */
79 err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
80 (USB3503_SPILOCK_CONNECT
81 | USB3503_SPILOCK_CONFIG));
82 if (err < 0) {
83 dev_err(dev, "SP_ILOCK failed (%d)\n", err);
84 return err;
85 }
86
87 /* PDS : Set the ports which are disabled in self-powered mode. */
88 if (hub->port_off_mask) {
89 err = regmap_update_bits(hub->regmap, USB3503_PDS,
90 hub->port_off_mask,
91 hub->port_off_mask);
92 if (err < 0) {
93 dev_err(dev, "PDS failed (%d)\n", err);
94 return err;
95 }
96 }
97
98 /* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
99 err = regmap_update_bits(hub->regmap, USB3503_CFG1,
100 USB3503_SELF_BUS_PWR,
101 USB3503_SELF_BUS_PWR);
102 if (err < 0) {
103 dev_err(dev, "CFG1 failed (%d)\n", err);
104 return err;
105 }
106
107 /* SP_LOCK: clear connect_n, config_n for hub connect */
108 err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
109 (USB3503_SPILOCK_CONNECT
110 | USB3503_SPILOCK_CONFIG), 0);
111 if (err < 0) {
112 dev_err(dev, "SP_ILOCK failed (%d)\n", err);
113 return err;
114 }
115 }
116
117 if (hub->connect)
118 gpiod_set_value_cansleep(hub->connect, 1);
119
120 hub->mode = USB3503_MODE_HUB;
121 dev_info(dev, "switched to HUB mode\n");
122
123 return 0;
124 }
125
usb3503_switch_mode(struct usb3503 * hub,enum usb3503_mode mode)126 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
127 {
128 struct device *dev = hub->dev;
129 int err = 0;
130
131 switch (mode) {
132 case USB3503_MODE_HUB:
133 err = usb3503_connect(hub);
134 break;
135
136 case USB3503_MODE_STANDBY:
137 usb3503_reset(hub, 0);
138 dev_info(dev, "switched to STANDBY mode\n");
139 break;
140
141 default:
142 dev_err(dev, "unknown mode is requested\n");
143 err = -EINVAL;
144 break;
145 }
146
147 return err;
148 }
149
150 static const struct regmap_config usb3503_regmap_config = {
151 .reg_bits = 8,
152 .val_bits = 8,
153
154 .max_register = USB3503_RESET,
155 };
156
usb3503_probe(struct usb3503 * hub)157 static int usb3503_probe(struct usb3503 *hub)
158 {
159 struct device *dev = hub->dev;
160 struct usb3503_platform_data *pdata = dev_get_platdata(dev);
161 struct device_node *np = dev->of_node;
162 int err;
163 bool is_clk_enabled = false;
164 u32 mode = USB3503_MODE_HUB;
165 const u32 *property;
166 enum gpiod_flags flags;
167 int len;
168
169 if (pdata) {
170 hub->port_off_mask = pdata->port_off_mask;
171 hub->mode = pdata->initial_mode;
172 } else if (np) {
173 u32 rate = 0;
174 hub->port_off_mask = 0;
175
176 if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
177 switch (rate) {
178 case 38400000:
179 case 26000000:
180 case 19200000:
181 case 12000000:
182 hub->secondary_ref_clk = 0;
183 break;
184 case 24000000:
185 case 27000000:
186 case 25000000:
187 case 50000000:
188 hub->secondary_ref_clk = 1;
189 break;
190 default:
191 dev_err(dev,
192 "unsupported reference clock rate (%d)\n",
193 (int) rate);
194 return -EINVAL;
195 }
196 }
197
198 hub->clk = devm_clk_get_optional(dev, "refclk");
199 if (IS_ERR(hub->clk)) {
200 dev_err(dev, "unable to request refclk (%ld)\n",
201 PTR_ERR(hub->clk));
202 return PTR_ERR(hub->clk);
203 }
204
205 if (rate != 0) {
206 err = clk_set_rate(hub->clk, rate);
207 if (err) {
208 dev_err(dev,
209 "unable to set reference clock rate to %d\n",
210 (int)rate);
211 return err;
212 }
213 }
214
215 err = clk_prepare_enable(hub->clk);
216 if (err) {
217 dev_err(dev, "unable to enable reference clock\n");
218 return err;
219 }
220
221 is_clk_enabled = true;
222 property = of_get_property(np, "disabled-ports", &len);
223 if (property && (len / sizeof(u32)) > 0) {
224 int i;
225 for (i = 0; i < len / sizeof(u32); i++) {
226 u32 port = be32_to_cpu(property[i]);
227 if ((1 <= port) && (port <= 3))
228 hub->port_off_mask |= (1 << port);
229 }
230 }
231
232 of_property_read_u32(np, "initial-mode", &mode);
233 hub->mode = mode;
234 }
235
236 if (hub->secondary_ref_clk)
237 flags = GPIOD_OUT_LOW;
238 else
239 flags = GPIOD_OUT_HIGH;
240 hub->intn = devm_gpiod_get_optional(dev, "intn", flags);
241 if (IS_ERR(hub->intn)) {
242 err = PTR_ERR(hub->intn);
243 goto err_clk;
244 }
245 if (hub->intn)
246 gpiod_set_consumer_name(hub->intn, "usb3503 intn");
247
248 hub->connect = devm_gpiod_get_optional(dev, "connect", GPIOD_OUT_LOW);
249 if (IS_ERR(hub->connect)) {
250 err = PTR_ERR(hub->connect);
251 goto err_clk;
252 }
253 if (hub->connect)
254 gpiod_set_consumer_name(hub->connect, "usb3503 connect");
255
256 hub->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
257 if (IS_ERR(hub->reset)) {
258 err = PTR_ERR(hub->reset);
259 goto err_clk;
260 }
261 if (hub->reset) {
262 /* Datasheet defines a hardware reset to be at least 100us */
263 usleep_range(100, 10000);
264 gpiod_set_consumer_name(hub->reset, "usb3503 reset");
265 }
266
267 if (hub->port_off_mask && !hub->regmap)
268 dev_err(dev, "Ports disabled with no control interface\n");
269
270 usb3503_switch_mode(hub, hub->mode);
271
272 dev_info(dev, "%s: probed in %s mode\n", __func__,
273 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
274
275 return 0;
276
277 err_clk:
278 if (is_clk_enabled)
279 clk_disable_unprepare(hub->clk);
280 return err;
281 }
282
usb3503_i2c_probe(struct i2c_client * i2c,const struct i2c_device_id * id)283 static int usb3503_i2c_probe(struct i2c_client *i2c,
284 const struct i2c_device_id *id)
285 {
286 struct usb3503 *hub;
287 int err;
288
289 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
290 if (!hub)
291 return -ENOMEM;
292
293 i2c_set_clientdata(i2c, hub);
294 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
295 if (IS_ERR(hub->regmap)) {
296 err = PTR_ERR(hub->regmap);
297 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
298 return err;
299 }
300 hub->dev = &i2c->dev;
301
302 return usb3503_probe(hub);
303 }
304
usb3503_i2c_remove(struct i2c_client * i2c)305 static void usb3503_i2c_remove(struct i2c_client *i2c)
306 {
307 struct usb3503 *hub;
308
309 hub = i2c_get_clientdata(i2c);
310 clk_disable_unprepare(hub->clk);
311 }
312
usb3503_platform_probe(struct platform_device * pdev)313 static int usb3503_platform_probe(struct platform_device *pdev)
314 {
315 struct usb3503 *hub;
316
317 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
318 if (!hub)
319 return -ENOMEM;
320 hub->dev = &pdev->dev;
321 platform_set_drvdata(pdev, hub);
322
323 return usb3503_probe(hub);
324 }
325
usb3503_platform_remove(struct platform_device * pdev)326 static int usb3503_platform_remove(struct platform_device *pdev)
327 {
328 struct usb3503 *hub;
329
330 hub = platform_get_drvdata(pdev);
331 clk_disable_unprepare(hub->clk);
332
333 return 0;
334 }
335
usb3503_suspend(struct usb3503 * hub)336 static int __maybe_unused usb3503_suspend(struct usb3503 *hub)
337 {
338 usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
339 clk_disable_unprepare(hub->clk);
340
341 return 0;
342 }
343
usb3503_resume(struct usb3503 * hub)344 static int __maybe_unused usb3503_resume(struct usb3503 *hub)
345 {
346 clk_prepare_enable(hub->clk);
347 usb3503_switch_mode(hub, hub->mode);
348
349 return 0;
350 }
351
usb3503_i2c_suspend(struct device * dev)352 static int __maybe_unused usb3503_i2c_suspend(struct device *dev)
353 {
354 struct i2c_client *client = to_i2c_client(dev);
355
356 return usb3503_suspend(i2c_get_clientdata(client));
357 }
358
usb3503_i2c_resume(struct device * dev)359 static int __maybe_unused usb3503_i2c_resume(struct device *dev)
360 {
361 struct i2c_client *client = to_i2c_client(dev);
362
363 return usb3503_resume(i2c_get_clientdata(client));
364 }
365
usb3503_platform_suspend(struct device * dev)366 static int __maybe_unused usb3503_platform_suspend(struct device *dev)
367 {
368 return usb3503_suspend(dev_get_drvdata(dev));
369 }
370
usb3503_platform_resume(struct device * dev)371 static int __maybe_unused usb3503_platform_resume(struct device *dev)
372 {
373 return usb3503_resume(dev_get_drvdata(dev));
374 }
375
376 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
377 usb3503_i2c_resume);
378
379 static SIMPLE_DEV_PM_OPS(usb3503_platform_pm_ops, usb3503_platform_suspend,
380 usb3503_platform_resume);
381
382 static const struct i2c_device_id usb3503_id[] = {
383 { USB3503_I2C_NAME, 0 },
384 { }
385 };
386 MODULE_DEVICE_TABLE(i2c, usb3503_id);
387
388 #ifdef CONFIG_OF
389 static const struct of_device_id usb3503_of_match[] = {
390 { .compatible = "smsc,usb3503", },
391 { .compatible = "smsc,usb3503a", },
392 {},
393 };
394 MODULE_DEVICE_TABLE(of, usb3503_of_match);
395 #endif
396
397 static struct i2c_driver usb3503_i2c_driver = {
398 .driver = {
399 .name = USB3503_I2C_NAME,
400 .pm = pm_ptr(&usb3503_i2c_pm_ops),
401 .of_match_table = of_match_ptr(usb3503_of_match),
402 },
403 .probe = usb3503_i2c_probe,
404 .remove = usb3503_i2c_remove,
405 .id_table = usb3503_id,
406 };
407
408 static struct platform_driver usb3503_platform_driver = {
409 .driver = {
410 .name = USB3503_I2C_NAME,
411 .of_match_table = of_match_ptr(usb3503_of_match),
412 .pm = pm_ptr(&usb3503_platform_pm_ops),
413 },
414 .probe = usb3503_platform_probe,
415 .remove = usb3503_platform_remove,
416 };
417
usb3503_init(void)418 static int __init usb3503_init(void)
419 {
420 int err;
421
422 err = i2c_add_driver(&usb3503_i2c_driver);
423 if (err) {
424 pr_err("usb3503: Failed to register I2C driver: %d\n", err);
425 return err;
426 }
427
428 err = platform_driver_register(&usb3503_platform_driver);
429 if (err) {
430 pr_err("usb3503: Failed to register platform driver: %d\n",
431 err);
432 i2c_del_driver(&usb3503_i2c_driver);
433 return err;
434 }
435
436 return 0;
437 }
438 module_init(usb3503_init);
439
usb3503_exit(void)440 static void __exit usb3503_exit(void)
441 {
442 platform_driver_unregister(&usb3503_platform_driver);
443 i2c_del_driver(&usb3503_i2c_driver);
444 }
445 module_exit(usb3503_exit);
446
447 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
448 MODULE_DESCRIPTION("USB3503 USB HUB driver");
449 MODULE_LICENSE("GPL");
450