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 u32 mode = USB3503_MODE_HUB;
164 const u32 *property;
165 enum gpiod_flags flags;
166 int len;
167
168 if (pdata) {
169 hub->port_off_mask = pdata->port_off_mask;
170 hub->mode = pdata->initial_mode;
171 } else if (np) {
172 u32 rate = 0;
173 hub->port_off_mask = 0;
174
175 if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
176 switch (rate) {
177 case 38400000:
178 case 26000000:
179 case 19200000:
180 case 12000000:
181 hub->secondary_ref_clk = 0;
182 break;
183 case 24000000:
184 case 27000000:
185 case 25000000:
186 case 50000000:
187 hub->secondary_ref_clk = 1;
188 break;
189 default:
190 dev_err(dev,
191 "unsupported reference clock rate (%d)\n",
192 (int) rate);
193 return -EINVAL;
194 }
195 }
196
197 hub->clk = devm_clk_get_optional(dev, "refclk");
198 if (IS_ERR(hub->clk)) {
199 dev_err(dev, "unable to request refclk (%ld)\n",
200 PTR_ERR(hub->clk));
201 return PTR_ERR(hub->clk);
202 }
203
204 if (rate != 0) {
205 err = clk_set_rate(hub->clk, rate);
206 if (err) {
207 dev_err(dev,
208 "unable to set reference clock rate to %d\n",
209 (int)rate);
210 return err;
211 }
212 }
213
214 err = clk_prepare_enable(hub->clk);
215 if (err) {
216 dev_err(dev, "unable to enable reference clock\n");
217 return err;
218 }
219
220 property = of_get_property(np, "disabled-ports", &len);
221 if (property && (len / sizeof(u32)) > 0) {
222 int i;
223 for (i = 0; i < len / sizeof(u32); i++) {
224 u32 port = be32_to_cpu(property[i]);
225 if ((1 <= port) && (port <= 3))
226 hub->port_off_mask |= (1 << port);
227 }
228 }
229
230 of_property_read_u32(np, "initial-mode", &mode);
231 hub->mode = mode;
232 }
233
234 if (hub->secondary_ref_clk)
235 flags = GPIOD_OUT_LOW;
236 else
237 flags = GPIOD_OUT_HIGH;
238 hub->intn = devm_gpiod_get_optional(dev, "intn", flags);
239 if (IS_ERR(hub->intn))
240 return PTR_ERR(hub->intn);
241 if (hub->intn)
242 gpiod_set_consumer_name(hub->intn, "usb3503 intn");
243
244 hub->connect = devm_gpiod_get_optional(dev, "connect", GPIOD_OUT_LOW);
245 if (IS_ERR(hub->connect))
246 return PTR_ERR(hub->connect);
247 if (hub->connect)
248 gpiod_set_consumer_name(hub->connect, "usb3503 connect");
249
250 hub->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
251 if (IS_ERR(hub->reset))
252 return PTR_ERR(hub->reset);
253 if (hub->reset) {
254 /* Datasheet defines a hardware reset to be at least 100us */
255 usleep_range(100, 10000);
256 gpiod_set_consumer_name(hub->reset, "usb3503 reset");
257 }
258
259 if (hub->port_off_mask && !hub->regmap)
260 dev_err(dev, "Ports disabled with no control interface\n");
261
262 usb3503_switch_mode(hub, hub->mode);
263
264 dev_info(dev, "%s: probed in %s mode\n", __func__,
265 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
266
267 return 0;
268 }
269
usb3503_i2c_probe(struct i2c_client * i2c,const struct i2c_device_id * id)270 static int usb3503_i2c_probe(struct i2c_client *i2c,
271 const struct i2c_device_id *id)
272 {
273 struct usb3503 *hub;
274 int err;
275
276 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
277 if (!hub)
278 return -ENOMEM;
279
280 i2c_set_clientdata(i2c, hub);
281 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
282 if (IS_ERR(hub->regmap)) {
283 err = PTR_ERR(hub->regmap);
284 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
285 return err;
286 }
287 hub->dev = &i2c->dev;
288
289 return usb3503_probe(hub);
290 }
291
usb3503_i2c_remove(struct i2c_client * i2c)292 static int usb3503_i2c_remove(struct i2c_client *i2c)
293 {
294 struct usb3503 *hub;
295
296 hub = i2c_get_clientdata(i2c);
297 clk_disable_unprepare(hub->clk);
298
299 return 0;
300 }
301
usb3503_platform_probe(struct platform_device * pdev)302 static int usb3503_platform_probe(struct platform_device *pdev)
303 {
304 struct usb3503 *hub;
305
306 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
307 if (!hub)
308 return -ENOMEM;
309 hub->dev = &pdev->dev;
310 platform_set_drvdata(pdev, hub);
311
312 return usb3503_probe(hub);
313 }
314
usb3503_platform_remove(struct platform_device * pdev)315 static int usb3503_platform_remove(struct platform_device *pdev)
316 {
317 struct usb3503 *hub;
318
319 hub = platform_get_drvdata(pdev);
320 clk_disable_unprepare(hub->clk);
321
322 return 0;
323 }
324
usb3503_suspend(struct usb3503 * hub)325 static int __maybe_unused usb3503_suspend(struct usb3503 *hub)
326 {
327 usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
328 clk_disable_unprepare(hub->clk);
329
330 return 0;
331 }
332
usb3503_resume(struct usb3503 * hub)333 static int __maybe_unused usb3503_resume(struct usb3503 *hub)
334 {
335 clk_prepare_enable(hub->clk);
336 usb3503_switch_mode(hub, hub->mode);
337
338 return 0;
339 }
340
usb3503_i2c_suspend(struct device * dev)341 static int __maybe_unused usb3503_i2c_suspend(struct device *dev)
342 {
343 struct i2c_client *client = to_i2c_client(dev);
344
345 return usb3503_suspend(i2c_get_clientdata(client));
346 }
347
usb3503_i2c_resume(struct device * dev)348 static int __maybe_unused usb3503_i2c_resume(struct device *dev)
349 {
350 struct i2c_client *client = to_i2c_client(dev);
351
352 return usb3503_resume(i2c_get_clientdata(client));
353 }
354
usb3503_platform_suspend(struct device * dev)355 static int __maybe_unused usb3503_platform_suspend(struct device *dev)
356 {
357 return usb3503_suspend(dev_get_drvdata(dev));
358 }
359
usb3503_platform_resume(struct device * dev)360 static int __maybe_unused usb3503_platform_resume(struct device *dev)
361 {
362 return usb3503_resume(dev_get_drvdata(dev));
363 }
364
365 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
366 usb3503_i2c_resume);
367
368 static SIMPLE_DEV_PM_OPS(usb3503_platform_pm_ops, usb3503_platform_suspend,
369 usb3503_platform_resume);
370
371 static const struct i2c_device_id usb3503_id[] = {
372 { USB3503_I2C_NAME, 0 },
373 { }
374 };
375 MODULE_DEVICE_TABLE(i2c, usb3503_id);
376
377 #ifdef CONFIG_OF
378 static const struct of_device_id usb3503_of_match[] = {
379 { .compatible = "smsc,usb3503", },
380 { .compatible = "smsc,usb3503a", },
381 {},
382 };
383 MODULE_DEVICE_TABLE(of, usb3503_of_match);
384 #endif
385
386 static struct i2c_driver usb3503_i2c_driver = {
387 .driver = {
388 .name = USB3503_I2C_NAME,
389 .pm = pm_ptr(&usb3503_i2c_pm_ops),
390 .of_match_table = of_match_ptr(usb3503_of_match),
391 },
392 .probe = usb3503_i2c_probe,
393 .remove = usb3503_i2c_remove,
394 .id_table = usb3503_id,
395 };
396
397 static struct platform_driver usb3503_platform_driver = {
398 .driver = {
399 .name = USB3503_I2C_NAME,
400 .of_match_table = of_match_ptr(usb3503_of_match),
401 .pm = pm_ptr(&usb3503_platform_pm_ops),
402 },
403 .probe = usb3503_platform_probe,
404 .remove = usb3503_platform_remove,
405 };
406
usb3503_init(void)407 static int __init usb3503_init(void)
408 {
409 int err;
410
411 err = i2c_add_driver(&usb3503_i2c_driver);
412 if (err != 0)
413 pr_err("usb3503: Failed to register I2C driver: %d\n", err);
414
415 err = platform_driver_register(&usb3503_platform_driver);
416 if (err != 0)
417 pr_err("usb3503: Failed to register platform driver: %d\n",
418 err);
419
420 return 0;
421 }
422 module_init(usb3503_init);
423
usb3503_exit(void)424 static void __exit usb3503_exit(void)
425 {
426 platform_driver_unregister(&usb3503_platform_driver);
427 i2c_del_driver(&usb3503_i2c_driver);
428 }
429 module_exit(usb3503_exit);
430
431 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
432 MODULE_DESCRIPTION("USB3503 USB HUB driver");
433 MODULE_LICENSE("GPL");
434