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1/*
2 * Tahvo USB transceiver driver
3 *
4 * Copyright (C) 2005-2006 Nokia Corporation
5 *
6 * Parts copied from isp1301_omap.c.
7 * Copyright (C) 2004 Texas Instruments
8 * Copyright (C) 2004 David Brownell
9 *
10 * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
11 * Modified for Retu/Tahvo MFD by Aaro Koskinen.
12 *
13 * This file is subject to the terms and conditions of the GNU General
14 * Public License. See the file "COPYING" in the main directory of this
15 * archive for more details.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 */
22
23#include <linux/io.h>
24#include <linux/clk.h>
25#include <linux/usb.h>
26#include <linux/extcon.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/usb/otg.h>
30#include <linux/mfd/retu.h>
31#include <linux/usb/gadget.h>
32#include <linux/platform_device.h>
33
34#define DRIVER_NAME "tahvo-usb"
35
36#define TAHVO_REG_IDSR 0x02
37#define TAHVO_REG_USBR 0x06
38
39#define USBR_SLAVE_CONTROL (1 << 8)
40#define USBR_VPPVIO_SW (1 << 7)
41#define USBR_SPEED (1 << 6)
42#define USBR_REGOUT (1 << 5)
43#define USBR_MASTER_SW2 (1 << 4)
44#define USBR_MASTER_SW1 (1 << 3)
45#define USBR_SLAVE_SW (1 << 2)
46#define USBR_NSUSPEND (1 << 1)
47#define USBR_SEMODE (1 << 0)
48
49#define TAHVO_MODE_HOST 0
50#define TAHVO_MODE_PERIPHERAL 1
51
52struct tahvo_usb {
53 struct platform_device *pt_dev;
54 struct usb_phy phy;
55 int vbus_state;
56 struct mutex serialize;
57 struct clk *ick;
58 int irq;
59 int tahvo_mode;
60 struct extcon_dev *extcon;
61};
62
63static const unsigned int tahvo_cable[] = {
64 EXTCON_USB,
65 EXTCON_USB_HOST,
66
67 EXTCON_NONE,
68};
69
70static ssize_t vbus_state_show(struct device *device,
71 struct device_attribute *attr, char *buf)
72{
73 struct tahvo_usb *tu = dev_get_drvdata(device);
74 return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
75}
76static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
77
78static void check_vbus_state(struct tahvo_usb *tu)
79{
80 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
81 int reg, prev_state;
82
83 reg = retu_read(rdev, TAHVO_REG_IDSR);
84 if (reg & TAHVO_STAT_VBUS) {
85 switch (tu->phy.otg->state) {
86 case OTG_STATE_B_IDLE:
87 /* Enable the gadget driver */
88 if (tu->phy.otg->gadget)
89 usb_gadget_vbus_connect(tu->phy.otg->gadget);
90 tu->phy.otg->state = OTG_STATE_B_PERIPHERAL;
91 usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
92 break;
93 case OTG_STATE_A_IDLE:
94 /*
95 * Session is now valid assuming the USB hub is driving
96 * Vbus.
97 */
98 tu->phy.otg->state = OTG_STATE_A_HOST;
99 break;
100 default:
101 break;
102 }
103 dev_info(&tu->pt_dev->dev, "USB cable connected\n");
104 } else {
105 switch (tu->phy.otg->state) {
106 case OTG_STATE_B_PERIPHERAL:
107 if (tu->phy.otg->gadget)
108 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
109 tu->phy.otg->state = OTG_STATE_B_IDLE;
110 usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
111 break;
112 case OTG_STATE_A_HOST:
113 tu->phy.otg->state = OTG_STATE_A_IDLE;
114 break;
115 default:
116 break;
117 }
118 dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
119 }
120
121 prev_state = tu->vbus_state;
122 tu->vbus_state = reg & TAHVO_STAT_VBUS;
123 if (prev_state != tu->vbus_state) {
124 extcon_set_cable_state_(tu->extcon, EXTCON_USB, tu->vbus_state);
125 sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
126 }
127}
128
129static void tahvo_usb_become_host(struct tahvo_usb *tu)
130{
131 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
132
133 extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST, true);
134
135 /* Power up the transceiver in USB host mode */
136 retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
137 USBR_MASTER_SW2 | USBR_MASTER_SW1);
138 tu->phy.otg->state = OTG_STATE_A_IDLE;
139
140 check_vbus_state(tu);
141}
142
143static void tahvo_usb_stop_host(struct tahvo_usb *tu)
144{
145 tu->phy.otg->state = OTG_STATE_A_IDLE;
146}
147
148static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
149{
150 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
151
152 extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST, false);
153
154 /* Power up transceiver and set it in USB peripheral mode */
155 retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
156 USBR_NSUSPEND | USBR_SLAVE_SW);
157 tu->phy.otg->state = OTG_STATE_B_IDLE;
158
159 check_vbus_state(tu);
160}
161
162static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
163{
164 if (tu->phy.otg->gadget)
165 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
166 tu->phy.otg->state = OTG_STATE_B_IDLE;
167}
168
169static void tahvo_usb_power_off(struct tahvo_usb *tu)
170{
171 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
172
173 /* Disable gadget controller if any */
174 if (tu->phy.otg->gadget)
175 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
176
177 /* Power off transceiver */
178 retu_write(rdev, TAHVO_REG_USBR, 0);
179 tu->phy.otg->state = OTG_STATE_UNDEFINED;
180}
181
182static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
183{
184 struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
185 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
186 u16 w;
187
188 dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
189
190 w = retu_read(rdev, TAHVO_REG_USBR);
191 if (suspend)
192 w &= ~USBR_NSUSPEND;
193 else
194 w |= USBR_NSUSPEND;
195 retu_write(rdev, TAHVO_REG_USBR, w);
196
197 return 0;
198}
199
200static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
201{
202 struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
203 phy);
204
205 dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
206
207 mutex_lock(&tu->serialize);
208
209 if (host == NULL) {
210 if (tu->tahvo_mode == TAHVO_MODE_HOST)
211 tahvo_usb_power_off(tu);
212 otg->host = NULL;
213 mutex_unlock(&tu->serialize);
214 return 0;
215 }
216
217 if (tu->tahvo_mode == TAHVO_MODE_HOST) {
218 otg->host = NULL;
219 tahvo_usb_become_host(tu);
220 }
221
222 otg->host = host;
223
224 mutex_unlock(&tu->serialize);
225
226 return 0;
227}
228
229static int tahvo_usb_set_peripheral(struct usb_otg *otg,
230 struct usb_gadget *gadget)
231{
232 struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
233 phy);
234
235 dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
236
237 mutex_lock(&tu->serialize);
238
239 if (!gadget) {
240 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
241 tahvo_usb_power_off(tu);
242 tu->phy.otg->gadget = NULL;
243 mutex_unlock(&tu->serialize);
244 return 0;
245 }
246
247 tu->phy.otg->gadget = gadget;
248 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
249 tahvo_usb_become_peripheral(tu);
250
251 mutex_unlock(&tu->serialize);
252
253 return 0;
254}
255
256static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
257{
258 struct tahvo_usb *tu = _tu;
259
260 mutex_lock(&tu->serialize);
261 check_vbus_state(tu);
262 mutex_unlock(&tu->serialize);
263
264 return IRQ_HANDLED;
265}
266
267static ssize_t otg_mode_show(struct device *device,
268 struct device_attribute *attr, char *buf)
269{
270 struct tahvo_usb *tu = dev_get_drvdata(device);
271
272 switch (tu->tahvo_mode) {
273 case TAHVO_MODE_HOST:
274 return sprintf(buf, "host\n");
275 case TAHVO_MODE_PERIPHERAL:
276 return sprintf(buf, "peripheral\n");
277 }
278
279 return -EINVAL;
280}
281
282static ssize_t otg_mode_store(struct device *device,
283 struct device_attribute *attr,
284 const char *buf, size_t count)
285{
286 struct tahvo_usb *tu = dev_get_drvdata(device);
287 int r;
288
289 mutex_lock(&tu->serialize);
290 if (count >= 4 && strncmp(buf, "host", 4) == 0) {
291 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
292 tahvo_usb_stop_peripheral(tu);
293 tu->tahvo_mode = TAHVO_MODE_HOST;
294 if (tu->phy.otg->host) {
295 dev_info(device, "HOST mode: host controller present\n");
296 tahvo_usb_become_host(tu);
297 } else {
298 dev_info(device, "HOST mode: no host controller, powering off\n");
299 tahvo_usb_power_off(tu);
300 }
301 r = strlen(buf);
302 } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
303 if (tu->tahvo_mode == TAHVO_MODE_HOST)
304 tahvo_usb_stop_host(tu);
305 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
306 if (tu->phy.otg->gadget) {
307 dev_info(device, "PERIPHERAL mode: gadget driver present\n");
308 tahvo_usb_become_peripheral(tu);
309 } else {
310 dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
311 tahvo_usb_power_off(tu);
312 }
313 r = strlen(buf);
314 } else {
315 r = -EINVAL;
316 }
317 mutex_unlock(&tu->serialize);
318
319 return r;
320}
321static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
322
323static struct attribute *tahvo_attributes[] = {
324 &dev_attr_vbus.attr,
325 &dev_attr_otg_mode.attr,
326 NULL
327};
328
329static struct attribute_group tahvo_attr_group = {
330 .attrs = tahvo_attributes,
331};
332
333static int tahvo_usb_probe(struct platform_device *pdev)
334{
335 struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
336 struct tahvo_usb *tu;
337 int ret;
338
339 tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
340 if (!tu)
341 return -ENOMEM;
342
343 tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
344 GFP_KERNEL);
345 if (!tu->phy.otg)
346 return -ENOMEM;
347
348 tu->pt_dev = pdev;
349
350 /* Default mode */
351#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
352 tu->tahvo_mode = TAHVO_MODE_HOST;
353#else
354 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
355#endif
356
357 mutex_init(&tu->serialize);
358
359 tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
360 if (!IS_ERR(tu->ick))
361 clk_enable(tu->ick);
362
363 /*
364 * Set initial state, so that we generate kevents only on state changes.
365 */
366 tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
367
368 tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable);
369 if (IS_ERR(tu->extcon)) {
370 dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
371 return -ENOMEM;
372 }
373
374 ret = devm_extcon_dev_register(&pdev->dev, tu->extcon);
375 if (ret) {
376 dev_err(&pdev->dev, "could not register extcon device: %d\n",
377 ret);
378 goto err_disable_clk;
379 }
380
381 /* Set the initial cable state. */
382 extcon_set_cable_state_(tu->extcon, EXTCON_USB_HOST,
383 tu->tahvo_mode == TAHVO_MODE_HOST);
384 extcon_set_cable_state_(tu->extcon, EXTCON_USB, tu->vbus_state);
385
386 /* Create OTG interface */
387 tahvo_usb_power_off(tu);
388 tu->phy.dev = &pdev->dev;
389 tu->phy.otg->state = OTG_STATE_UNDEFINED;
390 tu->phy.label = DRIVER_NAME;
391 tu->phy.set_suspend = tahvo_usb_set_suspend;
392
393 tu->phy.otg->usb_phy = &tu->phy;
394 tu->phy.otg->set_host = tahvo_usb_set_host;
395 tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
396
397 ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
398 if (ret < 0) {
399 dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
400 ret);
401 goto err_disable_clk;
402 }
403
404 dev_set_drvdata(&pdev->dev, tu);
405
406 tu->irq = platform_get_irq(pdev, 0);
407 ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt,
408 IRQF_ONESHOT,
409 "tahvo-vbus", tu);
410 if (ret) {
411 dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
412 ret);
413 goto err_remove_phy;
414 }
415
416 /* Attributes */
417 ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
418 if (ret) {
419 dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
420 goto err_free_irq;
421 }
422
423 return 0;
424
425err_free_irq:
426 free_irq(tu->irq, tu);
427err_remove_phy:
428 usb_remove_phy(&tu->phy);
429err_disable_clk:
430 if (!IS_ERR(tu->ick))
431 clk_disable(tu->ick);
432
433 return ret;
434}
435
436static int tahvo_usb_remove(struct platform_device *pdev)
437{
438 struct tahvo_usb *tu = platform_get_drvdata(pdev);
439
440 sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
441 free_irq(tu->irq, tu);
442 usb_remove_phy(&tu->phy);
443 if (!IS_ERR(tu->ick))
444 clk_disable(tu->ick);
445
446 return 0;
447}
448
449static struct platform_driver tahvo_usb_driver = {
450 .probe = tahvo_usb_probe,
451 .remove = tahvo_usb_remove,
452 .driver = {
453 .name = "tahvo-usb",
454 },
455};
456module_platform_driver(tahvo_usb_driver);
457
458MODULE_DESCRIPTION("Tahvo USB transceiver driver");
459MODULE_LICENSE("GPL");
460MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
461MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");