Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Tahvo USB transceiver driver
4 *
5 * Copyright (C) 2005-2006 Nokia Corporation
6 *
7 * Parts copied from isp1301_omap.c.
8 * Copyright (C) 2004 Texas Instruments
9 * Copyright (C) 2004 David Brownell
10 *
11 * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
12 * Modified for Retu/Tahvo MFD by Aaro Koskinen.
13 */
14
15#include <linux/io.h>
16#include <linux/clk.h>
17#include <linux/usb.h>
18#include <linux/extcon-provider.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/usb/otg.h>
22#include <linux/mfd/retu.h>
23#include <linux/usb/gadget.h>
24#include <linux/platform_device.h>
25
26#define DRIVER_NAME "tahvo-usb"
27
28#define TAHVO_REG_IDSR 0x02
29#define TAHVO_REG_USBR 0x06
30
31#define USBR_SLAVE_CONTROL (1 << 8)
32#define USBR_VPPVIO_SW (1 << 7)
33#define USBR_SPEED (1 << 6)
34#define USBR_REGOUT (1 << 5)
35#define USBR_MASTER_SW2 (1 << 4)
36#define USBR_MASTER_SW1 (1 << 3)
37#define USBR_SLAVE_SW (1 << 2)
38#define USBR_NSUSPEND (1 << 1)
39#define USBR_SEMODE (1 << 0)
40
41#define TAHVO_MODE_HOST 0
42#define TAHVO_MODE_PERIPHERAL 1
43
44struct tahvo_usb {
45 struct platform_device *pt_dev;
46 struct usb_phy phy;
47 int vbus_state;
48 struct mutex serialize;
49 struct clk *ick;
50 int irq;
51 int tahvo_mode;
52 struct extcon_dev *extcon;
53};
54
55static const unsigned int tahvo_cable[] = {
56 EXTCON_USB,
57 EXTCON_USB_HOST,
58
59 EXTCON_NONE,
60};
61
62static ssize_t vbus_show(struct device *device,
63 struct device_attribute *attr, char *buf)
64{
65 struct tahvo_usb *tu = dev_get_drvdata(device);
66 return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
67}
68static DEVICE_ATTR_RO(vbus);
69
70static void check_vbus_state(struct tahvo_usb *tu)
71{
72 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
73 int reg, prev_state;
74
75 reg = retu_read(rdev, TAHVO_REG_IDSR);
76 if (reg & TAHVO_STAT_VBUS) {
77 switch (tu->phy.otg->state) {
78 case OTG_STATE_B_IDLE:
79 /* Enable the gadget driver */
80 if (tu->phy.otg->gadget)
81 usb_gadget_vbus_connect(tu->phy.otg->gadget);
82 tu->phy.otg->state = OTG_STATE_B_PERIPHERAL;
83 usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
84 break;
85 case OTG_STATE_A_IDLE:
86 /*
87 * Session is now valid assuming the USB hub is driving
88 * Vbus.
89 */
90 tu->phy.otg->state = OTG_STATE_A_HOST;
91 break;
92 default:
93 break;
94 }
95 dev_info(&tu->pt_dev->dev, "USB cable connected\n");
96 } else {
97 switch (tu->phy.otg->state) {
98 case OTG_STATE_B_PERIPHERAL:
99 if (tu->phy.otg->gadget)
100 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
101 tu->phy.otg->state = OTG_STATE_B_IDLE;
102 usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
103 break;
104 case OTG_STATE_A_HOST:
105 tu->phy.otg->state = OTG_STATE_A_IDLE;
106 break;
107 default:
108 break;
109 }
110 dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
111 }
112
113 prev_state = tu->vbus_state;
114 tu->vbus_state = reg & TAHVO_STAT_VBUS;
115 if (prev_state != tu->vbus_state) {
116 extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state);
117 sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
118 }
119}
120
121static void tahvo_usb_become_host(struct tahvo_usb *tu)
122{
123 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
124
125 extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, true);
126
127 /* Power up the transceiver in USB host mode */
128 retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
129 USBR_MASTER_SW2 | USBR_MASTER_SW1);
130 tu->phy.otg->state = OTG_STATE_A_IDLE;
131
132 check_vbus_state(tu);
133}
134
135static void tahvo_usb_stop_host(struct tahvo_usb *tu)
136{
137 tu->phy.otg->state = OTG_STATE_A_IDLE;
138}
139
140static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
141{
142 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
143
144 extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, false);
145
146 /* Power up transceiver and set it in USB peripheral mode */
147 retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
148 USBR_NSUSPEND | USBR_SLAVE_SW);
149 tu->phy.otg->state = OTG_STATE_B_IDLE;
150
151 check_vbus_state(tu);
152}
153
154static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
155{
156 if (tu->phy.otg->gadget)
157 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
158 tu->phy.otg->state = OTG_STATE_B_IDLE;
159}
160
161static void tahvo_usb_power_off(struct tahvo_usb *tu)
162{
163 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
164
165 /* Disable gadget controller if any */
166 if (tu->phy.otg->gadget)
167 usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
168
169 /* Power off transceiver */
170 retu_write(rdev, TAHVO_REG_USBR, 0);
171 tu->phy.otg->state = OTG_STATE_UNDEFINED;
172}
173
174static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
175{
176 struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
177 struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
178 u16 w;
179
180 dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
181
182 w = retu_read(rdev, TAHVO_REG_USBR);
183 if (suspend)
184 w &= ~USBR_NSUSPEND;
185 else
186 w |= USBR_NSUSPEND;
187 retu_write(rdev, TAHVO_REG_USBR, w);
188
189 return 0;
190}
191
192static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
193{
194 struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
195 phy);
196
197 dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
198
199 mutex_lock(&tu->serialize);
200
201 if (host == NULL) {
202 if (tu->tahvo_mode == TAHVO_MODE_HOST)
203 tahvo_usb_power_off(tu);
204 otg->host = NULL;
205 mutex_unlock(&tu->serialize);
206 return 0;
207 }
208
209 if (tu->tahvo_mode == TAHVO_MODE_HOST) {
210 otg->host = NULL;
211 tahvo_usb_become_host(tu);
212 }
213
214 otg->host = host;
215
216 mutex_unlock(&tu->serialize);
217
218 return 0;
219}
220
221static int tahvo_usb_set_peripheral(struct usb_otg *otg,
222 struct usb_gadget *gadget)
223{
224 struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
225 phy);
226
227 dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
228
229 mutex_lock(&tu->serialize);
230
231 if (!gadget) {
232 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
233 tahvo_usb_power_off(tu);
234 tu->phy.otg->gadget = NULL;
235 mutex_unlock(&tu->serialize);
236 return 0;
237 }
238
239 tu->phy.otg->gadget = gadget;
240 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
241 tahvo_usb_become_peripheral(tu);
242
243 mutex_unlock(&tu->serialize);
244
245 return 0;
246}
247
248static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
249{
250 struct tahvo_usb *tu = _tu;
251
252 mutex_lock(&tu->serialize);
253 check_vbus_state(tu);
254 mutex_unlock(&tu->serialize);
255
256 return IRQ_HANDLED;
257}
258
259static ssize_t otg_mode_show(struct device *device,
260 struct device_attribute *attr, char *buf)
261{
262 struct tahvo_usb *tu = dev_get_drvdata(device);
263
264 switch (tu->tahvo_mode) {
265 case TAHVO_MODE_HOST:
266 return sprintf(buf, "host\n");
267 case TAHVO_MODE_PERIPHERAL:
268 return sprintf(buf, "peripheral\n");
269 }
270
271 return -EINVAL;
272}
273
274static ssize_t otg_mode_store(struct device *device,
275 struct device_attribute *attr,
276 const char *buf, size_t count)
277{
278 struct tahvo_usb *tu = dev_get_drvdata(device);
279 int r;
280
281 mutex_lock(&tu->serialize);
282 if (count >= 4 && strncmp(buf, "host", 4) == 0) {
283 if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
284 tahvo_usb_stop_peripheral(tu);
285 tu->tahvo_mode = TAHVO_MODE_HOST;
286 if (tu->phy.otg->host) {
287 dev_info(device, "HOST mode: host controller present\n");
288 tahvo_usb_become_host(tu);
289 } else {
290 dev_info(device, "HOST mode: no host controller, powering off\n");
291 tahvo_usb_power_off(tu);
292 }
293 r = strlen(buf);
294 } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
295 if (tu->tahvo_mode == TAHVO_MODE_HOST)
296 tahvo_usb_stop_host(tu);
297 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
298 if (tu->phy.otg->gadget) {
299 dev_info(device, "PERIPHERAL mode: gadget driver present\n");
300 tahvo_usb_become_peripheral(tu);
301 } else {
302 dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
303 tahvo_usb_power_off(tu);
304 }
305 r = strlen(buf);
306 } else {
307 r = -EINVAL;
308 }
309 mutex_unlock(&tu->serialize);
310
311 return r;
312}
313static DEVICE_ATTR_RW(otg_mode);
314
315static struct attribute *tahvo_attributes[] = {
316 &dev_attr_vbus.attr,
317 &dev_attr_otg_mode.attr,
318 NULL
319};
320
321static const struct attribute_group tahvo_attr_group = {
322 .attrs = tahvo_attributes,
323};
324
325static int tahvo_usb_probe(struct platform_device *pdev)
326{
327 struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
328 struct tahvo_usb *tu;
329 int ret;
330
331 tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
332 if (!tu)
333 return -ENOMEM;
334
335 tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
336 GFP_KERNEL);
337 if (!tu->phy.otg)
338 return -ENOMEM;
339
340 tu->pt_dev = pdev;
341
342 /* Default mode */
343#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
344 tu->tahvo_mode = TAHVO_MODE_HOST;
345#else
346 tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
347#endif
348
349 mutex_init(&tu->serialize);
350
351 tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
352 if (!IS_ERR(tu->ick))
353 clk_enable(tu->ick);
354
355 /*
356 * Set initial state, so that we generate kevents only on state changes.
357 */
358 tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
359
360 tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable);
361 if (IS_ERR(tu->extcon)) {
362 dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
363 ret = PTR_ERR(tu->extcon);
364 goto err_disable_clk;
365 }
366
367 ret = devm_extcon_dev_register(&pdev->dev, tu->extcon);
368 if (ret) {
369 dev_err(&pdev->dev, "could not register extcon device: %d\n",
370 ret);
371 goto err_disable_clk;
372 }
373
374 /* Set the initial cable state. */
375 extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST,
376 tu->tahvo_mode == TAHVO_MODE_HOST);
377 extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state);
378
379 /* Create OTG interface */
380 tahvo_usb_power_off(tu);
381 tu->phy.dev = &pdev->dev;
382 tu->phy.otg->state = OTG_STATE_UNDEFINED;
383 tu->phy.label = DRIVER_NAME;
384 tu->phy.set_suspend = tahvo_usb_set_suspend;
385
386 tu->phy.otg->usb_phy = &tu->phy;
387 tu->phy.otg->set_host = tahvo_usb_set_host;
388 tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
389
390 ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
391 if (ret < 0) {
392 dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
393 ret);
394 goto err_disable_clk;
395 }
396
397 dev_set_drvdata(&pdev->dev, tu);
398
399 tu->irq = platform_get_irq(pdev, 0);
400 ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt,
401 IRQF_ONESHOT,
402 "tahvo-vbus", tu);
403 if (ret) {
404 dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
405 ret);
406 goto err_remove_phy;
407 }
408
409 /* Attributes */
410 ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
411 if (ret) {
412 dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
413 goto err_free_irq;
414 }
415
416 return 0;
417
418err_free_irq:
419 free_irq(tu->irq, tu);
420err_remove_phy:
421 usb_remove_phy(&tu->phy);
422err_disable_clk:
423 if (!IS_ERR(tu->ick))
424 clk_disable(tu->ick);
425
426 return ret;
427}
428
429static int tahvo_usb_remove(struct platform_device *pdev)
430{
431 struct tahvo_usb *tu = platform_get_drvdata(pdev);
432
433 sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
434 free_irq(tu->irq, tu);
435 usb_remove_phy(&tu->phy);
436 if (!IS_ERR(tu->ick))
437 clk_disable(tu->ick);
438
439 return 0;
440}
441
442static struct platform_driver tahvo_usb_driver = {
443 .probe = tahvo_usb_probe,
444 .remove = tahvo_usb_remove,
445 .driver = {
446 .name = "tahvo-usb",
447 },
448};
449module_platform_driver(tahvo_usb_driver);
450
451MODULE_DESCRIPTION("Tahvo USB transceiver driver");
452MODULE_LICENSE("GPL");
453MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
454MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");