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 | |
44 | struct 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 | |
55 | static const unsigned int tahvo_cable[] = { |
56 | EXTCON_USB, |
57 | EXTCON_USB_HOST, |
58 | |
59 | EXTCON_NONE, |
60 | }; |
61 | |
62 | static ssize_t vbus_show(struct device *device, |
63 | struct device_attribute *attr, char *buf) |
64 | { |
65 | struct tahvo_usb *tu = dev_get_drvdata(dev: device); |
66 | return sprintf(buf, fmt: "%s\n" , tu->vbus_state ? "on" : "off" ); |
67 | } |
68 | static DEVICE_ATTR_RO(vbus); |
69 | |
70 | static void check_vbus_state(struct tahvo_usb *tu) |
71 | { |
72 | struct retu_dev *rdev = dev_get_drvdata(dev: 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(gadget: tu->phy.otg->gadget); |
82 | tu->phy.otg->state = OTG_STATE_B_PERIPHERAL; |
83 | usb_phy_set_event(x: &tu->phy, event: 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(gadget: tu->phy.otg->gadget); |
101 | tu->phy.otg->state = OTG_STATE_B_IDLE; |
102 | usb_phy_set_event(x: &tu->phy, event: 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(edev: tu->extcon, EXTCON_USB, state: tu->vbus_state); |
117 | sysfs_notify(kobj: &tu->pt_dev->dev.kobj, NULL, attr: "vbus_state" ); |
118 | } |
119 | } |
120 | |
121 | static void tahvo_usb_become_host(struct tahvo_usb *tu) |
122 | { |
123 | struct retu_dev *rdev = dev_get_drvdata(dev: tu->pt_dev->dev.parent); |
124 | |
125 | extcon_set_state_sync(edev: tu->extcon, EXTCON_USB_HOST, state: 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 | |
135 | static void tahvo_usb_stop_host(struct tahvo_usb *tu) |
136 | { |
137 | tu->phy.otg->state = OTG_STATE_A_IDLE; |
138 | } |
139 | |
140 | static void tahvo_usb_become_peripheral(struct tahvo_usb *tu) |
141 | { |
142 | struct retu_dev *rdev = dev_get_drvdata(dev: tu->pt_dev->dev.parent); |
143 | |
144 | extcon_set_state_sync(edev: tu->extcon, EXTCON_USB_HOST, state: 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 | |
154 | static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu) |
155 | { |
156 | if (tu->phy.otg->gadget) |
157 | usb_gadget_vbus_disconnect(gadget: tu->phy.otg->gadget); |
158 | tu->phy.otg->state = OTG_STATE_B_IDLE; |
159 | } |
160 | |
161 | static void tahvo_usb_power_off(struct tahvo_usb *tu) |
162 | { |
163 | struct retu_dev *rdev = dev_get_drvdata(dev: tu->pt_dev->dev.parent); |
164 | |
165 | /* Disable gadget controller if any */ |
166 | if (tu->phy.otg->gadget) |
167 | usb_gadget_vbus_disconnect(gadget: 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 | |
174 | static 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(dev: 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 | |
192 | static 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 | mutex_lock(&tu->serialize); |
198 | |
199 | if (host == NULL) { |
200 | if (tu->tahvo_mode == TAHVO_MODE_HOST) |
201 | tahvo_usb_power_off(tu); |
202 | otg->host = NULL; |
203 | mutex_unlock(lock: &tu->serialize); |
204 | return 0; |
205 | } |
206 | |
207 | if (tu->tahvo_mode == TAHVO_MODE_HOST) { |
208 | otg->host = NULL; |
209 | tahvo_usb_become_host(tu); |
210 | } |
211 | |
212 | otg->host = host; |
213 | |
214 | mutex_unlock(lock: &tu->serialize); |
215 | |
216 | return 0; |
217 | } |
218 | |
219 | static int tahvo_usb_set_peripheral(struct usb_otg *otg, |
220 | struct usb_gadget *gadget) |
221 | { |
222 | struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb, |
223 | phy); |
224 | |
225 | mutex_lock(&tu->serialize); |
226 | |
227 | if (!gadget) { |
228 | if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
229 | tahvo_usb_power_off(tu); |
230 | tu->phy.otg->gadget = NULL; |
231 | mutex_unlock(lock: &tu->serialize); |
232 | return 0; |
233 | } |
234 | |
235 | tu->phy.otg->gadget = gadget; |
236 | if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
237 | tahvo_usb_become_peripheral(tu); |
238 | |
239 | mutex_unlock(lock: &tu->serialize); |
240 | |
241 | return 0; |
242 | } |
243 | |
244 | static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu) |
245 | { |
246 | struct tahvo_usb *tu = _tu; |
247 | |
248 | mutex_lock(&tu->serialize); |
249 | check_vbus_state(tu); |
250 | mutex_unlock(lock: &tu->serialize); |
251 | |
252 | return IRQ_HANDLED; |
253 | } |
254 | |
255 | static ssize_t otg_mode_show(struct device *device, |
256 | struct device_attribute *attr, char *buf) |
257 | { |
258 | struct tahvo_usb *tu = dev_get_drvdata(dev: device); |
259 | |
260 | switch (tu->tahvo_mode) { |
261 | case TAHVO_MODE_HOST: |
262 | return sprintf(buf, fmt: "host\n" ); |
263 | case TAHVO_MODE_PERIPHERAL: |
264 | return sprintf(buf, fmt: "peripheral\n" ); |
265 | } |
266 | |
267 | return -EINVAL; |
268 | } |
269 | |
270 | static ssize_t otg_mode_store(struct device *device, |
271 | struct device_attribute *attr, |
272 | const char *buf, size_t count) |
273 | { |
274 | struct tahvo_usb *tu = dev_get_drvdata(dev: device); |
275 | int r; |
276 | |
277 | mutex_lock(&tu->serialize); |
278 | if (count >= 4 && strncmp(buf, "host" , 4) == 0) { |
279 | if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
280 | tahvo_usb_stop_peripheral(tu); |
281 | tu->tahvo_mode = TAHVO_MODE_HOST; |
282 | if (tu->phy.otg->host) { |
283 | dev_info(device, "HOST mode: host controller present\n" ); |
284 | tahvo_usb_become_host(tu); |
285 | } else { |
286 | dev_info(device, "HOST mode: no host controller, powering off\n" ); |
287 | tahvo_usb_power_off(tu); |
288 | } |
289 | r = strlen(buf); |
290 | } else if (count >= 10 && strncmp(buf, "peripheral" , 10) == 0) { |
291 | if (tu->tahvo_mode == TAHVO_MODE_HOST) |
292 | tahvo_usb_stop_host(tu); |
293 | tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; |
294 | if (tu->phy.otg->gadget) { |
295 | dev_info(device, "PERIPHERAL mode: gadget driver present\n" ); |
296 | tahvo_usb_become_peripheral(tu); |
297 | } else { |
298 | dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n" ); |
299 | tahvo_usb_power_off(tu); |
300 | } |
301 | r = strlen(buf); |
302 | } else { |
303 | r = -EINVAL; |
304 | } |
305 | mutex_unlock(lock: &tu->serialize); |
306 | |
307 | return r; |
308 | } |
309 | static DEVICE_ATTR_RW(otg_mode); |
310 | |
311 | static struct attribute *tahvo_attrs[] = { |
312 | &dev_attr_vbus.attr, |
313 | &dev_attr_otg_mode.attr, |
314 | NULL |
315 | }; |
316 | ATTRIBUTE_GROUPS(tahvo); |
317 | |
318 | static int tahvo_usb_probe(struct platform_device *pdev) |
319 | { |
320 | struct retu_dev *rdev = dev_get_drvdata(dev: pdev->dev.parent); |
321 | struct tahvo_usb *tu; |
322 | int ret; |
323 | |
324 | tu = devm_kzalloc(dev: &pdev->dev, size: sizeof(*tu), GFP_KERNEL); |
325 | if (!tu) |
326 | return -ENOMEM; |
327 | |
328 | tu->phy.otg = devm_kzalloc(dev: &pdev->dev, size: sizeof(*tu->phy.otg), |
329 | GFP_KERNEL); |
330 | if (!tu->phy.otg) |
331 | return -ENOMEM; |
332 | |
333 | tu->pt_dev = pdev; |
334 | |
335 | /* Default mode */ |
336 | #ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT |
337 | tu->tahvo_mode = TAHVO_MODE_HOST; |
338 | #else |
339 | tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; |
340 | #endif |
341 | |
342 | mutex_init(&tu->serialize); |
343 | |
344 | tu->ick = devm_clk_get(dev: &pdev->dev, id: "usb_l4_ick" ); |
345 | if (!IS_ERR(ptr: tu->ick)) |
346 | clk_enable(clk: tu->ick); |
347 | |
348 | /* |
349 | * Set initial state, so that we generate kevents only on state changes. |
350 | */ |
351 | tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS; |
352 | |
353 | tu->extcon = devm_extcon_dev_allocate(dev: &pdev->dev, cable: tahvo_cable); |
354 | if (IS_ERR(ptr: tu->extcon)) { |
355 | dev_err(&pdev->dev, "failed to allocate memory for extcon\n" ); |
356 | ret = PTR_ERR(ptr: tu->extcon); |
357 | goto err_disable_clk; |
358 | } |
359 | |
360 | ret = devm_extcon_dev_register(dev: &pdev->dev, edev: tu->extcon); |
361 | if (ret) { |
362 | dev_err(&pdev->dev, "could not register extcon device: %d\n" , |
363 | ret); |
364 | goto err_disable_clk; |
365 | } |
366 | |
367 | /* Set the initial cable state. */ |
368 | extcon_set_state_sync(edev: tu->extcon, EXTCON_USB_HOST, |
369 | state: tu->tahvo_mode == TAHVO_MODE_HOST); |
370 | extcon_set_state_sync(edev: tu->extcon, EXTCON_USB, state: tu->vbus_state); |
371 | |
372 | /* Create OTG interface */ |
373 | tahvo_usb_power_off(tu); |
374 | tu->phy.dev = &pdev->dev; |
375 | tu->phy.otg->state = OTG_STATE_UNDEFINED; |
376 | tu->phy.label = DRIVER_NAME; |
377 | tu->phy.set_suspend = tahvo_usb_set_suspend; |
378 | |
379 | tu->phy.otg->usb_phy = &tu->phy; |
380 | tu->phy.otg->set_host = tahvo_usb_set_host; |
381 | tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral; |
382 | |
383 | ret = usb_add_phy(&tu->phy, type: USB_PHY_TYPE_USB2); |
384 | if (ret < 0) { |
385 | dev_err(&pdev->dev, "cannot register USB transceiver: %d\n" , |
386 | ret); |
387 | goto err_disable_clk; |
388 | } |
389 | |
390 | dev_set_drvdata(dev: &pdev->dev, data: tu); |
391 | |
392 | tu->irq = ret = platform_get_irq(pdev, 0); |
393 | if (ret < 0) |
394 | goto err_remove_phy; |
395 | ret = request_threaded_irq(irq: tu->irq, NULL, thread_fn: tahvo_usb_vbus_interrupt, |
396 | IRQF_ONESHOT, |
397 | name: "tahvo-vbus" , dev: tu); |
398 | if (ret) { |
399 | dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n" , |
400 | ret); |
401 | goto err_remove_phy; |
402 | } |
403 | |
404 | return 0; |
405 | |
406 | err_remove_phy: |
407 | usb_remove_phy(&tu->phy); |
408 | err_disable_clk: |
409 | if (!IS_ERR(ptr: tu->ick)) |
410 | clk_disable(clk: tu->ick); |
411 | |
412 | return ret; |
413 | } |
414 | |
415 | static void tahvo_usb_remove(struct platform_device *pdev) |
416 | { |
417 | struct tahvo_usb *tu = platform_get_drvdata(pdev); |
418 | |
419 | free_irq(tu->irq, tu); |
420 | usb_remove_phy(&tu->phy); |
421 | if (!IS_ERR(ptr: tu->ick)) |
422 | clk_disable(clk: tu->ick); |
423 | } |
424 | |
425 | static struct platform_driver tahvo_usb_driver = { |
426 | .probe = tahvo_usb_probe, |
427 | .remove_new = tahvo_usb_remove, |
428 | .driver = { |
429 | .name = "tahvo-usb" , |
430 | .dev_groups = tahvo_groups, |
431 | }, |
432 | }; |
433 | module_platform_driver(tahvo_usb_driver); |
434 | |
435 | MODULE_DESCRIPTION("Tahvo USB transceiver driver" ); |
436 | MODULE_LICENSE("GPL" ); |
437 | MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs" ); |
438 | MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>" ); |
439 | |