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[mirror_ubuntu-zesty-kernel.git] / drivers / usb / phy / phy-gpio-vbus-usb.c
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1/*
2 * gpio-vbus.c - simple GPIO VBUS sensing driver for B peripheral devices
3 *
4 * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/platform_device.h>
13#include <linux/gpio.h>
6eb0de82 14#include <linux/module.h>
5a0e3ad6 15#include <linux/slab.h>
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16#include <linux/interrupt.h>
17#include <linux/usb.h>
c2344f13 18#include <linux/workqueue.h>
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19
20#include <linux/regulator/consumer.h>
21
22#include <linux/usb/gadget.h>
23#include <linux/usb/gpio_vbus.h>
24#include <linux/usb/otg.h>
25
26
27/*
28 * A simple GPIO VBUS sensing driver for B peripheral only devices
29 * with internal transceivers. It can control a D+ pullup GPIO and
30 * a regulator to limit the current drawn from VBUS.
31 *
32 * Needs to be loaded before the UDC driver that will use it.
33 */
34struct gpio_vbus_data {
16bc1bb2 35 struct usb_phy phy;
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36 struct device *dev;
37 struct regulator *vbus_draw;
38 int vbus_draw_enabled;
39 unsigned mA;
934ccec4 40 struct delayed_work work;
e44694e8 41 int vbus;
123bbcee 42 int irq;
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43};
44
45
46/*
47 * This driver relies on "both edges" triggering. VBUS has 100 msec to
48 * stabilize, so the peripheral controller driver may need to cope with
49 * some bouncing due to current surges (e.g. charging local capacitance)
50 * and contact chatter.
51 *
52 * REVISIT in desperate straits, toggling between rising and falling
53 * edges might be workable.
54 */
55#define VBUS_IRQ_FLAGS \
da020b49 56 (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
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57
58
59/* interface to regulator framework */
60static void set_vbus_draw(struct gpio_vbus_data *gpio_vbus, unsigned mA)
61{
62 struct regulator *vbus_draw = gpio_vbus->vbus_draw;
63 int enabled;
e8d891fb 64 int ret;
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65
66 if (!vbus_draw)
67 return;
68
69 enabled = gpio_vbus->vbus_draw_enabled;
70 if (mA) {
71 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
72 if (!enabled) {
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73 ret = regulator_enable(vbus_draw);
74 if (ret < 0)
75 return;
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76 gpio_vbus->vbus_draw_enabled = 1;
77 }
78 } else {
79 if (enabled) {
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80 ret = regulator_disable(vbus_draw);
81 if (ret < 0)
82 return;
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83 gpio_vbus->vbus_draw_enabled = 0;
84 }
85 }
86 gpio_vbus->mA = mA;
87}
88
c2344f13 89static int is_vbus_powered(struct gpio_vbus_mach_info *pdata)
6084f1bf 90{
c2344f13 91 int vbus;
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92
93 vbus = gpio_get_value(pdata->gpio_vbus);
94 if (pdata->gpio_vbus_inverted)
95 vbus = !vbus;
96
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97 return vbus;
98}
99
100static void gpio_vbus_work(struct work_struct *work)
101{
102 struct gpio_vbus_data *gpio_vbus =
934ccec4 103 container_of(work, struct gpio_vbus_data, work.work);
19f9e188 104 struct gpio_vbus_mach_info *pdata = dev_get_platdata(gpio_vbus->dev);
e44694e8 105 int gpio, status, vbus;
6084f1bf 106
16bc1bb2 107 if (!gpio_vbus->phy.otg->gadget)
c2344f13 108 return;
6084f1bf 109
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110 vbus = is_vbus_powered(pdata);
111 if ((vbus ^ gpio_vbus->vbus) == 0)
112 return;
113 gpio_vbus->vbus = vbus;
114
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115 /* Peripheral controllers which manage the pullup themselves won't have
116 * gpio_pullup configured here. If it's configured here, we'll do what
117 * isp1301_omap::b_peripheral() does and enable the pullup here... although
118 * that may complicate usb_gadget_{,dis}connect() support.
119 */
120 gpio = pdata->gpio_pullup;
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121
122 if (vbus) {
662c738d 123 status = USB_EVENT_VBUS;
e47d9254 124 gpio_vbus->phy.otg->state = OTG_STATE_B_PERIPHERAL;
662c738d 125 gpio_vbus->phy.last_event = status;
16bc1bb2 126 usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget);
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127
128 /* drawing a "unit load" is *always* OK, except for OTG */
129 set_vbus_draw(gpio_vbus, 100);
130
131 /* optionally enable D+ pullup */
132 if (gpio_is_valid(gpio))
133 gpio_set_value(gpio, !pdata->gpio_pullup_inverted);
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134
135 atomic_notifier_call_chain(&gpio_vbus->phy.notifier,
136 status, gpio_vbus->phy.otg->gadget);
b20f3f9e 137 usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_ENUMERATED);
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138 } else {
139 /* optionally disable D+ pullup */
140 if (gpio_is_valid(gpio))
141 gpio_set_value(gpio, pdata->gpio_pullup_inverted);
142
143 set_vbus_draw(gpio_vbus, 0);
144
16bc1bb2 145 usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
662c738d 146 status = USB_EVENT_NONE;
e47d9254 147 gpio_vbus->phy.otg->state = OTG_STATE_B_IDLE;
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148 gpio_vbus->phy.last_event = status;
149
150 atomic_notifier_call_chain(&gpio_vbus->phy.notifier,
151 status, gpio_vbus->phy.otg->gadget);
b20f3f9e 152 usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_NONE);
6084f1bf 153 }
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154}
155
156/* VBUS change IRQ handler */
157static irqreturn_t gpio_vbus_irq(int irq, void *data)
158{
159 struct platform_device *pdev = data;
19f9e188 160 struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev);
c2344f13 161 struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
16bc1bb2 162 struct usb_otg *otg = gpio_vbus->phy.otg;
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163
164 dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n",
165 is_vbus_powered(pdata) ? "supplied" : "inactive",
16bc1bb2 166 otg->gadget ? otg->gadget->name : "none");
c2344f13 167
16bc1bb2 168 if (otg->gadget)
934ccec4 169 schedule_delayed_work(&gpio_vbus->work, msecs_to_jiffies(100));
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170
171 return IRQ_HANDLED;
172}
173
174/* OTG transceiver interface */
175
176/* bind/unbind the peripheral controller */
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177static int gpio_vbus_set_peripheral(struct usb_otg *otg,
178 struct usb_gadget *gadget)
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179{
180 struct gpio_vbus_data *gpio_vbus;
181 struct gpio_vbus_mach_info *pdata;
182 struct platform_device *pdev;
123bbcee 183 int gpio;
6084f1bf 184
19c1eac2 185 gpio_vbus = container_of(otg->usb_phy, struct gpio_vbus_data, phy);
6084f1bf 186 pdev = to_platform_device(gpio_vbus->dev);
19f9e188 187 pdata = dev_get_platdata(gpio_vbus->dev);
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188 gpio = pdata->gpio_pullup;
189
190 if (!gadget) {
191 dev_dbg(&pdev->dev, "unregistering gadget '%s'\n",
192 otg->gadget->name);
193
194 /* optionally disable D+ pullup */
195 if (gpio_is_valid(gpio))
196 gpio_set_value(gpio, pdata->gpio_pullup_inverted);
197
198 set_vbus_draw(gpio_vbus, 0);
199
200 usb_gadget_vbus_disconnect(otg->gadget);
e47d9254 201 otg->state = OTG_STATE_UNDEFINED;
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202
203 otg->gadget = NULL;
204 return 0;
205 }
206
207 otg->gadget = gadget;
208 dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name);
209
210 /* initialize connection state */
e44694e8 211 gpio_vbus->vbus = 0; /* start with disconnected */
123bbcee 212 gpio_vbus_irq(gpio_vbus->irq, pdev);
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213 return 0;
214}
215
216/* effective for B devices, ignored for A-peripheral */
16bc1bb2 217static int gpio_vbus_set_power(struct usb_phy *phy, unsigned mA)
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218{
219 struct gpio_vbus_data *gpio_vbus;
220
16bc1bb2 221 gpio_vbus = container_of(phy, struct gpio_vbus_data, phy);
6084f1bf 222
e47d9254 223 if (phy->otg->state == OTG_STATE_B_PERIPHERAL)
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224 set_vbus_draw(gpio_vbus, mA);
225 return 0;
226}
227
228/* for non-OTG B devices: set/clear transceiver suspend mode */
16bc1bb2 229static int gpio_vbus_set_suspend(struct usb_phy *phy, int suspend)
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230{
231 struct gpio_vbus_data *gpio_vbus;
232
16bc1bb2 233 gpio_vbus = container_of(phy, struct gpio_vbus_data, phy);
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234
235 /* draw max 0 mA from vbus in suspend mode; or the previously
236 * recorded amount of current if not suspended
237 *
238 * NOTE: high powered configs (mA > 100) may draw up to 2.5 mA
239 * if they're wake-enabled ... we don't handle that yet.
240 */
16bc1bb2 241 return gpio_vbus_set_power(phy, suspend ? 0 : gpio_vbus->mA);
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242}
243
244/* platform driver interface */
245
eaaa775b 246static int gpio_vbus_probe(struct platform_device *pdev)
6084f1bf 247{
19f9e188 248 struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev);
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249 struct gpio_vbus_data *gpio_vbus;
250 struct resource *res;
251 int err, gpio, irq;
c8240c1b 252 unsigned long irqflags;
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253
254 if (!pdata || !gpio_is_valid(pdata->gpio_vbus))
255 return -EINVAL;
256 gpio = pdata->gpio_vbus;
257
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258 gpio_vbus = devm_kzalloc(&pdev->dev, sizeof(struct gpio_vbus_data),
259 GFP_KERNEL);
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260 if (!gpio_vbus)
261 return -ENOMEM;
262
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263 gpio_vbus->phy.otg = devm_kzalloc(&pdev->dev, sizeof(struct usb_otg),
264 GFP_KERNEL);
0c582408 265 if (!gpio_vbus->phy.otg)
16bc1bb2 266 return -ENOMEM;
16bc1bb2 267
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268 platform_set_drvdata(pdev, gpio_vbus);
269 gpio_vbus->dev = &pdev->dev;
16bc1bb2 270 gpio_vbus->phy.label = "gpio-vbus";
1abd8b31 271 gpio_vbus->phy.dev = gpio_vbus->dev;
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272 gpio_vbus->phy.set_power = gpio_vbus_set_power;
273 gpio_vbus->phy.set_suspend = gpio_vbus_set_suspend;
16bc1bb2 274
e47d9254 275 gpio_vbus->phy.otg->state = OTG_STATE_UNDEFINED;
19c1eac2 276 gpio_vbus->phy.otg->usb_phy = &gpio_vbus->phy;
16bc1bb2 277 gpio_vbus->phy.otg->set_peripheral = gpio_vbus_set_peripheral;
6084f1bf 278
9f7b23ce 279 err = devm_gpio_request(&pdev->dev, gpio, "vbus_detect");
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280 if (err) {
281 dev_err(&pdev->dev, "can't request vbus gpio %d, err: %d\n",
282 gpio, err);
9f7b23ce 283 return err;
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284 }
285 gpio_direction_input(gpio);
286
287 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
288 if (res) {
289 irq = res->start;
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290 irqflags = (res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
291 } else {
6084f1bf 292 irq = gpio_to_irq(gpio);
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293 irqflags = VBUS_IRQ_FLAGS;
294 }
6084f1bf 295
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296 gpio_vbus->irq = irq;
297
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298 /* if data line pullup is in use, initialize it to "not pulling up" */
299 gpio = pdata->gpio_pullup;
300 if (gpio_is_valid(gpio)) {
9f7b23ce 301 err = devm_gpio_request(&pdev->dev, gpio, "udc_pullup");
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302 if (err) {
303 dev_err(&pdev->dev,
304 "can't request pullup gpio %d, err: %d\n",
305 gpio, err);
9f7b23ce 306 return err;
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307 }
308 gpio_direction_output(gpio, pdata->gpio_pullup_inverted);
309 }
310
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311 err = devm_request_irq(&pdev->dev, irq, gpio_vbus_irq, irqflags,
312 "vbus_detect", pdev);
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313 if (err) {
314 dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
315 irq, err);
9f7b23ce 316 return err;
6084f1bf 317 }
662c738d 318
934ccec4 319 INIT_DELAYED_WORK(&gpio_vbus->work, gpio_vbus_work);
6084f1bf 320
9f7b23ce 321 gpio_vbus->vbus_draw = devm_regulator_get(&pdev->dev, "vbus_draw");
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322 if (IS_ERR(gpio_vbus->vbus_draw)) {
323 dev_dbg(&pdev->dev, "can't get vbus_draw regulator, err: %ld\n",
324 PTR_ERR(gpio_vbus->vbus_draw));
325 gpio_vbus->vbus_draw = NULL;
326 }
327
6084f1bf 328 /* only active when a gadget is registered */
662dca54 329 err = usb_add_phy(&gpio_vbus->phy, USB_PHY_TYPE_USB2);
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330 if (err) {
331 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
332 err);
9f7b23ce 333 return err;
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334 }
335
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336 device_init_wakeup(&pdev->dev, pdata->wakeup);
337
6084f1bf 338 return 0;
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339}
340
eaaa775b 341static int gpio_vbus_remove(struct platform_device *pdev)
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342{
343 struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
6084f1bf 344
7cbb062a 345 device_init_wakeup(&pdev->dev, 0);
ec1ac6e1 346 cancel_delayed_work_sync(&gpio_vbus->work);
6084f1bf 347
662dca54 348 usb_remove_phy(&gpio_vbus->phy);
6084f1bf 349
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350 return 0;
351}
352
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353#ifdef CONFIG_PM
354static int gpio_vbus_pm_suspend(struct device *dev)
355{
356 struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
357
358 if (device_may_wakeup(dev))
359 enable_irq_wake(gpio_vbus->irq);
360
361 return 0;
362}
363
364static int gpio_vbus_pm_resume(struct device *dev)
365{
366 struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
367
368 if (device_may_wakeup(dev))
369 disable_irq_wake(gpio_vbus->irq);
370
371 return 0;
372}
373
374static const struct dev_pm_ops gpio_vbus_dev_pm_ops = {
375 .suspend = gpio_vbus_pm_suspend,
376 .resume = gpio_vbus_pm_resume,
377};
378#endif
379
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380MODULE_ALIAS("platform:gpio-vbus");
381
382static struct platform_driver gpio_vbus_driver = {
383 .driver = {
384 .name = "gpio-vbus",
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385#ifdef CONFIG_PM
386 .pm = &gpio_vbus_dev_pm_ops,
387#endif
6084f1bf 388 },
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389 .probe = gpio_vbus_probe,
390 .remove = gpio_vbus_remove,
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391};
392
eaaa775b 393module_platform_driver(gpio_vbus_driver);
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394
395MODULE_DESCRIPTION("simple GPIO controlled OTG transceiver driver");
396MODULE_AUTHOR("Philipp Zabel");
397MODULE_LICENSE("GPL");