usb: gadget: fix ptr_ret.cocci warnings
[deliverable/linux.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;
16bc1bb2 124 gpio_vbus->phy.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);
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137 } else {
138 /* optionally disable D+ pullup */
139 if (gpio_is_valid(gpio))
140 gpio_set_value(gpio, pdata->gpio_pullup_inverted);
141
142 set_vbus_draw(gpio_vbus, 0);
143
16bc1bb2 144 usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
662c738d 145 status = USB_EVENT_NONE;
16bc1bb2 146 gpio_vbus->phy.state = OTG_STATE_B_IDLE;
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147 gpio_vbus->phy.last_event = status;
148
149 atomic_notifier_call_chain(&gpio_vbus->phy.notifier,
150 status, gpio_vbus->phy.otg->gadget);
6084f1bf 151 }
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152}
153
154/* VBUS change IRQ handler */
155static irqreturn_t gpio_vbus_irq(int irq, void *data)
156{
157 struct platform_device *pdev = data;
19f9e188 158 struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev);
c2344f13 159 struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
16bc1bb2 160 struct usb_otg *otg = gpio_vbus->phy.otg;
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161
162 dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n",
163 is_vbus_powered(pdata) ? "supplied" : "inactive",
16bc1bb2 164 otg->gadget ? otg->gadget->name : "none");
c2344f13 165
16bc1bb2 166 if (otg->gadget)
934ccec4 167 schedule_delayed_work(&gpio_vbus->work, msecs_to_jiffies(100));
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168
169 return IRQ_HANDLED;
170}
171
172/* OTG transceiver interface */
173
174/* bind/unbind the peripheral controller */
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175static int gpio_vbus_set_peripheral(struct usb_otg *otg,
176 struct usb_gadget *gadget)
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177{
178 struct gpio_vbus_data *gpio_vbus;
179 struct gpio_vbus_mach_info *pdata;
180 struct platform_device *pdev;
123bbcee 181 int gpio;
6084f1bf 182
16bc1bb2 183 gpio_vbus = container_of(otg->phy, struct gpio_vbus_data, phy);
6084f1bf 184 pdev = to_platform_device(gpio_vbus->dev);
19f9e188 185 pdata = dev_get_platdata(gpio_vbus->dev);
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186 gpio = pdata->gpio_pullup;
187
188 if (!gadget) {
189 dev_dbg(&pdev->dev, "unregistering gadget '%s'\n",
190 otg->gadget->name);
191
192 /* optionally disable D+ pullup */
193 if (gpio_is_valid(gpio))
194 gpio_set_value(gpio, pdata->gpio_pullup_inverted);
195
196 set_vbus_draw(gpio_vbus, 0);
197
198 usb_gadget_vbus_disconnect(otg->gadget);
16bc1bb2 199 otg->phy->state = OTG_STATE_UNDEFINED;
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200
201 otg->gadget = NULL;
202 return 0;
203 }
204
205 otg->gadget = gadget;
206 dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name);
207
208 /* initialize connection state */
e44694e8 209 gpio_vbus->vbus = 0; /* start with disconnected */
123bbcee 210 gpio_vbus_irq(gpio_vbus->irq, pdev);
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211 return 0;
212}
213
214/* effective for B devices, ignored for A-peripheral */
16bc1bb2 215static int gpio_vbus_set_power(struct usb_phy *phy, unsigned mA)
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216{
217 struct gpio_vbus_data *gpio_vbus;
218
16bc1bb2 219 gpio_vbus = container_of(phy, struct gpio_vbus_data, phy);
6084f1bf 220
16bc1bb2 221 if (phy->state == OTG_STATE_B_PERIPHERAL)
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222 set_vbus_draw(gpio_vbus, mA);
223 return 0;
224}
225
226/* for non-OTG B devices: set/clear transceiver suspend mode */
16bc1bb2 227static int gpio_vbus_set_suspend(struct usb_phy *phy, int suspend)
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228{
229 struct gpio_vbus_data *gpio_vbus;
230
16bc1bb2 231 gpio_vbus = container_of(phy, struct gpio_vbus_data, phy);
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232
233 /* draw max 0 mA from vbus in suspend mode; or the previously
234 * recorded amount of current if not suspended
235 *
236 * NOTE: high powered configs (mA > 100) may draw up to 2.5 mA
237 * if they're wake-enabled ... we don't handle that yet.
238 */
16bc1bb2 239 return gpio_vbus_set_power(phy, suspend ? 0 : gpio_vbus->mA);
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240}
241
242/* platform driver interface */
243
eaaa775b 244static int gpio_vbus_probe(struct platform_device *pdev)
6084f1bf 245{
19f9e188 246 struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev);
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247 struct gpio_vbus_data *gpio_vbus;
248 struct resource *res;
249 int err, gpio, irq;
c8240c1b 250 unsigned long irqflags;
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251
252 if (!pdata || !gpio_is_valid(pdata->gpio_vbus))
253 return -EINVAL;
254 gpio = pdata->gpio_vbus;
255
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256 gpio_vbus = devm_kzalloc(&pdev->dev, sizeof(struct gpio_vbus_data),
257 GFP_KERNEL);
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258 if (!gpio_vbus)
259 return -ENOMEM;
260
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261 gpio_vbus->phy.otg = devm_kzalloc(&pdev->dev, sizeof(struct usb_otg),
262 GFP_KERNEL);
0c582408 263 if (!gpio_vbus->phy.otg)
16bc1bb2 264 return -ENOMEM;
16bc1bb2 265
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266 platform_set_drvdata(pdev, gpio_vbus);
267 gpio_vbus->dev = &pdev->dev;
16bc1bb2 268 gpio_vbus->phy.label = "gpio-vbus";
1abd8b31 269 gpio_vbus->phy.dev = gpio_vbus->dev;
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270 gpio_vbus->phy.set_power = gpio_vbus_set_power;
271 gpio_vbus->phy.set_suspend = gpio_vbus_set_suspend;
272 gpio_vbus->phy.state = OTG_STATE_UNDEFINED;
273
274 gpio_vbus->phy.otg->phy = &gpio_vbus->phy;
275 gpio_vbus->phy.otg->set_peripheral = gpio_vbus_set_peripheral;
6084f1bf 276
9f7b23ce 277 err = devm_gpio_request(&pdev->dev, gpio, "vbus_detect");
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278 if (err) {
279 dev_err(&pdev->dev, "can't request vbus gpio %d, err: %d\n",
280 gpio, err);
9f7b23ce 281 return err;
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282 }
283 gpio_direction_input(gpio);
284
285 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
286 if (res) {
287 irq = res->start;
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288 irqflags = (res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
289 } else {
6084f1bf 290 irq = gpio_to_irq(gpio);
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291 irqflags = VBUS_IRQ_FLAGS;
292 }
6084f1bf 293
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294 gpio_vbus->irq = irq;
295
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296 /* if data line pullup is in use, initialize it to "not pulling up" */
297 gpio = pdata->gpio_pullup;
298 if (gpio_is_valid(gpio)) {
9f7b23ce 299 err = devm_gpio_request(&pdev->dev, gpio, "udc_pullup");
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300 if (err) {
301 dev_err(&pdev->dev,
302 "can't request pullup gpio %d, err: %d\n",
303 gpio, err);
9f7b23ce 304 return err;
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305 }
306 gpio_direction_output(gpio, pdata->gpio_pullup_inverted);
307 }
308
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309 err = devm_request_irq(&pdev->dev, irq, gpio_vbus_irq, irqflags,
310 "vbus_detect", pdev);
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311 if (err) {
312 dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
313 irq, err);
9f7b23ce 314 return err;
6084f1bf 315 }
662c738d 316
934ccec4 317 INIT_DELAYED_WORK(&gpio_vbus->work, gpio_vbus_work);
6084f1bf 318
9f7b23ce 319 gpio_vbus->vbus_draw = devm_regulator_get(&pdev->dev, "vbus_draw");
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320 if (IS_ERR(gpio_vbus->vbus_draw)) {
321 dev_dbg(&pdev->dev, "can't get vbus_draw regulator, err: %ld\n",
322 PTR_ERR(gpio_vbus->vbus_draw));
323 gpio_vbus->vbus_draw = NULL;
324 }
325
6084f1bf 326 /* only active when a gadget is registered */
662dca54 327 err = usb_add_phy(&gpio_vbus->phy, USB_PHY_TYPE_USB2);
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328 if (err) {
329 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
330 err);
9f7b23ce 331 return err;
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332 }
333
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334 device_init_wakeup(&pdev->dev, pdata->wakeup);
335
6084f1bf 336 return 0;
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337}
338
eaaa775b 339static int gpio_vbus_remove(struct platform_device *pdev)
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340{
341 struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
6084f1bf 342
7cbb062a 343 device_init_wakeup(&pdev->dev, 0);
ec1ac6e1 344 cancel_delayed_work_sync(&gpio_vbus->work);
6084f1bf 345
662dca54 346 usb_remove_phy(&gpio_vbus->phy);
6084f1bf 347
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348 return 0;
349}
350
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351#ifdef CONFIG_PM
352static int gpio_vbus_pm_suspend(struct device *dev)
353{
354 struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
355
356 if (device_may_wakeup(dev))
357 enable_irq_wake(gpio_vbus->irq);
358
359 return 0;
360}
361
362static int gpio_vbus_pm_resume(struct device *dev)
363{
364 struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
365
366 if (device_may_wakeup(dev))
367 disable_irq_wake(gpio_vbus->irq);
368
369 return 0;
370}
371
372static const struct dev_pm_ops gpio_vbus_dev_pm_ops = {
373 .suspend = gpio_vbus_pm_suspend,
374 .resume = gpio_vbus_pm_resume,
375};
376#endif
377
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378MODULE_ALIAS("platform:gpio-vbus");
379
380static struct platform_driver gpio_vbus_driver = {
381 .driver = {
382 .name = "gpio-vbus",
383 .owner = THIS_MODULE,
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384#ifdef CONFIG_PM
385 .pm = &gpio_vbus_dev_pm_ops,
386#endif
6084f1bf 387 },
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388 .probe = gpio_vbus_probe,
389 .remove = gpio_vbus_remove,
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390};
391
eaaa775b 392module_platform_driver(gpio_vbus_driver);
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393
394MODULE_DESCRIPTION("simple GPIO controlled OTG transceiver driver");
395MODULE_AUTHOR("Philipp Zabel");
396MODULE_LICENSE("GPL");
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