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Linux/drivers/usb/phy/phy-generic.c

  1 /*
  2  * NOP USB transceiver for all USB transceiver which are either built-in
  3  * into USB IP or which are mostly autonomous.
  4  *
  5  * Copyright (C) 2009 Texas Instruments Inc
  6  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License as published by
 10  * the Free Software Foundation; either version 2 of the License, or
 11  * (at your option) any later version.
 12  *
 13  * This program is distributed in the hope that it will be useful,
 14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16  * GNU General Public License for more details.
 17  *
 18  * You should have received a copy of the GNU General Public License
 19  * along with this program; if not, write to the Free Software
 20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 21  *
 22  * Current status:
 23  *      This provides a "nop" transceiver for PHYs which are
 24  *      autonomous such as isp1504, isp1707, etc.
 25  */
 26 
 27 #include <linux/module.h>
 28 #include <linux/platform_device.h>
 29 #include <linux/dma-mapping.h>
 30 #include <linux/usb/gadget.h>
 31 #include <linux/usb/otg.h>
 32 #include <linux/usb/usb_phy_generic.h>
 33 #include <linux/slab.h>
 34 #include <linux/clk.h>
 35 #include <linux/regulator/consumer.h>
 36 #include <linux/of.h>
 37 #include <linux/of_gpio.h>
 38 #include <linux/gpio.h>
 39 #include <linux/delay.h>
 40 
 41 #include "phy-generic.h"
 42 
 43 #define VBUS_IRQ_FLAGS \
 44         (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
 45                 IRQF_ONESHOT)
 46 
 47 struct platform_device *usb_phy_generic_register(void)
 48 {
 49         return platform_device_register_simple("usb_phy_generic",
 50                         PLATFORM_DEVID_AUTO, NULL, 0);
 51 }
 52 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
 53 
 54 void usb_phy_generic_unregister(struct platform_device *pdev)
 55 {
 56         platform_device_unregister(pdev);
 57 }
 58 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
 59 
 60 static int nop_set_suspend(struct usb_phy *x, int suspend)
 61 {
 62         struct usb_phy_generic *nop = dev_get_drvdata(x->dev);
 63 
 64         if (!IS_ERR(nop->clk)) {
 65                 if (suspend)
 66                         clk_disable_unprepare(nop->clk);
 67                 else
 68                         clk_prepare_enable(nop->clk);
 69         }
 70 
 71         return 0;
 72 }
 73 
 74 static void nop_reset(struct usb_phy_generic *nop)
 75 {
 76         if (!nop->gpiod_reset)
 77                 return;
 78 
 79         gpiod_set_value(nop->gpiod_reset, 1);
 80         usleep_range(10000, 20000);
 81         gpiod_set_value(nop->gpiod_reset, 0);
 82 }
 83 
 84 /* interface to regulator framework */
 85 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
 86 {
 87         struct regulator *vbus_draw = nop->vbus_draw;
 88         int enabled;
 89         int ret;
 90 
 91         if (!vbus_draw)
 92                 return;
 93 
 94         enabled = nop->vbus_draw_enabled;
 95         if (mA) {
 96                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
 97                 if (!enabled) {
 98                         ret = regulator_enable(vbus_draw);
 99                         if (ret < 0)
100                                 return;
101                         nop->vbus_draw_enabled = 1;
102                 }
103         } else {
104                 if (enabled) {
105                         ret = regulator_disable(vbus_draw);
106                         if (ret < 0)
107                                 return;
108                         nop->vbus_draw_enabled = 0;
109                 }
110         }
111         nop->mA = mA;
112 }
113 
114 
115 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
116 {
117         struct usb_phy_generic *nop = data;
118         struct usb_otg *otg = nop->phy.otg;
119         int vbus, status;
120 
121         vbus = gpiod_get_value(nop->gpiod_vbus);
122         if ((vbus ^ nop->vbus) == 0)
123                 return IRQ_HANDLED;
124         nop->vbus = vbus;
125 
126         if (vbus) {
127                 status = USB_EVENT_VBUS;
128                 otg->state = OTG_STATE_B_PERIPHERAL;
129                 nop->phy.last_event = status;
130 
131                 /* drawing a "unit load" is *always* OK, except for OTG */
132                 nop_set_vbus_draw(nop, 100);
133 
134                 atomic_notifier_call_chain(&nop->phy.notifier, status,
135                                            otg->gadget);
136         } else {
137                 nop_set_vbus_draw(nop, 0);
138 
139                 status = USB_EVENT_NONE;
140                 otg->state = OTG_STATE_B_IDLE;
141                 nop->phy.last_event = status;
142 
143                 atomic_notifier_call_chain(&nop->phy.notifier, status,
144                                            otg->gadget);
145         }
146         return IRQ_HANDLED;
147 }
148 
149 int usb_gen_phy_init(struct usb_phy *phy)
150 {
151         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
152         int ret;
153 
154         if (!IS_ERR(nop->vcc)) {
155                 if (regulator_enable(nop->vcc))
156                         dev_err(phy->dev, "Failed to enable power\n");
157         }
158 
159         if (!IS_ERR(nop->clk)) {
160                 ret = clk_prepare_enable(nop->clk);
161                 if (ret)
162                         return ret;
163         }
164 
165         nop_reset(nop);
166 
167         return 0;
168 }
169 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
170 
171 void usb_gen_phy_shutdown(struct usb_phy *phy)
172 {
173         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
174 
175         gpiod_set_value(nop->gpiod_reset, 1);
176 
177         if (!IS_ERR(nop->clk))
178                 clk_disable_unprepare(nop->clk);
179 
180         if (!IS_ERR(nop->vcc)) {
181                 if (regulator_disable(nop->vcc))
182                         dev_err(phy->dev, "Failed to disable power\n");
183         }
184 }
185 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
186 
187 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
188 {
189         if (!otg)
190                 return -ENODEV;
191 
192         if (!gadget) {
193                 otg->gadget = NULL;
194                 return -ENODEV;
195         }
196 
197         otg->gadget = gadget;
198         if (otg->state == OTG_STATE_B_PERIPHERAL)
199                 atomic_notifier_call_chain(&otg->usb_phy->notifier,
200                                            USB_EVENT_VBUS, otg->gadget);
201         else
202                 otg->state = OTG_STATE_B_IDLE;
203         return 0;
204 }
205 
206 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
207 {
208         if (!otg)
209                 return -ENODEV;
210 
211         if (!host) {
212                 otg->host = NULL;
213                 return -ENODEV;
214         }
215 
216         otg->host = host;
217         return 0;
218 }
219 
220 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
221                 struct usb_phy_generic_platform_data *pdata)
222 {
223         enum usb_phy_type type = USB_PHY_TYPE_USB2;
224         int err = 0;
225 
226         u32 clk_rate = 0;
227         bool needs_vcc = false;
228 
229         if (dev->of_node) {
230                 struct device_node *node = dev->of_node;
231 
232                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
233                         clk_rate = 0;
234 
235                 needs_vcc = of_property_read_bool(node, "vcc-supply");
236                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
237                                                            GPIOD_ASIS);
238                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
239                 if (!err) {
240                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
241                                                          "vbus-detect",
242                                                          GPIOD_ASIS);
243                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
244                 }
245         } else if (pdata) {
246                 type = pdata->type;
247                 clk_rate = pdata->clk_rate;
248                 needs_vcc = pdata->needs_vcc;
249                 if (gpio_is_valid(pdata->gpio_reset)) {
250                         err = devm_gpio_request_one(dev, pdata->gpio_reset,
251                                                     GPIOF_ACTIVE_LOW,
252                                                     dev_name(dev));
253                         if (!err)
254                                 nop->gpiod_reset =
255                                         gpio_to_desc(pdata->gpio_reset);
256                 }
257                 nop->gpiod_vbus = pdata->gpiod_vbus;
258         }
259 
260         if (err == -EPROBE_DEFER)
261                 return -EPROBE_DEFER;
262         if (err) {
263                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
264                 return err;
265         }
266         if (nop->gpiod_reset)
267                 gpiod_direction_output(nop->gpiod_reset, 1);
268 
269         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
270                         GFP_KERNEL);
271         if (!nop->phy.otg)
272                 return -ENOMEM;
273 
274         nop->clk = devm_clk_get(dev, "main_clk");
275         if (IS_ERR(nop->clk)) {
276                 dev_dbg(dev, "Can't get phy clock: %ld\n",
277                                         PTR_ERR(nop->clk));
278         }
279 
280         if (!IS_ERR(nop->clk) && clk_rate) {
281                 err = clk_set_rate(nop->clk, clk_rate);
282                 if (err) {
283                         dev_err(dev, "Error setting clock rate\n");
284                         return err;
285                 }
286         }
287 
288         nop->vcc = devm_regulator_get(dev, "vcc");
289         if (IS_ERR(nop->vcc)) {
290                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
291                                         PTR_ERR(nop->vcc));
292                 if (needs_vcc)
293                         return -EPROBE_DEFER;
294         }
295 
296         nop->dev                = dev;
297         nop->phy.dev            = nop->dev;
298         nop->phy.label          = "nop-xceiv";
299         nop->phy.set_suspend    = nop_set_suspend;
300         nop->phy.type           = type;
301 
302         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
303         nop->phy.otg->usb_phy           = &nop->phy;
304         nop->phy.otg->set_host          = nop_set_host;
305         nop->phy.otg->set_peripheral    = nop_set_peripheral;
306 
307         return 0;
308 }
309 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
310 
311 static int usb_phy_generic_probe(struct platform_device *pdev)
312 {
313         struct device *dev = &pdev->dev;
314         struct usb_phy_generic  *nop;
315         int err;
316 
317         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
318         if (!nop)
319                 return -ENOMEM;
320 
321         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
322         if (err)
323                 return err;
324         if (nop->gpiod_vbus) {
325                 err = devm_request_threaded_irq(&pdev->dev,
326                                                 gpiod_to_irq(nop->gpiod_vbus),
327                                                 NULL, nop_gpio_vbus_thread,
328                                                 VBUS_IRQ_FLAGS, "vbus_detect",
329                                                 nop);
330                 if (err) {
331                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
332                                 gpiod_to_irq(nop->gpiod_vbus), err);
333                         return err;
334                 }
335                 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
336                         OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
337         }
338 
339         nop->phy.init           = usb_gen_phy_init;
340         nop->phy.shutdown       = usb_gen_phy_shutdown;
341 
342         err = usb_add_phy_dev(&nop->phy);
343         if (err) {
344                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
345                         err);
346                 return err;
347         }
348 
349         platform_set_drvdata(pdev, nop);
350 
351         return 0;
352 }
353 
354 static int usb_phy_generic_remove(struct platform_device *pdev)
355 {
356         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
357 
358         usb_remove_phy(&nop->phy);
359 
360         return 0;
361 }
362 
363 static const struct of_device_id nop_xceiv_dt_ids[] = {
364         { .compatible = "usb-nop-xceiv" },
365         { }
366 };
367 
368 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
369 
370 static struct platform_driver usb_phy_generic_driver = {
371         .probe          = usb_phy_generic_probe,
372         .remove         = usb_phy_generic_remove,
373         .driver         = {
374                 .name   = "usb_phy_generic",
375                 .of_match_table = nop_xceiv_dt_ids,
376         },
377 };
378 
379 static int __init usb_phy_generic_init(void)
380 {
381         return platform_driver_register(&usb_phy_generic_driver);
382 }
383 subsys_initcall(usb_phy_generic_init);
384 
385 static void __exit usb_phy_generic_exit(void)
386 {
387         platform_driver_unregister(&usb_phy_generic_driver);
388 }
389 module_exit(usb_phy_generic_exit);
390 
391 MODULE_ALIAS("platform:usb_phy_generic");
392 MODULE_AUTHOR("Texas Instruments Inc");
393 MODULE_DESCRIPTION("NOP USB Transceiver driver");
394 MODULE_LICENSE("GPL");
395 

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