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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         return 0;
 63 }
 64 
 65 static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
 66 {
 67         if (!nop->gpiod_reset)
 68                 return;
 69 
 70         gpiod_direction_output(nop->gpiod_reset, !asserted);
 71         usleep_range(10000, 20000);
 72         gpiod_set_value(nop->gpiod_reset, asserted);
 73 }
 74 
 75 /* interface to regulator framework */
 76 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
 77 {
 78         struct regulator *vbus_draw = nop->vbus_draw;
 79         int enabled;
 80         int ret;
 81 
 82         if (!vbus_draw)
 83                 return;
 84 
 85         enabled = nop->vbus_draw_enabled;
 86         if (mA) {
 87                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
 88                 if (!enabled) {
 89                         ret = regulator_enable(vbus_draw);
 90                         if (ret < 0)
 91                                 return;
 92                         nop->vbus_draw_enabled = 1;
 93                 }
 94         } else {
 95                 if (enabled) {
 96                         ret = regulator_disable(vbus_draw);
 97                         if (ret < 0)
 98                                 return;
 99                         nop->vbus_draw_enabled = 0;
100                 }
101         }
102         nop->mA = mA;
103 }
104 
105 
106 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
107 {
108         struct usb_phy_generic *nop = data;
109         struct usb_otg *otg = nop->phy.otg;
110         int vbus, status;
111 
112         vbus = gpiod_get_value(nop->gpiod_vbus);
113         if ((vbus ^ nop->vbus) == 0)
114                 return IRQ_HANDLED;
115         nop->vbus = vbus;
116 
117         if (vbus) {
118                 status = USB_EVENT_VBUS;
119                 otg->state = OTG_STATE_B_PERIPHERAL;
120                 nop->phy.last_event = status;
121                 usb_gadget_vbus_connect(otg->gadget);
122 
123                 /* drawing a "unit load" is *always* OK, except for OTG */
124                 nop_set_vbus_draw(nop, 100);
125 
126                 atomic_notifier_call_chain(&nop->phy.notifier, status,
127                                            otg->gadget);
128         } else {
129                 nop_set_vbus_draw(nop, 0);
130 
131                 usb_gadget_vbus_disconnect(otg->gadget);
132                 status = USB_EVENT_NONE;
133                 otg->state = OTG_STATE_B_IDLE;
134                 nop->phy.last_event = status;
135 
136                 atomic_notifier_call_chain(&nop->phy.notifier, status,
137                                            otg->gadget);
138         }
139         return IRQ_HANDLED;
140 }
141 
142 int usb_gen_phy_init(struct usb_phy *phy)
143 {
144         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
145 
146         if (!IS_ERR(nop->vcc)) {
147                 if (regulator_enable(nop->vcc))
148                         dev_err(phy->dev, "Failed to enable power\n");
149         }
150 
151         if (!IS_ERR(nop->clk))
152                 clk_prepare_enable(nop->clk);
153 
154         /* De-assert RESET */
155         nop_reset_set(nop, 0);
156 
157         return 0;
158 }
159 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
160 
161 void usb_gen_phy_shutdown(struct usb_phy *phy)
162 {
163         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
164 
165         /* Assert RESET */
166         nop_reset_set(nop, 1);
167 
168         if (!IS_ERR(nop->clk))
169                 clk_disable_unprepare(nop->clk);
170 
171         if (!IS_ERR(nop->vcc)) {
172                 if (regulator_disable(nop->vcc))
173                         dev_err(phy->dev, "Failed to disable power\n");
174         }
175 }
176 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
177 
178 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
179 {
180         if (!otg)
181                 return -ENODEV;
182 
183         if (!gadget) {
184                 otg->gadget = NULL;
185                 return -ENODEV;
186         }
187 
188         otg->gadget = gadget;
189         otg->state = OTG_STATE_B_IDLE;
190         return 0;
191 }
192 
193 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
194 {
195         if (!otg)
196                 return -ENODEV;
197 
198         if (!host) {
199                 otg->host = NULL;
200                 return -ENODEV;
201         }
202 
203         otg->host = host;
204         return 0;
205 }
206 
207 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
208                 struct usb_phy_generic_platform_data *pdata)
209 {
210         enum usb_phy_type type = USB_PHY_TYPE_USB2;
211         int err = 0;
212 
213         u32 clk_rate = 0;
214         bool needs_vcc = false;
215 
216         if (dev->of_node) {
217                 struct device_node *node = dev->of_node;
218 
219                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
220                         clk_rate = 0;
221 
222                 needs_vcc = of_property_read_bool(node, "vcc-supply");
223                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset");
224                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
225                 if (!err) {
226                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
227                                                          "vbus-detect");
228                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
229                 }
230         } else if (pdata) {
231                 type = pdata->type;
232                 clk_rate = pdata->clk_rate;
233                 needs_vcc = pdata->needs_vcc;
234                 if (gpio_is_valid(pdata->gpio_reset)) {
235                         err = devm_gpio_request_one(dev, pdata->gpio_reset, 0,
236                                                     dev_name(dev));
237                         if (!err)
238                                 nop->gpiod_reset =
239                                         gpio_to_desc(pdata->gpio_reset);
240                 }
241                 nop->gpiod_vbus = pdata->gpiod_vbus;
242         }
243 
244         if (err == -EPROBE_DEFER)
245                 return -EPROBE_DEFER;
246         if (err) {
247                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
248                 return err;
249         }
250         if (nop->gpiod_reset)
251                 gpiod_direction_output(nop->gpiod_reset, 1);
252 
253         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
254                         GFP_KERNEL);
255         if (!nop->phy.otg)
256                 return -ENOMEM;
257 
258         nop->clk = devm_clk_get(dev, "main_clk");
259         if (IS_ERR(nop->clk)) {
260                 dev_dbg(dev, "Can't get phy clock: %ld\n",
261                                         PTR_ERR(nop->clk));
262         }
263 
264         if (!IS_ERR(nop->clk) && clk_rate) {
265                 err = clk_set_rate(nop->clk, clk_rate);
266                 if (err) {
267                         dev_err(dev, "Error setting clock rate\n");
268                         return err;
269                 }
270         }
271 
272         nop->vcc = devm_regulator_get(dev, "vcc");
273         if (IS_ERR(nop->vcc)) {
274                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
275                                         PTR_ERR(nop->vcc));
276                 if (needs_vcc)
277                         return -EPROBE_DEFER;
278         }
279 
280         nop->dev                = dev;
281         nop->phy.dev            = nop->dev;
282         nop->phy.label          = "nop-xceiv";
283         nop->phy.set_suspend    = nop_set_suspend;
284         nop->phy.type           = type;
285 
286         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
287         nop->phy.otg->usb_phy           = &nop->phy;
288         nop->phy.otg->set_host          = nop_set_host;
289         nop->phy.otg->set_peripheral    = nop_set_peripheral;
290 
291         return 0;
292 }
293 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
294 
295 static int usb_phy_generic_probe(struct platform_device *pdev)
296 {
297         struct device *dev = &pdev->dev;
298         struct usb_phy_generic  *nop;
299         int err;
300 
301         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
302         if (!nop)
303                 return -ENOMEM;
304 
305         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
306         if (err)
307                 return err;
308         if (nop->gpiod_vbus) {
309                 err = devm_request_threaded_irq(&pdev->dev,
310                                                 gpiod_to_irq(nop->gpiod_vbus),
311                                                 NULL, nop_gpio_vbus_thread,
312                                                 VBUS_IRQ_FLAGS, "vbus_detect",
313                                                 nop);
314                 if (err) {
315                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
316                                 gpiod_to_irq(nop->gpiod_vbus), err);
317                         return err;
318                 }
319         }
320 
321         nop->phy.init           = usb_gen_phy_init;
322         nop->phy.shutdown       = usb_gen_phy_shutdown;
323 
324         err = usb_add_phy_dev(&nop->phy);
325         if (err) {
326                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
327                         err);
328                 return err;
329         }
330 
331         platform_set_drvdata(pdev, nop);
332 
333         return 0;
334 }
335 
336 static int usb_phy_generic_remove(struct platform_device *pdev)
337 {
338         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
339 
340         usb_remove_phy(&nop->phy);
341 
342         return 0;
343 }
344 
345 static const struct of_device_id nop_xceiv_dt_ids[] = {
346         { .compatible = "usb-nop-xceiv" },
347         { }
348 };
349 
350 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
351 
352 static struct platform_driver usb_phy_generic_driver = {
353         .probe          = usb_phy_generic_probe,
354         .remove         = usb_phy_generic_remove,
355         .driver         = {
356                 .name   = "usb_phy_generic",
357                 .of_match_table = nop_xceiv_dt_ids,
358         },
359 };
360 
361 static int __init usb_phy_generic_init(void)
362 {
363         return platform_driver_register(&usb_phy_generic_driver);
364 }
365 subsys_initcall(usb_phy_generic_init);
366 
367 static void __exit usb_phy_generic_exit(void)
368 {
369         platform_driver_unregister(&usb_phy_generic_driver);
370 }
371 module_exit(usb_phy_generic_exit);
372 
373 MODULE_ALIAS("platform:usb_phy_generic");
374 MODULE_AUTHOR("Texas Instruments Inc");
375 MODULE_DESCRIPTION("NOP USB Transceiver driver");
376 MODULE_LICENSE("GPL");
377 

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