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

  1 /*
  2  * drivers/usb/otg/nop-usb-xceiv.c
  3  *
  4  * NOP USB transceiver for all USB transceiver which are either built-in
  5  * into USB IP or which are mostly autonomous.
  6  *
  7  * Copyright (C) 2009 Texas Instruments Inc
  8  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
  9  *
 10  * This program is free software; you can redistribute it and/or modify
 11  * it under the terms of the GNU General Public License as published by
 12  * the Free Software Foundation; either version 2 of the License, or
 13  * (at your option) any later version.
 14  *
 15  * This program is distributed in the hope that it will be useful,
 16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18  * GNU General Public License for more details.
 19  *
 20  * You should have received a copy of the GNU General Public License
 21  * along with this program; if not, write to the Free Software
 22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 23  *
 24  * Current status:
 25  *      This provides a "nop" transceiver for PHYs which are
 26  *      autonomous such as isp1504, isp1707, etc.
 27  */
 28 
 29 #include <linux/module.h>
 30 #include <linux/platform_device.h>
 31 #include <linux/dma-mapping.h>
 32 #include <linux/usb/otg.h>
 33 #include <linux/usb/usb_phy_gen_xceiv.h>
 34 #include <linux/slab.h>
 35 #include <linux/clk.h>
 36 #include <linux/regulator/consumer.h>
 37 #include <linux/of.h>
 38 #include <linux/of_gpio.h>
 39 #include <linux/gpio.h>
 40 #include <linux/delay.h>
 41 
 42 #include "phy-generic.h"
 43 
 44 static struct platform_device *pd;
 45 
 46 void usb_nop_xceiv_register(void)
 47 {
 48         if (pd)
 49                 return;
 50         pd = platform_device_register_simple("usb_phy_gen_xceiv", -1, NULL, 0);
 51         if (IS_ERR(pd)) {
 52                 pr_err("Unable to register generic usb transceiver\n");
 53                 pd = NULL;
 54                 return;
 55         }
 56 }
 57 EXPORT_SYMBOL(usb_nop_xceiv_register);
 58 
 59 void usb_nop_xceiv_unregister(void)
 60 {
 61         platform_device_unregister(pd);
 62         pd = NULL;
 63 }
 64 EXPORT_SYMBOL(usb_nop_xceiv_unregister);
 65 
 66 static int nop_set_suspend(struct usb_phy *x, int suspend)
 67 {
 68         return 0;
 69 }
 70 
 71 static void nop_reset_set(struct usb_phy_gen_xceiv *nop, int asserted)
 72 {
 73         int value;
 74 
 75         if (!gpio_is_valid(nop->gpio_reset))
 76                 return;
 77 
 78         value = asserted;
 79         if (nop->reset_active_low)
 80                 value = !value;
 81 
 82         gpio_set_value_cansleep(nop->gpio_reset, value);
 83 
 84         if (!asserted)
 85                 usleep_range(10000, 20000);
 86 }
 87 
 88 int usb_gen_phy_init(struct usb_phy *phy)
 89 {
 90         struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);
 91 
 92         if (!IS_ERR(nop->vcc)) {
 93                 if (regulator_enable(nop->vcc))
 94                         dev_err(phy->dev, "Failed to enable power\n");
 95         }
 96 
 97         if (!IS_ERR(nop->clk))
 98                 clk_prepare_enable(nop->clk);
 99 
100         /* De-assert RESET */
101         nop_reset_set(nop, 0);
102 
103         return 0;
104 }
105 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
106 
107 void usb_gen_phy_shutdown(struct usb_phy *phy)
108 {
109         struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);
110 
111         /* Assert RESET */
112         nop_reset_set(nop, 1);
113 
114         if (!IS_ERR(nop->clk))
115                 clk_disable_unprepare(nop->clk);
116 
117         if (!IS_ERR(nop->vcc)) {
118                 if (regulator_disable(nop->vcc))
119                         dev_err(phy->dev, "Failed to disable power\n");
120         }
121 }
122 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
123 
124 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
125 {
126         if (!otg)
127                 return -ENODEV;
128 
129         if (!gadget) {
130                 otg->gadget = NULL;
131                 return -ENODEV;
132         }
133 
134         otg->gadget = gadget;
135         otg->phy->state = OTG_STATE_B_IDLE;
136         return 0;
137 }
138 
139 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
140 {
141         if (!otg)
142                 return -ENODEV;
143 
144         if (!host) {
145                 otg->host = NULL;
146                 return -ENODEV;
147         }
148 
149         otg->host = host;
150         return 0;
151 }
152 
153 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_gen_xceiv *nop,
154                 struct usb_phy_gen_xceiv_platform_data *pdata)
155 {
156         enum usb_phy_type type = USB_PHY_TYPE_USB2;
157         int err;
158 
159         u32 clk_rate = 0;
160         bool needs_vcc = false;
161 
162         nop->reset_active_low = true;   /* default behaviour */
163 
164         if (dev->of_node) {
165                 struct device_node *node = dev->of_node;
166                 enum of_gpio_flags flags = 0;
167 
168                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
169                         clk_rate = 0;
170 
171                 needs_vcc = of_property_read_bool(node, "vcc-supply");
172                 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
173                                                                 0, &flags);
174                 if (nop->gpio_reset == -EPROBE_DEFER)
175                         return -EPROBE_DEFER;
176 
177                 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;
178 
179         } else if (pdata) {
180                 type = pdata->type;
181                 clk_rate = pdata->clk_rate;
182                 needs_vcc = pdata->needs_vcc;
183                 nop->gpio_reset = pdata->gpio_reset;
184         } else {
185                 nop->gpio_reset = -1;
186         }
187 
188         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
189                         GFP_KERNEL);
190         if (!nop->phy.otg)
191                 return -ENOMEM;
192 
193         nop->clk = devm_clk_get(dev, "main_clk");
194         if (IS_ERR(nop->clk)) {
195                 dev_dbg(dev, "Can't get phy clock: %ld\n",
196                                         PTR_ERR(nop->clk));
197         }
198 
199         if (!IS_ERR(nop->clk) && clk_rate) {
200                 err = clk_set_rate(nop->clk, clk_rate);
201                 if (err) {
202                         dev_err(dev, "Error setting clock rate\n");
203                         return err;
204                 }
205         }
206 
207         nop->vcc = devm_regulator_get(dev, "vcc");
208         if (IS_ERR(nop->vcc)) {
209                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
210                                         PTR_ERR(nop->vcc));
211                 if (needs_vcc)
212                         return -EPROBE_DEFER;
213         }
214 
215         if (gpio_is_valid(nop->gpio_reset)) {
216                 unsigned long gpio_flags;
217 
218                 /* Assert RESET */
219                 if (nop->reset_active_low)
220                         gpio_flags = GPIOF_OUT_INIT_LOW;
221                 else
222                         gpio_flags = GPIOF_OUT_INIT_HIGH;
223 
224                 err = devm_gpio_request_one(dev, nop->gpio_reset,
225                                                 gpio_flags, dev_name(dev));
226                 if (err) {
227                         dev_err(dev, "Error requesting RESET GPIO %d\n",
228                                         nop->gpio_reset);
229                         return err;
230                 }
231         }
232 
233         nop->dev                = dev;
234         nop->phy.dev            = nop->dev;
235         nop->phy.label          = "nop-xceiv";
236         nop->phy.set_suspend    = nop_set_suspend;
237         nop->phy.state          = OTG_STATE_UNDEFINED;
238         nop->phy.type           = type;
239 
240         nop->phy.otg->phy               = &nop->phy;
241         nop->phy.otg->set_host          = nop_set_host;
242         nop->phy.otg->set_peripheral    = nop_set_peripheral;
243 
244         return 0;
245 }
246 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
247 
248 static int usb_phy_gen_xceiv_probe(struct platform_device *pdev)
249 {
250         struct device *dev = &pdev->dev;
251         struct usb_phy_gen_xceiv        *nop;
252         int err;
253 
254         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
255         if (!nop)
256                 return -ENOMEM;
257 
258         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
259         if (err)
260                 return err;
261 
262         nop->phy.init           = usb_gen_phy_init;
263         nop->phy.shutdown       = usb_gen_phy_shutdown;
264 
265         err = usb_add_phy_dev(&nop->phy);
266         if (err) {
267                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
268                         err);
269                 return err;
270         }
271 
272         platform_set_drvdata(pdev, nop);
273 
274         return 0;
275 }
276 
277 static int usb_phy_gen_xceiv_remove(struct platform_device *pdev)
278 {
279         struct usb_phy_gen_xceiv *nop = platform_get_drvdata(pdev);
280 
281         usb_remove_phy(&nop->phy);
282 
283         return 0;
284 }
285 
286 static const struct of_device_id nop_xceiv_dt_ids[] = {
287         { .compatible = "usb-nop-xceiv" },
288         { }
289 };
290 
291 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
292 
293 static struct platform_driver usb_phy_gen_xceiv_driver = {
294         .probe          = usb_phy_gen_xceiv_probe,
295         .remove         = usb_phy_gen_xceiv_remove,
296         .driver         = {
297                 .name   = "usb_phy_gen_xceiv",
298                 .owner  = THIS_MODULE,
299                 .of_match_table = nop_xceiv_dt_ids,
300         },
301 };
302 
303 static int __init usb_phy_gen_xceiv_init(void)
304 {
305         return platform_driver_register(&usb_phy_gen_xceiv_driver);
306 }
307 subsys_initcall(usb_phy_gen_xceiv_init);
308 
309 static void __exit usb_phy_gen_xceiv_exit(void)
310 {
311         platform_driver_unregister(&usb_phy_gen_xceiv_driver);
312 }
313 module_exit(usb_phy_gen_xceiv_exit);
314 
315 MODULE_ALIAS("platform:usb_phy_gen_xceiv");
316 MODULE_AUTHOR("Texas Instruments Inc");
317 MODULE_DESCRIPTION("NOP USB Transceiver driver");
318 MODULE_LICENSE("GPL");
319 

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