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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/otg.h>
 31 #include <linux/usb/usb_phy_generic.h>
 32 #include <linux/slab.h>
 33 #include <linux/clk.h>
 34 #include <linux/regulator/consumer.h>
 35 #include <linux/of.h>
 36 #include <linux/of_gpio.h>
 37 #include <linux/gpio.h>
 38 #include <linux/delay.h>
 39 
 40 #include "phy-generic.h"
 41 
 42 struct platform_device *usb_phy_generic_register(void)
 43 {
 44         return platform_device_register_simple("usb_phy_generic",
 45                         PLATFORM_DEVID_AUTO, NULL, 0);
 46 }
 47 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
 48 
 49 void usb_phy_generic_unregister(struct platform_device *pdev)
 50 {
 51         platform_device_unregister(pdev);
 52 }
 53 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
 54 
 55 static int nop_set_suspend(struct usb_phy *x, int suspend)
 56 {
 57         return 0;
 58 }
 59 
 60 static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
 61 {
 62         int value;
 63 
 64         if (!gpio_is_valid(nop->gpio_reset))
 65                 return;
 66 
 67         value = asserted;
 68         if (nop->reset_active_low)
 69                 value = !value;
 70 
 71         gpio_set_value_cansleep(nop->gpio_reset, value);
 72 
 73         if (!asserted)
 74                 usleep_range(10000, 20000);
 75 }
 76 
 77 int usb_gen_phy_init(struct usb_phy *phy)
 78 {
 79         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 80 
 81         if (!IS_ERR(nop->vcc)) {
 82                 if (regulator_enable(nop->vcc))
 83                         dev_err(phy->dev, "Failed to enable power\n");
 84         }
 85 
 86         if (!IS_ERR(nop->clk))
 87                 clk_prepare_enable(nop->clk);
 88 
 89         /* De-assert RESET */
 90         nop_reset_set(nop, 0);
 91 
 92         return 0;
 93 }
 94 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 95 
 96 void usb_gen_phy_shutdown(struct usb_phy *phy)
 97 {
 98         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 99 
100         /* Assert RESET */
101         nop_reset_set(nop, 1);
102 
103         if (!IS_ERR(nop->clk))
104                 clk_disable_unprepare(nop->clk);
105 
106         if (!IS_ERR(nop->vcc)) {
107                 if (regulator_disable(nop->vcc))
108                         dev_err(phy->dev, "Failed to disable power\n");
109         }
110 }
111 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
112 
113 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
114 {
115         if (!otg)
116                 return -ENODEV;
117 
118         if (!gadget) {
119                 otg->gadget = NULL;
120                 return -ENODEV;
121         }
122 
123         otg->gadget = gadget;
124         otg->state = OTG_STATE_B_IDLE;
125         return 0;
126 }
127 
128 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
129 {
130         if (!otg)
131                 return -ENODEV;
132 
133         if (!host) {
134                 otg->host = NULL;
135                 return -ENODEV;
136         }
137 
138         otg->host = host;
139         return 0;
140 }
141 
142 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
143                 struct usb_phy_generic_platform_data *pdata)
144 {
145         enum usb_phy_type type = USB_PHY_TYPE_USB2;
146         int err;
147 
148         u32 clk_rate = 0;
149         bool needs_vcc = false;
150 
151         nop->reset_active_low = true;   /* default behaviour */
152 
153         if (dev->of_node) {
154                 struct device_node *node = dev->of_node;
155                 enum of_gpio_flags flags = 0;
156 
157                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
158                         clk_rate = 0;
159 
160                 needs_vcc = of_property_read_bool(node, "vcc-supply");
161                 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
162                                                                 0, &flags);
163                 if (nop->gpio_reset == -EPROBE_DEFER)
164                         return -EPROBE_DEFER;
165 
166                 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;
167 
168         } else if (pdata) {
169                 type = pdata->type;
170                 clk_rate = pdata->clk_rate;
171                 needs_vcc = pdata->needs_vcc;
172                 nop->gpio_reset = pdata->gpio_reset;
173         } else {
174                 nop->gpio_reset = -1;
175         }
176 
177         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
178                         GFP_KERNEL);
179         if (!nop->phy.otg)
180                 return -ENOMEM;
181 
182         nop->clk = devm_clk_get(dev, "main_clk");
183         if (IS_ERR(nop->clk)) {
184                 dev_dbg(dev, "Can't get phy clock: %ld\n",
185                                         PTR_ERR(nop->clk));
186         }
187 
188         if (!IS_ERR(nop->clk) && clk_rate) {
189                 err = clk_set_rate(nop->clk, clk_rate);
190                 if (err) {
191                         dev_err(dev, "Error setting clock rate\n");
192                         return err;
193                 }
194         }
195 
196         nop->vcc = devm_regulator_get(dev, "vcc");
197         if (IS_ERR(nop->vcc)) {
198                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
199                                         PTR_ERR(nop->vcc));
200                 if (needs_vcc)
201                         return -EPROBE_DEFER;
202         }
203 
204         if (gpio_is_valid(nop->gpio_reset)) {
205                 unsigned long gpio_flags;
206 
207                 /* Assert RESET */
208                 if (nop->reset_active_low)
209                         gpio_flags = GPIOF_OUT_INIT_LOW;
210                 else
211                         gpio_flags = GPIOF_OUT_INIT_HIGH;
212 
213                 err = devm_gpio_request_one(dev, nop->gpio_reset,
214                                                 gpio_flags, dev_name(dev));
215                 if (err) {
216                         dev_err(dev, "Error requesting RESET GPIO %d\n",
217                                         nop->gpio_reset);
218                         return err;
219                 }
220         }
221 
222         nop->dev                = dev;
223         nop->phy.dev            = nop->dev;
224         nop->phy.label          = "nop-xceiv";
225         nop->phy.set_suspend    = nop_set_suspend;
226         nop->phy.type           = type;
227 
228         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
229         nop->phy.otg->usb_phy           = &nop->phy;
230         nop->phy.otg->set_host          = nop_set_host;
231         nop->phy.otg->set_peripheral    = nop_set_peripheral;
232 
233         return 0;
234 }
235 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
236 
237 static int usb_phy_generic_probe(struct platform_device *pdev)
238 {
239         struct device *dev = &pdev->dev;
240         struct usb_phy_generic  *nop;
241         int err;
242 
243         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
244         if (!nop)
245                 return -ENOMEM;
246 
247         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
248         if (err)
249                 return err;
250 
251         nop->phy.init           = usb_gen_phy_init;
252         nop->phy.shutdown       = usb_gen_phy_shutdown;
253 
254         err = usb_add_phy_dev(&nop->phy);
255         if (err) {
256                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
257                         err);
258                 return err;
259         }
260 
261         platform_set_drvdata(pdev, nop);
262 
263         return 0;
264 }
265 
266 static int usb_phy_generic_remove(struct platform_device *pdev)
267 {
268         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
269 
270         usb_remove_phy(&nop->phy);
271 
272         return 0;
273 }
274 
275 static const struct of_device_id nop_xceiv_dt_ids[] = {
276         { .compatible = "usb-nop-xceiv" },
277         { }
278 };
279 
280 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
281 
282 static struct platform_driver usb_phy_generic_driver = {
283         .probe          = usb_phy_generic_probe,
284         .remove         = usb_phy_generic_remove,
285         .driver         = {
286                 .name   = "usb_phy_generic",
287                 .of_match_table = nop_xceiv_dt_ids,
288         },
289 };
290 
291 static int __init usb_phy_generic_init(void)
292 {
293         return platform_driver_register(&usb_phy_generic_driver);
294 }
295 subsys_initcall(usb_phy_generic_init);
296 
297 static void __exit usb_phy_generic_exit(void)
298 {
299         platform_driver_unregister(&usb_phy_generic_driver);
300 }
301 module_exit(usb_phy_generic_exit);
302 
303 MODULE_ALIAS("platform:usb_phy_generic");
304 MODULE_AUTHOR("Texas Instruments Inc");
305 MODULE_DESCRIPTION("NOP USB Transceiver driver");
306 MODULE_LICENSE("GPL");
307 

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