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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_generic.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 struct platform_device *usb_phy_generic_register(void)
 45 {
 46         return platform_device_register_simple("usb_phy_generic",
 47                         PLATFORM_DEVID_AUTO, NULL, 0);
 48 }
 49 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
 50 
 51 void usb_phy_generic_unregister(struct platform_device *pdev)
 52 {
 53         platform_device_unregister(pdev);
 54 }
 55 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
 56 
 57 static int nop_set_suspend(struct usb_phy *x, int suspend)
 58 {
 59         return 0;
 60 }
 61 
 62 static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
 63 {
 64         int value;
 65 
 66         if (!gpio_is_valid(nop->gpio_reset))
 67                 return;
 68 
 69         value = asserted;
 70         if (nop->reset_active_low)
 71                 value = !value;
 72 
 73         gpio_set_value_cansleep(nop->gpio_reset, value);
 74 
 75         if (!asserted)
 76                 usleep_range(10000, 20000);
 77 }
 78 
 79 int usb_gen_phy_init(struct usb_phy *phy)
 80 {
 81         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 82 
 83         if (!IS_ERR(nop->vcc)) {
 84                 if (regulator_enable(nop->vcc))
 85                         dev_err(phy->dev, "Failed to enable power\n");
 86         }
 87 
 88         if (!IS_ERR(nop->clk))
 89                 clk_prepare_enable(nop->clk);
 90 
 91         /* De-assert RESET */
 92         nop_reset_set(nop, 0);
 93 
 94         return 0;
 95 }
 96 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 97 
 98 void usb_gen_phy_shutdown(struct usb_phy *phy)
 99 {
100         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
101 
102         /* Assert RESET */
103         nop_reset_set(nop, 1);
104 
105         if (!IS_ERR(nop->clk))
106                 clk_disable_unprepare(nop->clk);
107 
108         if (!IS_ERR(nop->vcc)) {
109                 if (regulator_disable(nop->vcc))
110                         dev_err(phy->dev, "Failed to disable power\n");
111         }
112 }
113 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
114 
115 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
116 {
117         if (!otg)
118                 return -ENODEV;
119 
120         if (!gadget) {
121                 otg->gadget = NULL;
122                 return -ENODEV;
123         }
124 
125         otg->gadget = gadget;
126         otg->phy->state = OTG_STATE_B_IDLE;
127         return 0;
128 }
129 
130 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
131 {
132         if (!otg)
133                 return -ENODEV;
134 
135         if (!host) {
136                 otg->host = NULL;
137                 return -ENODEV;
138         }
139 
140         otg->host = host;
141         return 0;
142 }
143 
144 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
145                 struct usb_phy_generic_platform_data *pdata)
146 {
147         enum usb_phy_type type = USB_PHY_TYPE_USB2;
148         int err;
149 
150         u32 clk_rate = 0;
151         bool needs_vcc = false;
152 
153         nop->reset_active_low = true;   /* default behaviour */
154 
155         if (dev->of_node) {
156                 struct device_node *node = dev->of_node;
157                 enum of_gpio_flags flags = 0;
158 
159                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
160                         clk_rate = 0;
161 
162                 needs_vcc = of_property_read_bool(node, "vcc-supply");
163                 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
164                                                                 0, &flags);
165                 if (nop->gpio_reset == -EPROBE_DEFER)
166                         return -EPROBE_DEFER;
167 
168                 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;
169 
170         } else if (pdata) {
171                 type = pdata->type;
172                 clk_rate = pdata->clk_rate;
173                 needs_vcc = pdata->needs_vcc;
174                 nop->gpio_reset = pdata->gpio_reset;
175         } else {
176                 nop->gpio_reset = -1;
177         }
178 
179         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
180                         GFP_KERNEL);
181         if (!nop->phy.otg)
182                 return -ENOMEM;
183 
184         nop->clk = devm_clk_get(dev, "main_clk");
185         if (IS_ERR(nop->clk)) {
186                 dev_dbg(dev, "Can't get phy clock: %ld\n",
187                                         PTR_ERR(nop->clk));
188         }
189 
190         if (!IS_ERR(nop->clk) && clk_rate) {
191                 err = clk_set_rate(nop->clk, clk_rate);
192                 if (err) {
193                         dev_err(dev, "Error setting clock rate\n");
194                         return err;
195                 }
196         }
197 
198         nop->vcc = devm_regulator_get(dev, "vcc");
199         if (IS_ERR(nop->vcc)) {
200                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
201                                         PTR_ERR(nop->vcc));
202                 if (needs_vcc)
203                         return -EPROBE_DEFER;
204         }
205 
206         if (gpio_is_valid(nop->gpio_reset)) {
207                 unsigned long gpio_flags;
208 
209                 /* Assert RESET */
210                 if (nop->reset_active_low)
211                         gpio_flags = GPIOF_OUT_INIT_LOW;
212                 else
213                         gpio_flags = GPIOF_OUT_INIT_HIGH;
214 
215                 err = devm_gpio_request_one(dev, nop->gpio_reset,
216                                                 gpio_flags, dev_name(dev));
217                 if (err) {
218                         dev_err(dev, "Error requesting RESET GPIO %d\n",
219                                         nop->gpio_reset);
220                         return err;
221                 }
222         }
223 
224         nop->dev                = dev;
225         nop->phy.dev            = nop->dev;
226         nop->phy.label          = "nop-xceiv";
227         nop->phy.set_suspend    = nop_set_suspend;
228         nop->phy.state          = OTG_STATE_UNDEFINED;
229         nop->phy.type           = type;
230 
231         nop->phy.otg->phy               = &nop->phy;
232         nop->phy.otg->set_host          = nop_set_host;
233         nop->phy.otg->set_peripheral    = nop_set_peripheral;
234 
235         return 0;
236 }
237 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
238 
239 static int usb_phy_generic_probe(struct platform_device *pdev)
240 {
241         struct device *dev = &pdev->dev;
242         struct usb_phy_generic  *nop;
243         int err;
244 
245         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
246         if (!nop)
247                 return -ENOMEM;
248 
249         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
250         if (err)
251                 return err;
252 
253         nop->phy.init           = usb_gen_phy_init;
254         nop->phy.shutdown       = usb_gen_phy_shutdown;
255 
256         err = usb_add_phy_dev(&nop->phy);
257         if (err) {
258                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
259                         err);
260                 return err;
261         }
262 
263         platform_set_drvdata(pdev, nop);
264 
265         return 0;
266 }
267 
268 static int usb_phy_generic_remove(struct platform_device *pdev)
269 {
270         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
271 
272         usb_remove_phy(&nop->phy);
273 
274         return 0;
275 }
276 
277 static const struct of_device_id nop_xceiv_dt_ids[] = {
278         { .compatible = "usb-nop-xceiv" },
279         { }
280 };
281 
282 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
283 
284 static struct platform_driver usb_phy_generic_driver = {
285         .probe          = usb_phy_generic_probe,
286         .remove         = usb_phy_generic_remove,
287         .driver         = {
288                 .name   = "usb_phy_generic",
289                 .owner  = THIS_MODULE,
290                 .of_match_table = nop_xceiv_dt_ids,
291         },
292 };
293 
294 static int __init usb_phy_generic_init(void)
295 {
296         return platform_driver_register(&usb_phy_generic_driver);
297 }
298 subsys_initcall(usb_phy_generic_init);
299 
300 static void __exit usb_phy_generic_exit(void)
301 {
302         platform_driver_unregister(&usb_phy_generic_driver);
303 }
304 module_exit(usb_phy_generic_exit);
305 
306 MODULE_ALIAS("platform:usb_phy_generic");
307 MODULE_AUTHOR("Texas Instruments Inc");
308 MODULE_DESCRIPTION("NOP USB Transceiver driver");
309 MODULE_LICENSE("GPL");
310 

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