xref: /openbmc/linux/drivers/usb/phy/phy-generic.c (revision a2cce7a9)
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(struct usb_phy_generic *nop)
66 {
67 	if (!nop->gpiod_reset)
68 		return;
69 
70 	gpiod_set_value(nop->gpiod_reset, 1);
71 	usleep_range(10000, 20000);
72 	gpiod_set_value(nop->gpiod_reset, 0);
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 	nop_reset(nop);
155 
156 	return 0;
157 }
158 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
159 
160 void usb_gen_phy_shutdown(struct usb_phy *phy)
161 {
162 	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
163 
164 	gpiod_set_value(nop->gpiod_reset, 1);
165 
166 	if (!IS_ERR(nop->clk))
167 		clk_disable_unprepare(nop->clk);
168 
169 	if (!IS_ERR(nop->vcc)) {
170 		if (regulator_disable(nop->vcc))
171 			dev_err(phy->dev, "Failed to disable power\n");
172 	}
173 }
174 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
175 
176 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
177 {
178 	if (!otg)
179 		return -ENODEV;
180 
181 	if (!gadget) {
182 		otg->gadget = NULL;
183 		return -ENODEV;
184 	}
185 
186 	otg->gadget = gadget;
187 	otg->state = OTG_STATE_B_IDLE;
188 	return 0;
189 }
190 
191 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
192 {
193 	if (!otg)
194 		return -ENODEV;
195 
196 	if (!host) {
197 		otg->host = NULL;
198 		return -ENODEV;
199 	}
200 
201 	otg->host = host;
202 	return 0;
203 }
204 
205 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
206 		struct usb_phy_generic_platform_data *pdata)
207 {
208 	enum usb_phy_type type = USB_PHY_TYPE_USB2;
209 	int err = 0;
210 
211 	u32 clk_rate = 0;
212 	bool needs_vcc = false;
213 
214 	if (dev->of_node) {
215 		struct device_node *node = dev->of_node;
216 
217 		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
218 			clk_rate = 0;
219 
220 		needs_vcc = of_property_read_bool(node, "vcc-supply");
221 		nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
222 							   GPIOD_ASIS);
223 		err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
224 		if (!err) {
225 			nop->gpiod_vbus = devm_gpiod_get_optional(dev,
226 							 "vbus-detect",
227 							 GPIOD_ASIS);
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,
236 						    GPIOF_ACTIVE_LOW,
237 						    dev_name(dev));
238 			if (!err)
239 				nop->gpiod_reset =
240 					gpio_to_desc(pdata->gpio_reset);
241 		}
242 		nop->gpiod_vbus = pdata->gpiod_vbus;
243 	}
244 
245 	if (err == -EPROBE_DEFER)
246 		return -EPROBE_DEFER;
247 	if (err) {
248 		dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
249 		return err;
250 	}
251 	if (nop->gpiod_reset)
252 		gpiod_direction_output(nop->gpiod_reset, 1);
253 
254 	nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
255 			GFP_KERNEL);
256 	if (!nop->phy.otg)
257 		return -ENOMEM;
258 
259 	nop->clk = devm_clk_get(dev, "main_clk");
260 	if (IS_ERR(nop->clk)) {
261 		dev_dbg(dev, "Can't get phy clock: %ld\n",
262 					PTR_ERR(nop->clk));
263 	}
264 
265 	if (!IS_ERR(nop->clk) && clk_rate) {
266 		err = clk_set_rate(nop->clk, clk_rate);
267 		if (err) {
268 			dev_err(dev, "Error setting clock rate\n");
269 			return err;
270 		}
271 	}
272 
273 	nop->vcc = devm_regulator_get(dev, "vcc");
274 	if (IS_ERR(nop->vcc)) {
275 		dev_dbg(dev, "Error getting vcc regulator: %ld\n",
276 					PTR_ERR(nop->vcc));
277 		if (needs_vcc)
278 			return -EPROBE_DEFER;
279 	}
280 
281 	nop->dev		= dev;
282 	nop->phy.dev		= nop->dev;
283 	nop->phy.label		= "nop-xceiv";
284 	nop->phy.set_suspend	= nop_set_suspend;
285 	nop->phy.type		= type;
286 
287 	nop->phy.otg->state		= OTG_STATE_UNDEFINED;
288 	nop->phy.otg->usb_phy		= &nop->phy;
289 	nop->phy.otg->set_host		= nop_set_host;
290 	nop->phy.otg->set_peripheral	= nop_set_peripheral;
291 
292 	return 0;
293 }
294 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
295 
296 static int usb_phy_generic_probe(struct platform_device *pdev)
297 {
298 	struct device *dev = &pdev->dev;
299 	struct usb_phy_generic	*nop;
300 	int err;
301 
302 	nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
303 	if (!nop)
304 		return -ENOMEM;
305 
306 	err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
307 	if (err)
308 		return err;
309 	if (nop->gpiod_vbus) {
310 		err = devm_request_threaded_irq(&pdev->dev,
311 						gpiod_to_irq(nop->gpiod_vbus),
312 						NULL, nop_gpio_vbus_thread,
313 						VBUS_IRQ_FLAGS, "vbus_detect",
314 						nop);
315 		if (err) {
316 			dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
317 				gpiod_to_irq(nop->gpiod_vbus), err);
318 			return err;
319 		}
320 	}
321 
322 	nop->phy.init		= usb_gen_phy_init;
323 	nop->phy.shutdown	= usb_gen_phy_shutdown;
324 
325 	err = usb_add_phy_dev(&nop->phy);
326 	if (err) {
327 		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
328 			err);
329 		return err;
330 	}
331 
332 	platform_set_drvdata(pdev, nop);
333 
334 	return 0;
335 }
336 
337 static int usb_phy_generic_remove(struct platform_device *pdev)
338 {
339 	struct usb_phy_generic *nop = platform_get_drvdata(pdev);
340 
341 	usb_remove_phy(&nop->phy);
342 
343 	return 0;
344 }
345 
346 static const struct of_device_id nop_xceiv_dt_ids[] = {
347 	{ .compatible = "usb-nop-xceiv" },
348 	{ }
349 };
350 
351 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
352 
353 static struct platform_driver usb_phy_generic_driver = {
354 	.probe		= usb_phy_generic_probe,
355 	.remove		= usb_phy_generic_remove,
356 	.driver		= {
357 		.name	= "usb_phy_generic",
358 		.of_match_table = nop_xceiv_dt_ids,
359 	},
360 };
361 
362 static int __init usb_phy_generic_init(void)
363 {
364 	return platform_driver_register(&usb_phy_generic_driver);
365 }
366 subsys_initcall(usb_phy_generic_init);
367 
368 static void __exit usb_phy_generic_exit(void)
369 {
370 	platform_driver_unregister(&usb_phy_generic_driver);
371 }
372 module_exit(usb_phy_generic_exit);
373 
374 MODULE_ALIAS("platform:usb_phy_generic");
375 MODULE_AUTHOR("Texas Instruments Inc");
376 MODULE_DESCRIPTION("NOP USB Transceiver driver");
377 MODULE_LICENSE("GPL");
378