aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/phy/phy-generic.c
blob: bb394980532b147fb737a9ca099cd1a57656d574 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
/*
 * drivers/usb/otg/nop-usb-xceiv.c
 *
 * NOP USB transceiver for all USB transceiver which are either built-in
 * into USB IP or which are mostly autonomous.
 *
 * Copyright (C) 2009 Texas Instruments Inc
 * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Current status:
 *	This provides a "nop" transceiver for PHYs which are
 *	autonomous such as isp1504, isp1707, etc.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/usb/otg.h>
#include <linux/usb/usb_phy_gen_xceiv.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/delay.h>

#include "phy-generic.h"

static struct platform_device *pd;

void usb_nop_xceiv_register(void)
{
	if (pd)
		return;
	pd = platform_device_register_simple("usb_phy_gen_xceiv", -1, NULL, 0);
	if (IS_ERR(pd)) {
		pr_err("Unable to register generic usb transceiver\n");
		pd = NULL;
		return;
	}
}
EXPORT_SYMBOL(usb_nop_xceiv_register);

void usb_nop_xceiv_unregister(void)
{
	platform_device_unregister(pd);
	pd = NULL;
}
EXPORT_SYMBOL(usb_nop_xceiv_unregister);

static int nop_set_suspend(struct usb_phy *x, int suspend)
{
	return 0;
}

static void nop_reset_set(struct usb_phy_gen_xceiv *nop, int asserted)
{
	int value;

	if (!gpio_is_valid(nop->gpio_reset))
		return;

	value = asserted;
	if (nop->reset_active_low)
		value = !value;

	gpio_set_value_cansleep(nop->gpio_reset, value);

	if (!asserted)
		usleep_range(10000, 20000);
}

int usb_gen_phy_init(struct usb_phy *phy)
{
	struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);

	if (!IS_ERR(nop->vcc)) {
		if (regulator_enable(nop->vcc))
			dev_err(phy->dev, "Failed to enable power\n");
	}

	if (!IS_ERR(nop->clk))
		clk_prepare_enable(nop->clk);

	/* De-assert RESET */
	nop_reset_set(nop, 0);

	return 0;
}
EXPORT_SYMBOL_GPL(usb_gen_phy_init);

void usb_gen_phy_shutdown(struct usb_phy *phy)
{
	struct usb_phy_gen_xceiv *nop = dev_get_drvdata(phy->dev);

	/* Assert RESET */
	nop_reset_set(nop, 1);

	if (!IS_ERR(nop->clk))
		clk_disable_unprepare(nop->clk);

	if (!IS_ERR(nop->vcc)) {
		if (regulator_disable(nop->vcc))
			dev_err(phy->dev, "Failed to disable power\n");
	}
}
EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);

static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
{
	if (!otg)
		return -ENODEV;

	if (!gadget) {
		otg->gadget = NULL;
		return -ENODEV;
	}

	otg->gadget = gadget;
	otg->phy->state = OTG_STATE_B_IDLE;
	return 0;
}

static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
{
	if (!otg)
		return -ENODEV;

	if (!host) {
		otg->host = NULL;
		return -ENODEV;
	}

	otg->host = host;
	return 0;
}

int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_gen_xceiv *nop,
		struct usb_phy_gen_xceiv_platform_data *pdata)
{
	enum usb_phy_type type = USB_PHY_TYPE_USB2;
	int err;

	u32 clk_rate = 0;
	bool needs_vcc = false;

	nop->reset_active_low = true;	/* default behaviour */

	if (dev->of_node) {
		struct device_node *node = dev->of_node;
		enum of_gpio_flags flags = 0;

		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
			clk_rate = 0;

		needs_vcc = of_property_read_bool(node, "vcc-supply");
		nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
								0, &flags);
		if (nop->gpio_reset == -EPROBE_DEFER)
			return -EPROBE_DEFER;

		nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;

	} else if (pdata) {
		type = pdata->type;
		clk_rate = pdata->clk_rate;
		needs_vcc = pdata->needs_vcc;
		nop->gpio_reset = pdata->gpio_reset;
	} else {
		nop->gpio_reset = -1;
	}

	nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
			GFP_KERNEL);
	if (!nop->phy.otg)
		return -ENOMEM;

	nop->clk = devm_clk_get(dev, "main_clk");
	if (IS_ERR(nop->clk)) {
		dev_dbg(dev, "Can't get phy clock: %ld\n",
					PTR_ERR(nop->clk));
	}

	if (!IS_ERR(nop->clk) && clk_rate) {
		err = clk_set_rate(nop->clk, clk_rate);
		if (err) {
			dev_err(dev, "Error setting clock rate\n");
			return err;
		}
	}

	nop->vcc = devm_regulator_get(dev, "vcc");
	if (IS_ERR(nop->vcc)) {
		dev_dbg(dev, "Error getting vcc regulator: %ld\n",
					PTR_ERR(nop->vcc));
		if (needs_vcc)
			return -EPROBE_DEFER;
	}

	if (gpio_is_valid(nop->gpio_reset)) {
		unsigned long gpio_flags;

		/* Assert RESET */
		if (nop->reset_active_low)
			gpio_flags = GPIOF_OUT_INIT_LOW;
		else
			gpio_flags = GPIOF_OUT_INIT_HIGH;

		err = devm_gpio_request_one(dev, nop->gpio_reset,
						gpio_flags, dev_name(dev));
		if (err) {
			dev_err(dev, "Error requesting RESET GPIO %d\n",
					nop->gpio_reset);
			return err;
		}
	}

	nop->dev		= dev;
	nop->phy.dev		= nop->dev;
	nop->phy.label		= "nop-xceiv";
	nop->phy.set_suspend	= nop_set_suspend;
	nop->phy.state		= OTG_STATE_UNDEFINED;
	nop->phy.type		= type;

	nop->phy.otg->phy		= &nop->phy;
	nop->phy.otg->set_host		= nop_set_host;
	nop->phy.otg->set_peripheral	= nop_set_peripheral;

	return 0;
}
EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);

static int usb_phy_gen_xceiv_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct usb_phy_gen_xceiv	*nop;
	int err;

	nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
	if (!nop)
		return -ENOMEM;

	err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
	if (err)
		return err;

	nop->phy.init		= usb_gen_phy_init;
	nop->phy.shutdown	= usb_gen_phy_shutdown;

	err = usb_add_phy_dev(&nop->phy);
	if (err) {
		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
			err);
		return err;
	}

	platform_set_drvdata(pdev, nop);

	return 0;
}

static int usb_phy_gen_xceiv_remove(struct platform_device *pdev)
{
	struct usb_phy_gen_xceiv *nop = platform_get_drvdata(pdev);

	usb_remove_phy(&nop->phy);

	return 0;
}

static const struct of_device_id nop_xceiv_dt_ids[] = {
	{ .compatible = "usb-nop-xceiv" },
	{ }
};

MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);

static struct platform_driver usb_phy_gen_xceiv_driver = {
	.probe		= usb_phy_gen_xceiv_probe,
	.remove		= usb_phy_gen_xceiv_remove,
	.driver		= {
		.name	= "usb_phy_gen_xceiv",
		.owner	= THIS_MODULE,
		.of_match_table = nop_xceiv_dt_ids,
	},
};

static int __init usb_phy_gen_xceiv_init(void)
{
	return platform_driver_register(&usb_phy_gen_xceiv_driver);
}
subsys_initcall(usb_phy_gen_xceiv_init);

static void __exit usb_phy_gen_xceiv_exit(void)
{
	platform_driver_unregister(&usb_phy_gen_xceiv_driver);
}
module_exit(usb_phy_gen_xceiv_exit);

MODULE_ALIAS("platform:usb_phy_gen_xceiv");
MODULE_AUTHOR("Texas Instruments Inc");
MODULE_DESCRIPTION("NOP USB Transceiver driver");
MODULE_LICENSE("GPL");