[go: nahoru, domu]
1/*
2 * Tahvo USB transceiver driver
3 *
4 * Copyright (C) 2005-2006 Nokia Corporation
5 *
6 * Parts copied from isp1301_omap.c.
7 * Copyright (C) 2004 Texas Instruments
8 * Copyright (C) 2004 David Brownell
9 *
10 * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
11 * Modified for Retu/Tahvo MFD by Aaro Koskinen.
12 *
13 * This file is subject to the terms and conditions of the GNU General
14 * Public License. See the file "COPYING" in the main directory of this
15 * archive for more details.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 */
22
23#include <linux/io.h>
24#include <linux/clk.h>
25#include <linux/usb.h>
26#include <linux/extcon.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/usb/otg.h>
30#include <linux/mfd/retu.h>
31#include <linux/usb/gadget.h>
32#include <linux/platform_device.h>
33
34#define DRIVER_NAME     "tahvo-usb"
35
36#define TAHVO_REG_IDSR	0x02
37#define TAHVO_REG_USBR	0x06
38
39#define USBR_SLAVE_CONTROL	(1 << 8)
40#define USBR_VPPVIO_SW		(1 << 7)
41#define USBR_SPEED		(1 << 6)
42#define USBR_REGOUT		(1 << 5)
43#define USBR_MASTER_SW2		(1 << 4)
44#define USBR_MASTER_SW1		(1 << 3)
45#define USBR_SLAVE_SW		(1 << 2)
46#define USBR_NSUSPEND		(1 << 1)
47#define USBR_SEMODE		(1 << 0)
48
49#define TAHVO_MODE_HOST		0
50#define TAHVO_MODE_PERIPHERAL	1
51
52struct tahvo_usb {
53	struct platform_device	*pt_dev;
54	struct usb_phy		phy;
55	int			vbus_state;
56	struct mutex		serialize;
57	struct clk		*ick;
58	int			irq;
59	int			tahvo_mode;
60	struct extcon_dev	extcon;
61};
62
63static const char *tahvo_cable[] = {
64	"USB-HOST",
65	"USB",
66	NULL,
67};
68
69static ssize_t vbus_state_show(struct device *device,
70			       struct device_attribute *attr, char *buf)
71{
72	struct tahvo_usb *tu = dev_get_drvdata(device);
73	return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
74}
75static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
76
77static void check_vbus_state(struct tahvo_usb *tu)
78{
79	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
80	int reg, prev_state;
81
82	reg = retu_read(rdev, TAHVO_REG_IDSR);
83	if (reg & TAHVO_STAT_VBUS) {
84		switch (tu->phy.state) {
85		case OTG_STATE_B_IDLE:
86			/* Enable the gadget driver */
87			if (tu->phy.otg->gadget)
88				usb_gadget_vbus_connect(tu->phy.otg->gadget);
89			tu->phy.state = OTG_STATE_B_PERIPHERAL;
90			break;
91		case OTG_STATE_A_IDLE:
92			/*
93			 * Session is now valid assuming the USB hub is driving
94			 * Vbus.
95			 */
96			tu->phy.state = OTG_STATE_A_HOST;
97			break;
98		default:
99			break;
100		}
101		dev_info(&tu->pt_dev->dev, "USB cable connected\n");
102	} else {
103		switch (tu->phy.state) {
104		case OTG_STATE_B_PERIPHERAL:
105			if (tu->phy.otg->gadget)
106				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
107			tu->phy.state = OTG_STATE_B_IDLE;
108			break;
109		case OTG_STATE_A_HOST:
110			tu->phy.state = OTG_STATE_A_IDLE;
111			break;
112		default:
113			break;
114		}
115		dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
116	}
117
118	prev_state = tu->vbus_state;
119	tu->vbus_state = reg & TAHVO_STAT_VBUS;
120	if (prev_state != tu->vbus_state) {
121		extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
122		sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
123	}
124}
125
126static void tahvo_usb_become_host(struct tahvo_usb *tu)
127{
128	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
129
130	extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
131
132	/* Power up the transceiver in USB host mode */
133	retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
134		   USBR_MASTER_SW2 | USBR_MASTER_SW1);
135	tu->phy.state = OTG_STATE_A_IDLE;
136
137	check_vbus_state(tu);
138}
139
140static void tahvo_usb_stop_host(struct tahvo_usb *tu)
141{
142	tu->phy.state = OTG_STATE_A_IDLE;
143}
144
145static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
146{
147	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
148
149	extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
150
151	/* Power up transceiver and set it in USB peripheral mode */
152	retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
153		   USBR_NSUSPEND | USBR_SLAVE_SW);
154	tu->phy.state = OTG_STATE_B_IDLE;
155
156	check_vbus_state(tu);
157}
158
159static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
160{
161	if (tu->phy.otg->gadget)
162		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
163	tu->phy.state = OTG_STATE_B_IDLE;
164}
165
166static void tahvo_usb_power_off(struct tahvo_usb *tu)
167{
168	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
169
170	/* Disable gadget controller if any */
171	if (tu->phy.otg->gadget)
172		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
173
174	/* Power off transceiver */
175	retu_write(rdev, TAHVO_REG_USBR, 0);
176	tu->phy.state = OTG_STATE_UNDEFINED;
177}
178
179static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
180{
181	struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
182	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
183	u16 w;
184
185	dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
186
187	w = retu_read(rdev, TAHVO_REG_USBR);
188	if (suspend)
189		w &= ~USBR_NSUSPEND;
190	else
191		w |= USBR_NSUSPEND;
192	retu_write(rdev, TAHVO_REG_USBR, w);
193
194	return 0;
195}
196
197static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
198{
199	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
200
201	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
202
203	mutex_lock(&tu->serialize);
204
205	if (host == NULL) {
206		if (tu->tahvo_mode == TAHVO_MODE_HOST)
207			tahvo_usb_power_off(tu);
208		otg->host = NULL;
209		mutex_unlock(&tu->serialize);
210		return 0;
211	}
212
213	if (tu->tahvo_mode == TAHVO_MODE_HOST) {
214		otg->host = NULL;
215		tahvo_usb_become_host(tu);
216	}
217
218	otg->host = host;
219
220	mutex_unlock(&tu->serialize);
221
222	return 0;
223}
224
225static int tahvo_usb_set_peripheral(struct usb_otg *otg,
226				    struct usb_gadget *gadget)
227{
228	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
229
230	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
231
232	mutex_lock(&tu->serialize);
233
234	if (!gadget) {
235		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
236			tahvo_usb_power_off(tu);
237		tu->phy.otg->gadget = NULL;
238		mutex_unlock(&tu->serialize);
239		return 0;
240	}
241
242	tu->phy.otg->gadget = gadget;
243	if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
244		tahvo_usb_become_peripheral(tu);
245
246	mutex_unlock(&tu->serialize);
247
248	return 0;
249}
250
251static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
252{
253	struct tahvo_usb *tu = _tu;
254
255	mutex_lock(&tu->serialize);
256	check_vbus_state(tu);
257	mutex_unlock(&tu->serialize);
258
259	return IRQ_HANDLED;
260}
261
262static ssize_t otg_mode_show(struct device *device,
263			     struct device_attribute *attr, char *buf)
264{
265	struct tahvo_usb *tu = dev_get_drvdata(device);
266
267	switch (tu->tahvo_mode) {
268	case TAHVO_MODE_HOST:
269		return sprintf(buf, "host\n");
270	case TAHVO_MODE_PERIPHERAL:
271		return sprintf(buf, "peripheral\n");
272	}
273
274	return -EINVAL;
275}
276
277static ssize_t otg_mode_store(struct device *device,
278			      struct device_attribute *attr,
279			      const char *buf, size_t count)
280{
281	struct tahvo_usb *tu = dev_get_drvdata(device);
282	int r;
283
284	mutex_lock(&tu->serialize);
285	if (count >= 4 && strncmp(buf, "host", 4) == 0) {
286		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
287			tahvo_usb_stop_peripheral(tu);
288		tu->tahvo_mode = TAHVO_MODE_HOST;
289		if (tu->phy.otg->host) {
290			dev_info(device, "HOST mode: host controller present\n");
291			tahvo_usb_become_host(tu);
292		} else {
293			dev_info(device, "HOST mode: no host controller, powering off\n");
294			tahvo_usb_power_off(tu);
295		}
296		r = strlen(buf);
297	} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
298		if (tu->tahvo_mode == TAHVO_MODE_HOST)
299			tahvo_usb_stop_host(tu);
300		tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
301		if (tu->phy.otg->gadget) {
302			dev_info(device, "PERIPHERAL mode: gadget driver present\n");
303			tahvo_usb_become_peripheral(tu);
304		} else {
305			dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
306			tahvo_usb_power_off(tu);
307		}
308		r = strlen(buf);
309	} else {
310		r = -EINVAL;
311	}
312	mutex_unlock(&tu->serialize);
313
314	return r;
315}
316static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
317
318static struct attribute *tahvo_attributes[] = {
319	&dev_attr_vbus.attr,
320	&dev_attr_otg_mode.attr,
321	NULL
322};
323
324static struct attribute_group tahvo_attr_group = {
325	.attrs = tahvo_attributes,
326};
327
328static int tahvo_usb_probe(struct platform_device *pdev)
329{
330	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
331	struct tahvo_usb *tu;
332	int ret;
333
334	tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
335	if (!tu)
336		return -ENOMEM;
337
338	tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
339				   GFP_KERNEL);
340	if (!tu->phy.otg)
341		return -ENOMEM;
342
343	tu->pt_dev = pdev;
344
345	/* Default mode */
346#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
347	tu->tahvo_mode = TAHVO_MODE_HOST;
348#else
349	tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
350#endif
351
352	mutex_init(&tu->serialize);
353
354	tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
355	if (!IS_ERR(tu->ick))
356		clk_enable(tu->ick);
357
358	/*
359	 * Set initial state, so that we generate kevents only on state changes.
360	 */
361	tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
362
363	tu->extcon.name = DRIVER_NAME;
364	tu->extcon.supported_cable = tahvo_cable;
365	tu->extcon.dev.parent = &pdev->dev;
366
367	ret = extcon_dev_register(&tu->extcon);
368	if (ret) {
369		dev_err(&pdev->dev, "could not register extcon device: %d\n",
370			ret);
371		goto err_disable_clk;
372	}
373
374	/* Set the initial cable state. */
375	extcon_set_cable_state(&tu->extcon, "USB-HOST",
376			       tu->tahvo_mode == TAHVO_MODE_HOST);
377	extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
378
379	/* Create OTG interface */
380	tahvo_usb_power_off(tu);
381	tu->phy.dev = &pdev->dev;
382	tu->phy.state = OTG_STATE_UNDEFINED;
383	tu->phy.label = DRIVER_NAME;
384	tu->phy.set_suspend = tahvo_usb_set_suspend;
385
386	tu->phy.otg->phy = &tu->phy;
387	tu->phy.otg->set_host = tahvo_usb_set_host;
388	tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
389
390	ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
391	if (ret < 0) {
392		dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
393			ret);
394		goto err_extcon_unreg;
395	}
396
397	dev_set_drvdata(&pdev->dev, tu);
398
399	tu->irq = platform_get_irq(pdev, 0);
400	ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
401				   "tahvo-vbus", tu);
402	if (ret) {
403		dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
404			ret);
405		goto err_remove_phy;
406	}
407
408	/* Attributes */
409	ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
410	if (ret) {
411		dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
412		goto err_free_irq;
413	}
414
415	return 0;
416
417err_free_irq:
418	free_irq(tu->irq, tu);
419err_remove_phy:
420	usb_remove_phy(&tu->phy);
421err_extcon_unreg:
422	extcon_dev_unregister(&tu->extcon);
423err_disable_clk:
424	if (!IS_ERR(tu->ick))
425		clk_disable(tu->ick);
426
427	return ret;
428}
429
430static int tahvo_usb_remove(struct platform_device *pdev)
431{
432	struct tahvo_usb *tu = platform_get_drvdata(pdev);
433
434	sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
435	free_irq(tu->irq, tu);
436	usb_remove_phy(&tu->phy);
437	extcon_dev_unregister(&tu->extcon);
438	if (!IS_ERR(tu->ick))
439		clk_disable(tu->ick);
440
441	return 0;
442}
443
444static struct platform_driver tahvo_usb_driver = {
445	.probe		= tahvo_usb_probe,
446	.remove		= tahvo_usb_remove,
447	.driver		= {
448		.name	= "tahvo-usb",
449		.owner	= THIS_MODULE,
450	},
451};
452module_platform_driver(tahvo_usb_driver);
453
454MODULE_DESCRIPTION("Tahvo USB transceiver driver");
455MODULE_LICENSE("GPL");
456MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
457MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
458