1/*
2 * ISP1704 USB Charger Detection driver
3 *
4 * Copyright (C) 2010 Nokia Corporation
5 * Copyright (C) 2012 - 2013 Pali Rohár <pali.rohar@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/err.h>
25#include <linux/init.h>
26#include <linux/types.h>
27#include <linux/device.h>
28#include <linux/sysfs.h>
29#include <linux/platform_device.h>
30#include <linux/power_supply.h>
31#include <linux/delay.h>
32#include <linux/of.h>
33#include <linux/of_gpio.h>
34
35#include <linux/usb/otg.h>
36#include <linux/usb/ulpi.h>
37#include <linux/usb/ch9.h>
38#include <linux/usb/gadget.h>
39#include <linux/power/isp1704_charger.h>
40
41/* Vendor specific Power Control register */
42#define ISP1704_PWR_CTRL		0x3d
43#define ISP1704_PWR_CTRL_SWCTRL		(1 << 0)
44#define ISP1704_PWR_CTRL_DET_COMP	(1 << 1)
45#define ISP1704_PWR_CTRL_BVALID_RISE	(1 << 2)
46#define ISP1704_PWR_CTRL_BVALID_FALL	(1 << 3)
47#define ISP1704_PWR_CTRL_DP_WKPU_EN	(1 << 4)
48#define ISP1704_PWR_CTRL_VDAT_DET	(1 << 5)
49#define ISP1704_PWR_CTRL_DPVSRC_EN	(1 << 6)
50#define ISP1704_PWR_CTRL_HWDETECT	(1 << 7)
51
52#define NXP_VENDOR_ID			0x04cc
53
54static u16 isp170x_id[] = {
55	0x1704,
56	0x1707,
57};
58
59struct isp1704_charger {
60	struct device			*dev;
61	struct power_supply		*psy;
62	struct power_supply_desc	psy_desc;
63	struct usb_phy			*phy;
64	struct notifier_block		nb;
65	struct work_struct		work;
66
67	/* properties */
68	char			model[8];
69	unsigned		present:1;
70	unsigned		online:1;
71	unsigned		current_max;
72};
73
74static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
75{
76	return usb_phy_io_read(isp->phy, reg);
77}
78
79static inline int isp1704_write(struct isp1704_charger *isp, u32 val, u32 reg)
80{
81	return usb_phy_io_write(isp->phy, val, reg);
82}
83
84/*
85 * Disable/enable the power from the isp1704 if a function for it
86 * has been provided with platform data.
87 */
88static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
89{
90	struct isp1704_charger_data	*board = isp->dev->platform_data;
91
92	if (board && board->set_power)
93		board->set_power(on);
94	else if (board)
95		gpio_set_value(board->enable_gpio, on);
96}
97
98/*
99 * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
100 * chargers).
101 *
102 * REVISIT: The method is defined in Battery Charging Specification and is
103 * applicable to any ULPI transceiver. Nothing isp170x specific here.
104 */
105static inline int isp1704_charger_type(struct isp1704_charger *isp)
106{
107	u8 reg;
108	u8 func_ctrl;
109	u8 otg_ctrl;
110	int type = POWER_SUPPLY_TYPE_USB_DCP;
111
112	func_ctrl = isp1704_read(isp, ULPI_FUNC_CTRL);
113	otg_ctrl = isp1704_read(isp, ULPI_OTG_CTRL);
114
115	/* disable pulldowns */
116	reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
117	isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), reg);
118
119	/* full speed */
120	isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
121			ULPI_FUNC_CTRL_XCVRSEL_MASK);
122	isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL),
123			ULPI_FUNC_CTRL_FULL_SPEED);
124
125	/* Enable strong pull-up on DP (1.5K) and reset */
126	reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
127	isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), reg);
128	usleep_range(1000, 2000);
129
130	reg = isp1704_read(isp, ULPI_DEBUG);
131	if ((reg & 3) != 3)
132		type = POWER_SUPPLY_TYPE_USB_CDP;
133
134	/* recover original state */
135	isp1704_write(isp, ULPI_FUNC_CTRL, func_ctrl);
136	isp1704_write(isp, ULPI_OTG_CTRL, otg_ctrl);
137
138	return type;
139}
140
141/*
142 * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
143 * is actually a dedicated charger, the following steps need to be taken.
144 */
145static inline int isp1704_charger_verify(struct isp1704_charger *isp)
146{
147	int	ret = 0;
148	u8	r;
149
150	/* Reset the transceiver */
151	r = isp1704_read(isp, ULPI_FUNC_CTRL);
152	r |= ULPI_FUNC_CTRL_RESET;
153	isp1704_write(isp, ULPI_FUNC_CTRL, r);
154	usleep_range(1000, 2000);
155
156	/* Set normal mode */
157	r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
158	isp1704_write(isp, ULPI_FUNC_CTRL, r);
159
160	/* Clear the DP and DM pull-down bits */
161	r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
162	isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), r);
163
164	/* Enable strong pull-up on DP (1.5K) and reset */
165	r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
166	isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), r);
167	usleep_range(1000, 2000);
168
169	/* Read the line state */
170	if (!isp1704_read(isp, ULPI_DEBUG)) {
171		/* Disable strong pull-up on DP (1.5K) */
172		isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
173				ULPI_FUNC_CTRL_TERMSELECT);
174		return 1;
175	}
176
177	/* Is it a charger or PS/2 connection */
178
179	/* Enable weak pull-up resistor on DP */
180	isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
181			ISP1704_PWR_CTRL_DP_WKPU_EN);
182
183	/* Disable strong pull-up on DP (1.5K) */
184	isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
185			ULPI_FUNC_CTRL_TERMSELECT);
186
187	/* Enable weak pull-down resistor on DM */
188	isp1704_write(isp, ULPI_SET(ULPI_OTG_CTRL),
189			ULPI_OTG_CTRL_DM_PULLDOWN);
190
191	/* It's a charger if the line states are clear */
192	if (!(isp1704_read(isp, ULPI_DEBUG)))
193		ret = 1;
194
195	/* Disable weak pull-up resistor on DP */
196	isp1704_write(isp, ULPI_CLR(ISP1704_PWR_CTRL),
197			ISP1704_PWR_CTRL_DP_WKPU_EN);
198
199	return ret;
200}
201
202static inline int isp1704_charger_detect(struct isp1704_charger *isp)
203{
204	unsigned long	timeout;
205	u8		pwr_ctrl;
206	int		ret = 0;
207
208	pwr_ctrl = isp1704_read(isp, ISP1704_PWR_CTRL);
209
210	/* set SW control bit in PWR_CTRL register */
211	isp1704_write(isp, ISP1704_PWR_CTRL,
212			ISP1704_PWR_CTRL_SWCTRL);
213
214	/* enable manual charger detection */
215	isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
216			ISP1704_PWR_CTRL_SWCTRL
217			| ISP1704_PWR_CTRL_DPVSRC_EN);
218	usleep_range(1000, 2000);
219
220	timeout = jiffies + msecs_to_jiffies(300);
221	do {
222		/* Check if there is a charger */
223		if (isp1704_read(isp, ISP1704_PWR_CTRL)
224				& ISP1704_PWR_CTRL_VDAT_DET) {
225			ret = isp1704_charger_verify(isp);
226			break;
227		}
228	} while (!time_after(jiffies, timeout) && isp->online);
229
230	/* recover original state */
231	isp1704_write(isp, ISP1704_PWR_CTRL, pwr_ctrl);
232
233	return ret;
234}
235
236static inline int isp1704_charger_detect_dcp(struct isp1704_charger *isp)
237{
238	if (isp1704_charger_detect(isp) &&
239			isp1704_charger_type(isp) == POWER_SUPPLY_TYPE_USB_DCP)
240		return true;
241	else
242		return false;
243}
244
245static void isp1704_charger_work(struct work_struct *data)
246{
247	struct isp1704_charger	*isp =
248		container_of(data, struct isp1704_charger, work);
249	static DEFINE_MUTEX(lock);
250
251	mutex_lock(&lock);
252
253	switch (isp->phy->last_event) {
254	case USB_EVENT_VBUS:
255		/* do not call wall charger detection more times */
256		if (!isp->present) {
257			isp->online = true;
258			isp->present = 1;
259			isp1704_charger_set_power(isp, 1);
260
261			/* detect wall charger */
262			if (isp1704_charger_detect_dcp(isp)) {
263				isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_DCP;
264				isp->current_max = 1800;
265			} else {
266				isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
267				isp->current_max = 500;
268			}
269
270			/* enable data pullups */
271			if (isp->phy->otg->gadget)
272				usb_gadget_connect(isp->phy->otg->gadget);
273		}
274
275		if (isp->psy_desc.type != POWER_SUPPLY_TYPE_USB_DCP) {
276			/*
277			 * Only 500mA here or high speed chirp
278			 * handshaking may break
279			 */
280			if (isp->current_max > 500)
281				isp->current_max = 500;
282
283			if (isp->current_max > 100)
284				isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_CDP;
285		}
286		break;
287	case USB_EVENT_NONE:
288		isp->online = false;
289		isp->present = 0;
290		isp->current_max = 0;
291		isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
292
293		/*
294		 * Disable data pullups. We need to prevent the controller from
295		 * enumerating.
296		 *
297		 * FIXME: This is here to allow charger detection with Host/HUB
298		 * chargers. The pullups may be enabled elsewhere, so this can
299		 * not be the final solution.
300		 */
301		if (isp->phy->otg->gadget)
302			usb_gadget_disconnect(isp->phy->otg->gadget);
303
304		isp1704_charger_set_power(isp, 0);
305		break;
306	default:
307		goto out;
308	}
309
310	power_supply_changed(isp->psy);
311out:
312	mutex_unlock(&lock);
313}
314
315static int isp1704_notifier_call(struct notifier_block *nb,
316		unsigned long val, void *v)
317{
318	struct isp1704_charger *isp =
319		container_of(nb, struct isp1704_charger, nb);
320
321	schedule_work(&isp->work);
322
323	return NOTIFY_OK;
324}
325
326static int isp1704_charger_get_property(struct power_supply *psy,
327				enum power_supply_property psp,
328				union power_supply_propval *val)
329{
330	struct isp1704_charger *isp = power_supply_get_drvdata(psy);
331
332	switch (psp) {
333	case POWER_SUPPLY_PROP_PRESENT:
334		val->intval = isp->present;
335		break;
336	case POWER_SUPPLY_PROP_ONLINE:
337		val->intval = isp->online;
338		break;
339	case POWER_SUPPLY_PROP_CURRENT_MAX:
340		val->intval = isp->current_max;
341		break;
342	case POWER_SUPPLY_PROP_MODEL_NAME:
343		val->strval = isp->model;
344		break;
345	case POWER_SUPPLY_PROP_MANUFACTURER:
346		val->strval = "NXP";
347		break;
348	default:
349		return -EINVAL;
350	}
351	return 0;
352}
353
354static enum power_supply_property power_props[] = {
355	POWER_SUPPLY_PROP_PRESENT,
356	POWER_SUPPLY_PROP_ONLINE,
357	POWER_SUPPLY_PROP_CURRENT_MAX,
358	POWER_SUPPLY_PROP_MODEL_NAME,
359	POWER_SUPPLY_PROP_MANUFACTURER,
360};
361
362static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
363{
364	int vendor;
365	int product;
366	int i;
367	int ret = -ENODEV;
368
369	/* Test ULPI interface */
370	ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
371	if (ret < 0)
372		return ret;
373
374	ret = isp1704_read(isp, ULPI_SCRATCH);
375	if (ret < 0)
376		return ret;
377
378	if (ret != 0xaa)
379		return -ENODEV;
380
381	/* Verify the product and vendor id matches */
382	vendor = isp1704_read(isp, ULPI_VENDOR_ID_LOW);
383	vendor |= isp1704_read(isp, ULPI_VENDOR_ID_HIGH) << 8;
384	if (vendor != NXP_VENDOR_ID)
385		return -ENODEV;
386
387	product = isp1704_read(isp, ULPI_PRODUCT_ID_LOW);
388	product |= isp1704_read(isp, ULPI_PRODUCT_ID_HIGH) << 8;
389
390	for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
391		if (product == isp170x_id[i]) {
392			sprintf(isp->model, "isp%x", product);
393			return product;
394		}
395	}
396
397	dev_err(isp->dev, "product id %x not matching known ids", product);
398
399	return -ENODEV;
400}
401
402static int isp1704_charger_probe(struct platform_device *pdev)
403{
404	struct isp1704_charger	*isp;
405	int			ret = -ENODEV;
406	struct power_supply_config psy_cfg = {};
407
408	struct isp1704_charger_data *pdata = dev_get_platdata(&pdev->dev);
409	struct device_node *np = pdev->dev.of_node;
410
411	if (np) {
412		int gpio = of_get_named_gpio(np, "nxp,enable-gpio", 0);
413
414		if (gpio < 0)
415			return gpio;
416
417		pdata = devm_kzalloc(&pdev->dev,
418			sizeof(struct isp1704_charger_data), GFP_KERNEL);
419		pdata->enable_gpio = gpio;
420
421		dev_info(&pdev->dev, "init gpio %d\n", pdata->enable_gpio);
422
423		ret = devm_gpio_request_one(&pdev->dev, pdata->enable_gpio,
424					GPIOF_OUT_INIT_HIGH, "isp1704_reset");
425		if (ret)
426			goto fail0;
427	}
428
429	if (!pdata) {
430		dev_err(&pdev->dev, "missing platform data!\n");
431		return -ENODEV;
432	}
433
434
435	isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL);
436	if (!isp)
437		return -ENOMEM;
438
439	if (np)
440		isp->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0);
441	else
442		isp->phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
443
444	if (IS_ERR(isp->phy)) {
445		ret = PTR_ERR(isp->phy);
446		goto fail0;
447	}
448
449	isp->dev = &pdev->dev;
450	platform_set_drvdata(pdev, isp);
451
452	isp1704_charger_set_power(isp, 1);
453
454	ret = isp1704_test_ulpi(isp);
455	if (ret < 0)
456		goto fail1;
457
458	isp->psy_desc.name		= "isp1704";
459	isp->psy_desc.type		= POWER_SUPPLY_TYPE_USB;
460	isp->psy_desc.properties	= power_props;
461	isp->psy_desc.num_properties	= ARRAY_SIZE(power_props);
462	isp->psy_desc.get_property	= isp1704_charger_get_property;
463
464	psy_cfg.drv_data		= isp;
465
466	isp->psy = power_supply_register(isp->dev, &isp->psy_desc, &psy_cfg);
467	if (IS_ERR(isp->psy)) {
468		ret = PTR_ERR(isp->psy);
469		goto fail1;
470	}
471
472	/*
473	 * REVISIT: using work in order to allow the usb notifications to be
474	 * made atomically in the future.
475	 */
476	INIT_WORK(&isp->work, isp1704_charger_work);
477
478	isp->nb.notifier_call = isp1704_notifier_call;
479
480	ret = usb_register_notifier(isp->phy, &isp->nb);
481	if (ret)
482		goto fail2;
483
484	dev_info(isp->dev, "registered with product id %s\n", isp->model);
485
486	/*
487	 * Taking over the D+ pullup.
488	 *
489	 * FIXME: The device will be disconnected if it was already
490	 * enumerated. The charger driver should be always loaded before any
491	 * gadget is loaded.
492	 */
493	if (isp->phy->otg->gadget)
494		usb_gadget_disconnect(isp->phy->otg->gadget);
495
496	if (isp->phy->last_event == USB_EVENT_NONE)
497		isp1704_charger_set_power(isp, 0);
498
499	/* Detect charger if VBUS is valid (the cable was already plugged). */
500	if (isp->phy->last_event == USB_EVENT_VBUS &&
501			!isp->phy->otg->default_a)
502		schedule_work(&isp->work);
503
504	return 0;
505fail2:
506	power_supply_unregister(isp->psy);
507fail1:
508	isp1704_charger_set_power(isp, 0);
509fail0:
510	dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
511
512	return ret;
513}
514
515static int isp1704_charger_remove(struct platform_device *pdev)
516{
517	struct isp1704_charger *isp = platform_get_drvdata(pdev);
518
519	usb_unregister_notifier(isp->phy, &isp->nb);
520	power_supply_unregister(isp->psy);
521	isp1704_charger_set_power(isp, 0);
522
523	return 0;
524}
525
526#ifdef CONFIG_OF
527static const struct of_device_id omap_isp1704_of_match[] = {
528	{ .compatible = "nxp,isp1704", },
529	{},
530};
531MODULE_DEVICE_TABLE(of, omap_isp1704_of_match);
532#endif
533
534static struct platform_driver isp1704_charger_driver = {
535	.driver = {
536		.name = "isp1704_charger",
537		.of_match_table = of_match_ptr(omap_isp1704_of_match),
538	},
539	.probe = isp1704_charger_probe,
540	.remove = isp1704_charger_remove,
541};
542
543module_platform_driver(isp1704_charger_driver);
544
545MODULE_ALIAS("platform:isp1704_charger");
546MODULE_AUTHOR("Nokia Corporation");
547MODULE_DESCRIPTION("ISP170x USB Charger driver");
548MODULE_LICENSE("GPL");
549