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 
54 static u16 isp170x_id[] = {
55 	0x1704,
56 	0x1707,
57 };
58 
59 struct 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 
74 static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
75 {
76 	return usb_phy_io_read(isp->phy, reg);
77 }
78 
79 static inline int isp1704_write(struct isp1704_charger *isp, u32 reg, u32 val)
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  */
88 static 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  */
105 static 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  */
145 static 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 
202 static 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 
236 static 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 
245 static 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);
311 out:
312 	mutex_unlock(&lock);
313 }
314 
315 static 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 
326 static 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 
354 static 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 
362 static 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 
402 static 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 			dev_err(&pdev->dev, "missing DT GPIO nxp,enable-gpio\n");
416 			return gpio;
417 		}
418 
419 		pdata = devm_kzalloc(&pdev->dev,
420 			sizeof(struct isp1704_charger_data), GFP_KERNEL);
421 		pdata->enable_gpio = gpio;
422 
423 		dev_info(&pdev->dev, "init gpio %d\n", pdata->enable_gpio);
424 
425 		ret = devm_gpio_request_one(&pdev->dev, pdata->enable_gpio,
426 					GPIOF_OUT_INIT_HIGH, "isp1704_reset");
427 		if (ret) {
428 			dev_err(&pdev->dev, "gpio request failed\n");
429 			goto fail0;
430 		}
431 	}
432 
433 	if (!pdata) {
434 		dev_err(&pdev->dev, "missing platform data!\n");
435 		return -ENODEV;
436 	}
437 
438 
439 	isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL);
440 	if (!isp)
441 		return -ENOMEM;
442 
443 	if (np)
444 		isp->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0);
445 	else
446 		isp->phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
447 
448 	if (IS_ERR(isp->phy)) {
449 		ret = PTR_ERR(isp->phy);
450 		dev_err(&pdev->dev, "usb_get_phy failed\n");
451 		goto fail0;
452 	}
453 
454 	isp->dev = &pdev->dev;
455 	platform_set_drvdata(pdev, isp);
456 
457 	isp1704_charger_set_power(isp, 1);
458 
459 	ret = isp1704_test_ulpi(isp);
460 	if (ret < 0) {
461 		dev_err(&pdev->dev, "isp1704_test_ulpi failed\n");
462 		goto fail1;
463 	}
464 
465 	isp->psy_desc.name		= "isp1704";
466 	isp->psy_desc.type		= POWER_SUPPLY_TYPE_USB;
467 	isp->psy_desc.properties	= power_props;
468 	isp->psy_desc.num_properties	= ARRAY_SIZE(power_props);
469 	isp->psy_desc.get_property	= isp1704_charger_get_property;
470 
471 	psy_cfg.drv_data		= isp;
472 
473 	isp->psy = power_supply_register(isp->dev, &isp->psy_desc, &psy_cfg);
474 	if (IS_ERR(isp->psy)) {
475 		ret = PTR_ERR(isp->psy);
476 		dev_err(&pdev->dev, "power_supply_register failed\n");
477 		goto fail1;
478 	}
479 
480 	/*
481 	 * REVISIT: using work in order to allow the usb notifications to be
482 	 * made atomically in the future.
483 	 */
484 	INIT_WORK(&isp->work, isp1704_charger_work);
485 
486 	isp->nb.notifier_call = isp1704_notifier_call;
487 
488 	ret = usb_register_notifier(isp->phy, &isp->nb);
489 	if (ret) {
490 		dev_err(&pdev->dev, "usb_register_notifier failed\n");
491 		goto fail2;
492 	}
493 
494 	dev_info(isp->dev, "registered with product id %s\n", isp->model);
495 
496 	/*
497 	 * Taking over the D+ pullup.
498 	 *
499 	 * FIXME: The device will be disconnected if it was already
500 	 * enumerated. The charger driver should be always loaded before any
501 	 * gadget is loaded.
502 	 */
503 	if (isp->phy->otg->gadget)
504 		usb_gadget_disconnect(isp->phy->otg->gadget);
505 
506 	if (isp->phy->last_event == USB_EVENT_NONE)
507 		isp1704_charger_set_power(isp, 0);
508 
509 	/* Detect charger if VBUS is valid (the cable was already plugged). */
510 	if (isp->phy->last_event == USB_EVENT_VBUS &&
511 			!isp->phy->otg->default_a)
512 		schedule_work(&isp->work);
513 
514 	return 0;
515 fail2:
516 	power_supply_unregister(isp->psy);
517 fail1:
518 	isp1704_charger_set_power(isp, 0);
519 fail0:
520 	dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
521 
522 	return ret;
523 }
524 
525 static int isp1704_charger_remove(struct platform_device *pdev)
526 {
527 	struct isp1704_charger *isp = platform_get_drvdata(pdev);
528 
529 	usb_unregister_notifier(isp->phy, &isp->nb);
530 	power_supply_unregister(isp->psy);
531 	isp1704_charger_set_power(isp, 0);
532 
533 	return 0;
534 }
535 
536 #ifdef CONFIG_OF
537 static const struct of_device_id omap_isp1704_of_match[] = {
538 	{ .compatible = "nxp,isp1704", },
539 	{ .compatible = "nxp,isp1707", },
540 	{},
541 };
542 MODULE_DEVICE_TABLE(of, omap_isp1704_of_match);
543 #endif
544 
545 static struct platform_driver isp1704_charger_driver = {
546 	.driver = {
547 		.name = "isp1704_charger",
548 		.of_match_table = of_match_ptr(omap_isp1704_of_match),
549 	},
550 	.probe = isp1704_charger_probe,
551 	.remove = isp1704_charger_remove,
552 };
553 
554 module_platform_driver(isp1704_charger_driver);
555 
556 MODULE_ALIAS("platform:isp1704_charger");
557 MODULE_AUTHOR("Nokia Corporation");
558 MODULE_DESCRIPTION("ISP170x USB Charger driver");
559 MODULE_LICENSE("GPL");
560