1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ISP1704 USB Charger Detection driver
4 *
5 * Copyright (C) 2010 Nokia Corporation
6 * Copyright (C) 2012 - 2013 Pali Rohár <pali@kernel.org>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/device.h>
15 #include <linux/sysfs.h>
16 #include <linux/platform_device.h>
17 #include <linux/power_supply.h>
18 #include <linux/delay.h>
19 #include <linux/of.h>
20
21 #include <linux/gpio/consumer.h>
22 #include <linux/usb/otg.h>
23 #include <linux/usb/ulpi.h>
24 #include <linux/usb/ch9.h>
25 #include <linux/usb/gadget.h>
26
27 /* Vendor specific Power Control register */
28 #define ISP1704_PWR_CTRL 0x3d
29 #define ISP1704_PWR_CTRL_SWCTRL (1 << 0)
30 #define ISP1704_PWR_CTRL_DET_COMP (1 << 1)
31 #define ISP1704_PWR_CTRL_BVALID_RISE (1 << 2)
32 #define ISP1704_PWR_CTRL_BVALID_FALL (1 << 3)
33 #define ISP1704_PWR_CTRL_DP_WKPU_EN (1 << 4)
34 #define ISP1704_PWR_CTRL_VDAT_DET (1 << 5)
35 #define ISP1704_PWR_CTRL_DPVSRC_EN (1 << 6)
36 #define ISP1704_PWR_CTRL_HWDETECT (1 << 7)
37
38 #define NXP_VENDOR_ID 0x04cc
39
40 static u16 isp170x_id[] = {
41 0x1704,
42 0x1707,
43 };
44
45 struct isp1704_charger {
46 struct device *dev;
47 struct power_supply *psy;
48 struct power_supply_desc psy_desc;
49 struct gpio_desc *enable_gpio;
50 struct usb_phy *phy;
51 struct notifier_block nb;
52 struct work_struct work;
53
54 /* properties */
55 char model[8];
56 unsigned present:1;
57 unsigned online:1;
58 unsigned current_max;
59 };
60
isp1704_read(struct isp1704_charger * isp,u32 reg)61 static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
62 {
63 return usb_phy_io_read(isp->phy, reg);
64 }
65
isp1704_write(struct isp1704_charger * isp,u32 reg,u32 val)66 static inline int isp1704_write(struct isp1704_charger *isp, u32 reg, u32 val)
67 {
68 return usb_phy_io_write(isp->phy, val, reg);
69 }
70
isp1704_charger_set_power(struct isp1704_charger * isp,bool on)71 static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
72 {
73 gpiod_set_value(isp->enable_gpio, on);
74 }
75
76 /*
77 * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
78 * chargers).
79 *
80 * REVISIT: The method is defined in Battery Charging Specification and is
81 * applicable to any ULPI transceiver. Nothing isp170x specific here.
82 */
isp1704_charger_type(struct isp1704_charger * isp)83 static inline int isp1704_charger_type(struct isp1704_charger *isp)
84 {
85 u8 reg;
86 u8 func_ctrl;
87 u8 otg_ctrl;
88 int type = POWER_SUPPLY_TYPE_USB_DCP;
89
90 func_ctrl = isp1704_read(isp, ULPI_FUNC_CTRL);
91 otg_ctrl = isp1704_read(isp, ULPI_OTG_CTRL);
92
93 /* disable pulldowns */
94 reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
95 isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), reg);
96
97 /* full speed */
98 isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
99 ULPI_FUNC_CTRL_XCVRSEL_MASK);
100 isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL),
101 ULPI_FUNC_CTRL_FULL_SPEED);
102
103 /* Enable strong pull-up on DP (1.5K) and reset */
104 reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
105 isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), reg);
106 usleep_range(1000, 2000);
107
108 reg = isp1704_read(isp, ULPI_DEBUG);
109 if ((reg & 3) != 3)
110 type = POWER_SUPPLY_TYPE_USB_CDP;
111
112 /* recover original state */
113 isp1704_write(isp, ULPI_FUNC_CTRL, func_ctrl);
114 isp1704_write(isp, ULPI_OTG_CTRL, otg_ctrl);
115
116 return type;
117 }
118
119 /*
120 * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
121 * is actually a dedicated charger, the following steps need to be taken.
122 */
isp1704_charger_verify(struct isp1704_charger * isp)123 static inline int isp1704_charger_verify(struct isp1704_charger *isp)
124 {
125 int ret = 0;
126 u8 r;
127
128 /* Reset the transceiver */
129 r = isp1704_read(isp, ULPI_FUNC_CTRL);
130 r |= ULPI_FUNC_CTRL_RESET;
131 isp1704_write(isp, ULPI_FUNC_CTRL, r);
132 usleep_range(1000, 2000);
133
134 /* Set normal mode */
135 r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
136 isp1704_write(isp, ULPI_FUNC_CTRL, r);
137
138 /* Clear the DP and DM pull-down bits */
139 r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
140 isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), r);
141
142 /* Enable strong pull-up on DP (1.5K) and reset */
143 r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
144 isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), r);
145 usleep_range(1000, 2000);
146
147 /* Read the line state */
148 if (!isp1704_read(isp, ULPI_DEBUG)) {
149 /* Disable strong pull-up on DP (1.5K) */
150 isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
151 ULPI_FUNC_CTRL_TERMSELECT);
152 return 1;
153 }
154
155 /* Is it a charger or PS/2 connection */
156
157 /* Enable weak pull-up resistor on DP */
158 isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
159 ISP1704_PWR_CTRL_DP_WKPU_EN);
160
161 /* Disable strong pull-up on DP (1.5K) */
162 isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
163 ULPI_FUNC_CTRL_TERMSELECT);
164
165 /* Enable weak pull-down resistor on DM */
166 isp1704_write(isp, ULPI_SET(ULPI_OTG_CTRL),
167 ULPI_OTG_CTRL_DM_PULLDOWN);
168
169 /* It's a charger if the line states are clear */
170 if (!(isp1704_read(isp, ULPI_DEBUG)))
171 ret = 1;
172
173 /* Disable weak pull-up resistor on DP */
174 isp1704_write(isp, ULPI_CLR(ISP1704_PWR_CTRL),
175 ISP1704_PWR_CTRL_DP_WKPU_EN);
176
177 return ret;
178 }
179
isp1704_charger_detect(struct isp1704_charger * isp)180 static inline int isp1704_charger_detect(struct isp1704_charger *isp)
181 {
182 unsigned long timeout;
183 u8 pwr_ctrl;
184 int ret = 0;
185
186 pwr_ctrl = isp1704_read(isp, ISP1704_PWR_CTRL);
187
188 /* set SW control bit in PWR_CTRL register */
189 isp1704_write(isp, ISP1704_PWR_CTRL,
190 ISP1704_PWR_CTRL_SWCTRL);
191
192 /* enable manual charger detection */
193 isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
194 ISP1704_PWR_CTRL_SWCTRL
195 | ISP1704_PWR_CTRL_DPVSRC_EN);
196 usleep_range(1000, 2000);
197
198 timeout = jiffies + msecs_to_jiffies(300);
199 do {
200 /* Check if there is a charger */
201 if (isp1704_read(isp, ISP1704_PWR_CTRL)
202 & ISP1704_PWR_CTRL_VDAT_DET) {
203 ret = isp1704_charger_verify(isp);
204 break;
205 }
206 } while (!time_after(jiffies, timeout) && isp->online);
207
208 /* recover original state */
209 isp1704_write(isp, ISP1704_PWR_CTRL, pwr_ctrl);
210
211 return ret;
212 }
213
isp1704_charger_detect_dcp(struct isp1704_charger * isp)214 static inline int isp1704_charger_detect_dcp(struct isp1704_charger *isp)
215 {
216 if (isp1704_charger_detect(isp) &&
217 isp1704_charger_type(isp) == POWER_SUPPLY_TYPE_USB_DCP)
218 return true;
219 else
220 return false;
221 }
222
isp1704_charger_work(struct work_struct * data)223 static void isp1704_charger_work(struct work_struct *data)
224 {
225 struct isp1704_charger *isp =
226 container_of(data, struct isp1704_charger, work);
227 static DEFINE_MUTEX(lock);
228
229 mutex_lock(&lock);
230
231 switch (isp->phy->last_event) {
232 case USB_EVENT_VBUS:
233 /* do not call wall charger detection more times */
234 if (!isp->present) {
235 isp->online = true;
236 isp->present = 1;
237 isp1704_charger_set_power(isp, 1);
238
239 /* detect wall charger */
240 if (isp1704_charger_detect_dcp(isp)) {
241 isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_DCP;
242 isp->current_max = 1800;
243 } else {
244 isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
245 isp->current_max = 500;
246 }
247
248 /* enable data pullups */
249 if (isp->phy->otg->gadget)
250 usb_gadget_connect(isp->phy->otg->gadget);
251 }
252
253 if (isp->psy_desc.type != POWER_SUPPLY_TYPE_USB_DCP) {
254 /*
255 * Only 500mA here or high speed chirp
256 * handshaking may break
257 */
258 if (isp->current_max > 500)
259 isp->current_max = 500;
260
261 if (isp->current_max > 100)
262 isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_CDP;
263 }
264 break;
265 case USB_EVENT_NONE:
266 isp->online = false;
267 isp->present = 0;
268 isp->current_max = 0;
269 isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
270
271 /*
272 * Disable data pullups. We need to prevent the controller from
273 * enumerating.
274 *
275 * FIXME: This is here to allow charger detection with Host/HUB
276 * chargers. The pullups may be enabled elsewhere, so this can
277 * not be the final solution.
278 */
279 if (isp->phy->otg->gadget)
280 usb_gadget_disconnect(isp->phy->otg->gadget);
281
282 isp1704_charger_set_power(isp, 0);
283 break;
284 default:
285 goto out;
286 }
287
288 power_supply_changed(isp->psy);
289 out:
290 mutex_unlock(&lock);
291 }
292
isp1704_notifier_call(struct notifier_block * nb,unsigned long val,void * v)293 static int isp1704_notifier_call(struct notifier_block *nb,
294 unsigned long val, void *v)
295 {
296 struct isp1704_charger *isp =
297 container_of(nb, struct isp1704_charger, nb);
298
299 schedule_work(&isp->work);
300
301 return NOTIFY_OK;
302 }
303
isp1704_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)304 static int isp1704_charger_get_property(struct power_supply *psy,
305 enum power_supply_property psp,
306 union power_supply_propval *val)
307 {
308 struct isp1704_charger *isp = power_supply_get_drvdata(psy);
309
310 switch (psp) {
311 case POWER_SUPPLY_PROP_PRESENT:
312 val->intval = isp->present;
313 break;
314 case POWER_SUPPLY_PROP_ONLINE:
315 val->intval = isp->online;
316 break;
317 case POWER_SUPPLY_PROP_CURRENT_MAX:
318 val->intval = isp->current_max;
319 break;
320 case POWER_SUPPLY_PROP_MODEL_NAME:
321 val->strval = isp->model;
322 break;
323 case POWER_SUPPLY_PROP_MANUFACTURER:
324 val->strval = "NXP";
325 break;
326 default:
327 return -EINVAL;
328 }
329 return 0;
330 }
331
332 static enum power_supply_property power_props[] = {
333 POWER_SUPPLY_PROP_PRESENT,
334 POWER_SUPPLY_PROP_ONLINE,
335 POWER_SUPPLY_PROP_CURRENT_MAX,
336 POWER_SUPPLY_PROP_MODEL_NAME,
337 POWER_SUPPLY_PROP_MANUFACTURER,
338 };
339
isp1704_test_ulpi(struct isp1704_charger * isp)340 static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
341 {
342 int vendor;
343 int product;
344 int i;
345 int ret;
346
347 /* Test ULPI interface */
348 ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
349 if (ret < 0)
350 return ret;
351
352 ret = isp1704_read(isp, ULPI_SCRATCH);
353 if (ret < 0)
354 return ret;
355
356 if (ret != 0xaa)
357 return -ENODEV;
358
359 /* Verify the product and vendor id matches */
360 vendor = isp1704_read(isp, ULPI_VENDOR_ID_LOW);
361 vendor |= isp1704_read(isp, ULPI_VENDOR_ID_HIGH) << 8;
362 if (vendor != NXP_VENDOR_ID)
363 return -ENODEV;
364
365 product = isp1704_read(isp, ULPI_PRODUCT_ID_LOW);
366 product |= isp1704_read(isp, ULPI_PRODUCT_ID_HIGH) << 8;
367
368 for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
369 if (product == isp170x_id[i]) {
370 sprintf(isp->model, "isp%x", product);
371 return product;
372 }
373 }
374
375 dev_err(isp->dev, "product id %x not matching known ids", product);
376
377 return -ENODEV;
378 }
379
isp1704_charger_probe(struct platform_device * pdev)380 static int isp1704_charger_probe(struct platform_device *pdev)
381 {
382 struct isp1704_charger *isp;
383 int ret = -ENODEV;
384 struct power_supply_config psy_cfg = {};
385
386 isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL);
387 if (!isp)
388 return -ENOMEM;
389
390 isp->enable_gpio = devm_gpiod_get(&pdev->dev, "nxp,enable",
391 GPIOD_OUT_HIGH);
392 if (IS_ERR(isp->enable_gpio)) {
393 ret = PTR_ERR(isp->enable_gpio);
394 dev_err(&pdev->dev, "Could not get reset gpio: %d\n", ret);
395 return ret;
396 }
397
398 if (pdev->dev.of_node)
399 isp->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0);
400 else
401 isp->phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
402
403 if (IS_ERR(isp->phy)) {
404 ret = PTR_ERR(isp->phy);
405 dev_err(&pdev->dev, "usb_get_phy failed\n");
406 goto fail0;
407 }
408
409 isp->dev = &pdev->dev;
410 platform_set_drvdata(pdev, isp);
411
412 isp1704_charger_set_power(isp, 1);
413
414 ret = isp1704_test_ulpi(isp);
415 if (ret < 0) {
416 dev_err(&pdev->dev, "isp1704_test_ulpi failed\n");
417 goto fail1;
418 }
419
420 isp->psy_desc.name = "isp1704";
421 isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
422 isp->psy_desc.properties = power_props;
423 isp->psy_desc.num_properties = ARRAY_SIZE(power_props);
424 isp->psy_desc.get_property = isp1704_charger_get_property;
425
426 psy_cfg.drv_data = isp;
427
428 isp->psy = power_supply_register(isp->dev, &isp->psy_desc, &psy_cfg);
429 if (IS_ERR(isp->psy)) {
430 ret = PTR_ERR(isp->psy);
431 dev_err(&pdev->dev, "power_supply_register failed\n");
432 goto fail1;
433 }
434
435 /*
436 * REVISIT: using work in order to allow the usb notifications to be
437 * made atomically in the future.
438 */
439 INIT_WORK(&isp->work, isp1704_charger_work);
440
441 isp->nb.notifier_call = isp1704_notifier_call;
442
443 ret = usb_register_notifier(isp->phy, &isp->nb);
444 if (ret) {
445 dev_err(&pdev->dev, "usb_register_notifier failed\n");
446 goto fail2;
447 }
448
449 dev_info(isp->dev, "registered with product id %s\n", isp->model);
450
451 /*
452 * Taking over the D+ pullup.
453 *
454 * FIXME: The device will be disconnected if it was already
455 * enumerated. The charger driver should be always loaded before any
456 * gadget is loaded.
457 */
458 if (isp->phy->otg->gadget)
459 usb_gadget_disconnect(isp->phy->otg->gadget);
460
461 if (isp->phy->last_event == USB_EVENT_NONE)
462 isp1704_charger_set_power(isp, 0);
463
464 /* Detect charger if VBUS is valid (the cable was already plugged). */
465 if (isp->phy->last_event == USB_EVENT_VBUS &&
466 !isp->phy->otg->default_a)
467 schedule_work(&isp->work);
468
469 return 0;
470 fail2:
471 power_supply_unregister(isp->psy);
472 fail1:
473 isp1704_charger_set_power(isp, 0);
474 fail0:
475 dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
476
477 return ret;
478 }
479
isp1704_charger_remove(struct platform_device * pdev)480 static void isp1704_charger_remove(struct platform_device *pdev)
481 {
482 struct isp1704_charger *isp = platform_get_drvdata(pdev);
483
484 usb_unregister_notifier(isp->phy, &isp->nb);
485 power_supply_unregister(isp->psy);
486 isp1704_charger_set_power(isp, 0);
487 }
488
489 #ifdef CONFIG_OF
490 static const struct of_device_id omap_isp1704_of_match[] = {
491 { .compatible = "nxp,isp1704", },
492 { .compatible = "nxp,isp1707", },
493 {},
494 };
495 MODULE_DEVICE_TABLE(of, omap_isp1704_of_match);
496 #endif
497
498 static struct platform_driver isp1704_charger_driver = {
499 .driver = {
500 .name = "isp1704_charger",
501 .of_match_table = of_match_ptr(omap_isp1704_of_match),
502 },
503 .probe = isp1704_charger_probe,
504 .remove = isp1704_charger_remove,
505 };
506
507 module_platform_driver(isp1704_charger_driver);
508
509 MODULE_ALIAS("platform:isp1704_charger");
510 MODULE_AUTHOR("Nokia Corporation");
511 MODULE_DESCRIPTION("ISP170x USB Charger driver");
512 MODULE_LICENSE("GPL");
513