1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for UCS1002 Programmable USB Port Power Controller
4  *
5  * Copyright (C) 2019 Zodiac Inflight Innovations
6  */
7 #include <linux/bits.h>
8 #include <linux/freezer.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/kthread.h>
14 #include <linux/device.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_irq.h>
18 #include <linux/power_supply.h>
19 #include <linux/regmap.h>
20 #include <linux/regulator/driver.h>
21 #include <linux/regulator/of_regulator.h>
22 
23 /* UCS1002 Registers */
24 #define UCS1002_REG_CURRENT_MEASUREMENT	0x00
25 
26 /*
27  * The Total Accumulated Charge registers store the total accumulated
28  * charge delivered from the VS source to a portable device. The total
29  * value is calculated using four registers, from 01h to 04h. The bit
30  * weighting of the registers is given in mA/hrs.
31  */
32 #define UCS1002_REG_TOTAL_ACC_CHARGE	0x01
33 
34 /* Other Status Register */
35 #define UCS1002_REG_OTHER_STATUS	0x0f
36 #  define F_ADET_PIN			BIT(4)
37 #  define F_CHG_ACT			BIT(3)
38 
39 /* Interrupt Status */
40 #define UCS1002_REG_INTERRUPT_STATUS	0x10
41 #  define F_DISCHARGE_ERR		BIT(6)
42 #  define F_RESET			BIT(5)
43 #  define F_MIN_KEEP_OUT		BIT(4)
44 #  define F_TSD				BIT(3)
45 #  define F_OVER_VOLT			BIT(2)
46 #  define F_BACK_VOLT			BIT(1)
47 #  define F_OVER_ILIM			BIT(0)
48 
49 /* Pin Status Register */
50 #define UCS1002_REG_PIN_STATUS		0x14
51 #  define UCS1002_PWR_STATE_MASK	0x03
52 #  define F_PWR_EN_PIN			BIT(6)
53 #  define F_M2_PIN			BIT(5)
54 #  define F_M1_PIN			BIT(4)
55 #  define F_EM_EN_PIN			BIT(3)
56 #  define F_SEL_PIN			BIT(2)
57 #  define F_ACTIVE_MODE_MASK		GENMASK(5, 3)
58 #  define F_ACTIVE_MODE_PASSTHROUGH	F_M2_PIN
59 #  define F_ACTIVE_MODE_DEDICATED	F_EM_EN_PIN
60 #  define F_ACTIVE_MODE_BC12_DCP	(F_M2_PIN | F_EM_EN_PIN)
61 #  define F_ACTIVE_MODE_BC12_SDP	F_M1_PIN
62 #  define F_ACTIVE_MODE_BC12_CDP	(F_M1_PIN | F_M2_PIN | F_EM_EN_PIN)
63 
64 /* General Configuration Register */
65 #define UCS1002_REG_GENERAL_CFG		0x15
66 #  define F_RATION_EN			BIT(3)
67 
68 /* Emulation Configuration Register */
69 #define UCS1002_REG_EMU_CFG		0x16
70 
71 /* Switch Configuration Register */
72 #define UCS1002_REG_SWITCH_CFG		0x17
73 #  define F_PIN_IGNORE			BIT(7)
74 #  define F_EM_EN_SET			BIT(5)
75 #  define F_M2_SET			BIT(4)
76 #  define F_M1_SET			BIT(3)
77 #  define F_S0_SET			BIT(2)
78 #  define F_PWR_EN_SET			BIT(1)
79 #  define F_LATCH_SET			BIT(0)
80 #  define V_SET_ACTIVE_MODE_MASK	GENMASK(5, 3)
81 #  define V_SET_ACTIVE_MODE_PASSTHROUGH	F_M2_SET
82 #  define V_SET_ACTIVE_MODE_DEDICATED	F_EM_EN_SET
83 #  define V_SET_ACTIVE_MODE_BC12_DCP	(F_M2_SET | F_EM_EN_SET)
84 #  define V_SET_ACTIVE_MODE_BC12_SDP	F_M1_SET
85 #  define V_SET_ACTIVE_MODE_BC12_CDP	(F_M1_SET | F_M2_SET | F_EM_EN_SET)
86 
87 /* Current Limit Register */
88 #define UCS1002_REG_ILIMIT		0x19
89 #  define UCS1002_ILIM_SW_MASK		GENMASK(3, 0)
90 
91 /* Product ID */
92 #define UCS1002_REG_PRODUCT_ID		0xfd
93 #  define UCS1002_PRODUCT_ID		0x4e
94 
95 /* Manufacture name */
96 #define UCS1002_MANUFACTURER		"SMSC"
97 
98 struct ucs1002_info {
99 	struct power_supply *charger;
100 	struct i2c_client *client;
101 	struct regmap *regmap;
102 	struct regulator_desc *regulator_descriptor;
103 	bool present;
104 };
105 
106 static enum power_supply_property ucs1002_props[] = {
107 	POWER_SUPPLY_PROP_ONLINE,
108 	POWER_SUPPLY_PROP_CHARGE_NOW,
109 	POWER_SUPPLY_PROP_CURRENT_NOW,
110 	POWER_SUPPLY_PROP_CURRENT_MAX,
111 	POWER_SUPPLY_PROP_PRESENT, /* the presence of PED */
112 	POWER_SUPPLY_PROP_MANUFACTURER,
113 	POWER_SUPPLY_PROP_USB_TYPE,
114 	POWER_SUPPLY_PROP_HEALTH,
115 };
116 
117 static int ucs1002_get_online(struct ucs1002_info *info,
118 			      union power_supply_propval *val)
119 {
120 	unsigned int reg;
121 	int ret;
122 
123 	ret = regmap_read(info->regmap, UCS1002_REG_OTHER_STATUS, &reg);
124 	if (ret)
125 		return ret;
126 
127 	val->intval = !!(reg & F_CHG_ACT);
128 
129 	return 0;
130 }
131 
132 static int ucs1002_get_charge(struct ucs1002_info *info,
133 			      union power_supply_propval *val)
134 {
135 	/*
136 	 * To fit within 32 bits some values are rounded (uA/h)
137 	 *
138 	 * For Total Accumulated Charge Middle Low Byte register, addr
139 	 * 03h, byte 2
140 	 *
141 	 *   B0: 0.01084 mA/h rounded to 11 uA/h
142 	 *   B1: 0.02169 mA/h rounded to 22 uA/h
143 	 *   B2: 0.04340 mA/h rounded to 43 uA/h
144 	 *   B3: 0.08676 mA/h rounded to 87 uA/h
145 	 *   B4: 0.17350 mA/h rounded to 173 uÁ/h
146 	 *
147 	 * For Total Accumulated Charge Low Byte register, addr 04h,
148 	 * byte 3
149 	 *
150 	 *   B6: 0.00271 mA/h rounded to 3 uA/h
151 	 *   B7: 0.005422 mA/h rounded to 5 uA/h
152 	 */
153 	static const int bit_weights_uAh[BITS_PER_TYPE(u32)] = {
154 		/*
155 		 * Bit corresponding to low byte (offset 0x04)
156 		 * B0 B1 B2 B3 B4 B5 B6 B7
157 		 */
158 		0, 0, 0, 0, 0, 0, 3, 5,
159 		/*
160 		 * Bit corresponding to middle low byte (offset 0x03)
161 		 * B0 B1 B2 B3 B4 B5 B6 B7
162 		 */
163 		11, 22, 43, 87, 173, 347, 694, 1388,
164 		/*
165 		 * Bit corresponding to middle high byte (offset 0x02)
166 		 * B0 B1 B2 B3 B4 B5 B6 B7
167 		 */
168 		2776, 5552, 11105, 22210, 44420, 88840, 177700, 355400,
169 		/*
170 		 * Bit corresponding to high byte (offset 0x01)
171 		 * B0 B1 B2 B3 B4 B5 B6 B7
172 		 */
173 		710700, 1421000, 2843000, 5685000, 11371000, 22742000,
174 		45484000, 90968000,
175 	};
176 	unsigned long total_acc_charger;
177 	unsigned int reg;
178 	int i, ret;
179 
180 	ret = regmap_bulk_read(info->regmap, UCS1002_REG_TOTAL_ACC_CHARGE,
181 			       &reg, sizeof(u32));
182 	if (ret)
183 		return ret;
184 
185 	total_acc_charger = be32_to_cpu(reg); /* BE as per offsets above */
186 	val->intval = 0;
187 
188 	for_each_set_bit(i, &total_acc_charger, ARRAY_SIZE(bit_weights_uAh))
189 		val->intval += bit_weights_uAh[i];
190 
191 	return 0;
192 }
193 
194 static int ucs1002_get_current(struct ucs1002_info *info,
195 			       union power_supply_propval *val)
196 {
197 	/*
198 	 * The Current Measurement register stores the measured
199 	 * current value delivered to the portable device. The range
200 	 * is from 9.76 mA to 2.5 A.
201 	 */
202 	static const int bit_weights_uA[BITS_PER_TYPE(u8)] = {
203 		9760, 19500, 39000, 78100, 156200, 312300, 624600, 1249300,
204 	};
205 	unsigned long current_measurement;
206 	unsigned int reg;
207 	int i, ret;
208 
209 	ret = regmap_read(info->regmap, UCS1002_REG_CURRENT_MEASUREMENT, &reg);
210 	if (ret)
211 		return ret;
212 
213 	current_measurement = reg;
214 	val->intval = 0;
215 
216 	for_each_set_bit(i, &current_measurement, ARRAY_SIZE(bit_weights_uA))
217 		val->intval += bit_weights_uA[i];
218 
219 	return 0;
220 }
221 
222 /*
223  * The Current Limit register stores the maximum current used by the
224  * port switch. The range is from 500mA to 2.5 A.
225  */
226 static const u32 ucs1002_current_limit_uA[] = {
227 	500000, 900000, 1000000, 1200000, 1500000, 1800000, 2000000, 2500000,
228 };
229 
230 static int ucs1002_get_max_current(struct ucs1002_info *info,
231 				   union power_supply_propval *val)
232 {
233 	unsigned int reg;
234 	int ret;
235 
236 	ret = regmap_read(info->regmap, UCS1002_REG_ILIMIT, &reg);
237 	if (ret)
238 		return ret;
239 
240 	val->intval = ucs1002_current_limit_uA[reg & UCS1002_ILIM_SW_MASK];
241 
242 	return 0;
243 }
244 
245 static int ucs1002_set_max_current(struct ucs1002_info *info, u32 val)
246 {
247 	unsigned int reg;
248 	int ret, idx;
249 
250 	for (idx = 0; idx < ARRAY_SIZE(ucs1002_current_limit_uA); idx++) {
251 		if (val == ucs1002_current_limit_uA[idx])
252 			break;
253 	}
254 
255 	if (idx == ARRAY_SIZE(ucs1002_current_limit_uA))
256 		return -EINVAL;
257 
258 	ret = regmap_write(info->regmap, UCS1002_REG_ILIMIT, idx);
259 	if (ret)
260 		return ret;
261 	/*
262 	 * Any current limit setting exceeding the one set via ILIM
263 	 * pin will be rejected, so we read out freshly changed limit
264 	 * to make sure that it took effect.
265 	 */
266 	ret = regmap_read(info->regmap, UCS1002_REG_ILIMIT, &reg);
267 	if (ret)
268 		return ret;
269 
270 	if (reg != idx)
271 		return -EINVAL;
272 
273 	return 0;
274 }
275 
276 static enum power_supply_usb_type ucs1002_usb_types[] = {
277 	POWER_SUPPLY_USB_TYPE_PD,
278 	POWER_SUPPLY_USB_TYPE_SDP,
279 	POWER_SUPPLY_USB_TYPE_DCP,
280 	POWER_SUPPLY_USB_TYPE_CDP,
281 	POWER_SUPPLY_USB_TYPE_UNKNOWN,
282 };
283 
284 static int ucs1002_set_usb_type(struct ucs1002_info *info, int val)
285 {
286 	unsigned int mode;
287 
288 	if (val < 0 || val >= ARRAY_SIZE(ucs1002_usb_types))
289 		return -EINVAL;
290 
291 	switch (ucs1002_usb_types[val]) {
292 	case POWER_SUPPLY_USB_TYPE_PD:
293 		mode = V_SET_ACTIVE_MODE_DEDICATED;
294 		break;
295 	case POWER_SUPPLY_USB_TYPE_SDP:
296 		mode = V_SET_ACTIVE_MODE_BC12_SDP;
297 		break;
298 	case POWER_SUPPLY_USB_TYPE_DCP:
299 		mode = V_SET_ACTIVE_MODE_BC12_DCP;
300 		break;
301 	case POWER_SUPPLY_USB_TYPE_CDP:
302 		mode = V_SET_ACTIVE_MODE_BC12_CDP;
303 		break;
304 	default:
305 		return -EINVAL;
306 	}
307 
308 	return regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
309 				  V_SET_ACTIVE_MODE_MASK, mode);
310 }
311 
312 static int ucs1002_get_usb_type(struct ucs1002_info *info,
313 				union power_supply_propval *val)
314 {
315 	enum power_supply_usb_type type;
316 	unsigned int reg;
317 	int ret;
318 
319 	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS, &reg);
320 	if (ret)
321 		return ret;
322 
323 	switch (reg & F_ACTIVE_MODE_MASK) {
324 	default:
325 		type = POWER_SUPPLY_USB_TYPE_UNKNOWN;
326 		break;
327 	case F_ACTIVE_MODE_DEDICATED:
328 		type = POWER_SUPPLY_USB_TYPE_PD;
329 		break;
330 	case F_ACTIVE_MODE_BC12_SDP:
331 		type = POWER_SUPPLY_USB_TYPE_SDP;
332 		break;
333 	case F_ACTIVE_MODE_BC12_DCP:
334 		type = POWER_SUPPLY_USB_TYPE_DCP;
335 		break;
336 	case F_ACTIVE_MODE_BC12_CDP:
337 		type = POWER_SUPPLY_USB_TYPE_CDP;
338 		break;
339 	};
340 
341 	val->intval = type;
342 
343 	return 0;
344 }
345 
346 static int ucs1002_get_health(struct ucs1002_info *info,
347 			      union power_supply_propval *val)
348 {
349 	unsigned int reg;
350 	int ret, health;
351 
352 	ret = regmap_read(info->regmap, UCS1002_REG_INTERRUPT_STATUS, &reg);
353 	if (ret)
354 		return ret;
355 
356 	if (reg & F_TSD)
357 		health = POWER_SUPPLY_HEALTH_OVERHEAT;
358 	else if (reg & (F_OVER_VOLT | F_BACK_VOLT))
359 		health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
360 	else if (reg & F_OVER_ILIM)
361 		health = POWER_SUPPLY_HEALTH_OVERCURRENT;
362 	else if (reg & (F_DISCHARGE_ERR | F_MIN_KEEP_OUT))
363 		health = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
364 	else
365 		health = POWER_SUPPLY_HEALTH_GOOD;
366 
367 	val->intval = health;
368 
369 	return 0;
370 }
371 
372 static int ucs1002_get_property(struct power_supply *psy,
373 				enum power_supply_property psp,
374 				union power_supply_propval *val)
375 {
376 	struct ucs1002_info *info = power_supply_get_drvdata(psy);
377 
378 	switch (psp) {
379 	case POWER_SUPPLY_PROP_ONLINE:
380 		return ucs1002_get_online(info, val);
381 	case POWER_SUPPLY_PROP_CHARGE_NOW:
382 		return ucs1002_get_charge(info, val);
383 	case POWER_SUPPLY_PROP_CURRENT_NOW:
384 		return ucs1002_get_current(info, val);
385 	case POWER_SUPPLY_PROP_CURRENT_MAX:
386 		return ucs1002_get_max_current(info, val);
387 	case POWER_SUPPLY_PROP_USB_TYPE:
388 		return ucs1002_get_usb_type(info, val);
389 	case POWER_SUPPLY_PROP_HEALTH:
390 		return ucs1002_get_health(info, val);
391 	case POWER_SUPPLY_PROP_PRESENT:
392 		val->intval = info->present;
393 		return 0;
394 	case POWER_SUPPLY_PROP_MANUFACTURER:
395 		val->strval = UCS1002_MANUFACTURER;
396 		return 0;
397 	default:
398 		return -EINVAL;
399 	}
400 }
401 
402 static int ucs1002_set_property(struct power_supply *psy,
403 				enum power_supply_property psp,
404 				const union power_supply_propval *val)
405 {
406 	struct ucs1002_info *info = power_supply_get_drvdata(psy);
407 
408 	switch (psp) {
409 	case POWER_SUPPLY_PROP_CURRENT_MAX:
410 		return ucs1002_set_max_current(info, val->intval);
411 	case POWER_SUPPLY_PROP_USB_TYPE:
412 		return ucs1002_set_usb_type(info, val->intval);
413 	default:
414 		return -EINVAL;
415 	}
416 }
417 
418 static int ucs1002_property_is_writeable(struct power_supply *psy,
419 					 enum power_supply_property psp)
420 {
421 	switch (psp) {
422 	case POWER_SUPPLY_PROP_CURRENT_MAX:
423 	case POWER_SUPPLY_PROP_USB_TYPE:
424 		return true;
425 	default:
426 		return false;
427 	}
428 }
429 
430 static const struct power_supply_desc ucs1002_charger_desc = {
431 	.name			= "ucs1002",
432 	.type			= POWER_SUPPLY_TYPE_USB,
433 	.usb_types		= ucs1002_usb_types,
434 	.num_usb_types		= ARRAY_SIZE(ucs1002_usb_types),
435 	.get_property		= ucs1002_get_property,
436 	.set_property		= ucs1002_set_property,
437 	.property_is_writeable	= ucs1002_property_is_writeable,
438 	.properties		= ucs1002_props,
439 	.num_properties		= ARRAY_SIZE(ucs1002_props),
440 };
441 
442 static irqreturn_t ucs1002_charger_irq(int irq, void *data)
443 {
444 	int ret, regval;
445 	bool present;
446 	struct ucs1002_info *info = data;
447 
448 	present = info->present;
449 
450 	ret = regmap_read(info->regmap, UCS1002_REG_OTHER_STATUS, &regval);
451 	if (ret)
452 		return IRQ_HANDLED;
453 
454 	/* update attached status */
455 	info->present = regval & F_ADET_PIN;
456 
457 	/* notify the change */
458 	if (present != info->present)
459 		power_supply_changed(info->charger);
460 
461 	return IRQ_HANDLED;
462 }
463 
464 static irqreturn_t ucs1002_alert_irq(int irq, void *data)
465 {
466 	struct ucs1002_info *info = data;
467 
468 	power_supply_changed(info->charger);
469 
470 	return IRQ_HANDLED;
471 }
472 
473 static const struct regulator_ops ucs1002_regulator_ops = {
474 	.is_enabled	= regulator_is_enabled_regmap,
475 	.enable		= regulator_enable_regmap,
476 	.disable	= regulator_disable_regmap,
477 };
478 
479 static const struct regulator_desc ucs1002_regulator_descriptor = {
480 	.name		= "ucs1002-vbus",
481 	.ops		= &ucs1002_regulator_ops,
482 	.type		= REGULATOR_VOLTAGE,
483 	.owner		= THIS_MODULE,
484 	.enable_reg	= UCS1002_REG_SWITCH_CFG,
485 	.enable_mask	= F_PWR_EN_SET,
486 	.enable_val	= F_PWR_EN_SET,
487 	.fixed_uV	= 5000000,
488 	.n_voltages	= 1,
489 };
490 
491 static int ucs1002_probe(struct i2c_client *client,
492 			 const struct i2c_device_id *dev_id)
493 {
494 	struct device *dev = &client->dev;
495 	struct power_supply_config charger_config = {};
496 	const struct regmap_config regmap_config = {
497 		.reg_bits = 8,
498 		.val_bits = 8,
499 	};
500 	struct regulator_config regulator_config = {};
501 	int irq_a_det, irq_alert, ret;
502 	struct regulator_dev *rdev;
503 	struct ucs1002_info *info;
504 	unsigned int regval;
505 
506 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
507 	if (!info)
508 		return -ENOMEM;
509 
510 	info->regmap = devm_regmap_init_i2c(client, &regmap_config);
511 	ret = PTR_ERR_OR_ZERO(info->regmap);
512 	if (ret) {
513 		dev_err(dev, "Regmap initialization failed: %d\n", ret);
514 		return ret;
515 	}
516 
517 	info->client = client;
518 
519 	irq_a_det = of_irq_get_byname(dev->of_node, "a_det");
520 	irq_alert = of_irq_get_byname(dev->of_node, "alert");
521 
522 	charger_config.of_node = dev->of_node;
523 	charger_config.drv_data = info;
524 
525 	ret = regmap_read(info->regmap, UCS1002_REG_PRODUCT_ID, &regval);
526 	if (ret) {
527 		dev_err(dev, "Failed to read product ID: %d\n", ret);
528 		return ret;
529 	}
530 
531 	if (regval != UCS1002_PRODUCT_ID) {
532 		dev_err(dev,
533 			"Product ID does not match (0x%02x != 0x%02x)\n",
534 			regval, UCS1002_PRODUCT_ID);
535 		return -ENODEV;
536 	}
537 
538 	/* Enable charge rationing by default */
539 	ret = regmap_update_bits(info->regmap, UCS1002_REG_GENERAL_CFG,
540 				 F_RATION_EN, F_RATION_EN);
541 	if (ret) {
542 		dev_err(dev, "Failed to read general config: %d\n", ret);
543 		return ret;
544 	}
545 
546 	/*
547 	 * Ignore the M1, M2, PWR_EN, and EM_EN pin states. Set active
548 	 * mode selection to BC1.2 CDP.
549 	 */
550 	ret = regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
551 				 V_SET_ACTIVE_MODE_MASK | F_PIN_IGNORE,
552 				 V_SET_ACTIVE_MODE_BC12_CDP | F_PIN_IGNORE);
553 	if (ret) {
554 		dev_err(dev, "Failed to configure default mode: %d\n", ret);
555 		return ret;
556 	}
557 	/*
558 	 * Be safe and set initial current limit to 500mA
559 	 */
560 	ret = ucs1002_set_max_current(info, 500000);
561 	if (ret) {
562 		dev_err(dev, "Failed to set max current default: %d\n", ret);
563 		return ret;
564 	}
565 
566 	info->charger = devm_power_supply_register(dev, &ucs1002_charger_desc,
567 						   &charger_config);
568 	ret = PTR_ERR_OR_ZERO(info->charger);
569 	if (ret) {
570 		dev_err(dev, "Failed to register power supply: %d\n", ret);
571 		return ret;
572 	}
573 
574 	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS, &regval);
575 	if (ret) {
576 		dev_err(dev, "Failed to read pin status: %d\n", ret);
577 		return ret;
578 	}
579 
580 	info->regulator_descriptor =
581 		devm_kmemdup(dev, &ucs1002_regulator_descriptor,
582 			     sizeof(ucs1002_regulator_descriptor),
583 			     GFP_KERNEL);
584 	if (!info->regulator_descriptor)
585 		return -ENOMEM;
586 
587 	info->regulator_descriptor->enable_is_inverted = !(regval & F_SEL_PIN);
588 
589 	regulator_config.dev = dev;
590 	regulator_config.of_node = dev->of_node;
591 	regulator_config.regmap = info->regmap;
592 
593 	rdev = devm_regulator_register(dev, info->regulator_descriptor,
594 				       &regulator_config);
595 	ret = PTR_ERR_OR_ZERO(rdev);
596 	if (ret) {
597 		dev_err(dev, "Failed to register VBUS regulator: %d\n", ret);
598 		return ret;
599 	}
600 
601 	if (irq_a_det > 0) {
602 		ret = devm_request_threaded_irq(dev, irq_a_det, NULL,
603 						ucs1002_charger_irq,
604 						IRQF_ONESHOT,
605 						"ucs1002-a_det", info);
606 		if (ret) {
607 			dev_err(dev, "Failed to request A_DET threaded irq: %d\n",
608 				ret);
609 			return ret;
610 		}
611 	}
612 
613 	if (irq_alert > 0) {
614 		ret = devm_request_threaded_irq(dev, irq_alert, NULL,
615 						ucs1002_alert_irq,
616 						IRQF_ONESHOT,
617 						"ucs1002-alert", info);
618 		if (ret) {
619 			dev_err(dev, "Failed to request ALERT threaded irq: %d\n",
620 				ret);
621 			return ret;
622 		}
623 	}
624 
625 	return 0;
626 }
627 
628 static const struct of_device_id ucs1002_of_match[] = {
629 	{ .compatible = "microchip,ucs1002", },
630 	{ /* sentinel */ },
631 };
632 MODULE_DEVICE_TABLE(of, ucs1002_of_match);
633 
634 static struct i2c_driver ucs1002_driver = {
635 	.driver = {
636 		   .name = "ucs1002",
637 		   .of_match_table = ucs1002_of_match,
638 	},
639 	.probe = ucs1002_probe,
640 };
641 module_i2c_driver(ucs1002_driver);
642 
643 MODULE_DESCRIPTION("Microchip UCS1002 Programmable USB Port Power Controller");
644 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
645 MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
646 MODULE_LICENSE("GPL");
647