xref: /linux/drivers/regulator/max8973-regulator.c (revision 7255fcc80d4b525cc10cfaaf7f485830d4ed2000)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * max8973-regulator.c -- Maxim max8973A
4  *
5  * Regulator driver for MAXIM 8973A DC-DC step-down switching regulator.
6  *
7  * Copyright (c) 2012, NVIDIA Corporation.
8  *
9  * Author: Laxman Dewangan <ldewangan@nvidia.com>
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/err.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/regulator/driver.h>
20 #include <linux/regulator/machine.h>
21 #include <linux/regulator/max8973-regulator.h>
22 #include <linux/regulator/of_regulator.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/i2c.h>
25 #include <linux/slab.h>
26 #include <linux/regmap.h>
27 #include <linux/thermal.h>
28 #include <linux/irq.h>
29 #include <linux/interrupt.h>
30 
31 /* Register definitions */
32 #define MAX8973_VOUT					0x0
33 #define MAX8973_VOUT_DVS				0x1
34 #define MAX8973_CONTROL1				0x2
35 #define MAX8973_CONTROL2				0x3
36 #define MAX8973_CHIPID1					0x4
37 #define MAX8973_CHIPID2					0x5
38 
39 #define MAX8973_MAX_VOUT_REG				2
40 
41 /* MAX8973_VOUT */
42 #define MAX8973_VOUT_ENABLE				BIT(7)
43 #define MAX8973_VOUT_MASK				0x7F
44 
45 /* MAX8973_VOUT_DVS */
46 #define MAX8973_DVS_VOUT_MASK				0x7F
47 
48 /* MAX8973_CONTROL1 */
49 #define MAX8973_SNS_ENABLE				BIT(7)
50 #define MAX8973_FPWM_EN_M				BIT(6)
51 #define MAX8973_NFSR_ENABLE				BIT(5)
52 #define MAX8973_AD_ENABLE				BIT(4)
53 #define MAX8973_BIAS_ENABLE				BIT(3)
54 #define MAX8973_FREQSHIFT_9PER				BIT(2)
55 
56 #define MAX8973_RAMP_12mV_PER_US			0x0
57 #define MAX8973_RAMP_25mV_PER_US			0x1
58 #define MAX8973_RAMP_50mV_PER_US			0x2
59 #define MAX8973_RAMP_200mV_PER_US			0x3
60 #define MAX8973_RAMP_MASK				0x3
61 
62 /* MAX8973_CONTROL2 */
63 #define MAX8973_WDTMR_ENABLE				BIT(6)
64 #define MAX8973_DISCH_ENBABLE				BIT(5)
65 #define MAX8973_FT_ENABLE				BIT(4)
66 #define MAX77621_T_JUNCTION_120				BIT(7)
67 
68 #define MAX8973_CKKADV_TRIP_MASK			0xC
69 #define MAX8973_CKKADV_TRIP_DISABLE			0xC
70 #define MAX8973_CKKADV_TRIP_75mV_PER_US			0x0
71 #define MAX8973_CKKADV_TRIP_150mV_PER_US		0x4
72 #define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS	0x8
73 #define MAX8973_CONTROL_CLKADV_TRIP_MASK		0x00030000
74 
75 #define MAX8973_INDUCTOR_MIN_30_PER			0x0
76 #define MAX8973_INDUCTOR_NOMINAL			0x1
77 #define MAX8973_INDUCTOR_PLUS_30_PER			0x2
78 #define MAX8973_INDUCTOR_PLUS_60_PER			0x3
79 #define MAX8973_CONTROL_INDUCTOR_VALUE_MASK		0x00300000
80 
81 #define MAX8973_MIN_VOLATGE				606250
82 #define MAX8973_MAX_VOLATGE				1400000
83 #define MAX8973_VOLATGE_STEP				6250
84 #define MAX8973_BUCK_N_VOLTAGE				0x80
85 
86 #define MAX77621_CHIPID_TJINT_S				BIT(0)
87 
88 #define MAX77621_NORMAL_OPERATING_TEMP			100000
89 #define MAX77621_TJINT_WARNING_TEMP_120			120000
90 #define MAX77621_TJINT_WARNING_TEMP_140			140000
91 
92 enum device_id {
93 	MAX8973,
94 	MAX77621
95 };
96 
97 /* Maxim 8973 chip information */
98 struct max8973_chip {
99 	struct device *dev;
100 	struct regulator_desc desc;
101 	struct regmap *regmap;
102 	bool enable_external_control;
103 	struct gpio_desc *dvs_gpiod;
104 	int lru_index[MAX8973_MAX_VOUT_REG];
105 	int curr_vout_val[MAX8973_MAX_VOUT_REG];
106 	int curr_vout_reg;
107 	int curr_gpio_val;
108 	struct regulator_ops ops;
109 	enum device_id id;
110 	int junction_temp_warning;
111 	int irq;
112 	struct thermal_zone_device *tz_device;
113 };
114 
115 /*
116  * find_voltage_set_register: Find new voltage configuration register (VOUT).
117  * The finding of the new VOUT register will be based on the LRU mechanism.
118  * Each VOUT register will have different voltage configured . This
119  * Function will look if any of the VOUT register have requested voltage set
120  * or not.
121  *     - If it is already there then it will make that register as most
122  *       recently used and return as found so that caller need not to set
123  *       the VOUT register but need to set the proper gpios to select this
124  *       VOUT register.
125  *     - If requested voltage is not found then it will use the least
126  *       recently mechanism to get new VOUT register for new configuration
127  *       and will return not_found so that caller need to set new VOUT
128  *       register and then gpios (both).
129  */
130 static bool find_voltage_set_register(struct max8973_chip *tps,
131 		int req_vsel, int *vout_reg, int *gpio_val)
132 {
133 	int i;
134 	bool found = false;
135 	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
136 	int found_index = MAX8973_MAX_VOUT_REG - 1;
137 
138 	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
139 		if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
140 			new_vout_reg = tps->lru_index[i];
141 			found_index = i;
142 			found = true;
143 			goto update_lru_index;
144 		}
145 	}
146 
147 update_lru_index:
148 	for (i = found_index; i > 0; i--)
149 		tps->lru_index[i] = tps->lru_index[i - 1];
150 
151 	tps->lru_index[0] = new_vout_reg;
152 	*gpio_val = new_vout_reg;
153 	*vout_reg = MAX8973_VOUT + new_vout_reg;
154 	return found;
155 }
156 
157 static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
158 {
159 	struct max8973_chip *max = rdev_get_drvdata(rdev);
160 	unsigned int data;
161 	int ret;
162 
163 	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
164 	if (ret < 0) {
165 		dev_err(max->dev, "register %d read failed, err = %d\n",
166 			max->curr_vout_reg, ret);
167 		return ret;
168 	}
169 	return data & MAX8973_VOUT_MASK;
170 }
171 
172 static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
173 	     unsigned vsel)
174 {
175 	struct max8973_chip *max = rdev_get_drvdata(rdev);
176 	int ret;
177 	bool found = false;
178 	int vout_reg = max->curr_vout_reg;
179 	int gpio_val = max->curr_gpio_val;
180 
181 	/*
182 	 * If gpios are available to select the VOUT register then least
183 	 * recently used register for new configuration.
184 	 */
185 	if (max->dvs_gpiod)
186 		found = find_voltage_set_register(max, vsel,
187 					&vout_reg, &gpio_val);
188 
189 	if (!found) {
190 		ret = regmap_update_bits(max->regmap, vout_reg,
191 					MAX8973_VOUT_MASK, vsel);
192 		if (ret < 0) {
193 			dev_err(max->dev, "register %d update failed, err %d\n",
194 				 vout_reg, ret);
195 			return ret;
196 		}
197 		max->curr_vout_reg = vout_reg;
198 		max->curr_vout_val[gpio_val] = vsel;
199 	}
200 
201 	/* Select proper VOUT register vio gpios */
202 	if (max->dvs_gpiod) {
203 		gpiod_set_value_cansleep(max->dvs_gpiod, gpio_val & 0x1);
204 		max->curr_gpio_val = gpio_val;
205 	}
206 	return 0;
207 }
208 
209 static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
210 {
211 	struct max8973_chip *max = rdev_get_drvdata(rdev);
212 	int ret;
213 	int pwm;
214 
215 	/* Enable force PWM mode in FAST mode only. */
216 	switch (mode) {
217 	case REGULATOR_MODE_FAST:
218 		pwm = MAX8973_FPWM_EN_M;
219 		break;
220 
221 	case REGULATOR_MODE_NORMAL:
222 		pwm = 0;
223 		break;
224 
225 	default:
226 		return -EINVAL;
227 	}
228 
229 	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
230 				MAX8973_FPWM_EN_M, pwm);
231 	if (ret < 0)
232 		dev_err(max->dev, "register %d update failed, err %d\n",
233 				MAX8973_CONTROL1, ret);
234 	return ret;
235 }
236 
237 static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
238 {
239 	struct max8973_chip *max = rdev_get_drvdata(rdev);
240 	unsigned int data;
241 	int ret;
242 
243 	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
244 	if (ret < 0) {
245 		dev_err(max->dev, "register %d read failed, err %d\n",
246 				MAX8973_CONTROL1, ret);
247 		return ret;
248 	}
249 	return (data & MAX8973_FPWM_EN_M) ?
250 		REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
251 }
252 
253 static int max8973_set_current_limit(struct regulator_dev *rdev,
254 		int min_ua, int max_ua)
255 {
256 	struct max8973_chip *max = rdev_get_drvdata(rdev);
257 	unsigned int val;
258 	int ret;
259 
260 	if (max_ua <= 9000000)
261 		val = MAX8973_CKKADV_TRIP_75mV_PER_US;
262 	else if (max_ua <= 12000000)
263 		val = MAX8973_CKKADV_TRIP_150mV_PER_US;
264 	else
265 		val = MAX8973_CKKADV_TRIP_DISABLE;
266 
267 	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL2,
268 			MAX8973_CKKADV_TRIP_MASK, val);
269 	if (ret < 0) {
270 		dev_err(max->dev, "register %d update failed: %d\n",
271 				MAX8973_CONTROL2, ret);
272 		return ret;
273 	}
274 	return 0;
275 }
276 
277 static int max8973_get_current_limit(struct regulator_dev *rdev)
278 {
279 	struct max8973_chip *max = rdev_get_drvdata(rdev);
280 	unsigned int control2;
281 	int ret;
282 
283 	ret = regmap_read(max->regmap, MAX8973_CONTROL2, &control2);
284 	if (ret < 0) {
285 		dev_err(max->dev, "register %d read failed: %d\n",
286 				MAX8973_CONTROL2, ret);
287 		return ret;
288 	}
289 	switch (control2 & MAX8973_CKKADV_TRIP_MASK) {
290 	case MAX8973_CKKADV_TRIP_DISABLE:
291 		return 15000000;
292 	case MAX8973_CKKADV_TRIP_150mV_PER_US:
293 		return 12000000;
294 	case MAX8973_CKKADV_TRIP_75mV_PER_US:
295 		return 9000000;
296 	default:
297 		break;
298 	}
299 	return 9000000;
300 }
301 
302 static const unsigned int max8973_buck_ramp_table[] = {
303 	12000, 25000, 50000, 200000
304 };
305 
306 static const struct regulator_ops max8973_dcdc_ops = {
307 	.get_voltage_sel	= max8973_dcdc_get_voltage_sel,
308 	.set_voltage_sel	= max8973_dcdc_set_voltage_sel,
309 	.list_voltage		= regulator_list_voltage_linear,
310 	.set_mode		= max8973_dcdc_set_mode,
311 	.get_mode		= max8973_dcdc_get_mode,
312 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
313 	.set_ramp_delay		= regulator_set_ramp_delay_regmap,
314 };
315 
316 static int max8973_init_dcdc(struct max8973_chip *max,
317 			     struct max8973_regulator_platform_data *pdata)
318 {
319 	int ret;
320 	uint8_t	control1 = 0;
321 	uint8_t control2 = 0;
322 	unsigned int data;
323 
324 	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
325 	if (ret < 0) {
326 		dev_err(max->dev, "register %d read failed, err = %d",
327 				MAX8973_CONTROL1, ret);
328 		return ret;
329 	}
330 	control1 = data & MAX8973_RAMP_MASK;
331 	switch (control1) {
332 	case MAX8973_RAMP_12mV_PER_US:
333 		max->desc.ramp_delay = 12000;
334 		break;
335 	case MAX8973_RAMP_25mV_PER_US:
336 		max->desc.ramp_delay = 25000;
337 		break;
338 	case MAX8973_RAMP_50mV_PER_US:
339 		max->desc.ramp_delay = 50000;
340 		break;
341 	case MAX8973_RAMP_200mV_PER_US:
342 		max->desc.ramp_delay = 200000;
343 		break;
344 	}
345 
346 	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
347 		control1 |= MAX8973_SNS_ENABLE;
348 
349 	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
350 		control1 |= MAX8973_NFSR_ENABLE;
351 
352 	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
353 		control1 |= MAX8973_AD_ENABLE;
354 
355 	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE) {
356 		control1 |= MAX8973_BIAS_ENABLE;
357 		max->desc.enable_time = 20;
358 	} else {
359 		max->desc.enable_time = 240;
360 	}
361 
362 	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
363 		control1 |= MAX8973_FREQSHIFT_9PER;
364 
365 	if ((pdata->junction_temp_warning == MAX77621_TJINT_WARNING_TEMP_120) &&
366 	    (max->id == MAX77621))
367 		control2 |= MAX77621_T_JUNCTION_120;
368 
369 	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
370 		control2 |= MAX8973_DISCH_ENBABLE;
371 
372 	/*  Clock advance trip configuration */
373 	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
374 	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
375 		control2 |= MAX8973_CKKADV_TRIP_DISABLE;
376 		break;
377 
378 	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
379 		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US;
380 		break;
381 
382 	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
383 		control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US;
384 		break;
385 
386 	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
387 		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
388 		break;
389 	}
390 
391 	/* Configure inductor value */
392 	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
393 	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
394 		control2 |= MAX8973_INDUCTOR_NOMINAL;
395 		break;
396 
397 	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
398 		control2 |= MAX8973_INDUCTOR_MIN_30_PER;
399 		break;
400 
401 	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
402 		control2 |= MAX8973_INDUCTOR_PLUS_30_PER;
403 		break;
404 
405 	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
406 		control2 |= MAX8973_INDUCTOR_PLUS_60_PER;
407 		break;
408 	}
409 
410 	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
411 	if (ret < 0) {
412 		dev_err(max->dev, "register %d write failed, err = %d",
413 				MAX8973_CONTROL1, ret);
414 		return ret;
415 	}
416 
417 	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
418 	if (ret < 0) {
419 		dev_err(max->dev, "register %d write failed, err = %d",
420 				MAX8973_CONTROL2, ret);
421 		return ret;
422 	}
423 
424 	/* If external control is enabled then disable EN bit */
425 	if (max->enable_external_control && (max->id == MAX8973)) {
426 		ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
427 						MAX8973_VOUT_ENABLE, 0);
428 		if (ret < 0)
429 			dev_err(max->dev, "register %d update failed, err = %d",
430 				MAX8973_VOUT, ret);
431 	}
432 	return ret;
433 }
434 
435 static int max8973_thermal_read_temp(struct thermal_zone_device *tz, int *temp)
436 {
437 	struct max8973_chip *mchip = thermal_zone_device_priv(tz);
438 	unsigned int val;
439 	int ret;
440 
441 	ret = regmap_read(mchip->regmap, MAX8973_CHIPID1, &val);
442 	if (ret < 0) {
443 		dev_err(mchip->dev, "Failed to read register CHIPID1, %d", ret);
444 		return ret;
445 	}
446 
447 	/* +1 degC to trigger cool device */
448 	if (val & MAX77621_CHIPID_TJINT_S)
449 		*temp = mchip->junction_temp_warning + 1000;
450 	else
451 		*temp = MAX77621_NORMAL_OPERATING_TEMP;
452 
453 	return 0;
454 }
455 
456 static irqreturn_t max8973_thermal_irq(int irq, void *data)
457 {
458 	struct max8973_chip *mchip = data;
459 
460 	thermal_zone_device_update(mchip->tz_device,
461 				   THERMAL_EVENT_UNSPECIFIED);
462 
463 	return IRQ_HANDLED;
464 }
465 
466 static const struct thermal_zone_device_ops max77621_tz_ops = {
467 	.get_temp = max8973_thermal_read_temp,
468 };
469 
470 static int max8973_thermal_init(struct max8973_chip *mchip)
471 {
472 	struct thermal_zone_device *tzd;
473 	struct irq_data *irq_data;
474 	unsigned long irq_flags = 0;
475 	int ret;
476 
477 	if (mchip->id != MAX77621)
478 		return 0;
479 
480 	tzd = devm_thermal_of_zone_register(mchip->dev, 0, mchip,
481 					    &max77621_tz_ops);
482 	if (IS_ERR(tzd)) {
483 		ret = PTR_ERR(tzd);
484 		dev_err(mchip->dev, "Failed to register thermal sensor: %d\n",
485 			ret);
486 		return ret;
487 	}
488 
489 	if (mchip->irq <= 0)
490 		return 0;
491 
492 	irq_data = irq_get_irq_data(mchip->irq);
493 	if (irq_data)
494 		irq_flags = irqd_get_trigger_type(irq_data);
495 
496 	ret = devm_request_threaded_irq(mchip->dev, mchip->irq, NULL,
497 					max8973_thermal_irq,
498 					IRQF_ONESHOT | IRQF_SHARED | irq_flags,
499 					dev_name(mchip->dev), mchip);
500 	if (ret < 0) {
501 		dev_err(mchip->dev, "Failed to request irq %d, %d\n",
502 			mchip->irq, ret);
503 		return ret;
504 	}
505 
506 	return 0;
507 }
508 
509 static const struct regmap_config max8973_regmap_config = {
510 	.reg_bits		= 8,
511 	.val_bits		= 8,
512 	.max_register		= MAX8973_CHIPID2,
513 	.cache_type		= REGCACHE_RBTREE,
514 };
515 
516 static struct max8973_regulator_platform_data *max8973_parse_dt(
517 		struct device *dev)
518 {
519 	struct max8973_regulator_platform_data *pdata;
520 	struct device_node *np = dev->of_node;
521 	int ret;
522 	u32 pval;
523 	bool etr_enable;
524 	bool etr_sensitivity_high;
525 
526 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
527 	if (!pdata)
528 		return NULL;
529 
530 	pdata->enable_ext_control = of_property_read_bool(np,
531 						"maxim,externally-enable");
532 
533 	ret = of_property_read_u32(np, "maxim,dvs-default-state", &pval);
534 	if (!ret)
535 		pdata->dvs_def_state = pval;
536 
537 	if (of_property_read_bool(np, "maxim,enable-remote-sense"))
538 		pdata->control_flags  |= MAX8973_CONTROL_REMOTE_SENSE_ENABLE;
539 
540 	if (of_property_read_bool(np, "maxim,enable-falling-slew-rate"))
541 		pdata->control_flags  |=
542 				MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE;
543 
544 	if (of_property_read_bool(np, "maxim,enable-active-discharge"))
545 		pdata->control_flags  |=
546 				MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE;
547 
548 	if (of_property_read_bool(np, "maxim,enable-frequency-shift"))
549 		pdata->control_flags  |= MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE;
550 
551 	if (of_property_read_bool(np, "maxim,enable-bias-control"))
552 		pdata->control_flags  |= MAX8973_CONTROL_BIAS_ENABLE;
553 
554 	etr_enable = of_property_read_bool(np, "maxim,enable-etr");
555 	etr_sensitivity_high = of_property_read_bool(np,
556 				"maxim,enable-high-etr-sensitivity");
557 	if (etr_sensitivity_high)
558 		etr_enable = true;
559 
560 	if (etr_enable) {
561 		if (etr_sensitivity_high)
562 			pdata->control_flags |=
563 				MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US;
564 		else
565 			pdata->control_flags |=
566 				MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US;
567 	} else {
568 		pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED;
569 	}
570 
571 	pdata->junction_temp_warning = MAX77621_TJINT_WARNING_TEMP_140;
572 	ret = of_property_read_u32(np, "junction-warn-millicelsius", &pval);
573 	if (!ret && (pval <= MAX77621_TJINT_WARNING_TEMP_120))
574 		pdata->junction_temp_warning = MAX77621_TJINT_WARNING_TEMP_120;
575 
576 	return pdata;
577 }
578 
579 static const struct of_device_id of_max8973_match_tbl[] = {
580 	{ .compatible = "maxim,max8973", .data = (void *)MAX8973, },
581 	{ .compatible = "maxim,max77621", .data = (void *)MAX77621, },
582 	{ },
583 };
584 MODULE_DEVICE_TABLE(of, of_max8973_match_tbl);
585 
586 static int max8973_probe(struct i2c_client *client)
587 {
588 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
589 	struct max8973_regulator_platform_data *pdata;
590 	struct regulator_init_data *ridata;
591 	struct regulator_config config = { };
592 	struct regulator_dev *rdev;
593 	struct max8973_chip *max;
594 	bool pdata_from_dt = false;
595 	unsigned int chip_id;
596 	struct gpio_desc *gpiod;
597 	enum gpiod_flags gflags;
598 	int ret;
599 
600 	pdata = dev_get_platdata(&client->dev);
601 
602 	if (!pdata && client->dev.of_node) {
603 		pdata = max8973_parse_dt(&client->dev);
604 		pdata_from_dt = true;
605 	}
606 
607 	if (!pdata) {
608 		dev_err(&client->dev, "No Platform data");
609 		return -EIO;
610 	}
611 
612 	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
613 	if (!max)
614 		return -ENOMEM;
615 
616 	max->dvs_gpiod = devm_gpiod_get_optional(&client->dev, "maxim,dvs",
617 			 (pdata->dvs_def_state) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW);
618 	if (IS_ERR(max->dvs_gpiod))
619 		return dev_err_probe(&client->dev, PTR_ERR(max->dvs_gpiod),
620 				     "failed to obtain dvs gpio\n");
621 	gpiod_set_consumer_name(max->dvs_gpiod, "max8973-dvs");
622 
623 	max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
624 	if (IS_ERR(max->regmap)) {
625 		ret = PTR_ERR(max->regmap);
626 		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
627 		return ret;
628 	}
629 
630 	if (client->dev.of_node) {
631 		const struct of_device_id *match;
632 
633 		match = of_match_device(of_match_ptr(of_max8973_match_tbl),
634 				&client->dev);
635 		if (!match)
636 			return -ENODATA;
637 		max->id = (u32)((uintptr_t)match->data);
638 	} else {
639 		max->id = id->driver_data;
640 	}
641 
642 	ret = regmap_read(max->regmap, MAX8973_CHIPID1, &chip_id);
643 	if (ret < 0) {
644 		dev_err(&client->dev, "register CHIPID1 read failed, %d", ret);
645 		return ret;
646 	}
647 
648 	dev_info(&client->dev, "CHIP-ID OTP: 0x%02x ID_M: 0x%02x\n",
649 			(chip_id >> 4) & 0xF, (chip_id >> 1) & 0x7);
650 
651 	i2c_set_clientdata(client, max);
652 	max->ops = max8973_dcdc_ops;
653 	max->dev = &client->dev;
654 	max->desc.name = id->name;
655 	max->desc.id = 0;
656 	max->desc.ops = &max->ops;
657 	max->desc.type = REGULATOR_VOLTAGE;
658 	max->desc.owner = THIS_MODULE;
659 	max->desc.min_uV = MAX8973_MIN_VOLATGE;
660 	max->desc.uV_step = MAX8973_VOLATGE_STEP;
661 	max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
662 	max->desc.ramp_reg = MAX8973_CONTROL1;
663 	max->desc.ramp_mask = MAX8973_RAMP_MASK;
664 	max->desc.ramp_delay_table = max8973_buck_ramp_table;
665 	max->desc.n_ramp_values = ARRAY_SIZE(max8973_buck_ramp_table);
666 
667 	max->enable_external_control = pdata->enable_ext_control;
668 	max->curr_gpio_val = pdata->dvs_def_state;
669 	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
670 	max->junction_temp_warning = pdata->junction_temp_warning;
671 
672 	max->lru_index[0] = max->curr_vout_reg;
673 
674 	if (max->dvs_gpiod) {
675 		int i;
676 
677 		/*
678 		 * Initialize the lru index with vout_reg id
679 		 * The index 0 will be most recently used and
680 		 * set with the max->curr_vout_reg */
681 		for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
682 			max->lru_index[i] = i;
683 		max->lru_index[0] = max->curr_vout_reg;
684 		max->lru_index[max->curr_vout_reg] = 0;
685 	} else {
686 		/*
687 		 * If there is no DVS GPIO, the VOUT register
688 		 * address is fixed.
689 		 */
690 		max->ops.set_voltage_sel = regulator_set_voltage_sel_regmap;
691 		max->ops.get_voltage_sel = regulator_get_voltage_sel_regmap;
692 		max->desc.vsel_reg = max->curr_vout_reg;
693 		max->desc.vsel_mask = MAX8973_VOUT_MASK;
694 	}
695 
696 	if (pdata_from_dt)
697 		pdata->reg_init_data = of_get_regulator_init_data(&client->dev,
698 					client->dev.of_node, &max->desc);
699 
700 	ridata = pdata->reg_init_data;
701 	switch (max->id) {
702 	case MAX8973:
703 		if (!pdata->enable_ext_control) {
704 			max->desc.enable_reg = MAX8973_VOUT;
705 			max->desc.enable_mask = MAX8973_VOUT_ENABLE;
706 			max->ops.enable = regulator_enable_regmap;
707 			max->ops.disable = regulator_disable_regmap;
708 			max->ops.is_enabled = regulator_is_enabled_regmap;
709 			break;
710 		}
711 
712 		if (ridata && (ridata->constraints.always_on ||
713 			       ridata->constraints.boot_on))
714 			gflags = GPIOD_OUT_HIGH;
715 		else
716 			gflags = GPIOD_OUT_LOW;
717 		gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
718 		gpiod = devm_gpiod_get_optional(&client->dev,
719 						"maxim,enable",
720 						gflags);
721 		if (IS_ERR(gpiod))
722 			return PTR_ERR(gpiod);
723 		if (gpiod) {
724 			config.ena_gpiod = gpiod;
725 			max->enable_external_control = true;
726 		}
727 
728 		break;
729 
730 	case MAX77621:
731 		/*
732 		 * We do not let the core switch this regulator on/off,
733 		 * we just leave it on.
734 		 */
735 		gpiod = devm_gpiod_get_optional(&client->dev,
736 						"maxim,enable",
737 						GPIOD_OUT_HIGH);
738 		if (IS_ERR(gpiod))
739 			return PTR_ERR(gpiod);
740 		if (gpiod)
741 			max->enable_external_control = true;
742 
743 		max->desc.enable_reg = MAX8973_VOUT;
744 		max->desc.enable_mask = MAX8973_VOUT_ENABLE;
745 		max->ops.enable = regulator_enable_regmap;
746 		max->ops.disable = regulator_disable_regmap;
747 		max->ops.is_enabled = regulator_is_enabled_regmap;
748 		max->ops.set_current_limit = max8973_set_current_limit;
749 		max->ops.get_current_limit = max8973_get_current_limit;
750 		break;
751 	default:
752 		break;
753 	}
754 
755 	ret = max8973_init_dcdc(max, pdata);
756 	if (ret < 0) {
757 		dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
758 		return ret;
759 	}
760 
761 	config.dev = &client->dev;
762 	config.init_data = pdata->reg_init_data;
763 	config.driver_data = max;
764 	config.of_node = client->dev.of_node;
765 	config.regmap = max->regmap;
766 
767 	/*
768 	 * Register the regulators
769 	 * Turn the GPIO descriptor over to the regulator core for
770 	 * lifecycle management if we pass an ena_gpiod.
771 	 */
772 	if (config.ena_gpiod)
773 		devm_gpiod_unhinge(&client->dev, config.ena_gpiod);
774 	rdev = devm_regulator_register(&client->dev, &max->desc, &config);
775 	if (IS_ERR(rdev)) {
776 		ret = PTR_ERR(rdev);
777 		dev_err(max->dev, "regulator register failed, err %d\n", ret);
778 		return ret;
779 	}
780 
781 	max8973_thermal_init(max);
782 	return 0;
783 }
784 
785 static const struct i2c_device_id max8973_id[] = {
786 	{.name = "max8973", .driver_data = MAX8973},
787 	{.name = "max77621", .driver_data = MAX77621},
788 	{},
789 };
790 MODULE_DEVICE_TABLE(i2c, max8973_id);
791 
792 static struct i2c_driver max8973_i2c_driver = {
793 	.driver = {
794 		.name = "max8973",
795 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
796 		.of_match_table = of_max8973_match_tbl,
797 	},
798 	.probe = max8973_probe,
799 	.id_table = max8973_id,
800 };
801 
802 static int __init max8973_init(void)
803 {
804 	return i2c_add_driver(&max8973_i2c_driver);
805 }
806 subsys_initcall(max8973_init);
807 
808 static void __exit max8973_cleanup(void)
809 {
810 	i2c_del_driver(&max8973_i2c_driver);
811 }
812 module_exit(max8973_cleanup);
813 
814 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
815 MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
816 MODULE_LICENSE("GPL v2");
817