1/*
2 * max8973-regulator.c -- Maxim max8973
3 *
4 * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
5 *
6 * Copyright (c) 2012, NVIDIA Corporation.
7 *
8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation version 2.
13 *
14 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
15 * whether express or implied; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 * 02111-1307, USA
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/init.h>
28#include <linux/err.h>
29#include <linux/of.h>
30#include <linux/of_device.h>
31#include <linux/platform_device.h>
32#include <linux/regulator/driver.h>
33#include <linux/regulator/machine.h>
34#include <linux/regulator/max8973-regulator.h>
35#include <linux/regulator/of_regulator.h>
36#include <linux/gpio.h>
37#include <linux/of_gpio.h>
38#include <linux/i2c.h>
39#include <linux/slab.h>
40#include <linux/regmap.h>
41
42/* Register definitions */
43#define MAX8973_VOUT					0x0
44#define MAX8973_VOUT_DVS				0x1
45#define MAX8973_CONTROL1				0x2
46#define MAX8973_CONTROL2				0x3
47#define MAX8973_CHIPID1					0x4
48#define MAX8973_CHIPID2					0x5
49
50#define MAX8973_MAX_VOUT_REG				2
51
52/* MAX8973_VOUT */
53#define MAX8973_VOUT_ENABLE				BIT(7)
54#define MAX8973_VOUT_MASK				0x7F
55
56/* MAX8973_VOUT_DVS */
57#define MAX8973_DVS_VOUT_MASK				0x7F
58
59/* MAX8973_CONTROL1 */
60#define MAX8973_SNS_ENABLE				BIT(7)
61#define MAX8973_FPWM_EN_M				BIT(6)
62#define MAX8973_NFSR_ENABLE				BIT(5)
63#define MAX8973_AD_ENABLE				BIT(4)
64#define MAX8973_BIAS_ENABLE				BIT(3)
65#define MAX8973_FREQSHIFT_9PER				BIT(2)
66
67#define MAX8973_RAMP_12mV_PER_US			0x0
68#define MAX8973_RAMP_25mV_PER_US			0x1
69#define MAX8973_RAMP_50mV_PER_US			0x2
70#define MAX8973_RAMP_200mV_PER_US			0x3
71#define MAX8973_RAMP_MASK				0x3
72
73/* MAX8973_CONTROL2 */
74#define MAX8973_WDTMR_ENABLE				BIT(6)
75#define MAX8973_DISCH_ENBABLE				BIT(5)
76#define MAX8973_FT_ENABLE				BIT(4)
77
78#define MAX8973_CKKADV_TRIP_MASK			0xC
79#define MAX8973_CKKADV_TRIP_DISABLE			0xC
80#define MAX8973_CKKADV_TRIP_75mV_PER_US			0x0
81#define MAX8973_CKKADV_TRIP_150mV_PER_US		0x4
82#define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS	0x8
83#define MAX8973_CONTROL_CLKADV_TRIP_MASK		0x00030000
84
85#define MAX8973_INDUCTOR_MIN_30_PER			0x0
86#define MAX8973_INDUCTOR_NOMINAL			0x1
87#define MAX8973_INDUCTOR_PLUS_30_PER			0x2
88#define MAX8973_INDUCTOR_PLUS_60_PER			0x3
89#define MAX8973_CONTROL_INDUCTOR_VALUE_MASK		0x00300000
90
91#define MAX8973_MIN_VOLATGE				606250
92#define MAX8973_MAX_VOLATGE				1400000
93#define MAX8973_VOLATGE_STEP				6250
94#define MAX8973_BUCK_N_VOLTAGE				0x80
95
96enum device_id {
97	MAX8973,
98	MAX77621
99};
100
101/* Maxim 8973 chip information */
102struct max8973_chip {
103	struct device *dev;
104	struct regulator_desc desc;
105	struct regmap *regmap;
106	bool enable_external_control;
107	int enable_gpio;
108	int dvs_gpio;
109	int lru_index[MAX8973_MAX_VOUT_REG];
110	int curr_vout_val[MAX8973_MAX_VOUT_REG];
111	int curr_vout_reg;
112	int curr_gpio_val;
113	struct regulator_ops ops;
114	enum device_id id;
115};
116
117/*
118 * find_voltage_set_register: Find new voltage configuration register (VOUT).
119 * The finding of the new VOUT register will be based on the LRU mechanism.
120 * Each VOUT register will have different voltage configured . This
121 * Function will look if any of the VOUT register have requested voltage set
122 * or not.
123 *     - If it is already there then it will make that register as most
124 *       recently used and return as found so that caller need not to set
125 *       the VOUT register but need to set the proper gpios to select this
126 *       VOUT register.
127 *     - If requested voltage is not found then it will use the least
128 *       recently mechanism to get new VOUT register for new configuration
129 *       and will return not_found so that caller need to set new VOUT
130 *       register and then gpios (both).
131 */
132static bool find_voltage_set_register(struct max8973_chip *tps,
133		int req_vsel, int *vout_reg, int *gpio_val)
134{
135	int i;
136	bool found = false;
137	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
138	int found_index = MAX8973_MAX_VOUT_REG - 1;
139
140	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
141		if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
142			new_vout_reg = tps->lru_index[i];
143			found_index = i;
144			found = true;
145			goto update_lru_index;
146		}
147	}
148
149update_lru_index:
150	for (i = found_index; i > 0; i--)
151		tps->lru_index[i] = tps->lru_index[i - 1];
152
153	tps->lru_index[0] = new_vout_reg;
154	*gpio_val = new_vout_reg;
155	*vout_reg = MAX8973_VOUT + new_vout_reg;
156	return found;
157}
158
159static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
160{
161	struct max8973_chip *max = rdev_get_drvdata(rdev);
162	unsigned int data;
163	int ret;
164
165	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
166	if (ret < 0) {
167		dev_err(max->dev, "register %d read failed, err = %d\n",
168			max->curr_vout_reg, ret);
169		return ret;
170	}
171	return data & MAX8973_VOUT_MASK;
172}
173
174static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
175	     unsigned vsel)
176{
177	struct max8973_chip *max = rdev_get_drvdata(rdev);
178	int ret;
179	bool found = false;
180	int vout_reg = max->curr_vout_reg;
181	int gpio_val = max->curr_gpio_val;
182
183	/*
184	 * If gpios are available to select the VOUT register then least
185	 * recently used register for new configuration.
186	 */
187	if (gpio_is_valid(max->dvs_gpio))
188		found = find_voltage_set_register(max, vsel,
189					&vout_reg, &gpio_val);
190
191	if (!found) {
192		ret = regmap_update_bits(max->regmap, vout_reg,
193					MAX8973_VOUT_MASK, vsel);
194		if (ret < 0) {
195			dev_err(max->dev, "register %d update failed, err %d\n",
196				 vout_reg, ret);
197			return ret;
198		}
199		max->curr_vout_reg = vout_reg;
200		max->curr_vout_val[gpio_val] = vsel;
201	}
202
203	/* Select proper VOUT register vio gpios */
204	if (gpio_is_valid(max->dvs_gpio)) {
205		gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
206		max->curr_gpio_val = gpio_val;
207	}
208	return 0;
209}
210
211static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
212{
213	struct max8973_chip *max = rdev_get_drvdata(rdev);
214	int ret;
215	int pwm;
216
217	/* Enable force PWM mode in FAST mode only. */
218	switch (mode) {
219	case REGULATOR_MODE_FAST:
220		pwm = MAX8973_FPWM_EN_M;
221		break;
222
223	case REGULATOR_MODE_NORMAL:
224		pwm = 0;
225		break;
226
227	default:
228		return -EINVAL;
229	}
230
231	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
232				MAX8973_FPWM_EN_M, pwm);
233	if (ret < 0)
234		dev_err(max->dev, "register %d update failed, err %d\n",
235				MAX8973_CONTROL1, ret);
236	return ret;
237}
238
239static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
240{
241	struct max8973_chip *max = rdev_get_drvdata(rdev);
242	unsigned int data;
243	int ret;
244
245	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
246	if (ret < 0) {
247		dev_err(max->dev, "register %d read failed, err %d\n",
248				MAX8973_CONTROL1, ret);
249		return ret;
250	}
251	return (data & MAX8973_FPWM_EN_M) ?
252		REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
253}
254
255static int max8973_set_ramp_delay(struct regulator_dev *rdev,
256		int ramp_delay)
257{
258	struct max8973_chip *max = rdev_get_drvdata(rdev);
259	unsigned int control;
260	int ret;
261	int ret_val;
262
263	/* Set ramp delay */
264	if (ramp_delay < 25000) {
265		control = MAX8973_RAMP_12mV_PER_US;
266		ret_val = 12000;
267	} else if (ramp_delay < 50000) {
268		control = MAX8973_RAMP_25mV_PER_US;
269		ret_val = 25000;
270	} else if (ramp_delay < 200000) {
271		control = MAX8973_RAMP_50mV_PER_US;
272		ret_val = 50000;
273	} else {
274		control = MAX8973_RAMP_200mV_PER_US;
275		ret_val = 200000;
276	}
277
278	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
279			MAX8973_RAMP_MASK, control);
280	if (ret < 0)
281		dev_err(max->dev, "register %d update failed, %d",
282				MAX8973_CONTROL1, ret);
283	return ret;
284}
285
286static int max8973_set_current_limit(struct regulator_dev *rdev,
287		int min_ua, int max_ua)
288{
289	struct max8973_chip *max = rdev_get_drvdata(rdev);
290	unsigned int val;
291	int ret;
292
293	if (max_ua <= 9000000)
294		val = MAX8973_CKKADV_TRIP_75mV_PER_US;
295	else if (max_ua <= 12000000)
296		val = MAX8973_CKKADV_TRIP_150mV_PER_US;
297	else
298		val = MAX8973_CKKADV_TRIP_DISABLE;
299
300	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL2,
301			MAX8973_CKKADV_TRIP_MASK, val);
302	if (ret < 0) {
303		dev_err(max->dev, "register %d update failed: %d\n",
304				MAX8973_CONTROL2, ret);
305		return ret;
306	}
307	return 0;
308}
309
310static int max8973_get_current_limit(struct regulator_dev *rdev)
311{
312	struct max8973_chip *max = rdev_get_drvdata(rdev);
313	unsigned int control2;
314	int ret;
315
316	ret = regmap_read(max->regmap, MAX8973_CONTROL2, &control2);
317	if (ret < 0) {
318		dev_err(max->dev, "register %d read failed: %d\n",
319				MAX8973_CONTROL2, ret);
320		return ret;
321	}
322	switch (control2 & MAX8973_CKKADV_TRIP_MASK) {
323	case MAX8973_CKKADV_TRIP_DISABLE:
324		return 15000000;
325	case MAX8973_CKKADV_TRIP_150mV_PER_US:
326		return 12000000;
327	case MAX8973_CKKADV_TRIP_75mV_PER_US:
328		return 9000000;
329	default:
330		break;
331	}
332	return 9000000;
333}
334
335static const struct regulator_ops max8973_dcdc_ops = {
336	.get_voltage_sel	= max8973_dcdc_get_voltage_sel,
337	.set_voltage_sel	= max8973_dcdc_set_voltage_sel,
338	.list_voltage		= regulator_list_voltage_linear,
339	.set_mode		= max8973_dcdc_set_mode,
340	.get_mode		= max8973_dcdc_get_mode,
341	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
342	.set_ramp_delay		= max8973_set_ramp_delay,
343};
344
345static int max8973_init_dcdc(struct max8973_chip *max,
346			     struct max8973_regulator_platform_data *pdata)
347{
348	int ret;
349	uint8_t	control1 = 0;
350	uint8_t control2 = 0;
351	unsigned int data;
352
353	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
354	if (ret < 0) {
355		dev_err(max->dev, "register %d read failed, err = %d",
356				MAX8973_CONTROL1, ret);
357		return ret;
358	}
359	control1 = data & MAX8973_RAMP_MASK;
360	switch (control1) {
361	case MAX8973_RAMP_12mV_PER_US:
362		max->desc.ramp_delay = 12000;
363		break;
364	case MAX8973_RAMP_25mV_PER_US:
365		max->desc.ramp_delay = 25000;
366		break;
367	case MAX8973_RAMP_50mV_PER_US:
368		max->desc.ramp_delay = 50000;
369		break;
370	case MAX8973_RAMP_200mV_PER_US:
371		max->desc.ramp_delay = 200000;
372		break;
373	}
374
375	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
376		control1 |= MAX8973_SNS_ENABLE;
377
378	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
379		control1 |= MAX8973_NFSR_ENABLE;
380
381	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
382		control1 |= MAX8973_AD_ENABLE;
383
384	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE) {
385		control1 |= MAX8973_BIAS_ENABLE;
386		max->desc.enable_time = 20;
387	} else {
388		max->desc.enable_time = 240;
389	}
390
391	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
392		control1 |= MAX8973_FREQSHIFT_9PER;
393
394	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
395		control2 |= MAX8973_DISCH_ENBABLE;
396
397	/*  Clock advance trip configuration */
398	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
399	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
400		control2 |= MAX8973_CKKADV_TRIP_DISABLE;
401		break;
402
403	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
404		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US;
405		break;
406
407	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
408		control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US;
409		break;
410
411	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
412		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
413		break;
414	}
415
416	/* Configure inductor value */
417	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
418	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
419		control2 |= MAX8973_INDUCTOR_NOMINAL;
420		break;
421
422	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
423		control2 |= MAX8973_INDUCTOR_MIN_30_PER;
424		break;
425
426	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
427		control2 |= MAX8973_INDUCTOR_PLUS_30_PER;
428		break;
429
430	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
431		control2 |= MAX8973_INDUCTOR_PLUS_60_PER;
432		break;
433	}
434
435	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
436	if (ret < 0) {
437		dev_err(max->dev, "register %d write failed, err = %d",
438				MAX8973_CONTROL1, ret);
439		return ret;
440	}
441
442	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
443	if (ret < 0) {
444		dev_err(max->dev, "register %d write failed, err = %d",
445				MAX8973_CONTROL2, ret);
446		return ret;
447	}
448
449	/* If external control is enabled then disable EN bit */
450	if (max->enable_external_control && (max->id == MAX8973)) {
451		ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
452						MAX8973_VOUT_ENABLE, 0);
453		if (ret < 0)
454			dev_err(max->dev, "register %d update failed, err = %d",
455				MAX8973_VOUT, ret);
456	}
457	return ret;
458}
459
460static const struct regmap_config max8973_regmap_config = {
461	.reg_bits		= 8,
462	.val_bits		= 8,
463	.max_register		= MAX8973_CHIPID2,
464	.cache_type		= REGCACHE_RBTREE,
465};
466
467static struct max8973_regulator_platform_data *max8973_parse_dt(
468		struct device *dev)
469{
470	struct max8973_regulator_platform_data *pdata;
471	struct device_node *np = dev->of_node;
472	int ret;
473	u32 pval;
474	bool etr_enable;
475	bool etr_sensitivity_high;
476
477	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
478	if (!pdata)
479		return NULL;
480
481	pdata->enable_ext_control = of_property_read_bool(np,
482						"maxim,externally-enable");
483	pdata->enable_gpio = of_get_named_gpio(np, "maxim,enable-gpio", 0);
484	pdata->dvs_gpio = of_get_named_gpio(np, "maxim,dvs-gpio", 0);
485
486	ret = of_property_read_u32(np, "maxim,dvs-default-state", &pval);
487	if (!ret)
488		pdata->dvs_def_state = pval;
489
490	if (of_property_read_bool(np, "maxim,enable-remote-sense"))
491		pdata->control_flags  |= MAX8973_CONTROL_REMOTE_SENSE_ENABLE;
492
493	if (of_property_read_bool(np, "maxim,enable-falling-slew-rate"))
494		pdata->control_flags  |=
495				MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE;
496
497	if (of_property_read_bool(np, "maxim,enable-active-discharge"))
498		pdata->control_flags  |=
499				MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE;
500
501	if (of_property_read_bool(np, "maxim,enable-frequency-shift"))
502		pdata->control_flags  |= MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE;
503
504	if (of_property_read_bool(np, "maxim,enable-bias-control"))
505		pdata->control_flags  |= MAX8973_CONTROL_BIAS_ENABLE;
506
507	etr_enable = of_property_read_bool(np, "maxim,enable-etr");
508	etr_sensitivity_high = of_property_read_bool(np,
509				"maxim,enable-high-etr-sensitivity");
510	if (etr_sensitivity_high)
511		etr_enable = true;
512
513	if (etr_enable) {
514		if (etr_sensitivity_high)
515			pdata->control_flags |=
516				MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US;
517		else
518			pdata->control_flags |=
519				MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US;
520	} else {
521		pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED;
522	}
523
524	return pdata;
525}
526
527static const struct of_device_id of_max8973_match_tbl[] = {
528	{ .compatible = "maxim,max8973", .data = (void *)MAX8973, },
529	{ .compatible = "maxim,max77621", .data = (void *)MAX77621, },
530	{ },
531};
532MODULE_DEVICE_TABLE(of, of_max8973_match_tbl);
533
534static int max8973_probe(struct i2c_client *client,
535			 const struct i2c_device_id *id)
536{
537	struct max8973_regulator_platform_data *pdata;
538	struct regulator_init_data *ridata;
539	struct regulator_config config = { };
540	struct regulator_dev *rdev;
541	struct max8973_chip *max;
542	bool pdata_from_dt = false;
543	unsigned int chip_id;
544	int ret;
545
546	pdata = dev_get_platdata(&client->dev);
547
548	if (!pdata && client->dev.of_node) {
549		pdata = max8973_parse_dt(&client->dev);
550		pdata_from_dt = true;
551	}
552
553	if (!pdata) {
554		dev_err(&client->dev, "No Platform data");
555		return -EIO;
556	}
557
558	if ((pdata->dvs_gpio == -EPROBE_DEFER) ||
559		(pdata->enable_gpio == -EPROBE_DEFER))
560		return -EPROBE_DEFER;
561
562	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
563	if (!max)
564		return -ENOMEM;
565
566	max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
567	if (IS_ERR(max->regmap)) {
568		ret = PTR_ERR(max->regmap);
569		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
570		return ret;
571	}
572
573	if (client->dev.of_node) {
574		const struct of_device_id *match;
575
576		match = of_match_device(of_match_ptr(of_max8973_match_tbl),
577				&client->dev);
578		if (!match)
579			return -ENODATA;
580		max->id = (u32)((uintptr_t)match->data);
581	} else {
582		max->id = id->driver_data;
583	}
584
585	ret = regmap_read(max->regmap, MAX8973_CHIPID1, &chip_id);
586	if (ret < 0) {
587		dev_err(&client->dev, "register CHIPID1 read failed, %d", ret);
588		return ret;
589	}
590
591	dev_info(&client->dev, "CHIP-ID OTP: 0x%02x ID_M: 0x%02x\n",
592			(chip_id >> 4) & 0xF, (chip_id >> 1) & 0x7);
593
594	i2c_set_clientdata(client, max);
595	max->ops = max8973_dcdc_ops;
596	max->dev = &client->dev;
597	max->desc.name = id->name;
598	max->desc.id = 0;
599	max->desc.ops = &max->ops;
600	max->desc.type = REGULATOR_VOLTAGE;
601	max->desc.owner = THIS_MODULE;
602	max->desc.min_uV = MAX8973_MIN_VOLATGE;
603	max->desc.uV_step = MAX8973_VOLATGE_STEP;
604	max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
605
606	max->dvs_gpio = (pdata->dvs_gpio) ? pdata->dvs_gpio : -EINVAL;
607	max->enable_gpio = (pdata->enable_gpio) ? pdata->enable_gpio : -EINVAL;
608	max->enable_external_control = pdata->enable_ext_control;
609	max->curr_gpio_val = pdata->dvs_def_state;
610	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
611
612	if (gpio_is_valid(max->enable_gpio))
613		max->enable_external_control = true;
614
615	max->lru_index[0] = max->curr_vout_reg;
616
617	if (gpio_is_valid(max->dvs_gpio)) {
618		int gpio_flags;
619		int i;
620
621		gpio_flags = (pdata->dvs_def_state) ?
622				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
623		ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
624				gpio_flags, "max8973-dvs");
625		if (ret) {
626			dev_err(&client->dev,
627				"gpio_request for gpio %d failed, err = %d\n",
628				max->dvs_gpio, ret);
629			return ret;
630		}
631
632		/*
633		 * Initialize the lru index with vout_reg id
634		 * The index 0 will be most recently used and
635		 * set with the max->curr_vout_reg */
636		for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
637			max->lru_index[i] = i;
638		max->lru_index[0] = max->curr_vout_reg;
639		max->lru_index[max->curr_vout_reg] = 0;
640	} else {
641		/*
642		 * If there is no DVS GPIO, the VOUT register
643		 * address is fixed.
644		 */
645		max->ops.set_voltage_sel = regulator_set_voltage_sel_regmap;
646		max->ops.get_voltage_sel = regulator_get_voltage_sel_regmap;
647		max->desc.vsel_reg = max->curr_vout_reg;
648		max->desc.vsel_mask = MAX8973_VOUT_MASK;
649	}
650
651	if (pdata_from_dt)
652		pdata->reg_init_data = of_get_regulator_init_data(&client->dev,
653					client->dev.of_node, &max->desc);
654
655	ridata = pdata->reg_init_data;
656	switch (max->id) {
657	case MAX8973:
658		if (!pdata->enable_ext_control) {
659			max->desc.enable_reg = MAX8973_VOUT;
660			max->desc.enable_mask = MAX8973_VOUT_ENABLE;
661			max->ops.enable = regulator_enable_regmap;
662			max->ops.disable = regulator_disable_regmap;
663			max->ops.is_enabled = regulator_is_enabled_regmap;
664			break;
665		}
666
667		if (gpio_is_valid(max->enable_gpio)) {
668			config.ena_gpio_flags = GPIOF_OUT_INIT_LOW;
669			if (ridata && (ridata->constraints.always_on ||
670					ridata->constraints.boot_on))
671				config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
672			config.ena_gpio = max->enable_gpio;
673		}
674		break;
675
676	case MAX77621:
677		if (gpio_is_valid(max->enable_gpio)) {
678			ret = devm_gpio_request_one(&client->dev,
679					max->enable_gpio, GPIOF_OUT_INIT_HIGH,
680					"max8973-en-gpio");
681			if (ret) {
682				dev_err(&client->dev,
683					"gpio_request for gpio %d failed: %d\n",
684					max->enable_gpio, ret);
685				return ret;
686			}
687		}
688
689		max->desc.enable_reg = MAX8973_VOUT;
690		max->desc.enable_mask = MAX8973_VOUT_ENABLE;
691		max->ops.enable = regulator_enable_regmap;
692		max->ops.disable = regulator_disable_regmap;
693		max->ops.is_enabled = regulator_is_enabled_regmap;
694		max->ops.set_current_limit = max8973_set_current_limit;
695		max->ops.get_current_limit = max8973_get_current_limit;
696		break;
697	default:
698		break;
699	}
700
701	ret = max8973_init_dcdc(max, pdata);
702	if (ret < 0) {
703		dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
704		return ret;
705	}
706
707	config.dev = &client->dev;
708	config.init_data = pdata->reg_init_data;
709	config.driver_data = max;
710	config.of_node = client->dev.of_node;
711	config.regmap = max->regmap;
712
713	/* Register the regulators */
714	rdev = devm_regulator_register(&client->dev, &max->desc, &config);
715	if (IS_ERR(rdev)) {
716		ret = PTR_ERR(rdev);
717		dev_err(max->dev, "regulator register failed, err %d\n", ret);
718		return ret;
719	}
720
721	return 0;
722}
723
724static const struct i2c_device_id max8973_id[] = {
725	{.name = "max8973", .driver_data = MAX8973},
726	{.name = "max77621", .driver_data = MAX77621},
727	{},
728};
729MODULE_DEVICE_TABLE(i2c, max8973_id);
730
731static struct i2c_driver max8973_i2c_driver = {
732	.driver = {
733		.name = "max8973",
734		.of_match_table = of_max8973_match_tbl,
735	},
736	.probe = max8973_probe,
737	.id_table = max8973_id,
738};
739
740static int __init max8973_init(void)
741{
742	return i2c_add_driver(&max8973_i2c_driver);
743}
744subsys_initcall(max8973_init);
745
746static void __exit max8973_cleanup(void)
747{
748	i2c_del_driver(&max8973_i2c_driver);
749}
750module_exit(max8973_cleanup);
751
752MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
753MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
754MODULE_LICENSE("GPL v2");
755