2 * max8973-regulator.c -- Maxim max8973
4 * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
6 * Copyright (c) 2012, NVIDIA Corporation.
8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
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.
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.
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
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/err.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>
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
50 #define MAX8973_MAX_VOUT_REG 2
53 #define MAX8973_VOUT_ENABLE BIT(7)
54 #define MAX8973_VOUT_MASK 0x7F
56 /* MAX8973_VOUT_DVS */
57 #define MAX8973_DVS_VOUT_MASK 0x7F
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)
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
73 /* MAX8973_CONTROL2 */
74 #define MAX8973_WDTMR_ENABLE BIT(6)
75 #define MAX8973_DISCH_ENBABLE BIT(5)
76 #define MAX8973_FT_ENABLE BIT(4)
78 #define MAX8973_CKKADV_TRIP_DISABLE 0xC
79 #define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0
80 #define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4
81 #define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8
82 #define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000
84 #define MAX8973_INDUCTOR_MIN_30_PER 0x0
85 #define MAX8973_INDUCTOR_NOMINAL 0x1
86 #define MAX8973_INDUCTOR_PLUS_30_PER 0x2
87 #define MAX8973_INDUCTOR_PLUS_60_PER 0x3
88 #define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000
90 #define MAX8973_MIN_VOLATGE 606250
91 #define MAX8973_MAX_VOLATGE 1400000
92 #define MAX8973_VOLATGE_STEP 6250
93 #define MAX8973_BUCK_N_VOLTAGE 0x80
100 /* Maxim 8973 chip information */
101 struct max8973_chip {
103 struct regulator_desc desc;
104 struct regmap *regmap;
105 bool enable_external_control;
108 int lru_index[MAX8973_MAX_VOUT_REG];
109 int curr_vout_val[MAX8973_MAX_VOUT_REG];
112 struct regulator_ops ops;
117 * find_voltage_set_register: Find new voltage configuration register (VOUT).
118 * The finding of the new VOUT register will be based on the LRU mechanism.
119 * Each VOUT register will have different voltage configured . This
120 * Function will look if any of the VOUT register have requested voltage set
122 * - If it is already there then it will make that register as most
123 * recently used and return as found so that caller need not to set
124 * the VOUT register but need to set the proper gpios to select this
126 * - If requested voltage is not found then it will use the least
127 * recently mechanism to get new VOUT register for new configuration
128 * and will return not_found so that caller need to set new VOUT
129 * register and then gpios (both).
131 static bool find_voltage_set_register(struct max8973_chip *tps,
132 int req_vsel, int *vout_reg, int *gpio_val)
136 int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
137 int found_index = MAX8973_MAX_VOUT_REG - 1;
139 for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
140 if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
141 new_vout_reg = tps->lru_index[i];
144 goto update_lru_index;
149 for (i = found_index; i > 0; i--)
150 tps->lru_index[i] = tps->lru_index[i - 1];
152 tps->lru_index[0] = new_vout_reg;
153 *gpio_val = new_vout_reg;
154 *vout_reg = MAX8973_VOUT + new_vout_reg;
158 static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
160 struct max8973_chip *max = rdev_get_drvdata(rdev);
164 ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
166 dev_err(max->dev, "register %d read failed, err = %d\n",
167 max->curr_vout_reg, ret);
170 return data & MAX8973_VOUT_MASK;
173 static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
176 struct max8973_chip *max = rdev_get_drvdata(rdev);
179 int vout_reg = max->curr_vout_reg;
180 int gpio_val = max->curr_gpio_val;
183 * If gpios are available to select the VOUT register then least
184 * recently used register for new configuration.
186 if (gpio_is_valid(max->dvs_gpio))
187 found = find_voltage_set_register(max, vsel,
188 &vout_reg, &gpio_val);
191 ret = regmap_update_bits(max->regmap, vout_reg,
192 MAX8973_VOUT_MASK, vsel);
194 dev_err(max->dev, "register %d update failed, err %d\n",
198 max->curr_vout_reg = vout_reg;
199 max->curr_vout_val[gpio_val] = vsel;
202 /* Select proper VOUT register vio gpios */
203 if (gpio_is_valid(max->dvs_gpio)) {
204 gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
205 max->curr_gpio_val = gpio_val;
210 static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
212 struct max8973_chip *max = rdev_get_drvdata(rdev);
216 /* Enable force PWM mode in FAST mode only. */
218 case REGULATOR_MODE_FAST:
219 pwm = MAX8973_FPWM_EN_M;
222 case REGULATOR_MODE_NORMAL:
230 ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
231 MAX8973_FPWM_EN_M, pwm);
233 dev_err(max->dev, "register %d update failed, err %d\n",
234 MAX8973_CONTROL1, ret);
238 static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
240 struct max8973_chip *max = rdev_get_drvdata(rdev);
244 ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
246 dev_err(max->dev, "register %d read failed, err %d\n",
247 MAX8973_CONTROL1, ret);
250 return (data & MAX8973_FPWM_EN_M) ?
251 REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
254 static int max8973_set_ramp_delay(struct regulator_dev *rdev,
257 struct max8973_chip *max = rdev_get_drvdata(rdev);
258 unsigned int control;
263 if (ramp_delay < 25000) {
264 control = MAX8973_RAMP_12mV_PER_US;
266 } else if (ramp_delay < 50000) {
267 control = MAX8973_RAMP_25mV_PER_US;
269 } else if (ramp_delay < 200000) {
270 control = MAX8973_RAMP_50mV_PER_US;
273 control = MAX8973_RAMP_200mV_PER_US;
277 ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
278 MAX8973_RAMP_MASK, control);
280 dev_err(max->dev, "register %d update failed, %d",
281 MAX8973_CONTROL1, ret);
285 static const struct regulator_ops max8973_dcdc_ops = {
286 .get_voltage_sel = max8973_dcdc_get_voltage_sel,
287 .set_voltage_sel = max8973_dcdc_set_voltage_sel,
288 .list_voltage = regulator_list_voltage_linear,
289 .set_mode = max8973_dcdc_set_mode,
290 .get_mode = max8973_dcdc_get_mode,
291 .set_voltage_time_sel = regulator_set_voltage_time_sel,
292 .set_ramp_delay = max8973_set_ramp_delay,
295 static int max8973_init_dcdc(struct max8973_chip *max,
296 struct max8973_regulator_platform_data *pdata)
299 uint8_t control1 = 0;
300 uint8_t control2 = 0;
303 ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
305 dev_err(max->dev, "register %d read failed, err = %d",
306 MAX8973_CONTROL1, ret);
309 control1 = data & MAX8973_RAMP_MASK;
311 case MAX8973_RAMP_12mV_PER_US:
312 max->desc.ramp_delay = 12000;
314 case MAX8973_RAMP_25mV_PER_US:
315 max->desc.ramp_delay = 25000;
317 case MAX8973_RAMP_50mV_PER_US:
318 max->desc.ramp_delay = 50000;
320 case MAX8973_RAMP_200mV_PER_US:
321 max->desc.ramp_delay = 200000;
325 if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
326 control1 |= MAX8973_SNS_ENABLE;
328 if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
329 control1 |= MAX8973_NFSR_ENABLE;
331 if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
332 control1 |= MAX8973_AD_ENABLE;
334 if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE) {
335 control1 |= MAX8973_BIAS_ENABLE;
336 max->desc.enable_time = 20;
338 max->desc.enable_time = 240;
341 if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
342 control1 |= MAX8973_FREQSHIFT_9PER;
344 if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
345 control2 |= MAX8973_DISCH_ENBABLE;
347 /* Clock advance trip configuration */
348 switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
349 case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
350 control2 |= MAX8973_CKKADV_TRIP_DISABLE;
353 case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
354 control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US;
357 case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
358 control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US;
361 case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
362 control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
366 /* Configure inductor value */
367 switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
368 case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
369 control2 |= MAX8973_INDUCTOR_NOMINAL;
372 case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
373 control2 |= MAX8973_INDUCTOR_MIN_30_PER;
376 case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
377 control2 |= MAX8973_INDUCTOR_PLUS_30_PER;
380 case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
381 control2 |= MAX8973_INDUCTOR_PLUS_60_PER;
385 ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
387 dev_err(max->dev, "register %d write failed, err = %d",
388 MAX8973_CONTROL1, ret);
392 ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
394 dev_err(max->dev, "register %d write failed, err = %d",
395 MAX8973_CONTROL2, ret);
399 /* If external control is enabled then disable EN bit */
400 if (max->enable_external_control && (max->id == MAX8973)) {
401 ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
402 MAX8973_VOUT_ENABLE, 0);
404 dev_err(max->dev, "register %d update failed, err = %d",
410 static const struct regmap_config max8973_regmap_config = {
413 .max_register = MAX8973_CHIPID2,
414 .cache_type = REGCACHE_RBTREE,
417 static struct max8973_regulator_platform_data *max8973_parse_dt(
420 struct max8973_regulator_platform_data *pdata;
421 struct device_node *np = dev->of_node;
425 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
429 pdata->enable_ext_control = of_property_read_bool(np,
430 "maxim,externally-enable");
431 pdata->enable_gpio = of_get_named_gpio(np, "maxim,enable-gpio", 0);
432 pdata->dvs_gpio = of_get_named_gpio(np, "maxim,dvs-gpio", 0);
434 ret = of_property_read_u32(np, "maxim,dvs-default-state", &pval);
436 pdata->dvs_def_state = pval;
438 if (of_property_read_bool(np, "maxim,enable-remote-sense"))
439 pdata->control_flags |= MAX8973_CONTROL_REMOTE_SENSE_ENABLE;
441 if (of_property_read_bool(np, "maxim,enable-falling-slew-rate"))
442 pdata->control_flags |=
443 MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE;
445 if (of_property_read_bool(np, "maxim,enable-active-discharge"))
446 pdata->control_flags |=
447 MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE;
449 if (of_property_read_bool(np, "maxim,enable-frequency-shift"))
450 pdata->control_flags |= MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE;
452 if (of_property_read_bool(np, "maxim,enable-bias-control"))
453 pdata->control_flags |= MAX8973_BIAS_ENABLE;
458 static const struct of_device_id of_max8973_match_tbl[] = {
459 { .compatible = "maxim,max8973", .data = (void *)MAX8973, },
460 { .compatible = "maxim,max77621", .data = (void *)MAX77621, },
463 MODULE_DEVICE_TABLE(of, of_max8973_match_tbl);
465 static int max8973_probe(struct i2c_client *client,
466 const struct i2c_device_id *id)
468 struct max8973_regulator_platform_data *pdata;
469 struct regulator_init_data *ridata;
470 struct regulator_config config = { };
471 struct regulator_dev *rdev;
472 struct max8973_chip *max;
473 bool pdata_from_dt = false;
474 unsigned int chip_id;
477 pdata = dev_get_platdata(&client->dev);
479 if (!pdata && client->dev.of_node) {
480 pdata = max8973_parse_dt(&client->dev);
481 pdata_from_dt = true;
485 dev_err(&client->dev, "No Platform data");
489 if ((pdata->dvs_gpio == -EPROBE_DEFER) ||
490 (pdata->enable_gpio == -EPROBE_DEFER))
491 return -EPROBE_DEFER;
493 max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
497 max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
498 if (IS_ERR(max->regmap)) {
499 ret = PTR_ERR(max->regmap);
500 dev_err(&client->dev, "regmap init failed, err %d\n", ret);
504 if (client->dev.of_node) {
505 const struct of_device_id *match;
507 match = of_match_device(of_match_ptr(of_max8973_match_tbl),
511 max->id = (u32)((uintptr_t)match->data);
513 max->id = id->driver_data;
516 ret = regmap_read(max->regmap, MAX8973_CHIPID1, &chip_id);
518 dev_err(&client->dev, "register CHIPID1 read failed, %d", ret);
522 dev_info(&client->dev, "CHIP-ID OTP: 0x%02x ID_M: 0x%02x\n",
523 (chip_id >> 4) & 0xF, (chip_id >> 1) & 0x7);
525 i2c_set_clientdata(client, max);
526 max->ops = max8973_dcdc_ops;
527 max->dev = &client->dev;
528 max->desc.name = id->name;
530 max->desc.ops = &max->ops;
531 max->desc.type = REGULATOR_VOLTAGE;
532 max->desc.owner = THIS_MODULE;
533 max->desc.min_uV = MAX8973_MIN_VOLATGE;
534 max->desc.uV_step = MAX8973_VOLATGE_STEP;
535 max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
537 max->dvs_gpio = (pdata->dvs_gpio) ? pdata->dvs_gpio : -EINVAL;
538 max->enable_gpio = (pdata->enable_gpio) ? pdata->enable_gpio : -EINVAL;
539 max->enable_external_control = pdata->enable_ext_control;
540 max->curr_gpio_val = pdata->dvs_def_state;
541 max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
543 if (gpio_is_valid(max->enable_gpio))
544 max->enable_external_control = true;
546 max->lru_index[0] = max->curr_vout_reg;
548 if (gpio_is_valid(max->dvs_gpio)) {
552 gpio_flags = (pdata->dvs_def_state) ?
553 GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
554 ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
555 gpio_flags, "max8973-dvs");
557 dev_err(&client->dev,
558 "gpio_request for gpio %d failed, err = %d\n",
564 * Initialize the lru index with vout_reg id
565 * The index 0 will be most recently used and
566 * set with the max->curr_vout_reg */
567 for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
568 max->lru_index[i] = i;
569 max->lru_index[0] = max->curr_vout_reg;
570 max->lru_index[max->curr_vout_reg] = 0;
574 pdata->reg_init_data = of_get_regulator_init_data(&client->dev,
575 client->dev.of_node, &max->desc);
577 ridata = pdata->reg_init_data;
580 if (!pdata->enable_ext_control) {
581 max->desc.enable_reg = MAX8973_VOUT;
582 max->desc.enable_mask = MAX8973_VOUT_ENABLE;
583 max->ops.enable = regulator_enable_regmap;
584 max->ops.disable = regulator_disable_regmap;
585 max->ops.is_enabled = regulator_is_enabled_regmap;
589 if (gpio_is_valid(max->enable_gpio)) {
590 config.ena_gpio_flags = GPIOF_OUT_INIT_LOW;
591 if (ridata && (ridata->constraints.always_on ||
592 ridata->constraints.boot_on))
593 config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
594 config.ena_gpio = max->enable_gpio;
599 if (gpio_is_valid(max->enable_gpio)) {
600 ret = devm_gpio_request_one(&client->dev,
601 max->enable_gpio, GPIOF_OUT_INIT_HIGH,
604 dev_err(&client->dev,
605 "gpio_request for gpio %d failed: %d\n",
606 max->enable_gpio, ret);
611 max->desc.enable_reg = MAX8973_VOUT;
612 max->desc.enable_mask = MAX8973_VOUT_ENABLE;
613 max->ops.enable = regulator_enable_regmap;
614 max->ops.disable = regulator_disable_regmap;
615 max->ops.is_enabled = regulator_is_enabled_regmap;
621 ret = max8973_init_dcdc(max, pdata);
623 dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
627 config.dev = &client->dev;
628 config.init_data = pdata->reg_init_data;
629 config.driver_data = max;
630 config.of_node = client->dev.of_node;
631 config.regmap = max->regmap;
633 /* Register the regulators */
634 rdev = devm_regulator_register(&client->dev, &max->desc, &config);
637 dev_err(max->dev, "regulator register failed, err %d\n", ret);
644 static const struct i2c_device_id max8973_id[] = {
645 {.name = "max8973", .driver_data = MAX8973},
646 {.name = "max77621", .driver_data = MAX77621},
649 MODULE_DEVICE_TABLE(i2c, max8973_id);
651 static struct i2c_driver max8973_i2c_driver = {
654 .of_match_table = of_max8973_match_tbl,
655 .owner = THIS_MODULE,
657 .probe = max8973_probe,
658 .id_table = max8973_id,
661 static int __init max8973_init(void)
663 return i2c_add_driver(&max8973_i2c_driver);
665 subsys_initcall(max8973_init);
667 static void __exit max8973_cleanup(void)
669 i2c_del_driver(&max8973_i2c_driver);
671 module_exit(max8973_cleanup);
673 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
674 MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
675 MODULE_LICENSE("GPL v2");