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_CONTROL_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");