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/platform_device.h>
31 #include <linux/regulator/driver.h>
32 #include <linux/regulator/machine.h>
33 #include <linux/regulator/max8973-regulator.h>
34 #include <linux/regulator/of_regulator.h>
35 #include <linux/gpio.h>
36 #include <linux/of_gpio.h>
37 #include <linux/i2c.h>
38 #include <linux/slab.h>
39 #include <linux/regmap.h>
41 /* Register definitions */
42 #define MAX8973_VOUT 0x0
43 #define MAX8973_VOUT_DVS 0x1
44 #define MAX8973_CONTROL1 0x2
45 #define MAX8973_CONTROL2 0x3
46 #define MAX8973_CHIPID1 0x4
47 #define MAX8973_CHIPID2 0x5
49 #define MAX8973_MAX_VOUT_REG 2
52 #define MAX8973_VOUT_ENABLE BIT(7)
53 #define MAX8973_VOUT_MASK 0x7F
55 /* MAX8973_VOUT_DVS */
56 #define MAX8973_DVS_VOUT_MASK 0x7F
58 /* MAX8973_CONTROL1 */
59 #define MAX8973_SNS_ENABLE BIT(7)
60 #define MAX8973_FPWM_EN_M BIT(6)
61 #define MAX8973_NFSR_ENABLE BIT(5)
62 #define MAX8973_AD_ENABLE BIT(4)
63 #define MAX8973_BIAS_ENABLE BIT(3)
64 #define MAX8973_FREQSHIFT_9PER BIT(2)
66 #define MAX8973_RAMP_12mV_PER_US 0x0
67 #define MAX8973_RAMP_25mV_PER_US 0x1
68 #define MAX8973_RAMP_50mV_PER_US 0x2
69 #define MAX8973_RAMP_200mV_PER_US 0x3
70 #define MAX8973_RAMP_MASK 0x3
72 /* MAX8973_CONTROL2 */
73 #define MAX8973_WDTMR_ENABLE BIT(6)
74 #define MAX8973_DISCH_ENBABLE BIT(5)
75 #define MAX8973_FT_ENABLE BIT(4)
77 #define MAX8973_CKKADV_TRIP_DISABLE 0xC
78 #define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0
79 #define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4
80 #define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8
81 #define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000
83 #define MAX8973_INDUCTOR_MIN_30_PER 0x0
84 #define MAX8973_INDUCTOR_NOMINAL 0x1
85 #define MAX8973_INDUCTOR_PLUS_30_PER 0x2
86 #define MAX8973_INDUCTOR_PLUS_60_PER 0x3
87 #define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000
89 #define MAX8973_MIN_VOLATGE 606250
90 #define MAX8973_MAX_VOLATGE 1400000
91 #define MAX8973_VOLATGE_STEP 6250
92 #define MAX8973_BUCK_N_VOLTAGE 0x80
94 /* Maxim 8973 chip information */
97 struct regulator_desc desc
;
98 struct regmap
*regmap
;
99 bool enable_external_control
;
102 int lru_index
[MAX8973_MAX_VOUT_REG
];
103 int curr_vout_val
[MAX8973_MAX_VOUT_REG
];
106 struct regulator_ops ops
;
110 * find_voltage_set_register: Find new voltage configuration register (VOUT).
111 * The finding of the new VOUT register will be based on the LRU mechanism.
112 * Each VOUT register will have different voltage configured . This
113 * Function will look if any of the VOUT register have requested voltage set
115 * - If it is already there then it will make that register as most
116 * recently used and return as found so that caller need not to set
117 * the VOUT register but need to set the proper gpios to select this
119 * - If requested voltage is not found then it will use the least
120 * recently mechanism to get new VOUT register for new configuration
121 * and will return not_found so that caller need to set new VOUT
122 * register and then gpios (both).
124 static bool find_voltage_set_register(struct max8973_chip
*tps
,
125 int req_vsel
, int *vout_reg
, int *gpio_val
)
129 int new_vout_reg
= tps
->lru_index
[MAX8973_MAX_VOUT_REG
- 1];
130 int found_index
= MAX8973_MAX_VOUT_REG
- 1;
132 for (i
= 0; i
< MAX8973_MAX_VOUT_REG
; ++i
) {
133 if (tps
->curr_vout_val
[tps
->lru_index
[i
]] == req_vsel
) {
134 new_vout_reg
= tps
->lru_index
[i
];
137 goto update_lru_index
;
142 for (i
= found_index
; i
> 0; i
--)
143 tps
->lru_index
[i
] = tps
->lru_index
[i
- 1];
145 tps
->lru_index
[0] = new_vout_reg
;
146 *gpio_val
= new_vout_reg
;
147 *vout_reg
= MAX8973_VOUT
+ new_vout_reg
;
151 static int max8973_dcdc_get_voltage_sel(struct regulator_dev
*rdev
)
153 struct max8973_chip
*max
= rdev_get_drvdata(rdev
);
157 ret
= regmap_read(max
->regmap
, max
->curr_vout_reg
, &data
);
159 dev_err(max
->dev
, "register %d read failed, err = %d\n",
160 max
->curr_vout_reg
, ret
);
163 return data
& MAX8973_VOUT_MASK
;
166 static int max8973_dcdc_set_voltage_sel(struct regulator_dev
*rdev
,
169 struct max8973_chip
*max
= rdev_get_drvdata(rdev
);
172 int vout_reg
= max
->curr_vout_reg
;
173 int gpio_val
= max
->curr_gpio_val
;
176 * If gpios are available to select the VOUT register then least
177 * recently used register for new configuration.
179 if (gpio_is_valid(max
->dvs_gpio
))
180 found
= find_voltage_set_register(max
, vsel
,
181 &vout_reg
, &gpio_val
);
184 ret
= regmap_update_bits(max
->regmap
, vout_reg
,
185 MAX8973_VOUT_MASK
, vsel
);
187 dev_err(max
->dev
, "register %d update failed, err %d\n",
191 max
->curr_vout_reg
= vout_reg
;
192 max
->curr_vout_val
[gpio_val
] = vsel
;
195 /* Select proper VOUT register vio gpios */
196 if (gpio_is_valid(max
->dvs_gpio
)) {
197 gpio_set_value_cansleep(max
->dvs_gpio
, gpio_val
& 0x1);
198 max
->curr_gpio_val
= gpio_val
;
203 static int max8973_dcdc_set_mode(struct regulator_dev
*rdev
, unsigned int mode
)
205 struct max8973_chip
*max
= rdev_get_drvdata(rdev
);
209 /* Enable force PWM mode in FAST mode only. */
211 case REGULATOR_MODE_FAST
:
212 pwm
= MAX8973_FPWM_EN_M
;
215 case REGULATOR_MODE_NORMAL
:
223 ret
= regmap_update_bits(max
->regmap
, MAX8973_CONTROL1
,
224 MAX8973_FPWM_EN_M
, pwm
);
226 dev_err(max
->dev
, "register %d update failed, err %d\n",
227 MAX8973_CONTROL1
, ret
);
231 static unsigned int max8973_dcdc_get_mode(struct regulator_dev
*rdev
)
233 struct max8973_chip
*max
= rdev_get_drvdata(rdev
);
237 ret
= regmap_read(max
->regmap
, MAX8973_CONTROL1
, &data
);
239 dev_err(max
->dev
, "register %d read failed, err %d\n",
240 MAX8973_CONTROL1
, ret
);
243 return (data
& MAX8973_FPWM_EN_M
) ?
244 REGULATOR_MODE_FAST
: REGULATOR_MODE_NORMAL
;
247 static int max8973_set_ramp_delay(struct regulator_dev
*rdev
,
250 struct max8973_chip
*max
= rdev_get_drvdata(rdev
);
251 unsigned int control
;
256 if (ramp_delay
< 25000) {
257 control
= MAX8973_RAMP_12mV_PER_US
;
259 } else if (ramp_delay
< 50000) {
260 control
= MAX8973_RAMP_25mV_PER_US
;
262 } else if (ramp_delay
< 200000) {
263 control
= MAX8973_RAMP_50mV_PER_US
;
266 control
= MAX8973_RAMP_200mV_PER_US
;
270 ret
= regmap_update_bits(max
->regmap
, MAX8973_CONTROL1
,
271 MAX8973_RAMP_MASK
, control
);
273 dev_err(max
->dev
, "register %d update failed, %d",
274 MAX8973_CONTROL1
, ret
);
278 static const struct regulator_ops max8973_dcdc_ops
= {
279 .get_voltage_sel
= max8973_dcdc_get_voltage_sel
,
280 .set_voltage_sel
= max8973_dcdc_set_voltage_sel
,
281 .list_voltage
= regulator_list_voltage_linear
,
282 .set_mode
= max8973_dcdc_set_mode
,
283 .get_mode
= max8973_dcdc_get_mode
,
284 .set_voltage_time_sel
= regulator_set_voltage_time_sel
,
285 .set_ramp_delay
= max8973_set_ramp_delay
,
288 static int max8973_init_dcdc(struct max8973_chip
*max
,
289 struct max8973_regulator_platform_data
*pdata
)
292 uint8_t control1
= 0;
293 uint8_t control2
= 0;
296 ret
= regmap_read(max
->regmap
, MAX8973_CONTROL1
, &data
);
298 dev_err(max
->dev
, "register %d read failed, err = %d",
299 MAX8973_CONTROL1
, ret
);
302 control1
= data
& MAX8973_RAMP_MASK
;
304 case MAX8973_RAMP_12mV_PER_US
:
305 max
->desc
.ramp_delay
= 12000;
307 case MAX8973_RAMP_25mV_PER_US
:
308 max
->desc
.ramp_delay
= 252000;
310 case MAX8973_RAMP_50mV_PER_US
:
311 max
->desc
.ramp_delay
= 50000;
313 case MAX8973_RAMP_200mV_PER_US
:
314 max
->desc
.ramp_delay
= 200000;
318 if (pdata
->control_flags
& MAX8973_CONTROL_REMOTE_SENSE_ENABLE
)
319 control1
|= MAX8973_SNS_ENABLE
;
321 if (!(pdata
->control_flags
& MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE
))
322 control1
|= MAX8973_NFSR_ENABLE
;
324 if (pdata
->control_flags
& MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE
)
325 control1
|= MAX8973_AD_ENABLE
;
327 if (pdata
->control_flags
& MAX8973_CONTROL_BIAS_ENABLE
) {
328 control1
|= MAX8973_BIAS_ENABLE
;
329 max
->desc
.enable_time
= 20;
331 max
->desc
.enable_time
= 240;
334 if (pdata
->control_flags
& MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE
)
335 control1
|= MAX8973_FREQSHIFT_9PER
;
337 if (!(pdata
->control_flags
& MAX8973_CONTROL_PULL_DOWN_ENABLE
))
338 control2
|= MAX8973_DISCH_ENBABLE
;
340 /* Clock advance trip configuration */
341 switch (pdata
->control_flags
& MAX8973_CONTROL_CLKADV_TRIP_MASK
) {
342 case MAX8973_CONTROL_CLKADV_TRIP_DISABLED
:
343 control2
|= MAX8973_CKKADV_TRIP_DISABLE
;
346 case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US
:
347 control2
|= MAX8973_CKKADV_TRIP_75mV_PER_US
;
350 case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US
:
351 control2
|= MAX8973_CKKADV_TRIP_150mV_PER_US
;
354 case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS
:
355 control2
|= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS
;
359 /* Configure inductor value */
360 switch (pdata
->control_flags
& MAX8973_CONTROL_INDUCTOR_VALUE_MASK
) {
361 case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL
:
362 control2
|= MAX8973_INDUCTOR_NOMINAL
;
365 case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER
:
366 control2
|= MAX8973_INDUCTOR_MIN_30_PER
;
369 case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER
:
370 control2
|= MAX8973_INDUCTOR_PLUS_30_PER
;
373 case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER
:
374 control2
|= MAX8973_INDUCTOR_PLUS_60_PER
;
378 ret
= regmap_write(max
->regmap
, MAX8973_CONTROL1
, control1
);
380 dev_err(max
->dev
, "register %d write failed, err = %d",
381 MAX8973_CONTROL1
, ret
);
385 ret
= regmap_write(max
->regmap
, MAX8973_CONTROL2
, control2
);
387 dev_err(max
->dev
, "register %d write failed, err = %d",
388 MAX8973_CONTROL2
, ret
);
392 /* If external control is enabled then disable EN bit */
393 if (max
->enable_external_control
) {
394 ret
= regmap_update_bits(max
->regmap
, MAX8973_VOUT
,
395 MAX8973_VOUT_ENABLE
, 0);
397 dev_err(max
->dev
, "register %d update failed, err = %d",
403 static const struct regmap_config max8973_regmap_config
= {
406 .max_register
= MAX8973_CHIPID2
,
407 .cache_type
= REGCACHE_RBTREE
,
410 static struct max8973_regulator_platform_data
*max8973_parse_dt(
413 struct max8973_regulator_platform_data
*pdata
;
414 struct device_node
*np
= dev
->of_node
;
418 pdata
= devm_kzalloc(dev
, sizeof(*pdata
), GFP_KERNEL
);
422 pdata
->enable_ext_control
= of_property_read_bool(np
,
423 "maxim,externally-enable");
424 pdata
->enable_gpio
= of_get_named_gpio(np
, "maxim,enable-gpio", 0);
425 pdata
->dvs_gpio
= of_get_named_gpio(np
, "maxim,dvs-gpio", 0);
427 ret
= of_property_read_u32(np
, "maxim,dvs-default-state", &pval
);
429 pdata
->dvs_def_state
= pval
;
431 if (of_property_read_bool(np
, "maxim,enable-remote-sense"))
432 pdata
->control_flags
|= MAX8973_CONTROL_REMOTE_SENSE_ENABLE
;
434 if (of_property_read_bool(np
, "maxim,enable-falling-slew-rate"))
435 pdata
->control_flags
|=
436 MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE
;
438 if (of_property_read_bool(np
, "maxim,enable-active-discharge"))
439 pdata
->control_flags
|=
440 MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE
;
442 if (of_property_read_bool(np
, "maxim,enable-frequency-shift"))
443 pdata
->control_flags
|= MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE
;
445 if (of_property_read_bool(np
, "maxim,enable-bias-control"))
446 pdata
->control_flags
|= MAX8973_BIAS_ENABLE
;
451 static int max8973_probe(struct i2c_client
*client
,
452 const struct i2c_device_id
*id
)
454 struct max8973_regulator_platform_data
*pdata
;
455 struct regulator_init_data
*ridata
;
456 struct regulator_config config
= { };
457 struct regulator_dev
*rdev
;
458 struct max8973_chip
*max
;
459 bool pdata_from_dt
= false;
462 pdata
= dev_get_platdata(&client
->dev
);
464 if (!pdata
&& client
->dev
.of_node
) {
465 pdata
= max8973_parse_dt(&client
->dev
);
466 pdata_from_dt
= true;
470 dev_err(&client
->dev
, "No Platform data");
474 if ((pdata
->dvs_gpio
== -EPROBE_DEFER
) ||
475 (pdata
->enable_gpio
== -EPROBE_DEFER
))
476 return -EPROBE_DEFER
;
478 max
= devm_kzalloc(&client
->dev
, sizeof(*max
), GFP_KERNEL
);
482 max
->regmap
= devm_regmap_init_i2c(client
, &max8973_regmap_config
);
483 if (IS_ERR(max
->regmap
)) {
484 ret
= PTR_ERR(max
->regmap
);
485 dev_err(&client
->dev
, "regmap init failed, err %d\n", ret
);
489 i2c_set_clientdata(client
, max
);
490 max
->ops
= max8973_dcdc_ops
;
491 max
->dev
= &client
->dev
;
492 max
->desc
.name
= id
->name
;
494 max
->desc
.ops
= &max
->ops
;
495 max
->desc
.type
= REGULATOR_VOLTAGE
;
496 max
->desc
.owner
= THIS_MODULE
;
497 max
->desc
.min_uV
= MAX8973_MIN_VOLATGE
;
498 max
->desc
.uV_step
= MAX8973_VOLATGE_STEP
;
499 max
->desc
.n_voltages
= MAX8973_BUCK_N_VOLTAGE
;
501 max
->dvs_gpio
= (pdata
->dvs_gpio
) ? pdata
->dvs_gpio
: -EINVAL
;
502 max
->enable_gpio
= (pdata
->enable_gpio
) ? pdata
->enable_gpio
: -EINVAL
;
503 max
->enable_external_control
= pdata
->enable_ext_control
;
504 max
->curr_gpio_val
= pdata
->dvs_def_state
;
505 max
->curr_vout_reg
= MAX8973_VOUT
+ pdata
->dvs_def_state
;
507 if (gpio_is_valid(max
->enable_gpio
))
508 max
->enable_external_control
= true;
510 if (!pdata
->enable_ext_control
) {
511 max
->desc
.enable_reg
= MAX8973_VOUT
;
512 max
->desc
.enable_mask
= MAX8973_VOUT_ENABLE
;
513 max
->ops
.enable
= regulator_enable_regmap
;
514 max
->ops
.disable
= regulator_disable_regmap
;
515 max
->ops
.is_enabled
= regulator_is_enabled_regmap
;
518 max
->lru_index
[0] = max
->curr_vout_reg
;
520 if (gpio_is_valid(max
->dvs_gpio
)) {
524 gpio_flags
= (pdata
->dvs_def_state
) ?
525 GPIOF_OUT_INIT_HIGH
: GPIOF_OUT_INIT_LOW
;
526 ret
= devm_gpio_request_one(&client
->dev
, max
->dvs_gpio
,
527 gpio_flags
, "max8973-dvs");
529 dev_err(&client
->dev
,
530 "gpio_request for gpio %d failed, err = %d\n",
536 * Initialize the lru index with vout_reg id
537 * The index 0 will be most recently used and
538 * set with the max->curr_vout_reg */
539 for (i
= 0; i
< MAX8973_MAX_VOUT_REG
; ++i
)
540 max
->lru_index
[i
] = i
;
541 max
->lru_index
[0] = max
->curr_vout_reg
;
542 max
->lru_index
[max
->curr_vout_reg
] = 0;
546 pdata
->reg_init_data
= of_get_regulator_init_data(&client
->dev
,
547 client
->dev
.of_node
, &max
->desc
);
549 ret
= max8973_init_dcdc(max
, pdata
);
551 dev_err(max
->dev
, "Max8973 Init failed, err = %d\n", ret
);
555 config
.dev
= &client
->dev
;
556 config
.init_data
= pdata
->reg_init_data
;
557 config
.driver_data
= max
;
558 config
.of_node
= client
->dev
.of_node
;
559 config
.regmap
= max
->regmap
;
561 if (gpio_is_valid(max
->enable_gpio
)) {
562 ridata
= pdata
->reg_init_data
;
563 config
.ena_gpio_flags
= GPIOF_OUT_INIT_LOW
;
564 if (ridata
&& (ridata
->constraints
.always_on
||
565 ridata
->constraints
.boot_on
))
566 config
.ena_gpio_flags
= GPIOF_OUT_INIT_HIGH
;
567 config
.ena_gpio
= max
->enable_gpio
;
570 /* Register the regulators */
571 rdev
= devm_regulator_register(&client
->dev
, &max
->desc
, &config
);
574 dev_err(max
->dev
, "regulator register failed, err %d\n", ret
);
581 static const struct i2c_device_id max8973_id
[] = {
582 {.name
= "max8973",},
586 MODULE_DEVICE_TABLE(i2c
, max8973_id
);
588 static struct i2c_driver max8973_i2c_driver
= {
591 .owner
= THIS_MODULE
,
593 .probe
= max8973_probe
,
594 .id_table
= max8973_id
,
597 static int __init
max8973_init(void)
599 return i2c_add_driver(&max8973_i2c_driver
);
601 subsys_initcall(max8973_init
);
603 static void __exit
max8973_cleanup(void)
605 i2c_del_driver(&max8973_i2c_driver
);
607 module_exit(max8973_cleanup
);
609 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
610 MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
611 MODULE_LICENSE("GPL v2");