2 * Regulator driver for PWM Regulators
4 * Copyright (C) 2014 - STMicroelectronics Inc.
6 * Author: Lee Jones <lee.jones@linaro.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/delay.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/err.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/regulator/machine.h>
19 #include <linux/regulator/of_regulator.h>
21 #include <linux/of_device.h>
22 #include <linux/pwm.h>
24 struct pwm_regulator_data
{
26 struct pwm_device
*pwm
;
29 struct pwm_voltages
*duty_cycle_table
;
31 /* regulator descriptor */
32 struct regulator_desc desc
;
35 struct regulator_ops ops
;
39 /* Continuous voltage */
45 unsigned int dutycycle
;
49 * Voltage table call-backs
51 static int pwm_regulator_get_voltage_sel(struct regulator_dev
*rdev
)
53 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(rdev
);
55 return drvdata
->state
;
58 static int pwm_regulator_set_voltage_sel(struct regulator_dev
*rdev
,
61 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(rdev
);
62 struct pwm_args pargs
;
66 pwm_get_args(drvdata
->pwm
, &pargs
);
68 dutycycle
= (pargs
.period
*
69 drvdata
->duty_cycle_table
[selector
].dutycycle
) / 100;
71 ret
= pwm_config(drvdata
->pwm
, dutycycle
, pargs
.period
);
73 dev_err(&rdev
->dev
, "Failed to configure PWM\n");
77 drvdata
->state
= selector
;
82 static int pwm_regulator_list_voltage(struct regulator_dev
*rdev
,
85 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(rdev
);
87 if (selector
>= rdev
->desc
->n_voltages
)
90 return drvdata
->duty_cycle_table
[selector
].uV
;
93 static int pwm_regulator_enable(struct regulator_dev
*dev
)
95 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(dev
);
97 return pwm_enable(drvdata
->pwm
);
100 static int pwm_regulator_disable(struct regulator_dev
*dev
)
102 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(dev
);
104 pwm_disable(drvdata
->pwm
);
109 static int pwm_regulator_is_enabled(struct regulator_dev
*dev
)
111 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(dev
);
113 return pwm_is_enabled(drvdata
->pwm
);
117 * Continuous voltage call-backs
119 static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev
*rdev
, int req_uV
)
121 int min_uV
= rdev
->constraints
->min_uV
;
122 int max_uV
= rdev
->constraints
->max_uV
;
123 int diff
= max_uV
- min_uV
;
125 return ((req_uV
* 100) - (min_uV
* 100)) / diff
;
128 static int pwm_regulator_get_voltage(struct regulator_dev
*rdev
)
130 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(rdev
);
132 return drvdata
->volt_uV
;
135 static int pwm_regulator_set_voltage(struct regulator_dev
*rdev
,
136 int min_uV
, int max_uV
,
139 struct pwm_regulator_data
*drvdata
= rdev_get_drvdata(rdev
);
140 unsigned int ramp_delay
= rdev
->constraints
->ramp_delay
;
141 struct pwm_args pargs
;
145 pwm_get_args(drvdata
->pwm
, &pargs
);
146 duty_cycle
= pwm_voltage_to_duty_cycle_percentage(rdev
, min_uV
);
148 ret
= pwm_config(drvdata
->pwm
, (pargs
.period
/ 100) * duty_cycle
,
151 dev_err(&rdev
->dev
, "Failed to configure PWM\n");
155 ret
= pwm_enable(drvdata
->pwm
);
157 dev_err(&rdev
->dev
, "Failed to enable PWM\n");
160 drvdata
->volt_uV
= min_uV
;
162 /* Delay required by PWM regulator to settle to the new voltage */
163 usleep_range(ramp_delay
, ramp_delay
+ 1000);
168 static struct regulator_ops pwm_regulator_voltage_table_ops
= {
169 .set_voltage_sel
= pwm_regulator_set_voltage_sel
,
170 .get_voltage_sel
= pwm_regulator_get_voltage_sel
,
171 .list_voltage
= pwm_regulator_list_voltage
,
172 .map_voltage
= regulator_map_voltage_iterate
,
173 .enable
= pwm_regulator_enable
,
174 .disable
= pwm_regulator_disable
,
175 .is_enabled
= pwm_regulator_is_enabled
,
178 static struct regulator_ops pwm_regulator_voltage_continuous_ops
= {
179 .get_voltage
= pwm_regulator_get_voltage
,
180 .set_voltage
= pwm_regulator_set_voltage
,
181 .enable
= pwm_regulator_enable
,
182 .disable
= pwm_regulator_disable
,
183 .is_enabled
= pwm_regulator_is_enabled
,
186 static struct regulator_desc pwm_regulator_desc
= {
187 .name
= "pwm-regulator",
188 .type
= REGULATOR_VOLTAGE
,
189 .owner
= THIS_MODULE
,
190 .supply_name
= "pwm",
193 static int pwm_regulator_init_table(struct platform_device
*pdev
,
194 struct pwm_regulator_data
*drvdata
)
196 struct device_node
*np
= pdev
->dev
.of_node
;
197 struct pwm_voltages
*duty_cycle_table
;
198 unsigned int length
= 0;
201 of_find_property(np
, "voltage-table", &length
);
203 if ((length
< sizeof(*duty_cycle_table
)) ||
204 (length
% sizeof(*duty_cycle_table
))) {
206 "voltage-table length(%d) is invalid\n",
211 duty_cycle_table
= devm_kzalloc(&pdev
->dev
, length
, GFP_KERNEL
);
212 if (!duty_cycle_table
)
215 ret
= of_property_read_u32_array(np
, "voltage-table",
216 (u32
*)duty_cycle_table
,
217 length
/ sizeof(u32
));
219 dev_err(&pdev
->dev
, "Failed to read voltage-table\n");
223 drvdata
->duty_cycle_table
= duty_cycle_table
;
224 memcpy(&drvdata
->ops
, &pwm_regulator_voltage_table_ops
,
225 sizeof(drvdata
->ops
));
226 drvdata
->desc
.ops
= &drvdata
->ops
;
227 drvdata
->desc
.n_voltages
= length
/ sizeof(*duty_cycle_table
);
232 static int pwm_regulator_init_continuous(struct platform_device
*pdev
,
233 struct pwm_regulator_data
*drvdata
)
235 memcpy(&drvdata
->ops
, &pwm_regulator_voltage_continuous_ops
,
236 sizeof(drvdata
->ops
));
237 drvdata
->desc
.ops
= &drvdata
->ops
;
238 drvdata
->desc
.continuous_voltage_range
= true;
243 static int pwm_regulator_probe(struct platform_device
*pdev
)
245 const struct regulator_init_data
*init_data
;
246 struct pwm_regulator_data
*drvdata
;
247 struct regulator_dev
*regulator
;
248 struct regulator_config config
= { };
249 struct device_node
*np
= pdev
->dev
.of_node
;
253 dev_err(&pdev
->dev
, "Device Tree node missing\n");
257 drvdata
= devm_kzalloc(&pdev
->dev
, sizeof(*drvdata
), GFP_KERNEL
);
261 memcpy(&drvdata
->desc
, &pwm_regulator_desc
, sizeof(drvdata
->desc
));
263 if (of_find_property(np
, "voltage-table", NULL
))
264 ret
= pwm_regulator_init_table(pdev
, drvdata
);
266 ret
= pwm_regulator_init_continuous(pdev
, drvdata
);
270 init_data
= of_get_regulator_init_data(&pdev
->dev
, np
,
276 config
.dev
= &pdev
->dev
;
277 config
.driver_data
= drvdata
;
278 config
.init_data
= init_data
;
280 drvdata
->pwm
= devm_pwm_get(&pdev
->dev
, NULL
);
281 if (IS_ERR(drvdata
->pwm
)) {
282 dev_err(&pdev
->dev
, "Failed to get PWM\n");
283 return PTR_ERR(drvdata
->pwm
);
287 * FIXME: pwm_apply_args() should be removed when switching to the
290 pwm_apply_args(drvdata
->pwm
);
292 regulator
= devm_regulator_register(&pdev
->dev
,
293 &drvdata
->desc
, &config
);
294 if (IS_ERR(regulator
)) {
295 dev_err(&pdev
->dev
, "Failed to register regulator %s\n",
297 return PTR_ERR(regulator
);
303 static const struct of_device_id pwm_of_match
[] = {
304 { .compatible
= "pwm-regulator" },
307 MODULE_DEVICE_TABLE(of
, pwm_of_match
);
309 static struct platform_driver pwm_regulator_driver
= {
311 .name
= "pwm-regulator",
312 .of_match_table
= of_match_ptr(pwm_of_match
),
314 .probe
= pwm_regulator_probe
,
317 module_platform_driver(pwm_regulator_driver
);
319 MODULE_LICENSE("GPL");
320 MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
321 MODULE_DESCRIPTION("PWM Regulator Driver");
322 MODULE_ALIAS("platform:pwm-regulator");