Commit | Line | Data |
---|---|---|
aa66cc66 CZ |
1 | /* |
2 | * Regulator driver for PWM Regulators | |
3 | * | |
4 | * Copyright (C) 2014 - STMicroelectronics Inc. | |
5 | * | |
6 | * Author: Lee Jones <lee.jones@linaro.org> | |
7 | * | |
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. | |
11 | */ | |
12 | ||
4773be18 | 13 | #include <linux/delay.h> |
aa66cc66 CZ |
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> | |
20 | #include <linux/of.h> | |
21 | #include <linux/of_device.h> | |
22 | #include <linux/pwm.h> | |
23 | ||
24 | struct pwm_regulator_data { | |
4773be18 | 25 | /* Shared */ |
aa66cc66 | 26 | struct pwm_device *pwm; |
4773be18 LJ |
27 | |
28 | /* Voltage table */ | |
29 | struct pwm_voltages *duty_cycle_table; | |
f907a0a9 LD |
30 | |
31 | /* regulator descriptor */ | |
32 | struct regulator_desc desc; | |
33 | ||
34 | /* Regulator ops */ | |
35 | struct regulator_ops ops; | |
36 | ||
aa66cc66 | 37 | int state; |
4773be18 LJ |
38 | |
39 | /* Continuous voltage */ | |
4773be18 | 40 | int volt_uV; |
aa66cc66 CZ |
41 | }; |
42 | ||
43 | struct pwm_voltages { | |
44 | unsigned int uV; | |
45 | unsigned int dutycycle; | |
46 | }; | |
47 | ||
4773be18 LJ |
48 | /** |
49 | * Voltage table call-backs | |
50 | */ | |
ab101e35 | 51 | static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) |
aa66cc66 | 52 | { |
ab101e35 | 53 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
aa66cc66 CZ |
54 | |
55 | return drvdata->state; | |
56 | } | |
57 | ||
ab101e35 | 58 | static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, |
aa66cc66 CZ |
59 | unsigned selector) |
60 | { | |
ab101e35 | 61 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
aa66cc66 CZ |
62 | unsigned int pwm_reg_period; |
63 | int dutycycle; | |
64 | int ret; | |
65 | ||
66 | pwm_reg_period = pwm_get_period(drvdata->pwm); | |
67 | ||
68 | dutycycle = (pwm_reg_period * | |
69 | drvdata->duty_cycle_table[selector].dutycycle) / 100; | |
70 | ||
71 | ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); | |
72 | if (ret) { | |
ab101e35 | 73 | dev_err(&rdev->dev, "Failed to configure PWM\n"); |
aa66cc66 CZ |
74 | return ret; |
75 | } | |
76 | ||
77 | drvdata->state = selector; | |
78 | ||
aa66cc66 CZ |
79 | return 0; |
80 | } | |
81 | ||
ab101e35 | 82 | static int pwm_regulator_list_voltage(struct regulator_dev *rdev, |
aa66cc66 CZ |
83 | unsigned selector) |
84 | { | |
ab101e35 | 85 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
aa66cc66 | 86 | |
ab101e35 | 87 | if (selector >= rdev->desc->n_voltages) |
aa66cc66 CZ |
88 | return -EINVAL; |
89 | ||
90 | return drvdata->duty_cycle_table[selector].uV; | |
91 | } | |
4773be18 | 92 | |
1de7d802 BB |
93 | static int pwm_regulator_enable(struct regulator_dev *dev) |
94 | { | |
95 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
96 | ||
97 | return pwm_enable(drvdata->pwm); | |
98 | } | |
99 | ||
100 | static int pwm_regulator_disable(struct regulator_dev *dev) | |
101 | { | |
102 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
103 | ||
104 | pwm_disable(drvdata->pwm); | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | static int pwm_regulator_is_enabled(struct regulator_dev *dev) | |
110 | { | |
111 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
112 | ||
113 | return pwm_is_enabled(drvdata->pwm); | |
114 | } | |
115 | ||
4773be18 LJ |
116 | /** |
117 | * Continuous voltage call-backs | |
118 | */ | |
f3f6439d | 119 | static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int req_uV) |
4773be18 | 120 | { |
cae897de LJ |
121 | int min_uV = rdev->constraints->min_uV; |
122 | int max_uV = rdev->constraints->max_uV; | |
123 | int diff = max_uV - min_uV; | |
124 | ||
1aaab348 | 125 | return ((req_uV * 100) - (min_uV * 100)) / diff; |
4773be18 LJ |
126 | } |
127 | ||
128 | static int pwm_regulator_get_voltage(struct regulator_dev *rdev) | |
129 | { | |
130 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
131 | ||
132 | return drvdata->volt_uV; | |
133 | } | |
134 | ||
135 | static int pwm_regulator_set_voltage(struct regulator_dev *rdev, | |
136 | int min_uV, int max_uV, | |
137 | unsigned *selector) | |
138 | { | |
139 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
140 | unsigned int ramp_delay = rdev->constraints->ramp_delay; | |
f3f6439d | 141 | unsigned int period = pwm_get_period(drvdata->pwm); |
4773be18 LJ |
142 | int duty_cycle; |
143 | int ret; | |
144 | ||
f3f6439d | 145 | duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV); |
4773be18 | 146 | |
f3f6439d | 147 | ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period); |
4773be18 LJ |
148 | if (ret) { |
149 | dev_err(&rdev->dev, "Failed to configure PWM\n"); | |
150 | return ret; | |
151 | } | |
152 | ||
153 | ret = pwm_enable(drvdata->pwm); | |
154 | if (ret) { | |
155 | dev_err(&rdev->dev, "Failed to enable PWM\n"); | |
156 | return ret; | |
157 | } | |
158 | drvdata->volt_uV = min_uV; | |
159 | ||
160 | /* Delay required by PWM regulator to settle to the new voltage */ | |
161 | usleep_range(ramp_delay, ramp_delay + 1000); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
f9178dad | 166 | static struct regulator_ops pwm_regulator_voltage_table_ops = { |
aa66cc66 CZ |
167 | .set_voltage_sel = pwm_regulator_set_voltage_sel, |
168 | .get_voltage_sel = pwm_regulator_get_voltage_sel, | |
169 | .list_voltage = pwm_regulator_list_voltage, | |
170 | .map_voltage = regulator_map_voltage_iterate, | |
1de7d802 BB |
171 | .enable = pwm_regulator_enable, |
172 | .disable = pwm_regulator_disable, | |
173 | .is_enabled = pwm_regulator_is_enabled, | |
aa66cc66 CZ |
174 | }; |
175 | ||
4773be18 LJ |
176 | static struct regulator_ops pwm_regulator_voltage_continuous_ops = { |
177 | .get_voltage = pwm_regulator_get_voltage, | |
178 | .set_voltage = pwm_regulator_set_voltage, | |
1de7d802 BB |
179 | .enable = pwm_regulator_enable, |
180 | .disable = pwm_regulator_disable, | |
181 | .is_enabled = pwm_regulator_is_enabled, | |
4773be18 LJ |
182 | }; |
183 | ||
b6f55e74 | 184 | static struct regulator_desc pwm_regulator_desc = { |
aa66cc66 | 185 | .name = "pwm-regulator", |
aa66cc66 CZ |
186 | .type = REGULATOR_VOLTAGE, |
187 | .owner = THIS_MODULE, | |
188 | .supply_name = "pwm", | |
189 | }; | |
190 | ||
f9178dad LJ |
191 | static int pwm_regulator_init_table(struct platform_device *pdev, |
192 | struct pwm_regulator_data *drvdata) | |
193 | { | |
194 | struct device_node *np = pdev->dev.of_node; | |
195 | struct pwm_voltages *duty_cycle_table; | |
60cb65eb | 196 | unsigned int length = 0; |
f9178dad LJ |
197 | int ret; |
198 | ||
199 | of_find_property(np, "voltage-table", &length); | |
200 | ||
201 | if ((length < sizeof(*duty_cycle_table)) || | |
202 | (length % sizeof(*duty_cycle_table))) { | |
203 | dev_err(&pdev->dev, | |
204 | "voltage-table length(%d) is invalid\n", | |
205 | length); | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); | |
210 | if (!duty_cycle_table) | |
211 | return -ENOMEM; | |
212 | ||
213 | ret = of_property_read_u32_array(np, "voltage-table", | |
214 | (u32 *)duty_cycle_table, | |
215 | length / sizeof(u32)); | |
216 | if (ret) { | |
217 | dev_err(&pdev->dev, "Failed to read voltage-table\n"); | |
218 | return ret; | |
219 | } | |
220 | ||
221 | drvdata->duty_cycle_table = duty_cycle_table; | |
f907a0a9 LD |
222 | memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops, |
223 | sizeof(drvdata->ops)); | |
224 | drvdata->desc.ops = &drvdata->ops; | |
225 | drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table); | |
f9178dad LJ |
226 | |
227 | return 0; | |
228 | } | |
229 | ||
4773be18 LJ |
230 | static int pwm_regulator_init_continuous(struct platform_device *pdev, |
231 | struct pwm_regulator_data *drvdata) | |
232 | { | |
f907a0a9 LD |
233 | memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops, |
234 | sizeof(drvdata->ops)); | |
235 | drvdata->desc.ops = &drvdata->ops; | |
236 | drvdata->desc.continuous_voltage_range = true; | |
4773be18 LJ |
237 | |
238 | return 0; | |
239 | } | |
240 | ||
aa66cc66 CZ |
241 | static int pwm_regulator_probe(struct platform_device *pdev) |
242 | { | |
5ad2cb14 | 243 | const struct regulator_init_data *init_data; |
aa66cc66 | 244 | struct pwm_regulator_data *drvdata; |
aa66cc66 CZ |
245 | struct regulator_dev *regulator; |
246 | struct regulator_config config = { }; | |
247 | struct device_node *np = pdev->dev.of_node; | |
f9178dad | 248 | int ret; |
aa66cc66 CZ |
249 | |
250 | if (!np) { | |
251 | dev_err(&pdev->dev, "Device Tree node missing\n"); | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); | |
256 | if (!drvdata) | |
257 | return -ENOMEM; | |
258 | ||
f907a0a9 LD |
259 | memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc)); |
260 | ||
4773be18 | 261 | if (of_find_property(np, "voltage-table", NULL)) |
f9178dad | 262 | ret = pwm_regulator_init_table(pdev, drvdata); |
4773be18 LJ |
263 | else |
264 | ret = pwm_regulator_init_continuous(pdev, drvdata); | |
265 | if (ret) | |
266 | return ret; | |
aa66cc66 | 267 | |
5ad2cb14 | 268 | init_data = of_get_regulator_init_data(&pdev->dev, np, |
f907a0a9 | 269 | &drvdata->desc); |
5ad2cb14 | 270 | if (!init_data) |
aa66cc66 CZ |
271 | return -ENOMEM; |
272 | ||
273 | config.of_node = np; | |
274 | config.dev = &pdev->dev; | |
275 | config.driver_data = drvdata; | |
5ad2cb14 | 276 | config.init_data = init_data; |
aa66cc66 CZ |
277 | |
278 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); | |
279 | if (IS_ERR(drvdata->pwm)) { | |
280 | dev_err(&pdev->dev, "Failed to get PWM\n"); | |
281 | return PTR_ERR(drvdata->pwm); | |
282 | } | |
283 | ||
284 | regulator = devm_regulator_register(&pdev->dev, | |
f907a0a9 | 285 | &drvdata->desc, &config); |
aa66cc66 CZ |
286 | if (IS_ERR(regulator)) { |
287 | dev_err(&pdev->dev, "Failed to register regulator %s\n", | |
f907a0a9 | 288 | drvdata->desc.name); |
aa66cc66 CZ |
289 | return PTR_ERR(regulator); |
290 | } | |
291 | ||
292 | return 0; | |
293 | } | |
294 | ||
295 | static const struct of_device_id pwm_of_match[] = { | |
296 | { .compatible = "pwm-regulator" }, | |
297 | { }, | |
298 | }; | |
299 | MODULE_DEVICE_TABLE(of, pwm_of_match); | |
300 | ||
301 | static struct platform_driver pwm_regulator_driver = { | |
302 | .driver = { | |
303 | .name = "pwm-regulator", | |
aa66cc66 CZ |
304 | .of_match_table = of_match_ptr(pwm_of_match), |
305 | }, | |
306 | .probe = pwm_regulator_probe, | |
307 | }; | |
308 | ||
309 | module_platform_driver(pwm_regulator_driver); | |
310 | ||
311 | MODULE_LICENSE("GPL"); | |
312 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
313 | MODULE_DESCRIPTION("PWM Regulator Driver"); | |
314 | MODULE_ALIAS("platform:pwm-regulator"); |