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