Commit | Line | Data |
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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; | |
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); |
8c12ad8e | 62 | struct pwm_args pargs; |
aa66cc66 CZ |
63 | int dutycycle; |
64 | int ret; | |
65 | ||
8c12ad8e | 66 | pwm_get_args(drvdata->pwm, &pargs); |
aa66cc66 | 67 | |
8c12ad8e | 68 | dutycycle = (pargs.period * |
aa66cc66 CZ |
69 | drvdata->duty_cycle_table[selector].dutycycle) / 100; |
70 | ||
8c12ad8e | 71 | ret = pwm_config(drvdata->pwm, dutycycle, pargs.period); |
aa66cc66 | 72 | if (ret) { |
5bf59bd5 | 73 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
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 | static int pwm_regulator_get_voltage(struct regulator_dev *rdev) |
117 | { | |
118 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
119 | ||
120 | return drvdata->volt_uV; | |
121 | } | |
122 | ||
123 | static int pwm_regulator_set_voltage(struct regulator_dev *rdev, | |
124 | int min_uV, int max_uV, | |
125 | unsigned *selector) | |
126 | { | |
127 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); | |
128 | unsigned int ramp_delay = rdev->constraints->ramp_delay; | |
8c12ad8e | 129 | struct pwm_args pargs; |
fd786fb0 LD |
130 | unsigned int req_diff = min_uV - rdev->constraints->min_uV; |
131 | unsigned int diff; | |
132 | unsigned int duty_pulse; | |
133 | u64 req_period; | |
134 | u32 rem; | |
4773be18 LJ |
135 | int ret; |
136 | ||
8c12ad8e | 137 | pwm_get_args(drvdata->pwm, &pargs); |
fd786fb0 LD |
138 | diff = rdev->constraints->max_uV - rdev->constraints->min_uV; |
139 | ||
140 | /* First try to find out if we get the iduty cycle time which is | |
141 | * factor of PWM period time. If (request_diff_to_min * pwm_period) | |
142 | * is perfect divided by voltage_range_diff then it is possible to | |
143 | * get duty cycle time which is factor of PWM period. This will help | |
144 | * to get output voltage nearer to requested value as there is no | |
145 | * calculation loss. | |
146 | */ | |
bc0868c6 | 147 | req_period = req_diff * pargs.period; |
fd786fb0 LD |
148 | div_u64_rem(req_period, diff, &rem); |
149 | if (!rem) { | |
150 | do_div(req_period, diff); | |
151 | duty_pulse = (unsigned int)req_period; | |
152 | } else { | |
bc0868c6 | 153 | duty_pulse = (pargs.period / 100) * ((req_diff * 100) / diff); |
fd786fb0 | 154 | } |
4773be18 | 155 | |
bc0868c6 | 156 | ret = pwm_config(drvdata->pwm, duty_pulse, pargs.period); |
4773be18 | 157 | if (ret) { |
5bf59bd5 | 158 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
4773be18 LJ |
159 | return ret; |
160 | } | |
161 | ||
162 | ret = pwm_enable(drvdata->pwm); | |
163 | if (ret) { | |
5bf59bd5 | 164 | dev_err(&rdev->dev, "Failed to enable PWM: %d\n", ret); |
4773be18 LJ |
165 | return ret; |
166 | } | |
167 | drvdata->volt_uV = min_uV; | |
168 | ||
169 | /* Delay required by PWM regulator to settle to the new voltage */ | |
170 | usleep_range(ramp_delay, ramp_delay + 1000); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
f9178dad | 175 | static struct regulator_ops pwm_regulator_voltage_table_ops = { |
aa66cc66 CZ |
176 | .set_voltage_sel = pwm_regulator_set_voltage_sel, |
177 | .get_voltage_sel = pwm_regulator_get_voltage_sel, | |
178 | .list_voltage = pwm_regulator_list_voltage, | |
179 | .map_voltage = regulator_map_voltage_iterate, | |
1de7d802 BB |
180 | .enable = pwm_regulator_enable, |
181 | .disable = pwm_regulator_disable, | |
182 | .is_enabled = pwm_regulator_is_enabled, | |
aa66cc66 CZ |
183 | }; |
184 | ||
4773be18 LJ |
185 | static struct regulator_ops pwm_regulator_voltage_continuous_ops = { |
186 | .get_voltage = pwm_regulator_get_voltage, | |
187 | .set_voltage = pwm_regulator_set_voltage, | |
1de7d802 BB |
188 | .enable = pwm_regulator_enable, |
189 | .disable = pwm_regulator_disable, | |
190 | .is_enabled = pwm_regulator_is_enabled, | |
4773be18 LJ |
191 | }; |
192 | ||
b6f55e74 | 193 | static struct regulator_desc pwm_regulator_desc = { |
aa66cc66 | 194 | .name = "pwm-regulator", |
aa66cc66 CZ |
195 | .type = REGULATOR_VOLTAGE, |
196 | .owner = THIS_MODULE, | |
197 | .supply_name = "pwm", | |
198 | }; | |
199 | ||
f9178dad LJ |
200 | static int pwm_regulator_init_table(struct platform_device *pdev, |
201 | struct pwm_regulator_data *drvdata) | |
202 | { | |
203 | struct device_node *np = pdev->dev.of_node; | |
204 | struct pwm_voltages *duty_cycle_table; | |
60cb65eb | 205 | unsigned int length = 0; |
f9178dad LJ |
206 | int ret; |
207 | ||
208 | of_find_property(np, "voltage-table", &length); | |
209 | ||
210 | if ((length < sizeof(*duty_cycle_table)) || | |
211 | (length % sizeof(*duty_cycle_table))) { | |
5bf59bd5 | 212 | dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", |
f9178dad LJ |
213 | length); |
214 | return -EINVAL; | |
215 | } | |
216 | ||
217 | duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); | |
218 | if (!duty_cycle_table) | |
219 | return -ENOMEM; | |
220 | ||
221 | ret = of_property_read_u32_array(np, "voltage-table", | |
222 | (u32 *)duty_cycle_table, | |
223 | length / sizeof(u32)); | |
224 | if (ret) { | |
5bf59bd5 | 225 | dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret); |
f9178dad LJ |
226 | return ret; |
227 | } | |
228 | ||
229 | drvdata->duty_cycle_table = duty_cycle_table; | |
f907a0a9 LD |
230 | memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops, |
231 | sizeof(drvdata->ops)); | |
232 | drvdata->desc.ops = &drvdata->ops; | |
233 | drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table); | |
f9178dad LJ |
234 | |
235 | return 0; | |
236 | } | |
237 | ||
4773be18 LJ |
238 | static int pwm_regulator_init_continuous(struct platform_device *pdev, |
239 | struct pwm_regulator_data *drvdata) | |
240 | { | |
f907a0a9 LD |
241 | memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops, |
242 | sizeof(drvdata->ops)); | |
243 | drvdata->desc.ops = &drvdata->ops; | |
244 | drvdata->desc.continuous_voltage_range = true; | |
4773be18 LJ |
245 | |
246 | return 0; | |
247 | } | |
248 | ||
aa66cc66 CZ |
249 | static int pwm_regulator_probe(struct platform_device *pdev) |
250 | { | |
5ad2cb14 | 251 | const struct regulator_init_data *init_data; |
aa66cc66 | 252 | struct pwm_regulator_data *drvdata; |
aa66cc66 CZ |
253 | struct regulator_dev *regulator; |
254 | struct regulator_config config = { }; | |
255 | struct device_node *np = pdev->dev.of_node; | |
f9178dad | 256 | int ret; |
aa66cc66 CZ |
257 | |
258 | if (!np) { | |
259 | dev_err(&pdev->dev, "Device Tree node missing\n"); | |
260 | return -EINVAL; | |
261 | } | |
262 | ||
263 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); | |
264 | if (!drvdata) | |
265 | return -ENOMEM; | |
266 | ||
f907a0a9 LD |
267 | memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc)); |
268 | ||
4773be18 | 269 | if (of_find_property(np, "voltage-table", NULL)) |
f9178dad | 270 | ret = pwm_regulator_init_table(pdev, drvdata); |
4773be18 LJ |
271 | else |
272 | ret = pwm_regulator_init_continuous(pdev, drvdata); | |
273 | if (ret) | |
274 | return ret; | |
aa66cc66 | 275 | |
5ad2cb14 | 276 | init_data = of_get_regulator_init_data(&pdev->dev, np, |
f907a0a9 | 277 | &drvdata->desc); |
5ad2cb14 | 278 | if (!init_data) |
aa66cc66 CZ |
279 | return -ENOMEM; |
280 | ||
281 | config.of_node = np; | |
282 | config.dev = &pdev->dev; | |
283 | config.driver_data = drvdata; | |
5ad2cb14 | 284 | config.init_data = init_data; |
aa66cc66 CZ |
285 | |
286 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); | |
287 | if (IS_ERR(drvdata->pwm)) { | |
5bf59bd5 LD |
288 | ret = PTR_ERR(drvdata->pwm); |
289 | dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret); | |
290 | return ret; | |
aa66cc66 CZ |
291 | } |
292 | ||
8c12ad8e BB |
293 | /* |
294 | * FIXME: pwm_apply_args() should be removed when switching to the | |
295 | * atomic PWM API. | |
296 | */ | |
297 | pwm_apply_args(drvdata->pwm); | |
298 | ||
aa66cc66 | 299 | regulator = devm_regulator_register(&pdev->dev, |
f907a0a9 | 300 | &drvdata->desc, &config); |
aa66cc66 | 301 | if (IS_ERR(regulator)) { |
5bf59bd5 LD |
302 | ret = PTR_ERR(regulator); |
303 | dev_err(&pdev->dev, "Failed to register regulator %s: %d\n", | |
304 | drvdata->desc.name, ret); | |
305 | return ret; | |
aa66cc66 CZ |
306 | } |
307 | ||
308 | return 0; | |
309 | } | |
310 | ||
311 | static const struct of_device_id pwm_of_match[] = { | |
312 | { .compatible = "pwm-regulator" }, | |
313 | { }, | |
314 | }; | |
315 | MODULE_DEVICE_TABLE(of, pwm_of_match); | |
316 | ||
317 | static struct platform_driver pwm_regulator_driver = { | |
318 | .driver = { | |
319 | .name = "pwm-regulator", | |
aa66cc66 CZ |
320 | .of_match_table = of_match_ptr(pwm_of_match), |
321 | }, | |
322 | .probe = pwm_regulator_probe, | |
323 | }; | |
324 | ||
325 | module_platform_driver(pwm_regulator_driver); | |
326 | ||
327 | MODULE_LICENSE("GPL"); | |
328 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
329 | MODULE_DESCRIPTION("PWM Regulator Driver"); | |
330 | MODULE_ALIAS("platform:pwm-regulator"); |