Commit | Line | Data |
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88b613e6 ST |
1 | /* |
2 | * Driver for PCA9685 16-channel 12-bit PWM LED controller | |
3 | * | |
4 | * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de> | |
01ec8472 | 5 | * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com> |
88b613e6 ST |
6 | * |
7 | * based on the pwm-twl-led.c driver | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public License version 2 as published by | |
11 | * the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
16 | * more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License along with | |
19 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
20 | */ | |
21 | ||
912b8439 | 22 | #include <linux/acpi.h> |
88b613e6 ST |
23 | #include <linux/i2c.h> |
24 | #include <linux/module.h> | |
25 | #include <linux/platform_device.h> | |
912b8439 | 26 | #include <linux/property.h> |
88b613e6 ST |
27 | #include <linux/pwm.h> |
28 | #include <linux/regmap.h> | |
29 | #include <linux/slab.h> | |
01ec8472 CG |
30 | #include <linux/delay.h> |
31 | ||
32 | /* | |
33 | * Because the PCA9685 has only one prescaler per chip, changing the period of | |
34 | * one channel affects the period of all 16 PWM outputs! | |
35 | * However, the ratio between each configured duty cycle and the chip-wide | |
36 | * period remains constant, because the OFF time is set in proportion to the | |
37 | * counter range. | |
38 | */ | |
88b613e6 ST |
39 | |
40 | #define PCA9685_MODE1 0x00 | |
41 | #define PCA9685_MODE2 0x01 | |
42 | #define PCA9685_SUBADDR1 0x02 | |
43 | #define PCA9685_SUBADDR2 0x03 | |
44 | #define PCA9685_SUBADDR3 0x04 | |
45 | #define PCA9685_ALLCALLADDR 0x05 | |
46 | #define PCA9685_LEDX_ON_L 0x06 | |
47 | #define PCA9685_LEDX_ON_H 0x07 | |
48 | #define PCA9685_LEDX_OFF_L 0x08 | |
49 | #define PCA9685_LEDX_OFF_H 0x09 | |
50 | ||
51 | #define PCA9685_ALL_LED_ON_L 0xFA | |
52 | #define PCA9685_ALL_LED_ON_H 0xFB | |
53 | #define PCA9685_ALL_LED_OFF_L 0xFC | |
54 | #define PCA9685_ALL_LED_OFF_H 0xFD | |
55 | #define PCA9685_PRESCALE 0xFE | |
56 | ||
01ec8472 CG |
57 | #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */ |
58 | #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */ | |
59 | ||
60 | #define PCA9685_COUNTER_RANGE 4096 | |
61 | #define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */ | |
62 | #define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */ | |
63 | ||
88b613e6 ST |
64 | #define PCA9685_NUMREGS 0xFF |
65 | #define PCA9685_MAXCHAN 0x10 | |
66 | ||
67 | #define LED_FULL (1 << 4) | |
01ec8472 | 68 | #define MODE1_RESTART (1 << 7) |
88b613e6 ST |
69 | #define MODE1_SLEEP (1 << 4) |
70 | #define MODE2_INVRT (1 << 4) | |
71 | #define MODE2_OUTDRV (1 << 2) | |
72 | ||
73 | #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N))) | |
74 | #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N))) | |
75 | #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) | |
76 | #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) | |
77 | ||
78 | struct pca9685 { | |
79 | struct pwm_chip chip; | |
80 | struct regmap *regmap; | |
81 | int active_cnt; | |
01ec8472 CG |
82 | int duty_ns; |
83 | int period_ns; | |
88b613e6 ST |
84 | }; |
85 | ||
86 | static inline struct pca9685 *to_pca(struct pwm_chip *chip) | |
87 | { | |
88 | return container_of(chip, struct pca9685, chip); | |
89 | } | |
90 | ||
91 | static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
92 | int duty_ns, int period_ns) | |
93 | { | |
94 | struct pca9685 *pca = to_pca(chip); | |
95 | unsigned long long duty; | |
96 | unsigned int reg; | |
01ec8472 CG |
97 | int prescale; |
98 | ||
99 | if (period_ns != pca->period_ns) { | |
100 | prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns, | |
101 | PCA9685_COUNTER_RANGE * 1000) - 1; | |
102 | ||
103 | if (prescale >= PCA9685_PRESCALE_MIN && | |
104 | prescale <= PCA9685_PRESCALE_MAX) { | |
105 | /* Put chip into sleep mode */ | |
106 | regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
107 | MODE1_SLEEP, MODE1_SLEEP); | |
108 | ||
109 | /* Change the chip-wide output frequency */ | |
110 | regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); | |
111 | ||
112 | /* Wake the chip up */ | |
113 | regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
114 | MODE1_SLEEP, 0x0); | |
115 | ||
116 | /* Wait 500us for the oscillator to be back up */ | |
117 | udelay(500); | |
118 | ||
119 | pca->period_ns = period_ns; | |
120 | ||
121 | /* | |
122 | * If the duty cycle did not change, restart PWM with | |
123 | * the same duty cycle to period ratio and return. | |
124 | */ | |
125 | if (duty_ns == pca->duty_ns) { | |
126 | regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
127 | MODE1_RESTART, 0x1); | |
128 | return 0; | |
129 | } | |
130 | } else { | |
131 | dev_err(chip->dev, | |
132 | "prescaler not set: period out of bounds!\n"); | |
133 | return -EINVAL; | |
134 | } | |
135 | } | |
136 | ||
137 | pca->duty_ns = duty_ns; | |
88b613e6 ST |
138 | |
139 | if (duty_ns < 1) { | |
140 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
141 | reg = PCA9685_ALL_LED_OFF_H; | |
142 | else | |
143 | reg = LED_N_OFF_H(pwm->hwpwm); | |
144 | ||
145 | regmap_write(pca->regmap, reg, LED_FULL); | |
146 | ||
147 | return 0; | |
148 | } | |
149 | ||
150 | if (duty_ns == period_ns) { | |
4a627b52 CG |
151 | /* Clear both OFF registers */ |
152 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
153 | reg = PCA9685_ALL_LED_OFF_L; | |
154 | else | |
155 | reg = LED_N_OFF_L(pwm->hwpwm); | |
156 | ||
157 | regmap_write(pca->regmap, reg, 0x0); | |
158 | ||
159 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
160 | reg = PCA9685_ALL_LED_OFF_H; | |
161 | else | |
162 | reg = LED_N_OFF_H(pwm->hwpwm); | |
163 | ||
164 | regmap_write(pca->regmap, reg, 0x0); | |
165 | ||
166 | /* Set the full ON bit */ | |
88b613e6 ST |
167 | if (pwm->hwpwm >= PCA9685_MAXCHAN) |
168 | reg = PCA9685_ALL_LED_ON_H; | |
169 | else | |
170 | reg = LED_N_ON_H(pwm->hwpwm); | |
171 | ||
172 | regmap_write(pca->regmap, reg, LED_FULL); | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
01ec8472 | 177 | duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns; |
88b613e6 ST |
178 | duty = DIV_ROUND_UP_ULL(duty, period_ns); |
179 | ||
180 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
181 | reg = PCA9685_ALL_LED_OFF_L; | |
182 | else | |
183 | reg = LED_N_OFF_L(pwm->hwpwm); | |
184 | ||
185 | regmap_write(pca->regmap, reg, (int)duty & 0xff); | |
186 | ||
187 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
188 | reg = PCA9685_ALL_LED_OFF_H; | |
189 | else | |
190 | reg = LED_N_OFF_H(pwm->hwpwm); | |
191 | ||
192 | regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); | |
193 | ||
4a627b52 CG |
194 | /* Clear the full ON bit, otherwise the set OFF time has no effect */ |
195 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
196 | reg = PCA9685_ALL_LED_ON_H; | |
197 | else | |
198 | reg = LED_N_ON_H(pwm->hwpwm); | |
199 | ||
200 | regmap_write(pca->regmap, reg, 0); | |
201 | ||
88b613e6 ST |
202 | return 0; |
203 | } | |
204 | ||
205 | static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
206 | { | |
207 | struct pca9685 *pca = to_pca(chip); | |
208 | unsigned int reg; | |
209 | ||
210 | /* | |
211 | * The PWM subsystem does not support a pre-delay. | |
212 | * So, set the ON-timeout to 0 | |
213 | */ | |
214 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
215 | reg = PCA9685_ALL_LED_ON_L; | |
216 | else | |
217 | reg = LED_N_ON_L(pwm->hwpwm); | |
218 | ||
219 | regmap_write(pca->regmap, reg, 0); | |
220 | ||
221 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
222 | reg = PCA9685_ALL_LED_ON_H; | |
223 | else | |
224 | reg = LED_N_ON_H(pwm->hwpwm); | |
225 | ||
226 | regmap_write(pca->regmap, reg, 0); | |
227 | ||
228 | /* | |
229 | * Clear the full-off bit. | |
230 | * It has precedence over the others and must be off. | |
231 | */ | |
232 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
233 | reg = PCA9685_ALL_LED_OFF_H; | |
234 | else | |
235 | reg = LED_N_OFF_H(pwm->hwpwm); | |
236 | ||
237 | regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0); | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
243 | { | |
244 | struct pca9685 *pca = to_pca(chip); | |
245 | unsigned int reg; | |
246 | ||
247 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
248 | reg = PCA9685_ALL_LED_OFF_H; | |
249 | else | |
250 | reg = LED_N_OFF_H(pwm->hwpwm); | |
251 | ||
252 | regmap_write(pca->regmap, reg, LED_FULL); | |
253 | ||
254 | /* Clear the LED_OFF counter. */ | |
255 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
256 | reg = PCA9685_ALL_LED_OFF_L; | |
257 | else | |
258 | reg = LED_N_OFF_L(pwm->hwpwm); | |
259 | ||
260 | regmap_write(pca->regmap, reg, 0x0); | |
261 | } | |
262 | ||
263 | static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) | |
264 | { | |
265 | struct pca9685 *pca = to_pca(chip); | |
266 | ||
267 | if (pca->active_cnt++ == 0) | |
268 | return regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
269 | MODE1_SLEEP, 0x0); | |
270 | ||
271 | return 0; | |
272 | } | |
273 | ||
274 | static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
275 | { | |
276 | struct pca9685 *pca = to_pca(chip); | |
277 | ||
278 | if (--pca->active_cnt == 0) | |
279 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, | |
fed1bf8d | 280 | MODE1_SLEEP); |
88b613e6 ST |
281 | } |
282 | ||
283 | static const struct pwm_ops pca9685_pwm_ops = { | |
284 | .enable = pca9685_pwm_enable, | |
285 | .disable = pca9685_pwm_disable, | |
286 | .config = pca9685_pwm_config, | |
287 | .request = pca9685_pwm_request, | |
288 | .free = pca9685_pwm_free, | |
3dd0a909 | 289 | .owner = THIS_MODULE, |
88b613e6 ST |
290 | }; |
291 | ||
c456fbb2 | 292 | static const struct regmap_config pca9685_regmap_i2c_config = { |
88b613e6 ST |
293 | .reg_bits = 8, |
294 | .val_bits = 8, | |
295 | .max_register = PCA9685_NUMREGS, | |
296 | .cache_type = REGCACHE_NONE, | |
297 | }; | |
298 | ||
299 | static int pca9685_pwm_probe(struct i2c_client *client, | |
300 | const struct i2c_device_id *id) | |
301 | { | |
88b613e6 ST |
302 | struct pca9685 *pca; |
303 | int ret; | |
304 | int mode2; | |
305 | ||
306 | pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); | |
307 | if (!pca) | |
308 | return -ENOMEM; | |
309 | ||
310 | pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config); | |
311 | if (IS_ERR(pca->regmap)) { | |
312 | ret = PTR_ERR(pca->regmap); | |
313 | dev_err(&client->dev, "Failed to initialize register map: %d\n", | |
314 | ret); | |
315 | return ret; | |
316 | } | |
01ec8472 CG |
317 | pca->duty_ns = 0; |
318 | pca->period_ns = PCA9685_DEFAULT_PERIOD; | |
88b613e6 ST |
319 | |
320 | i2c_set_clientdata(client, pca); | |
321 | ||
322 | regmap_read(pca->regmap, PCA9685_MODE2, &mode2); | |
323 | ||
912b8439 | 324 | if (device_property_read_bool(&client->dev, "invert")) |
88b613e6 ST |
325 | mode2 |= MODE2_INVRT; |
326 | else | |
327 | mode2 &= ~MODE2_INVRT; | |
328 | ||
912b8439 | 329 | if (device_property_read_bool(&client->dev, "open-drain")) |
88b613e6 ST |
330 | mode2 &= ~MODE2_OUTDRV; |
331 | else | |
332 | mode2 |= MODE2_OUTDRV; | |
333 | ||
334 | regmap_write(pca->regmap, PCA9685_MODE2, mode2); | |
335 | ||
336 | /* clear all "full off" bits */ | |
337 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); | |
338 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); | |
339 | ||
340 | pca->chip.ops = &pca9685_pwm_ops; | |
341 | /* add an extra channel for ALL_LED */ | |
342 | pca->chip.npwm = PCA9685_MAXCHAN + 1; | |
343 | ||
344 | pca->chip.dev = &client->dev; | |
345 | pca->chip.base = -1; | |
346 | pca->chip.can_sleep = true; | |
347 | ||
348 | return pwmchip_add(&pca->chip); | |
349 | } | |
350 | ||
351 | static int pca9685_pwm_remove(struct i2c_client *client) | |
352 | { | |
353 | struct pca9685 *pca = i2c_get_clientdata(client); | |
354 | ||
fed1bf8d AL |
355 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, |
356 | MODE1_SLEEP); | |
88b613e6 ST |
357 | |
358 | return pwmchip_remove(&pca->chip); | |
359 | } | |
360 | ||
361 | static const struct i2c_device_id pca9685_id[] = { | |
362 | { "pca9685", 0 }, | |
363 | { /* sentinel */ }, | |
364 | }; | |
365 | MODULE_DEVICE_TABLE(i2c, pca9685_id); | |
366 | ||
912b8439 AS |
367 | #ifdef CONFIG_ACPI |
368 | static const struct acpi_device_id pca9685_acpi_ids[] = { | |
369 | { "INT3492", 0 }, | |
370 | { /* sentinel */ }, | |
371 | }; | |
372 | MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids); | |
373 | #endif | |
374 | ||
375 | #ifdef CONFIG_OF | |
88b613e6 ST |
376 | static const struct of_device_id pca9685_dt_ids[] = { |
377 | { .compatible = "nxp,pca9685-pwm", }, | |
378 | { /* sentinel */ } | |
379 | }; | |
380 | MODULE_DEVICE_TABLE(of, pca9685_dt_ids); | |
912b8439 | 381 | #endif |
88b613e6 ST |
382 | |
383 | static struct i2c_driver pca9685_i2c_driver = { | |
384 | .driver = { | |
385 | .name = "pca9685-pwm", | |
912b8439 AS |
386 | .acpi_match_table = ACPI_PTR(pca9685_acpi_ids), |
387 | .of_match_table = of_match_ptr(pca9685_dt_ids), | |
88b613e6 ST |
388 | }, |
389 | .probe = pca9685_pwm_probe, | |
390 | .remove = pca9685_pwm_remove, | |
391 | .id_table = pca9685_id, | |
392 | }; | |
393 | ||
394 | module_i2c_driver(pca9685_i2c_driver); | |
395 | ||
396 | MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>"); | |
397 | MODULE_DESCRIPTION("PWM driver for PCA9685"); | |
398 | MODULE_LICENSE("GPL"); |