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