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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) | |
68 | #define MODE1_SLEEP (1 << 4) | |
69 | #define MODE2_INVRT (1 << 4) | |
70 | #define MODE2_OUTDRV (1 << 2) | |
71 | ||
72 | #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N))) | |
73 | #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N))) | |
74 | #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) | |
75 | #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) | |
76 | ||
77 | struct pca9685 { | |
78 | struct pwm_chip chip; | |
79 | struct regmap *regmap; | |
80 | int active_cnt; | |
01ec8472 CG |
81 | int duty_ns; |
82 | int period_ns; | |
88b613e6 ST |
83 | }; |
84 | ||
85 | static inline struct pca9685 *to_pca(struct pwm_chip *chip) | |
86 | { | |
87 | return container_of(chip, struct pca9685, chip); | |
88 | } | |
89 | ||
90 | static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
91 | int duty_ns, int period_ns) | |
92 | { | |
93 | struct pca9685 *pca = to_pca(chip); | |
94 | unsigned long long duty; | |
95 | unsigned int reg; | |
01ec8472 CG |
96 | int prescale; |
97 | ||
98 | if (period_ns != pca->period_ns) { | |
99 | prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns, | |
100 | PCA9685_COUNTER_RANGE * 1000) - 1; | |
101 | ||
102 | if (prescale >= PCA9685_PRESCALE_MIN && | |
103 | prescale <= PCA9685_PRESCALE_MAX) { | |
104 | /* Put chip into sleep mode */ | |
105 | regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
106 | MODE1_SLEEP, MODE1_SLEEP); | |
107 | ||
108 | /* Change the chip-wide output frequency */ | |
109 | regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); | |
110 | ||
111 | /* Wake the chip up */ | |
112 | regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
113 | MODE1_SLEEP, 0x0); | |
114 | ||
115 | /* Wait 500us for the oscillator to be back up */ | |
116 | udelay(500); | |
117 | ||
118 | pca->period_ns = period_ns; | |
01ec8472 CG |
119 | } else { |
120 | dev_err(chip->dev, | |
121 | "prescaler not set: period out of bounds!\n"); | |
122 | return -EINVAL; | |
123 | } | |
124 | } | |
125 | ||
126 | pca->duty_ns = duty_ns; | |
88b613e6 ST |
127 | |
128 | if (duty_ns < 1) { | |
129 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
130 | reg = PCA9685_ALL_LED_OFF_H; | |
131 | else | |
132 | reg = LED_N_OFF_H(pwm->hwpwm); | |
133 | ||
134 | regmap_write(pca->regmap, reg, LED_FULL); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | if (duty_ns == period_ns) { | |
4a627b52 CG |
140 | /* Clear both OFF registers */ |
141 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
142 | reg = PCA9685_ALL_LED_OFF_L; | |
143 | else | |
144 | reg = LED_N_OFF_L(pwm->hwpwm); | |
145 | ||
146 | regmap_write(pca->regmap, reg, 0x0); | |
147 | ||
148 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
149 | reg = PCA9685_ALL_LED_OFF_H; | |
150 | else | |
151 | reg = LED_N_OFF_H(pwm->hwpwm); | |
152 | ||
153 | regmap_write(pca->regmap, reg, 0x0); | |
154 | ||
155 | /* Set the full ON bit */ | |
88b613e6 ST |
156 | if (pwm->hwpwm >= PCA9685_MAXCHAN) |
157 | reg = PCA9685_ALL_LED_ON_H; | |
158 | else | |
159 | reg = LED_N_ON_H(pwm->hwpwm); | |
160 | ||
161 | regmap_write(pca->regmap, reg, LED_FULL); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
01ec8472 | 166 | duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns; |
88b613e6 ST |
167 | duty = DIV_ROUND_UP_ULL(duty, period_ns); |
168 | ||
169 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
170 | reg = PCA9685_ALL_LED_OFF_L; | |
171 | else | |
172 | reg = LED_N_OFF_L(pwm->hwpwm); | |
173 | ||
174 | regmap_write(pca->regmap, reg, (int)duty & 0xff); | |
175 | ||
176 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
177 | reg = PCA9685_ALL_LED_OFF_H; | |
178 | else | |
179 | reg = LED_N_OFF_H(pwm->hwpwm); | |
180 | ||
181 | regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); | |
182 | ||
4a627b52 CG |
183 | /* Clear the full ON bit, otherwise the set OFF time has no effect */ |
184 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
185 | reg = PCA9685_ALL_LED_ON_H; | |
186 | else | |
187 | reg = LED_N_ON_H(pwm->hwpwm); | |
188 | ||
189 | regmap_write(pca->regmap, reg, 0); | |
190 | ||
88b613e6 ST |
191 | return 0; |
192 | } | |
193 | ||
194 | static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
195 | { | |
196 | struct pca9685 *pca = to_pca(chip); | |
197 | unsigned int reg; | |
198 | ||
199 | /* | |
200 | * The PWM subsystem does not support a pre-delay. | |
201 | * So, set the ON-timeout to 0 | |
202 | */ | |
203 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
204 | reg = PCA9685_ALL_LED_ON_L; | |
205 | else | |
206 | reg = LED_N_ON_L(pwm->hwpwm); | |
207 | ||
208 | regmap_write(pca->regmap, reg, 0); | |
209 | ||
210 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
211 | reg = PCA9685_ALL_LED_ON_H; | |
212 | else | |
213 | reg = LED_N_ON_H(pwm->hwpwm); | |
214 | ||
215 | regmap_write(pca->regmap, reg, 0); | |
216 | ||
217 | /* | |
218 | * Clear the full-off bit. | |
219 | * It has precedence over the others and must be off. | |
220 | */ | |
221 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
222 | reg = PCA9685_ALL_LED_OFF_H; | |
223 | else | |
224 | reg = LED_N_OFF_H(pwm->hwpwm); | |
225 | ||
226 | regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0); | |
227 | ||
228 | return 0; | |
229 | } | |
230 | ||
231 | static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
232 | { | |
233 | struct pca9685 *pca = to_pca(chip); | |
234 | unsigned int reg; | |
235 | ||
236 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
237 | reg = PCA9685_ALL_LED_OFF_H; | |
238 | else | |
239 | reg = LED_N_OFF_H(pwm->hwpwm); | |
240 | ||
241 | regmap_write(pca->regmap, reg, LED_FULL); | |
242 | ||
243 | /* Clear the LED_OFF counter. */ | |
244 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
245 | reg = PCA9685_ALL_LED_OFF_L; | |
246 | else | |
247 | reg = LED_N_OFF_L(pwm->hwpwm); | |
248 | ||
249 | regmap_write(pca->regmap, reg, 0x0); | |
250 | } | |
251 | ||
252 | static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) | |
253 | { | |
254 | struct pca9685 *pca = to_pca(chip); | |
255 | ||
256 | if (pca->active_cnt++ == 0) | |
257 | return regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
258 | MODE1_SLEEP, 0x0); | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
263 | static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
264 | { | |
265 | struct pca9685 *pca = to_pca(chip); | |
266 | ||
267 | if (--pca->active_cnt == 0) | |
268 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, | |
fed1bf8d | 269 | MODE1_SLEEP); |
88b613e6 ST |
270 | } |
271 | ||
272 | static const struct pwm_ops pca9685_pwm_ops = { | |
273 | .enable = pca9685_pwm_enable, | |
274 | .disable = pca9685_pwm_disable, | |
275 | .config = pca9685_pwm_config, | |
276 | .request = pca9685_pwm_request, | |
277 | .free = pca9685_pwm_free, | |
3dd0a909 | 278 | .owner = THIS_MODULE, |
88b613e6 ST |
279 | }; |
280 | ||
c456fbb2 | 281 | static const struct regmap_config pca9685_regmap_i2c_config = { |
88b613e6 ST |
282 | .reg_bits = 8, |
283 | .val_bits = 8, | |
284 | .max_register = PCA9685_NUMREGS, | |
285 | .cache_type = REGCACHE_NONE, | |
286 | }; | |
287 | ||
288 | static int pca9685_pwm_probe(struct i2c_client *client, | |
289 | const struct i2c_device_id *id) | |
290 | { | |
88b613e6 ST |
291 | struct pca9685 *pca; |
292 | int ret; | |
293 | int mode2; | |
294 | ||
295 | pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); | |
296 | if (!pca) | |
297 | return -ENOMEM; | |
298 | ||
299 | pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config); | |
300 | if (IS_ERR(pca->regmap)) { | |
301 | ret = PTR_ERR(pca->regmap); | |
302 | dev_err(&client->dev, "Failed to initialize register map: %d\n", | |
303 | ret); | |
304 | return ret; | |
305 | } | |
01ec8472 CG |
306 | pca->duty_ns = 0; |
307 | pca->period_ns = PCA9685_DEFAULT_PERIOD; | |
88b613e6 ST |
308 | |
309 | i2c_set_clientdata(client, pca); | |
310 | ||
311 | regmap_read(pca->regmap, PCA9685_MODE2, &mode2); | |
312 | ||
912b8439 | 313 | if (device_property_read_bool(&client->dev, "invert")) |
88b613e6 ST |
314 | mode2 |= MODE2_INVRT; |
315 | else | |
316 | mode2 &= ~MODE2_INVRT; | |
317 | ||
912b8439 | 318 | if (device_property_read_bool(&client->dev, "open-drain")) |
88b613e6 ST |
319 | mode2 &= ~MODE2_OUTDRV; |
320 | else | |
321 | mode2 |= MODE2_OUTDRV; | |
322 | ||
323 | regmap_write(pca->regmap, PCA9685_MODE2, mode2); | |
324 | ||
325 | /* clear all "full off" bits */ | |
326 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); | |
327 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); | |
328 | ||
329 | pca->chip.ops = &pca9685_pwm_ops; | |
330 | /* add an extra channel for ALL_LED */ | |
331 | pca->chip.npwm = PCA9685_MAXCHAN + 1; | |
332 | ||
333 | pca->chip.dev = &client->dev; | |
334 | pca->chip.base = -1; | |
335 | pca->chip.can_sleep = true; | |
336 | ||
337 | return pwmchip_add(&pca->chip); | |
338 | } | |
339 | ||
340 | static int pca9685_pwm_remove(struct i2c_client *client) | |
341 | { | |
342 | struct pca9685 *pca = i2c_get_clientdata(client); | |
343 | ||
fed1bf8d AL |
344 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, |
345 | MODE1_SLEEP); | |
88b613e6 ST |
346 | |
347 | return pwmchip_remove(&pca->chip); | |
348 | } | |
349 | ||
350 | static const struct i2c_device_id pca9685_id[] = { | |
351 | { "pca9685", 0 }, | |
352 | { /* sentinel */ }, | |
353 | }; | |
354 | MODULE_DEVICE_TABLE(i2c, pca9685_id); | |
355 | ||
912b8439 AS |
356 | #ifdef CONFIG_ACPI |
357 | static const struct acpi_device_id pca9685_acpi_ids[] = { | |
358 | { "INT3492", 0 }, | |
359 | { /* sentinel */ }, | |
360 | }; | |
361 | MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids); | |
362 | #endif | |
363 | ||
364 | #ifdef CONFIG_OF | |
88b613e6 ST |
365 | static const struct of_device_id pca9685_dt_ids[] = { |
366 | { .compatible = "nxp,pca9685-pwm", }, | |
367 | { /* sentinel */ } | |
368 | }; | |
369 | MODULE_DEVICE_TABLE(of, pca9685_dt_ids); | |
912b8439 | 370 | #endif |
88b613e6 ST |
371 | |
372 | static struct i2c_driver pca9685_i2c_driver = { | |
373 | .driver = { | |
374 | .name = "pca9685-pwm", | |
912b8439 AS |
375 | .acpi_match_table = ACPI_PTR(pca9685_acpi_ids), |
376 | .of_match_table = of_match_ptr(pca9685_dt_ids), | |
88b613e6 ST |
377 | }, |
378 | .probe = pca9685_pwm_probe, | |
379 | .remove = pca9685_pwm_remove, | |
380 | .id_table = pca9685_id, | |
381 | }; | |
382 | ||
383 | module_i2c_driver(pca9685_i2c_driver); | |
384 | ||
385 | MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>"); | |
386 | MODULE_DESCRIPTION("PWM driver for PCA9685"); | |
387 | MODULE_LICENSE("GPL"); |