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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> | |
5 | * | |
6 | * based on the pwm-twl-led.c driver | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published by | |
10 | * the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
15 | * more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along with | |
18 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
20 | ||
21 | #include <linux/i2c.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/pwm.h> | |
25 | #include <linux/regmap.h> | |
26 | #include <linux/slab.h> | |
27 | ||
28 | #define PCA9685_MODE1 0x00 | |
29 | #define PCA9685_MODE2 0x01 | |
30 | #define PCA9685_SUBADDR1 0x02 | |
31 | #define PCA9685_SUBADDR2 0x03 | |
32 | #define PCA9685_SUBADDR3 0x04 | |
33 | #define PCA9685_ALLCALLADDR 0x05 | |
34 | #define PCA9685_LEDX_ON_L 0x06 | |
35 | #define PCA9685_LEDX_ON_H 0x07 | |
36 | #define PCA9685_LEDX_OFF_L 0x08 | |
37 | #define PCA9685_LEDX_OFF_H 0x09 | |
38 | ||
39 | #define PCA9685_ALL_LED_ON_L 0xFA | |
40 | #define PCA9685_ALL_LED_ON_H 0xFB | |
41 | #define PCA9685_ALL_LED_OFF_L 0xFC | |
42 | #define PCA9685_ALL_LED_OFF_H 0xFD | |
43 | #define PCA9685_PRESCALE 0xFE | |
44 | ||
45 | #define PCA9685_NUMREGS 0xFF | |
46 | #define PCA9685_MAXCHAN 0x10 | |
47 | ||
48 | #define LED_FULL (1 << 4) | |
49 | #define MODE1_SLEEP (1 << 4) | |
50 | #define MODE2_INVRT (1 << 4) | |
51 | #define MODE2_OUTDRV (1 << 2) | |
52 | ||
53 | #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N))) | |
54 | #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N))) | |
55 | #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) | |
56 | #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) | |
57 | ||
58 | struct pca9685 { | |
59 | struct pwm_chip chip; | |
60 | struct regmap *regmap; | |
61 | int active_cnt; | |
62 | }; | |
63 | ||
64 | static inline struct pca9685 *to_pca(struct pwm_chip *chip) | |
65 | { | |
66 | return container_of(chip, struct pca9685, chip); | |
67 | } | |
68 | ||
69 | static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
70 | int duty_ns, int period_ns) | |
71 | { | |
72 | struct pca9685 *pca = to_pca(chip); | |
73 | unsigned long long duty; | |
74 | unsigned int reg; | |
75 | ||
76 | if (duty_ns < 1) { | |
77 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
78 | reg = PCA9685_ALL_LED_OFF_H; | |
79 | else | |
80 | reg = LED_N_OFF_H(pwm->hwpwm); | |
81 | ||
82 | regmap_write(pca->regmap, reg, LED_FULL); | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | if (duty_ns == period_ns) { | |
88 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
89 | reg = PCA9685_ALL_LED_ON_H; | |
90 | else | |
91 | reg = LED_N_ON_H(pwm->hwpwm); | |
92 | ||
93 | regmap_write(pca->regmap, reg, LED_FULL); | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | duty = 4096 * (unsigned long long)duty_ns; | |
99 | duty = DIV_ROUND_UP_ULL(duty, period_ns); | |
100 | ||
101 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
102 | reg = PCA9685_ALL_LED_OFF_L; | |
103 | else | |
104 | reg = LED_N_OFF_L(pwm->hwpwm); | |
105 | ||
106 | regmap_write(pca->regmap, reg, (int)duty & 0xff); | |
107 | ||
108 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
109 | reg = PCA9685_ALL_LED_OFF_H; | |
110 | else | |
111 | reg = LED_N_OFF_H(pwm->hwpwm); | |
112 | ||
113 | regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
119 | { | |
120 | struct pca9685 *pca = to_pca(chip); | |
121 | unsigned int reg; | |
122 | ||
123 | /* | |
124 | * The PWM subsystem does not support a pre-delay. | |
125 | * So, set the ON-timeout to 0 | |
126 | */ | |
127 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
128 | reg = PCA9685_ALL_LED_ON_L; | |
129 | else | |
130 | reg = LED_N_ON_L(pwm->hwpwm); | |
131 | ||
132 | regmap_write(pca->regmap, reg, 0); | |
133 | ||
134 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
135 | reg = PCA9685_ALL_LED_ON_H; | |
136 | else | |
137 | reg = LED_N_ON_H(pwm->hwpwm); | |
138 | ||
139 | regmap_write(pca->regmap, reg, 0); | |
140 | ||
141 | /* | |
142 | * Clear the full-off bit. | |
143 | * It has precedence over the others and must be off. | |
144 | */ | |
145 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
146 | reg = PCA9685_ALL_LED_OFF_H; | |
147 | else | |
148 | reg = LED_N_OFF_H(pwm->hwpwm); | |
149 | ||
150 | regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0); | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
156 | { | |
157 | struct pca9685 *pca = to_pca(chip); | |
158 | unsigned int reg; | |
159 | ||
160 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
161 | reg = PCA9685_ALL_LED_OFF_H; | |
162 | else | |
163 | reg = LED_N_OFF_H(pwm->hwpwm); | |
164 | ||
165 | regmap_write(pca->regmap, reg, LED_FULL); | |
166 | ||
167 | /* Clear the LED_OFF counter. */ | |
168 | if (pwm->hwpwm >= PCA9685_MAXCHAN) | |
169 | reg = PCA9685_ALL_LED_OFF_L; | |
170 | else | |
171 | reg = LED_N_OFF_L(pwm->hwpwm); | |
172 | ||
173 | regmap_write(pca->regmap, reg, 0x0); | |
174 | } | |
175 | ||
176 | static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) | |
177 | { | |
178 | struct pca9685 *pca = to_pca(chip); | |
179 | ||
180 | if (pca->active_cnt++ == 0) | |
181 | return regmap_update_bits(pca->regmap, PCA9685_MODE1, | |
182 | MODE1_SLEEP, 0x0); | |
183 | ||
184 | return 0; | |
185 | } | |
186 | ||
187 | static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
188 | { | |
189 | struct pca9685 *pca = to_pca(chip); | |
190 | ||
191 | if (--pca->active_cnt == 0) | |
192 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, | |
fed1bf8d | 193 | MODE1_SLEEP); |
88b613e6 ST |
194 | } |
195 | ||
196 | static const struct pwm_ops pca9685_pwm_ops = { | |
197 | .enable = pca9685_pwm_enable, | |
198 | .disable = pca9685_pwm_disable, | |
199 | .config = pca9685_pwm_config, | |
200 | .request = pca9685_pwm_request, | |
201 | .free = pca9685_pwm_free, | |
3dd0a909 | 202 | .owner = THIS_MODULE, |
88b613e6 ST |
203 | }; |
204 | ||
c456fbb2 | 205 | static const struct regmap_config pca9685_regmap_i2c_config = { |
88b613e6 ST |
206 | .reg_bits = 8, |
207 | .val_bits = 8, | |
208 | .max_register = PCA9685_NUMREGS, | |
209 | .cache_type = REGCACHE_NONE, | |
210 | }; | |
211 | ||
212 | static int pca9685_pwm_probe(struct i2c_client *client, | |
213 | const struct i2c_device_id *id) | |
214 | { | |
215 | struct device_node *np = client->dev.of_node; | |
216 | struct pca9685 *pca; | |
217 | int ret; | |
218 | int mode2; | |
219 | ||
220 | pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); | |
221 | if (!pca) | |
222 | return -ENOMEM; | |
223 | ||
224 | pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config); | |
225 | if (IS_ERR(pca->regmap)) { | |
226 | ret = PTR_ERR(pca->regmap); | |
227 | dev_err(&client->dev, "Failed to initialize register map: %d\n", | |
228 | ret); | |
229 | return ret; | |
230 | } | |
231 | ||
232 | i2c_set_clientdata(client, pca); | |
233 | ||
234 | regmap_read(pca->regmap, PCA9685_MODE2, &mode2); | |
235 | ||
236 | if (of_property_read_bool(np, "invert")) | |
237 | mode2 |= MODE2_INVRT; | |
238 | else | |
239 | mode2 &= ~MODE2_INVRT; | |
240 | ||
241 | if (of_property_read_bool(np, "open-drain")) | |
242 | mode2 &= ~MODE2_OUTDRV; | |
243 | else | |
244 | mode2 |= MODE2_OUTDRV; | |
245 | ||
246 | regmap_write(pca->regmap, PCA9685_MODE2, mode2); | |
247 | ||
248 | /* clear all "full off" bits */ | |
249 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); | |
250 | regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); | |
251 | ||
252 | pca->chip.ops = &pca9685_pwm_ops; | |
253 | /* add an extra channel for ALL_LED */ | |
254 | pca->chip.npwm = PCA9685_MAXCHAN + 1; | |
255 | ||
256 | pca->chip.dev = &client->dev; | |
257 | pca->chip.base = -1; | |
258 | pca->chip.can_sleep = true; | |
259 | ||
260 | return pwmchip_add(&pca->chip); | |
261 | } | |
262 | ||
263 | static int pca9685_pwm_remove(struct i2c_client *client) | |
264 | { | |
265 | struct pca9685 *pca = i2c_get_clientdata(client); | |
266 | ||
fed1bf8d AL |
267 | regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, |
268 | MODE1_SLEEP); | |
88b613e6 ST |
269 | |
270 | return pwmchip_remove(&pca->chip); | |
271 | } | |
272 | ||
273 | static const struct i2c_device_id pca9685_id[] = { | |
274 | { "pca9685", 0 }, | |
275 | { /* sentinel */ }, | |
276 | }; | |
277 | MODULE_DEVICE_TABLE(i2c, pca9685_id); | |
278 | ||
279 | static const struct of_device_id pca9685_dt_ids[] = { | |
280 | { .compatible = "nxp,pca9685-pwm", }, | |
281 | { /* sentinel */ } | |
282 | }; | |
283 | MODULE_DEVICE_TABLE(of, pca9685_dt_ids); | |
284 | ||
285 | static struct i2c_driver pca9685_i2c_driver = { | |
286 | .driver = { | |
287 | .name = "pca9685-pwm", | |
288 | .owner = THIS_MODULE, | |
289 | .of_match_table = pca9685_dt_ids, | |
290 | }, | |
291 | .probe = pca9685_pwm_probe, | |
292 | .remove = pca9685_pwm_remove, | |
293 | .id_table = pca9685_id, | |
294 | }; | |
295 | ||
296 | module_i2c_driver(pca9685_i2c_driver); | |
297 | ||
298 | MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>"); | |
299 | MODULE_DESCRIPTION("PWM driver for PCA9685"); | |
300 | MODULE_LICENSE("GPL"); |