1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver |
4 | * |
5 | * Copyright (C) 2012 Texas Instruments |
6 | * Author: Peter Ujfalusi <peter.ujfalusi@ti.com> |
7 | * |
8 | * This driver is a complete rewrite of the former pwm-twl6030.c authorded by: |
9 | * Hemanth V <hemanthv@ti.com> |
10 | * |
11 | * Reference manual for the twl6030 is available at: |
12 | * https://www.ti.com/lit/ds/symlink/twl6030.pdf |
13 | * |
14 | * Limitations: |
15 | * - The twl6030 hardware only supports two period lengths (128 clock ticks and |
16 | * 64 clock ticks), the driver only uses 128 ticks |
17 | * - The hardware doesn't support ON = 0, so the active part of a period doesn't |
18 | * start at its beginning. |
19 | * - The hardware could support inverted polarity (with a similar limitation as |
20 | * for normal: the last clock tick is always inactive). |
21 | * - The hardware emits a constant low output when disabled. |
22 | * - A request for .duty_cycle = 0 results in an output wave with one active |
23 | * clock tick per period. This should better use the disabled state. |
24 | * - The driver only implements setting the relative duty cycle. |
25 | * - The driver doesn't implement .get_state(). |
26 | */ |
27 | |
28 | #include <linux/module.h> |
29 | #include <linux/of.h> |
30 | #include <linux/platform_device.h> |
31 | #include <linux/pwm.h> |
32 | #include <linux/mfd/twl.h> |
33 | #include <linux/slab.h> |
34 | |
35 | /* |
36 | * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030. |
37 | * To generate the signal on TWL4030: |
38 | * - LEDA uses PWMA |
39 | * - LEDB uses PWMB |
40 | * TWL6030 has one LED pin with dedicated LEDPWM |
41 | */ |
42 | |
43 | #define TWL4030_LED_MAX 0x7f |
44 | #define TWL6030_LED_MAX 0xff |
45 | |
46 | /* Registers, bits and macro for TWL4030 */ |
47 | #define TWL4030_LEDEN_REG 0x00 |
48 | #define TWL4030_PWMA_REG 0x01 |
49 | |
50 | #define TWL4030_LEDXON (1 << 0) |
51 | #define TWL4030_LEDXPWM (1 << 4) |
52 | #define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM) |
53 | #define TWL4030_LED_TOGGLE(led, x) ((x) << (led)) |
54 | |
55 | /* Register, bits and macro for TWL6030 */ |
56 | #define TWL6030_LED_PWM_CTRL1 0xf4 |
57 | #define TWL6030_LED_PWM_CTRL2 0xf5 |
58 | |
59 | #define TWL6040_LED_MODE_HW 0x00 |
60 | #define TWL6040_LED_MODE_ON 0x01 |
61 | #define TWL6040_LED_MODE_OFF 0x02 |
62 | #define TWL6040_LED_MODE_MASK 0x03 |
63 | |
64 | struct twl_pwmled_chip { |
65 | struct pwm_chip chip; |
66 | struct mutex mutex; |
67 | }; |
68 | |
69 | static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip) |
70 | { |
71 | return container_of(chip, struct twl_pwmled_chip, chip); |
72 | } |
73 | |
74 | static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm, |
75 | int duty_ns, int period_ns) |
76 | { |
77 | int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1; |
78 | u8 pwm_config[2] = { 1, 0 }; |
79 | int base, ret; |
80 | |
81 | /* |
82 | * To configure the duty period: |
83 | * On-cycle is set to 1 (the minimum allowed value) |
84 | * The off time of 0 is not configurable, so the mapping is: |
85 | * 0 -> off cycle = 2, |
86 | * 1 -> off cycle = 2, |
87 | * 2 -> off cycle = 3, |
88 | * 126 - > off cycle 127, |
89 | * 127 - > off cycle 1 |
90 | * When on cycle == off cycle the PWM will be always on |
91 | */ |
92 | if (duty_cycle == 1) |
93 | duty_cycle = 2; |
94 | else if (duty_cycle > TWL4030_LED_MAX) |
95 | duty_cycle = 1; |
96 | |
97 | base = pwm->hwpwm * 2 + TWL4030_PWMA_REG; |
98 | |
99 | pwm_config[1] = duty_cycle; |
100 | |
101 | ret = twl_i2c_write(TWL4030_MODULE_LED, value: pwm_config, reg: base, num_bytes: 2); |
102 | if (ret < 0) |
103 | dev_err(chip->dev, "%s: Failed to configure PWM\n" , pwm->label); |
104 | |
105 | return ret; |
106 | } |
107 | |
108 | static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
109 | { |
110 | struct twl_pwmled_chip *twl = to_twl(chip); |
111 | int ret; |
112 | u8 val; |
113 | |
114 | mutex_lock(&twl->mutex); |
115 | ret = twl_i2c_read_u8(TWL4030_MODULE_LED, val: &val, TWL4030_LEDEN_REG); |
116 | if (ret < 0) { |
117 | dev_err(chip->dev, "%s: Failed to read LEDEN\n" , pwm->label); |
118 | goto out; |
119 | } |
120 | |
121 | val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS); |
122 | |
123 | ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG); |
124 | if (ret < 0) |
125 | dev_err(chip->dev, "%s: Failed to enable PWM\n" , pwm->label); |
126 | |
127 | out: |
128 | mutex_unlock(lock: &twl->mutex); |
129 | return ret; |
130 | } |
131 | |
132 | static void twl4030_pwmled_disable(struct pwm_chip *chip, |
133 | struct pwm_device *pwm) |
134 | { |
135 | struct twl_pwmled_chip *twl = to_twl(chip); |
136 | int ret; |
137 | u8 val; |
138 | |
139 | mutex_lock(&twl->mutex); |
140 | ret = twl_i2c_read_u8(TWL4030_MODULE_LED, val: &val, TWL4030_LEDEN_REG); |
141 | if (ret < 0) { |
142 | dev_err(chip->dev, "%s: Failed to read LEDEN\n" , pwm->label); |
143 | goto out; |
144 | } |
145 | |
146 | val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS); |
147 | |
148 | ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG); |
149 | if (ret < 0) |
150 | dev_err(chip->dev, "%s: Failed to disable PWM\n" , pwm->label); |
151 | |
152 | out: |
153 | mutex_unlock(lock: &twl->mutex); |
154 | } |
155 | |
156 | static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
157 | const struct pwm_state *state) |
158 | { |
159 | int ret; |
160 | |
161 | if (state->polarity != PWM_POLARITY_NORMAL) |
162 | return -EINVAL; |
163 | |
164 | if (!state->enabled) { |
165 | if (pwm->state.enabled) |
166 | twl4030_pwmled_disable(chip, pwm); |
167 | |
168 | return 0; |
169 | } |
170 | |
171 | /* |
172 | * We cannot skip calling ->config even if state->period == |
173 | * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle |
174 | * because we might have exited early in the last call to |
175 | * pwm_apply_state because of !state->enabled and so the two values in |
176 | * pwm->state might not be configured in hardware. |
177 | */ |
178 | ret = twl4030_pwmled_config(chip: pwm->chip, pwm, |
179 | duty_ns: state->duty_cycle, period_ns: state->period); |
180 | if (ret) |
181 | return ret; |
182 | |
183 | if (!pwm->state.enabled) |
184 | ret = twl4030_pwmled_enable(chip, pwm); |
185 | |
186 | return ret; |
187 | } |
188 | |
189 | |
190 | static const struct pwm_ops twl4030_pwmled_ops = { |
191 | .apply = twl4030_pwmled_apply, |
192 | .owner = THIS_MODULE, |
193 | }; |
194 | |
195 | static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm, |
196 | int duty_ns, int period_ns) |
197 | { |
198 | int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns; |
199 | u8 on_time; |
200 | int ret; |
201 | |
202 | on_time = duty_cycle & 0xff; |
203 | |
204 | ret = twl_i2c_write_u8(mod_no: TWL6030_MODULE_ID1, val: on_time, |
205 | TWL6030_LED_PWM_CTRL1); |
206 | if (ret < 0) |
207 | dev_err(chip->dev, "%s: Failed to configure PWM\n" , pwm->label); |
208 | |
209 | return ret; |
210 | } |
211 | |
212 | static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
213 | { |
214 | struct twl_pwmled_chip *twl = to_twl(chip); |
215 | int ret; |
216 | u8 val; |
217 | |
218 | mutex_lock(&twl->mutex); |
219 | ret = twl_i2c_read_u8(mod_no: TWL6030_MODULE_ID1, val: &val, TWL6030_LED_PWM_CTRL2); |
220 | if (ret < 0) { |
221 | dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n" , |
222 | pwm->label); |
223 | goto out; |
224 | } |
225 | |
226 | val &= ~TWL6040_LED_MODE_MASK; |
227 | val |= TWL6040_LED_MODE_ON; |
228 | |
229 | ret = twl_i2c_write_u8(mod_no: TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); |
230 | if (ret < 0) |
231 | dev_err(chip->dev, "%s: Failed to enable PWM\n" , pwm->label); |
232 | |
233 | out: |
234 | mutex_unlock(lock: &twl->mutex); |
235 | return ret; |
236 | } |
237 | |
238 | static void twl6030_pwmled_disable(struct pwm_chip *chip, |
239 | struct pwm_device *pwm) |
240 | { |
241 | struct twl_pwmled_chip *twl = to_twl(chip); |
242 | int ret; |
243 | u8 val; |
244 | |
245 | mutex_lock(&twl->mutex); |
246 | ret = twl_i2c_read_u8(mod_no: TWL6030_MODULE_ID1, val: &val, TWL6030_LED_PWM_CTRL2); |
247 | if (ret < 0) { |
248 | dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n" , |
249 | pwm->label); |
250 | goto out; |
251 | } |
252 | |
253 | val &= ~TWL6040_LED_MODE_MASK; |
254 | val |= TWL6040_LED_MODE_OFF; |
255 | |
256 | ret = twl_i2c_write_u8(mod_no: TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); |
257 | if (ret < 0) |
258 | dev_err(chip->dev, "%s: Failed to disable PWM\n" , pwm->label); |
259 | |
260 | out: |
261 | mutex_unlock(lock: &twl->mutex); |
262 | } |
263 | |
264 | static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
265 | const struct pwm_state *state) |
266 | { |
267 | int err; |
268 | |
269 | if (state->polarity != pwm->state.polarity) |
270 | return -EINVAL; |
271 | |
272 | if (!state->enabled) { |
273 | if (pwm->state.enabled) |
274 | twl6030_pwmled_disable(chip, pwm); |
275 | |
276 | return 0; |
277 | } |
278 | |
279 | err = twl6030_pwmled_config(chip: pwm->chip, pwm, |
280 | duty_ns: state->duty_cycle, period_ns: state->period); |
281 | if (err) |
282 | return err; |
283 | |
284 | if (!pwm->state.enabled) |
285 | err = twl6030_pwmled_enable(chip, pwm); |
286 | |
287 | return err; |
288 | } |
289 | |
290 | static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm) |
291 | { |
292 | struct twl_pwmled_chip *twl = to_twl(chip); |
293 | int ret; |
294 | u8 val; |
295 | |
296 | mutex_lock(&twl->mutex); |
297 | ret = twl_i2c_read_u8(mod_no: TWL6030_MODULE_ID1, val: &val, TWL6030_LED_PWM_CTRL2); |
298 | if (ret < 0) { |
299 | dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n" , |
300 | pwm->label); |
301 | goto out; |
302 | } |
303 | |
304 | val &= ~TWL6040_LED_MODE_MASK; |
305 | val |= TWL6040_LED_MODE_OFF; |
306 | |
307 | ret = twl_i2c_write_u8(mod_no: TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); |
308 | if (ret < 0) |
309 | dev_err(chip->dev, "%s: Failed to request PWM\n" , pwm->label); |
310 | |
311 | out: |
312 | mutex_unlock(lock: &twl->mutex); |
313 | return ret; |
314 | } |
315 | |
316 | static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm) |
317 | { |
318 | struct twl_pwmled_chip *twl = to_twl(chip); |
319 | int ret; |
320 | u8 val; |
321 | |
322 | mutex_lock(&twl->mutex); |
323 | ret = twl_i2c_read_u8(mod_no: TWL6030_MODULE_ID1, val: &val, TWL6030_LED_PWM_CTRL2); |
324 | if (ret < 0) { |
325 | dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n" , |
326 | pwm->label); |
327 | goto out; |
328 | } |
329 | |
330 | val &= ~TWL6040_LED_MODE_MASK; |
331 | val |= TWL6040_LED_MODE_HW; |
332 | |
333 | ret = twl_i2c_write_u8(mod_no: TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); |
334 | if (ret < 0) |
335 | dev_err(chip->dev, "%s: Failed to free PWM\n" , pwm->label); |
336 | |
337 | out: |
338 | mutex_unlock(lock: &twl->mutex); |
339 | } |
340 | |
341 | static const struct pwm_ops twl6030_pwmled_ops = { |
342 | .apply = twl6030_pwmled_apply, |
343 | .request = twl6030_pwmled_request, |
344 | .free = twl6030_pwmled_free, |
345 | .owner = THIS_MODULE, |
346 | }; |
347 | |
348 | static int twl_pwmled_probe(struct platform_device *pdev) |
349 | { |
350 | struct twl_pwmled_chip *twl; |
351 | |
352 | twl = devm_kzalloc(dev: &pdev->dev, size: sizeof(*twl), GFP_KERNEL); |
353 | if (!twl) |
354 | return -ENOMEM; |
355 | |
356 | if (twl_class_is_4030()) { |
357 | twl->chip.ops = &twl4030_pwmled_ops; |
358 | twl->chip.npwm = 2; |
359 | } else { |
360 | twl->chip.ops = &twl6030_pwmled_ops; |
361 | twl->chip.npwm = 1; |
362 | } |
363 | |
364 | twl->chip.dev = &pdev->dev; |
365 | |
366 | mutex_init(&twl->mutex); |
367 | |
368 | return devm_pwmchip_add(dev: &pdev->dev, chip: &twl->chip); |
369 | } |
370 | |
371 | #ifdef CONFIG_OF |
372 | static const struct of_device_id twl_pwmled_of_match[] = { |
373 | { .compatible = "ti,twl4030-pwmled" }, |
374 | { .compatible = "ti,twl6030-pwmled" }, |
375 | { }, |
376 | }; |
377 | MODULE_DEVICE_TABLE(of, twl_pwmled_of_match); |
378 | #endif |
379 | |
380 | static struct platform_driver twl_pwmled_driver = { |
381 | .driver = { |
382 | .name = "twl-pwmled" , |
383 | .of_match_table = of_match_ptr(twl_pwmled_of_match), |
384 | }, |
385 | .probe = twl_pwmled_probe, |
386 | }; |
387 | module_platform_driver(twl_pwmled_driver); |
388 | |
389 | MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>" ); |
390 | MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs" ); |
391 | MODULE_ALIAS("platform:twl-pwmled" ); |
392 | MODULE_LICENSE("GPL" ); |
393 | |