Loading...
Note: File does not exist in v3.1.
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
64struct twl_pwmled_chip {
65 struct pwm_chip chip;
66 struct mutex mutex;
67};
68
69static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
70{
71 return container_of(chip, struct twl_pwmled_chip, chip);
72}
73
74static 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, pwm_config, base, 2);
102 if (ret < 0)
103 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
104
105 return ret;
106}
107
108static 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, 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
127out:
128 mutex_unlock(&twl->mutex);
129 return ret;
130}
131
132static 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, 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
152out:
153 mutex_unlock(&twl->mutex);
154}
155
156static 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(pwm->chip, pwm,
179 state->duty_cycle, 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
190static const struct pwm_ops twl4030_pwmled_ops = {
191 .apply = twl4030_pwmled_apply,
192 .owner = THIS_MODULE,
193};
194
195static 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(TWL6030_MODULE_ID1, 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
212static 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(TWL6030_MODULE_ID1, &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(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
233out:
234 mutex_unlock(&twl->mutex);
235 return ret;
236}
237
238static 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(TWL6030_MODULE_ID1, &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(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
260out:
261 mutex_unlock(&twl->mutex);
262}
263
264static 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(pwm->chip, pwm,
280 state->duty_cycle, 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
290static 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(TWL6030_MODULE_ID1, &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(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
311out:
312 mutex_unlock(&twl->mutex);
313 return ret;
314}
315
316static 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(TWL6030_MODULE_ID1, &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(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
337out:
338 mutex_unlock(&twl->mutex);
339}
340
341static 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
348static int twl_pwmled_probe(struct platform_device *pdev)
349{
350 struct twl_pwmled_chip *twl;
351
352 twl = devm_kzalloc(&pdev->dev, 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(&pdev->dev, &twl->chip);
369}
370
371#ifdef CONFIG_OF
372static const struct of_device_id twl_pwmled_of_match[] = {
373 { .compatible = "ti,twl4030-pwmled" },
374 { .compatible = "ti,twl6030-pwmled" },
375 { },
376};
377MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
378#endif
379
380static 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};
387module_platform_driver(twl_pwmled_driver);
388
389MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
390MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
391MODULE_ALIAS("platform:twl-pwmled");
392MODULE_LICENSE("GPL");