aboutsummaryrefslogtreecommitdiff
path: root/drivers/pwm/pwm-twl-led.c
blob: 9dfa0f3eca3032917bc48066e9edf6e3b218eecb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
/*
 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
 *
 * Copyright (C) 2012 Texas Instruments
 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 *
 * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
 * Hemanth V <hemanthv@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/i2c/twl.h>
#include <linux/slab.h>

/*
 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
 * To generate the signal on TWL4030:
 *  - LEDA uses PWMA
 *  - LEDB uses PWMB
 * TWL6030 has one LED pin with dedicated LEDPWM
 */

#define TWL4030_LED_MAX		0x7f
#define TWL6030_LED_MAX		0xff

/* Registers, bits and macro for TWL4030 */
#define TWL4030_LEDEN_REG	0x00
#define TWL4030_PWMA_REG	0x01

#define TWL4030_LEDXON		(1 << 0)
#define TWL4030_LEDXPWM		(1 << 4)
#define TWL4030_LED_PINS	(TWL4030_LEDXON | TWL4030_LEDXPWM)
#define TWL4030_LED_TOGGLE(led, x)	((x) << (led))

/* Register, bits and macro for TWL6030 */
#define TWL6030_LED_PWM_CTRL1	0xf4
#define TWL6030_LED_PWM_CTRL2	0xf5

#define TWL6040_LED_MODE_HW	0x00
#define TWL6040_LED_MODE_ON	0x01
#define TWL6040_LED_MODE_OFF	0x02
#define TWL6040_LED_MODE_MASK	0x03

struct twl_pwmled_chip {
	struct pwm_chip chip;
	struct mutex mutex;
};

static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
{
	return container_of(chip, struct twl_pwmled_chip, chip);
}

static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
			      int duty_ns, int period_ns)
{
	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
	u8 pwm_config[2] = { 1, 0 };
	int base, ret;

	/*
	 * To configure the duty period:
	 * On-cycle is set to 1 (the minimum allowed value)
	 * The off time of 0 is not configurable, so the mapping is:
	 * 0 -> off cycle = 2,
	 * 1 -> off cycle = 2,
	 * 2 -> off cycle = 3,
	 * 126 - > off cycle 127,
	 * 127 - > off cycle 1
	 * When on cycle == off cycle the PWM will be always on
	 */
	if (duty_cycle == 1)
		duty_cycle = 2;
	else if (duty_cycle > TWL4030_LED_MAX)
		duty_cycle = 1;

	base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;

	pwm_config[1] = duty_cycle;

	ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

	return ret;
}

static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
		goto out;
	}

	val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
	return ret;
}

static void twl4030_pwmled_disable(struct pwm_chip *chip,
				   struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
		goto out;
	}

	val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);

	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
}

static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
			      int duty_ns, int period_ns)
{
	int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
	u8 on_time;
	int ret;

	on_time = duty_cycle & 0xff;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
			       TWL6030_LED_PWM_CTRL1);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);

	return ret;
}

static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
			pwm->label);
		goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val |= TWL6040_LED_MODE_ON;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
	return ret;
}

static void twl6030_pwmled_disable(struct pwm_chip *chip,
				   struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
			pwm->label);
		goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val |= TWL6040_LED_MODE_OFF;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
}

static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
			pwm->label);
		goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val |= TWL6040_LED_MODE_OFF;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
	return ret;
}

static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct twl_pwmled_chip *twl = to_twl(chip);
	int ret;
	u8 val;

	mutex_lock(&twl->mutex);
	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0) {
		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
			pwm->label);
		goto out;
	}

	val &= ~TWL6040_LED_MODE_MASK;
	val |= TWL6040_LED_MODE_HW;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
	if (ret < 0)
		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);

out:
	mutex_unlock(&twl->mutex);
}

static const struct pwm_ops twl4030_pwmled_ops = {
	.enable = twl4030_pwmled_enable,
	.disable = twl4030_pwmled_disable,
	.config = twl4030_pwmled_config,
};

static const struct pwm_ops twl6030_pwmled_ops = {
	.enable = twl6030_pwmled_enable,
	.disable = twl6030_pwmled_disable,
	.config = twl6030_pwmled_config,
	.request = twl6030_pwmled_request,
	.free = twl6030_pwmled_free,
};

static int twl_pwmled_probe(struct platform_device *pdev)
{
	struct twl_pwmled_chip *twl;
	int ret;

	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
	if (!twl)
		return -ENOMEM;

	if (twl_class_is_4030()) {
		twl->chip.ops = &twl4030_pwmled_ops;
		twl->chip.npwm = 2;
	} else {
		twl->chip.ops = &twl6030_pwmled_ops;
		twl->chip.npwm = 1;
	}

	twl->chip.dev = &pdev->dev;
	twl->chip.base = -1;

	mutex_init(&twl->mutex);

	ret = pwmchip_add(&twl->chip);
	if (ret < 0)
		return ret;

	platform_set_drvdata(pdev, twl);

	return 0;
}

static int twl_pwmled_remove(struct platform_device *pdev)
{
	struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);

	return pwmchip_remove(&twl->chip);
}

#ifdef CONFIG_OF
static struct of_device_id twl_pwmled_of_match[] = {
	{ .compatible = "ti,twl4030-pwmled" },
	{ .compatible = "ti,twl6030-pwmled" },
	{ },
};
MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
#endif

static struct platform_driver twl_pwmled_driver = {
	.driver = {
		.name = "twl-pwmled",
		.of_match_table = of_match_ptr(twl_pwmled_of_match),
	},
	.probe = twl_pwmled_probe,
	.remove = twl_pwmled_remove,
};
module_platform_driver(twl_pwmled_driver);

MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
MODULE_ALIAS("platform:twl-pwmled");
MODULE_LICENSE("GPL");