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1/*
2 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
3 *
4 * Copyright (C) 2012 Texas Instruments
5 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
6 *
7 * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
8 * Hemanth V <hemanthv@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published by
12 * the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17 * more details.
18 *
19 * You should have received a copy of the GNU General Public License along with
20 * this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/platform_device.h>
26#include <linux/pwm.h>
27#include <linux/i2c/twl.h>
28#include <linux/slab.h>
29
30/*
31 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
32 * To generate the signal on TWL4030:
33 *  - LEDA uses PWMA
34 *  - LEDB uses PWMB
35 * TWL6030 has one LED pin with dedicated LEDPWM
36 */
37
38#define TWL4030_LED_MAX		0x7f
39#define TWL6030_LED_MAX		0xff
40
41/* Registers, bits and macro for TWL4030 */
42#define TWL4030_LEDEN_REG	0x00
43#define TWL4030_PWMA_REG	0x01
44
45#define TWL4030_LEDXON		(1 << 0)
46#define TWL4030_LEDXPWM		(1 << 4)
47#define TWL4030_LED_PINS	(TWL4030_LEDXON | TWL4030_LEDXPWM)
48#define TWL4030_LED_TOGGLE(led, x)	((x) << (led))
49
50/* Register, bits and macro for TWL6030 */
51#define TWL6030_LED_PWM_CTRL1	0xf4
52#define TWL6030_LED_PWM_CTRL2	0xf5
53
54#define TWL6040_LED_MODE_HW	0x00
55#define TWL6040_LED_MODE_ON	0x01
56#define TWL6040_LED_MODE_OFF	0x02
57#define TWL6040_LED_MODE_MASK	0x03
58
59struct twl_pwmled_chip {
60	struct pwm_chip chip;
61	struct mutex mutex;
62};
63
64static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
65{
66	return container_of(chip, struct twl_pwmled_chip, chip);
67}
68
69static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
70			      int duty_ns, int period_ns)
71{
72	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
73	u8 pwm_config[2] = { 1, 0 };
74	int base, ret;
75
76	/*
77	 * To configure the duty period:
78	 * On-cycle is set to 1 (the minimum allowed value)
79	 * The off time of 0 is not configurable, so the mapping is:
80	 * 0 -> off cycle = 2,
81	 * 1 -> off cycle = 2,
82	 * 2 -> off cycle = 3,
83	 * 126 - > off cycle 127,
84	 * 127 - > off cycle 1
85	 * When on cycle == off cycle the PWM will be always on
86	 */
87	if (duty_cycle == 1)
88		duty_cycle = 2;
89	else if (duty_cycle > TWL4030_LED_MAX)
90		duty_cycle = 1;
91
92	base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
93
94	pwm_config[1] = duty_cycle;
95
96	ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
97	if (ret < 0)
98		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
99
100	return ret;
101}
102
103static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
104{
105	struct twl_pwmled_chip *twl = to_twl(chip);
106	int ret;
107	u8 val;
108
109	mutex_lock(&twl->mutex);
110	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
111	if (ret < 0) {
112		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
113		goto out;
114	}
115
116	val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
117
118	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
119	if (ret < 0)
120		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
121
122out:
123	mutex_unlock(&twl->mutex);
124	return ret;
125}
126
127static void twl4030_pwmled_disable(struct pwm_chip *chip,
128				   struct pwm_device *pwm)
129{
130	struct twl_pwmled_chip *twl = to_twl(chip);
131	int ret;
132	u8 val;
133
134	mutex_lock(&twl->mutex);
135	ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
136	if (ret < 0) {
137		dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
138		goto out;
139	}
140
141	val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
142
143	ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
144	if (ret < 0)
145		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
146
147out:
148	mutex_unlock(&twl->mutex);
149}
150
151static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
152			      int duty_ns, int period_ns)
153{
154	int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
155	u8 on_time;
156	int ret;
157
158	on_time = duty_cycle & 0xff;
159
160	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
161			       TWL6030_LED_PWM_CTRL1);
162	if (ret < 0)
163		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
164
165	return ret;
166}
167
168static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
169{
170	struct twl_pwmled_chip *twl = to_twl(chip);
171	int ret;
172	u8 val;
173
174	mutex_lock(&twl->mutex);
175	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
176	if (ret < 0) {
177		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
178			pwm->label);
179		goto out;
180	}
181
182	val &= ~TWL6040_LED_MODE_MASK;
183	val |= TWL6040_LED_MODE_ON;
184
185	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
186	if (ret < 0)
187		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
188
189out:
190	mutex_unlock(&twl->mutex);
191	return ret;
192}
193
194static void twl6030_pwmled_disable(struct pwm_chip *chip,
195				   struct pwm_device *pwm)
196{
197	struct twl_pwmled_chip *twl = to_twl(chip);
198	int ret;
199	u8 val;
200
201	mutex_lock(&twl->mutex);
202	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
203	if (ret < 0) {
204		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
205			pwm->label);
206		goto out;
207	}
208
209	val &= ~TWL6040_LED_MODE_MASK;
210	val |= TWL6040_LED_MODE_OFF;
211
212	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
213	if (ret < 0)
214		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
215
216out:
217	mutex_unlock(&twl->mutex);
218}
219
220static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
221{
222	struct twl_pwmled_chip *twl = to_twl(chip);
223	int ret;
224	u8 val;
225
226	mutex_lock(&twl->mutex);
227	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
228	if (ret < 0) {
229		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
230			pwm->label);
231		goto out;
232	}
233
234	val &= ~TWL6040_LED_MODE_MASK;
235	val |= TWL6040_LED_MODE_OFF;
236
237	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
238	if (ret < 0)
239		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
240
241out:
242	mutex_unlock(&twl->mutex);
243	return ret;
244}
245
246static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
247{
248	struct twl_pwmled_chip *twl = to_twl(chip);
249	int ret;
250	u8 val;
251
252	mutex_lock(&twl->mutex);
253	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
254	if (ret < 0) {
255		dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
256			pwm->label);
257		goto out;
258	}
259
260	val &= ~TWL6040_LED_MODE_MASK;
261	val |= TWL6040_LED_MODE_HW;
262
263	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
264	if (ret < 0)
265		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
266
267out:
268	mutex_unlock(&twl->mutex);
269}
270
271static const struct pwm_ops twl4030_pwmled_ops = {
272	.enable = twl4030_pwmled_enable,
273	.disable = twl4030_pwmled_disable,
274	.config = twl4030_pwmled_config,
275	.owner = THIS_MODULE,
276};
277
278static const struct pwm_ops twl6030_pwmled_ops = {
279	.enable = twl6030_pwmled_enable,
280	.disable = twl6030_pwmled_disable,
281	.config = twl6030_pwmled_config,
282	.request = twl6030_pwmled_request,
283	.free = twl6030_pwmled_free,
284	.owner = THIS_MODULE,
285};
286
287static int twl_pwmled_probe(struct platform_device *pdev)
288{
289	struct twl_pwmled_chip *twl;
290	int ret;
291
292	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
293	if (!twl)
294		return -ENOMEM;
295
296	if (twl_class_is_4030()) {
297		twl->chip.ops = &twl4030_pwmled_ops;
298		twl->chip.npwm = 2;
299	} else {
300		twl->chip.ops = &twl6030_pwmled_ops;
301		twl->chip.npwm = 1;
302	}
303
304	twl->chip.dev = &pdev->dev;
305	twl->chip.base = -1;
306	twl->chip.can_sleep = true;
307
308	mutex_init(&twl->mutex);
309
310	ret = pwmchip_add(&twl->chip);
311	if (ret < 0)
312		return ret;
313
314	platform_set_drvdata(pdev, twl);
315
316	return 0;
317}
318
319static int twl_pwmled_remove(struct platform_device *pdev)
320{
321	struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);
322
323	return pwmchip_remove(&twl->chip);
324}
325
326#ifdef CONFIG_OF
327static const struct of_device_id twl_pwmled_of_match[] = {
328	{ .compatible = "ti,twl4030-pwmled" },
329	{ .compatible = "ti,twl6030-pwmled" },
330	{ },
331};
332MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
333#endif
334
335static struct platform_driver twl_pwmled_driver = {
336	.driver = {
337		.name = "twl-pwmled",
338		.of_match_table = of_match_ptr(twl_pwmled_of_match),
339	},
340	.probe = twl_pwmled_probe,
341	.remove = twl_pwmled_remove,
342};
343module_platform_driver(twl_pwmled_driver);
344
345MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
346MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
347MODULE_ALIAS("platform:twl-pwmled");
348MODULE_LICENSE("GPL");
349