[go: nahoru, domu]
1/*
2 * Driver for TWL4030/6030 Generic Pulse Width Modulator
3 *
4 * Copyright (C) 2012 Texas Instruments
5 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/platform_device.h>
23#include <linux/pwm.h>
24#include <linux/i2c/twl.h>
25#include <linux/slab.h>
26
27/*
28 * This driver handles the PWMs of TWL4030 and TWL6030.
29 * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
30 * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
31 */
32
33#define TWL_PWM_MAX		0x7f
34
35/* Registers, bits and macro for TWL4030 */
36#define TWL4030_GPBR1_REG	0x0c
37#define TWL4030_PMBR1_REG	0x0d
38
39/* GPBR1 register bits */
40#define TWL4030_PWMXCLK_ENABLE	(1 << 0)
41#define TWL4030_PWMX_ENABLE	(1 << 2)
42#define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
43#define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm))
44
45/* PMBR1 register bits */
46#define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2)
47#define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2)
48#define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4)
49#define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4)
50
51/* Register, bits and macro for TWL6030 */
52#define TWL6030_TOGGLE3_REG	0x92
53
54#define TWL6030_PWMXR		(1 << 0)
55#define TWL6030_PWMXS		(1 << 1)
56#define TWL6030_PWMXEN		(1 << 2)
57#define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3))
58
59struct twl_pwm_chip {
60	struct pwm_chip chip;
61	struct mutex mutex;
62	u8 twl6030_toggle3;
63	u8 twl4030_pwm_mux;
64};
65
66static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
67{
68	return container_of(chip, struct twl_pwm_chip, chip);
69}
70
71static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
72			      int duty_ns, int period_ns)
73{
74	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
75	u8 pwm_config[2] = { 1, 0 };
76	int base, ret;
77
78	/*
79	 * To configure the duty period:
80	 * On-cycle is set to 1 (the minimum allowed value)
81	 * The off time of 0 is not configurable, so the mapping is:
82	 * 0 -> off cycle = 2,
83	 * 1 -> off cycle = 2,
84	 * 2 -> off cycle = 3,
85	 * 126 - > off cycle 127,
86	 * 127 - > off cycle 1
87	 * When on cycle == off cycle the PWM will be always on
88	 */
89	if (duty_cycle == 1)
90		duty_cycle = 2;
91	else if (duty_cycle > TWL_PWM_MAX)
92		duty_cycle = 1;
93
94	base = pwm->hwpwm * 3;
95
96	pwm_config[1] = duty_cycle;
97
98	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
99	if (ret < 0)
100		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
101
102	return ret;
103}
104
105static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
106{
107	struct twl_pwm_chip *twl = to_twl(chip);
108	int ret;
109	u8 val;
110
111	mutex_lock(&twl->mutex);
112	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
113	if (ret < 0) {
114		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
115		goto out;
116	}
117
118	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
119
120	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
121	if (ret < 0)
122		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
123
124	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
125
126	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
127	if (ret < 0)
128		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
129
130out:
131	mutex_unlock(&twl->mutex);
132	return ret;
133}
134
135static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
136{
137	struct twl_pwm_chip *twl = to_twl(chip);
138	int ret;
139	u8 val;
140
141	mutex_lock(&twl->mutex);
142	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
143	if (ret < 0) {
144		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
145		goto out;
146	}
147
148	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
149
150	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
151	if (ret < 0)
152		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
153
154	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
155
156	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
157	if (ret < 0)
158		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
159
160out:
161	mutex_unlock(&twl->mutex);
162}
163
164static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
165{
166	struct twl_pwm_chip *twl = to_twl(chip);
167	int ret;
168	u8 val, mask, bits;
169
170	if (pwm->hwpwm == 1) {
171		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
172		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
173	} else {
174		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
175		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
176	}
177
178	mutex_lock(&twl->mutex);
179	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
180	if (ret < 0) {
181		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
182		goto out;
183	}
184
185	/* Save the current MUX configuration for the PWM */
186	twl->twl4030_pwm_mux &= ~mask;
187	twl->twl4030_pwm_mux |= (val & mask);
188
189	/* Select PWM functionality */
190	val &= ~mask;
191	val |= bits;
192
193	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
194	if (ret < 0)
195		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
196
197out:
198	mutex_unlock(&twl->mutex);
199	return ret;
200}
201
202static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
203{
204	struct twl_pwm_chip *twl = to_twl(chip);
205	int ret;
206	u8 val, mask;
207
208	if (pwm->hwpwm == 1)
209		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
210	else
211		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
212
213	mutex_lock(&twl->mutex);
214	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
215	if (ret < 0) {
216		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
217		goto out;
218	}
219
220	/* Restore the MUX configuration for the PWM */
221	val &= ~mask;
222	val |= (twl->twl4030_pwm_mux & mask);
223
224	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
225	if (ret < 0)
226		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
227
228out:
229	mutex_unlock(&twl->mutex);
230}
231
232static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
233{
234	struct twl_pwm_chip *twl = to_twl(chip);
235	int ret;
236	u8 val;
237
238	mutex_lock(&twl->mutex);
239	val = twl->twl6030_toggle3;
240	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
241	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
242
243	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
244	if (ret < 0) {
245		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
246		goto out;
247	}
248
249	twl->twl6030_toggle3 = val;
250out:
251	mutex_unlock(&twl->mutex);
252	return ret;
253}
254
255static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
256{
257	struct twl_pwm_chip *twl = to_twl(chip);
258	int ret;
259	u8 val;
260
261	mutex_lock(&twl->mutex);
262	val = twl->twl6030_toggle3;
263	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
264	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
265
266	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
267	if (ret < 0) {
268		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
269		goto out;
270	}
271
272	twl->twl6030_toggle3 = val;
273out:
274	mutex_unlock(&twl->mutex);
275}
276
277static const struct pwm_ops twl4030_pwm_ops = {
278	.config = twl_pwm_config,
279	.enable = twl4030_pwm_enable,
280	.disable = twl4030_pwm_disable,
281	.request = twl4030_pwm_request,
282	.free = twl4030_pwm_free,
283	.owner = THIS_MODULE,
284};
285
286static const struct pwm_ops twl6030_pwm_ops = {
287	.config = twl_pwm_config,
288	.enable = twl6030_pwm_enable,
289	.disable = twl6030_pwm_disable,
290	.owner = THIS_MODULE,
291};
292
293static int twl_pwm_probe(struct platform_device *pdev)
294{
295	struct twl_pwm_chip *twl;
296	int ret;
297
298	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
299	if (!twl)
300		return -ENOMEM;
301
302	if (twl_class_is_4030())
303		twl->chip.ops = &twl4030_pwm_ops;
304	else
305		twl->chip.ops = &twl6030_pwm_ops;
306
307	twl->chip.dev = &pdev->dev;
308	twl->chip.base = -1;
309	twl->chip.npwm = 2;
310	twl->chip.can_sleep = true;
311
312	mutex_init(&twl->mutex);
313
314	ret = pwmchip_add(&twl->chip);
315	if (ret < 0)
316		return ret;
317
318	platform_set_drvdata(pdev, twl);
319
320	return 0;
321}
322
323static int twl_pwm_remove(struct platform_device *pdev)
324{
325	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
326
327	return pwmchip_remove(&twl->chip);
328}
329
330#ifdef CONFIG_OF
331static const struct of_device_id twl_pwm_of_match[] = {
332	{ .compatible = "ti,twl4030-pwm" },
333	{ .compatible = "ti,twl6030-pwm" },
334	{ },
335};
336MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
337#endif
338
339static struct platform_driver twl_pwm_driver = {
340	.driver = {
341		.name = "twl-pwm",
342		.of_match_table = of_match_ptr(twl_pwm_of_match),
343	},
344	.probe = twl_pwm_probe,
345	.remove = twl_pwm_remove,
346};
347module_platform_driver(twl_pwm_driver);
348
349MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
350MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
351MODULE_ALIAS("platform:twl-pwm");
352MODULE_LICENSE("GPL");
353