[net-next-2.6.git] / drivers / mfd / twl6030-pwm.c

/*
 * twl6030_pwm.c
 * Driver for PHOENIX (TWL6030) Pulse Width Modulator
 *
 * Copyright (C) 2010 Texas Instruments
 * Author: 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/i2c/twl.h>
#include <linux/slab.h>

#define LED_PWM_CTRL1	0xF4
#define LED_PWM_CTRL2	0xF5

/* Max value for CTRL1 register */
#define PWM_CTRL1_MAX	255

/* Pull down disable */
#define PWM_CTRL2_DIS_PD	(1 << 6)

/* Current control 2.5 milli Amps */
#define PWM_CTRL2_CURR_02	(2 << 4)

/* LED supply source */
#define PWM_CTRL2_SRC_VAC	(1 << 2)

/* LED modes */
#define PWM_CTRL2_MODE_HW	(0 << 0)
#define PWM_CTRL2_MODE_SW	(1 << 0)
#define PWM_CTRL2_MODE_DIS	(2 << 0)

#define PWM_CTRL2_MODE_MASK	0x3

struct pwm_device {
	const char *label;
	unsigned int pwm_id;
};

int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
	u8 duty_cycle;
	int ret;

	if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
		return -EINVAL;

	duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1);

	if (ret < 0) {
		pr_err("%s: Failed to configure PWM, Error %d\n",
			pwm->label, ret);
		return ret;
	}
	return 0;
}
EXPORT_SYMBOL(pwm_config);

int pwm_enable(struct pwm_device *pwm)
{
	u8 val;
	int ret;

	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
	if (ret < 0) {
		pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
		return ret;
	}

	/* Change mode to software control */
	val &= ~PWM_CTRL2_MODE_MASK;
	val |= PWM_CTRL2_MODE_SW;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
	if (ret < 0) {
		pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
		return ret;
	}

	twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
	return 0;
}
EXPORT_SYMBOL(pwm_enable);

void pwm_disable(struct pwm_device *pwm)
{
	u8 val;
	int ret;

	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
	if (ret < 0) {
		pr_err("%s: Failed to disable PWM, Error %d\n",
			pwm->label, ret);
		return;
	}

	val &= ~PWM_CTRL2_MODE_MASK;
	val |= PWM_CTRL2_MODE_HW;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
	if (ret < 0) {
		pr_err("%s: Failed to disable PWM, Error %d\n",
			pwm->label, ret);
		return;
	}
	return;
}
EXPORT_SYMBOL(pwm_disable);

struct pwm_device *pwm_request(int pwm_id, const char *label)
{
	u8 val;
	int ret;
	struct pwm_device *pwm;

	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
	if (pwm == NULL) {
		pr_err("%s: failed to allocate memory\n", label);
		return NULL;
	}

	pwm->label = label;
	pwm->pwm_id = pwm_id;

	/* Configure PWM */
	val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VAC |
		PWM_CTRL2_MODE_HW;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);

	if (ret < 0) {
		pr_err("%s: Failed to configure PWM, Error %d\n",
			 pwm->label, ret);

		kfree(pwm);
		return NULL;
	}

	return pwm;
}
EXPORT_SYMBOL(pwm_request);

void pwm_free(struct pwm_device *pwm)
{
	pwm_disable(pwm);
	kfree(pwm);
}
EXPORT_SYMBOL(pwm_free);
Commit	Line	Data
31fc03df H	1	/*
	2	* twl6030_pwm.c
	3	* Driver for PHOENIX (TWL6030) Pulse Width Modulator
	4	*
	5	* Copyright (C) 2010 Texas Instruments
	6	* Author: Hemanth V <hemanthv@ti.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License version 2 as published by
	10	* the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but WITHOUT
	13	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	15	* more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along with
	18	* this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/i2c/twl.h>
	24	#include <linux/slab.h>
	25
	26	#define LED_PWM_CTRL1 0xF4
	27	#define LED_PWM_CTRL2 0xF5
	28
	29	/* Max value for CTRL1 register */
	30	#define PWM_CTRL1_MAX 255
	31
	32	/* Pull down disable */
	33	#define PWM_CTRL2_DIS_PD (1 << 6)
	34
	35	/* Current control 2.5 milli Amps */
	36	#define PWM_CTRL2_CURR_02 (2 << 4)
	37
	38	/* LED supply source */
	39	#define PWM_CTRL2_SRC_VAC (1 << 2)
	40
	41	/* LED modes */
	42	#define PWM_CTRL2_MODE_HW (0 << 0)
	43	#define PWM_CTRL2_MODE_SW (1 << 0)
	44	#define PWM_CTRL2_MODE_DIS (2 << 0)
	45
	46	#define PWM_CTRL2_MODE_MASK 0x3
	47
	48	struct pwm_device {
	49	const char *label;
	50	unsigned int pwm_id;
	51	};
	52
	53	int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
	54	{
	55	u8 duty_cycle;
	56	int ret;
	57
	58	if (pwm == NULL \|\| period_ns == 0 \|\| duty_ns > period_ns)
	59	return -EINVAL;
	60
	61	duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;
	62
	63	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1);
	64
65	if (ret < 0) {
66	pr_err("%s: Failed to configure PWM, Error %d\n",
67	pwm->label, ret);
68	return ret;
69	}
70	return 0;
71	}
72	EXPORT_SYMBOL(pwm_config);
73
74	int pwm_enable(struct pwm_device *pwm)
75	{
76	u8 val;
77	int ret;
78
79	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
80	if (ret < 0) {
81	pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
82	return ret;
83	}
84
85	/* Change mode to software control */
86	val &= ~PWM_CTRL2_MODE_MASK;
87	val \|= PWM_CTRL2_MODE_SW;
88
89	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
90	if (ret < 0) {
91	pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
92	return ret;
93	}
94
95	twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
96	return 0;
97	}
98	EXPORT_SYMBOL(pwm_enable);
99
100	void pwm_disable(struct pwm_device *pwm)
101	{
102	u8 val;
103	int ret;
104
105	ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
106	if (ret < 0) {
107	pr_err("%s: Failed to disable PWM, Error %d\n",
108	pwm->label, ret);
109	return;
110	}
111
112	val &= ~PWM_CTRL2_MODE_MASK;
113	val \|= PWM_CTRL2_MODE_HW;
114
115	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
116	if (ret < 0) {
117	pr_err("%s: Failed to disable PWM, Error %d\n",
118	pwm->label, ret);
119	return;
120	}
121	return;
122	}
123	EXPORT_SYMBOL(pwm_disable);
124
125	struct pwm_device pwm_request(int pwm_id, const char label)
126	{
127	u8 val;
128	int ret;
129	struct pwm_device *pwm;
130
131	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
132	if (pwm == NULL) {
133	pr_err("%s: failed to allocate memory\n", label);
134	return NULL;
135	}
136
137	pwm->label = label;
138	pwm->pwm_id = pwm_id;
139
140	/* Configure PWM */
141	val = PWM_CTRL2_DIS_PD \| PWM_CTRL2_CURR_02 \| PWM_CTRL2_SRC_VAC \|
142	PWM_CTRL2_MODE_HW;
143
144	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
145
146	if (ret < 0) {
147	pr_err("%s: Failed to configure PWM, Error %d\n",
148	pwm->label, ret);
149
150	kfree(pwm);
151	return NULL;
152	}
153
154	return pwm;
155	}
156	EXPORT_SYMBOL(pwm_request);
157
158	void pwm_free(struct pwm_device *pwm)
159	{
160	pwm_disable(pwm);
161	kfree(pwm);
162	}
163	EXPORT_SYMBOL(pwm_free);