/*
* 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/pwm.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 twl6030_pwm_chip {
struct pwm_chip chip;
};
static int twl6030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
u8 val;
/* 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) {
dev_err(chip->dev, "%s: Failed to configure PWM, Error %d\n",
pwm->label, ret);
return ret;
}
return 0;
}
static int twl6030_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
u8 duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;
int ret;
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;
}
static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
u8 val;
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
if (ret < 0) {
dev_err(chip->dev, "%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) {
dev_err(chip->dev, "%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;
}
static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
u8 val;
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
if (ret < 0) {
dev_err(chip->dev, "%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) {
dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
pwm->label, ret);
}
}
static const struct pwm_ops twl6030_pwm_ops = {
.request = twl6030_pwm_request,
.config = twl6030_pwm_config,
.enable = twl6030_pwm_enable,
.disable = twl6030_pwm_disable,
};
static int twl6030_pwm_probe(struct platform_device *pdev)
{
struct twl6030_pwm_chip *twl6030;
int ret;
twl6030 = devm_kzalloc(&pdev->dev, sizeof(*twl6030), GFP_KERNEL);
if (!twl6030)
return -ENOMEM;
twl6030->chip.dev = &pdev->dev;
twl6030->chip.ops = &twl6030_pwm_ops;
twl6030->chip.base = -1;
twl6030->chip.npwm = 1;
ret = pwmchip_add(&twl6030->chip);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, twl6030);
return 0;
}
static int twl6030_pwm_remove(struct platform_device *pdev)
{
struct twl6030_pwm_chip *twl6030 = platform_get_drvdata(pdev);
return pwmchip_remove(&twl6030->chip);
}
static struct platform_driver twl6030_pwm_driver = {
.driver = {
.name = "twl6030-pwm",
},
.probe = twl6030_pwm_probe,
.remove = __devexit_p(twl6030_pwm_remove),
};
module_platform_driver(twl6030_pwm_driver);
MODULE_ALIAS("platform:twl6030-pwm");
MODULE_LICENSE("GPL");
