/*
* 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,
.owner = THIS_MODULE,
};
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,
.owner = THIS_MODULE,
};
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;
twl->chip.can_sleep = true;
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 const 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");
