/*
* Copyright (C) ST-Ericsson SA 2010
*
* Author: Arun R Murthy <arun.murthy@stericsson.com>
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pwm.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/module.h>
/*
* PWM Out generators
* Bank: 0x10
*/
#define AB8500_PWM_OUT_CTRL1_REG 0x60
#define AB8500_PWM_OUT_CTRL2_REG 0x61
#define AB8500_PWM_OUT_CTRL7_REG 0x66
/* backlight driver constants */
#define ENABLE_PWM 1
#define DISABLE_PWM 0
struct pwm_device {
struct device *dev;
struct list_head node;
const char *label;
unsigned int pwm_id;
};
static LIST_HEAD(pwm_list);
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
int ret = 0;
unsigned int higher_val, lower_val;
u8 reg;
/*
* get the first 8 bits that are be written to
* AB8500_PWM_OUT_CTRL1_REG[0:7]
*/
lower_val = duty_ns & 0x00FF;
/*
* get bits [9:10] that are to be written to
* AB8500_PWM_OUT_CTRL2_REG[0:1]
*/
higher_val = ((duty_ns & 0x0300) >> 8);
reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);
ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
reg, (u8)lower_val);
if (ret < 0)
return ret;
ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
(reg + 1), (u8)higher_val);
return ret;
}
EXPORT_SYMBOL(pwm_config);
int pwm_enable(struct pwm_device *pwm)
{
int ret;
ret = abx500_mask_and_set_register_interruptible(pwm->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (pwm->pwm_id-1), ENABLE_PWM);
if (ret < 0)
dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
pwm->label, ret);
return ret;
}
EXPORT_SYMBOL(pwm_enable);
void pwm_disable(struct pwm_device *pwm)
{
int ret;
ret = abx500_mask_and_set_register_interruptible(pwm->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (pwm->pwm_id-1), DISABLE_PWM);
if (ret < 0)
dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
pwm->label, ret);
return;
}
EXPORT_SYMBOL(pwm_disable);
struct pwm_device *pwm_request(int pwm_id, const char *label)
{
struct pwm_device *pwm;
list_for_each_entry(pwm, &pwm_list, node) {
if (pwm->pwm_id == pwm_id) {
pwm->label = label;
pwm->pwm_id = pwm_id;
return pwm;
}
}
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(pwm_request);
void pwm_free(struct pwm_device *pwm)
{
pwm_disable(pwm);
}
EXPORT_SYMBOL(pwm_free);
static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
{
struct pwm_device *pwm;
/*
* Nothing to be done in probe, this is required to get the
* device which is required for ab8500 read and write
*/
pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
if (pwm == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
}
pwm->dev = &pdev->dev;
pwm->pwm_id = pdev->id;
list_add_tail(&pwm->node, &pwm_list);
platform_set_drvdata(pdev, pwm);
dev_dbg(pwm->dev, "pwm probe successful\n");
return 0;
}
static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
{
struct pwm_device *pwm = platform_get_drvdata(pdev);
list_del(&pwm->node);
dev_dbg(&pdev->dev, "pwm driver removed\n");
kfree(pwm);
return 0;
}
static struct platform_driver ab8500_pwm_driver = {
.driver = {
.name = "ab8500-pwm",
.owner = THIS_MODULE,
},
.probe = ab8500_pwm_probe,
.remove = __devexit_p(ab8500_pwm_remove),
};
static int __init ab8500_pwm_init(void)
{
return platform_driver_register(&ab8500_pwm_driver);
}
static void __exit ab8500_pwm_exit(void)
{
platform_driver_unregister(&ab8500_pwm_driver);
}
subsys_initcall(ab8500_pwm_init);
module_exit(ab8500_pwm_exit);
MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
MODULE_ALIAS("platform:ab8500-pwm");
MODULE_LICENSE("GPL v2");
