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drivers/pwm: add duty_ns and period_ns to core pwm chip 

Add variables to control the duty_ns and period_ns of PWM
chips. When these variables are set, a call to either
pwm_enable() or pwm_config() is performed to enforce the
setup values.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Robert Jarzmik 2012-02-16 19:23:46 +01:00 committed by Sascha Hauer
parent f917e6f866
commit 6fa3e3119f
2 changed files with 81 additions and 2 deletions
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76
drivers/pwm/core.c
View File

@ -29,10 +29,23 @@ struct pwm_device {
#define FLAG_REQUESTED 0
#define FLAG_ENABLED 1
struct list_head node;
struct device_d *dev;
};
static LIST_HEAD(pwm_list);
static struct pwm_device *dev_to_pwm(struct device_d *dev)
{
struct pwm_device *pwm;
list_for_each_entry(pwm, &pwm_list, node) {
if (pwm->dev == dev)
return pwm;
}
return NULL;
}
static struct pwm_device *_find_pwm(const char *devname)
{
struct pwm_device *pwm;
@ -45,6 +58,63 @@ static struct pwm_device *_find_pwm(const char *devname)
return NULL;
}
static int set_period_ns(struct device_d *dev, struct param_d *p,
const char *val)
{
struct pwm_device *pwm = dev_to_pwm(dev);
int period_ns;
if (!val)
return dev_param_set_generic(dev, p, NULL);
period_ns = simple_strtoul(val, NULL, 0);
pwm_config(pwm, pwm->chip->duty_ns, period_ns);
return dev_param_set_generic(dev, p, val);
}
static int set_duty_ns(struct device_d *dev, struct param_d *p, const char *val)
{
struct pwm_device *pwm = dev_to_pwm(dev);
int duty_ns;
if (!val)
return dev_param_set_generic(dev, p, NULL);
duty_ns = simple_strtoul(val, NULL, 0);
pwm_config(pwm, duty_ns, pwm->chip->period_ns);
return dev_param_set_generic(dev, p, val);
}
static int set_enable(struct device_d *dev, struct param_d *p, const char *val)
{
struct pwm_device *pwm = dev_to_pwm(dev);
int enable;
if (!val)
return dev_param_set_generic(dev, p, NULL);
enable = !!simple_strtoul(val, NULL, 0);
if (enable)
pwm_enable(pwm);
else
pwm_disable(pwm);
return dev_param_set_generic(dev, p, enable ? "1" : "0");
}
static int pwm_register_vars(struct device_d *dev)
{
int ret;
ret = dev_add_param(dev, "duty_ns", set_duty_ns, NULL, 0);
if (!ret)
ret = dev_add_param(dev, "period_ns", set_period_ns, NULL, 0);
if (!ret)
ret = dev_add_param(dev, "enable", set_enable, NULL, 0);
if (!ret)
ret = dev_set_param(dev, "enable", 0);
return ret;
}
/**
* pwmchip_add() - register a new pwm
* @chip: the pwm
@ -52,7 +122,7 @@ static struct pwm_device *_find_pwm(const char *devname)
* register a new pwm. pwm->devname must be initialized, usually
* from dev_name(dev) from the hardware driver.
*/
int pwmchip_add(struct pwm_chip *chip)
int pwmchip_add(struct pwm_chip *chip, struct device_d *dev)
{
struct pwm_device *pwm;
int ret = 0;
@ -62,8 +132,10 @@ int pwmchip_add(struct pwm_chip *chip)
pwm = xzalloc(sizeof(*pwm));
pwm->chip = chip;
pwm->dev = dev;
list_add_tail(&pwm->node, &pwm_list);
pwm_register_vars(dev);
return ret;
}
@ -136,6 +208,8 @@ EXPORT_SYMBOL_GPL(pwm_free);
*/
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
pwm->chip->duty_ns = duty_ns;
pwm->chip->period_ns = period_ns;
return pwm->chip->ops->config(pwm->chip, duty_ns, period_ns);
}
EXPORT_SYMBOL_GPL(pwm_config);

7
include/pwm.h
View File

@ -2,6 +2,7 @@
#define __PWM_H
struct pwm_device;
struct device_d;
/*
* pwm_request - request a PWM device
@ -51,13 +52,17 @@ struct pwm_ops {
* struct pwm_chip - abstract a PWM
* @devname: unique identifier for this pwm
* @ops: The callbacks for this PWM
* @duty_ns: The duty cycle of the PWM, in nano-seconds
* @period_ns: The period of the PWM, in nano-seconds
*/
struct pwm_chip {
const char *devname;
struct pwm_ops *ops;
int duty_ns;
int period_ns;
};
int pwmchip_add(struct pwm_chip *chip);
int pwmchip_add(struct pwm_chip *chip, struct device_d *dev);
int pwmchip_remove(struct pwm_chip *chip);
#endif /* __PWM_H */