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PWM: Implement devicetree support 

This implements of_pwm_request() for PWM client drivers.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Sascha Hauer 2014-02-28 13:29:06 +01:00
parent 37acfdf97d
commit ea0ed15786
2 changed files with 68 additions and 9 deletions
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75
drivers/pwm/core.c
View File

@ -143,6 +143,24 @@ int pwmchip_remove(struct pwm_chip *chip)
}
EXPORT_SYMBOL_GPL(pwmchip_remove);
static int __pwm_request(struct pwm_device *pwm)
{
int ret;
if (test_bit(FLAG_REQUESTED, &pwm->flags))
return -EBUSY;
if (pwm->chip->ops->request) {
ret = pwm->chip->ops->request(pwm->chip);
if (ret)
return ret;
}
set_bit(FLAG_REQUESTED, &pwm->flags);
return 0;
}
/*
* pwm_request - request a PWM device
*/
@ -155,21 +173,60 @@ struct pwm_device *pwm_request(const char *devname)
if (!pwm)
return NULL;
if (test_bit(FLAG_REQUESTED, &pwm->flags))
ret = __pwm_request(pwm);
if (ret)
return NULL;
if (pwm->chip->ops->request) {
ret = pwm->chip->ops->request(pwm->chip);
if (ret)
return NULL;
}
set_bit(FLAG_REQUESTED, &pwm->flags);
return pwm;
}
EXPORT_SYMBOL_GPL(pwm_request);
static struct pwm_device *of_node_to_pwm_device(struct device_node *np)
{
struct pwm_device *pwm;
list_for_each_entry(pwm, &pwm_list, node) {
if (pwm->hwdev && pwm->hwdev->device_node == np)
return pwm;
}
return ERR_PTR(-ENODEV);
}
struct pwm_device *of_pwm_request(struct device_node *np, const char *con_id)
{
struct of_phandle_args args;
int index = 0;
struct pwm_device *pwm;
int ret;
if (con_id)
return ERR_PTR(-EINVAL);
ret = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
&args);
if (ret) {
pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
return ERR_PTR(ret);
}
pwm = of_node_to_pwm_device(args.np);
if (IS_ERR(pwm)) {
pr_debug("%s(): PWM chip not found\n", __func__);
return pwm;
}
if (args.args_count > 1)
pwm_set_period(pwm, args.args[1]);
ret = __pwm_request(pwm);
if (ret)
return ERR_PTR(-ret);
return pwm;
}
EXPORT_SYMBOL_GPL(of_pwm_request);
/*
* pwm_free - free a PWM device
*/

2
include/pwm.h
View File

@ -9,6 +9,8 @@ struct device_d;
*/
struct pwm_device *pwm_request(const char *pwmname);
struct pwm_device *of_pwm_request(struct device_node *np, const char *con_id);
/*
* pwm_free - free a PWM device
*/