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authorSascha Hauer <s.hauer@pengutronix.de>2014-02-28 13:29:06 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2014-02-28 15:05:46 +0100
commitea0ed157863b7b650e3eff485a49cbc0925f5265 (patch)
tree53c9144fbe0a8701e3137fabc0c05a0b8e514a51
parent37acfdf97d1ebddb431e2ed9a9aa4482ac1a474a (diff)
downloadbarebox-ea0ed157863b7b650e3eff485a49cbc0925f5265.tar.gz
PWM: Implement devicetree support
This implements of_pwm_request() for PWM client drivers. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--drivers/pwm/core.c71
-rw-r--r--include/pwm.h2
2 files changed, 66 insertions, 7 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 7f30724..cc33dec 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -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
*/
@@ -155,20 +173,59 @@ 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;
+ 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;
}
- set_bit(FLAG_REQUESTED, &pwm->flags);
+ 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(pwm_request);
+EXPORT_SYMBOL_GPL(of_pwm_request);
/*
* pwm_free - free a PWM device
diff --git a/include/pwm.h b/include/pwm.h
index 5ca9fa0..59d86d4 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -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
*/