This patch introduces of_pwm_get_index() (and its devm based friend)
which works like of_pwm_get() except that you are able to specify which
pwm you need instead using a name (which is optional anyway).
This comes handy if you have multiple pwms specified in device tree and
you need to grab one by one (in a loop) and you don't have any specific
names for them.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/pwm/core.c | 101 +++++++++++++++++++++++++++++++++++++---------------
include/linux/pwm.h | 16 +++++++++
2 files changed, 88 insertions(+), 29 deletions(-)
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 966497d10c6e..f9b679c5d9fa 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -493,35 +493,24 @@ static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
}
/**
- * of_pwm_get() - request a PWM via the PWM framework
+ * of_pwm_get_index() - request a PWM via the PWM framework
* @np: device node to get the PWM from
- * @con_id: consumer name
+ * @index: The number of the PWN within the property
*
* Returns the PWM device parsed from the phandle and index specified in the
* "pwms" property of a device tree node or a negative error-code on failure.
* Values parsed from the device tree are stored in the returned PWM device
* object.
*
- * If con_id is NULL, the first PWM device listed in the "pwms" property will
- * be requested. Otherwise the "pwm-names" property is used to do a reverse
- * lookup of the PWM index. This also means that the "pwm-names" property
- * becomes mandatory for devices that look up the PWM device via the con_id
- * parameter.
*/
-struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
+struct pwm_device *of_pwm_get_index(struct device_node *np, int index)
{
- struct pwm_device *pwm = NULL;
+ struct pwm_device *pwm;
struct of_phandle_args args;
+ const char *con_id;
struct pwm_chip *pc;
- int index = 0;
int err;
- if (con_id) {
- index = of_property_match_string(np, "pwm-names", con_id);
- if (index < 0)
- return ERR_PTR(index);
- }
-
err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
&args);
if (err) {
@@ -547,23 +536,47 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
if (IS_ERR(pwm))
goto put;
- /*
- * If a consumer name was not given, try to look it up from the
- * "pwm-names" property if it exists. Otherwise use the name of
- * the user device node.
- */
- if (!con_id) {
- err = of_property_read_string_index(np, "pwm-names", index,
- &con_id);
- if (err < 0)
- con_id = np->name;
+ err = of_property_read_string_index(np, "pwm-names", index,
+ &con_id);
+ if (err < 0) {
+ con_id = np->name;
+ pwm->label = con_id;
}
-
- pwm->label = con_id;
-
put:
of_node_put(args.np);
+ return pwm;
+}
+EXPORT_SYMBOL_GPL(of_pwm_get_index);
+/**
+ * of_pwm_get() - request a PWM via the PWM framework
+ * @np: device node to get the PWM from
+ * @con_id: consumer name
+ *
+ * Returns the PWM device parsed from the phandle and index specified in the
+ * "pwms" property of a device tree node or a negative error-code on failure.
+ * Values parsed from the device tree are stored in the returned PWM device
+ * object.
+ *
+ * If con_id is NULL, the first PWM device listed in the "pwms" property will
+ * be requested. Otherwise the "pwm-names" property is used to do a reverse
+ * lookup of the PWM index. This also means that the "pwm-names" property
+ * becomes mandatory for devices that look up the PWM device via the con_id
+ * parameter.
+ */
+struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
+{
+ struct pwm_device *pwm;
+ int index = 0;
+
+ if (con_id) {
+ index = of_property_match_string(np, "pwm-names", con_id);
+ if (index < 0)
+ return ERR_PTR(index);
+ }
+
+ pwm = of_pwm_get_index(np, index);
+ pwm->label = con_id;
return pwm;
}
EXPORT_SYMBOL_GPL(of_pwm_get);
@@ -740,6 +753,36 @@ struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
EXPORT_SYMBOL_GPL(devm_pwm_get);
/**
+ * devm_of_pwm_get_index() - resource managed of_pwm_get_index()
+ * @dev: device for PWM consumer
+ * @np: device node to get the PWM from
+ * @index: pwm index
+ *
+ * This function performs like of_pwm_get_index() but the acquired PWM device
+ * will automatically be released on driver detach.
+ */
+struct pwm_device *devm_of_pwm_get_index(struct device *dev,
+ struct device_node *np, int index)
+{
+ struct pwm_device **ptr, *pwm;
+
+ ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ pwm = of_pwm_get_index(np, index);
+ if (!IS_ERR(pwm)) {
+ *ptr = pwm;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return pwm;
+}
+EXPORT_SYMBOL_GPL(devm_of_pwm_get_index);
+
+/**
* devm_of_pwm_get() - resource managed of_pwm_get()
* @dev: device for PWM consumer
* @np: device node to get the PWM from
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index e90628cac8fa..91eb4404bc19 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -192,10 +192,13 @@ struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
const struct of_phandle_args *args);
struct pwm_device *pwm_get(struct device *dev, const char *con_id);
+struct pwm_device *of_pwm_get_index(struct device_node *np, int index);
struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
void pwm_put(struct pwm_device *pwm);
struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
+struct pwm_device *devm_of_pwm_get_index(struct device *dev,
+ struct device_node *np, int index);
struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
const char *con_id);
void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
@@ -235,6 +238,12 @@ static inline struct pwm_device *pwm_get(struct device *dev,
return ERR_PTR(-ENODEV);
}
+static inline struct pwm_device *of_pwm_get_index(struct device_node *np,
+ int index)
+{
+ return ERR_PTR(-ENODEV);
+}
+
static inline struct pwm_device *of_pwm_get(struct device_node *np,
const char *con_id)
{
@@ -251,6 +260,13 @@ static inline struct pwm_device *devm_pwm_get(struct device *dev,
return ERR_PTR(-ENODEV);
}
+static inline struct pwm_device *devm_of_pwm_get_index(struct device *dev,
+ struct device_node *np,
+ int index)
+{
+ return ERR_PTR(-ENODEV);
+}
+
static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
struct device_node *np,
const char *con_id)
--
2.1.4
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