static void of_pwmchip_remove(struct pwm_chip *chip)
{
- if (chip->dev && chip->dev->of_node)
+ if (chip->dev)
of_node_put(chip->dev->of_node);
}
* pwm_set_chip_data() - set private chip data for a PWM
* @pwm: PWM device
* @data: pointer to chip-specific data
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_set_chip_data(struct pwm_device *pwm, void *data)
{
/**
* pwm_get_chip_data() - get private chip data for a PWM
* @pwm: PWM device
+ *
+ * Returns: A pointer to the chip-private data for the PWM device.
*/
void *pwm_get_chip_data(struct pwm_device *pwm)
{
EXPORT_SYMBOL_GPL(pwm_get_chip_data);
/**
- * pwmchip_add() - register a new PWM chip
+ * pwmchip_add_with_polarity() - register a new PWM chip
* @chip: the PWM chip to add
+ * @polarity: initial polarity of PWM channels
*
* Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
- * will be used.
+ * will be used. The initial polarity for all channels is specified by the
+ * @polarity parameter.
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
-int pwmchip_add(struct pwm_chip *chip)
+int pwmchip_add_with_polarity(struct pwm_chip *chip,
+ enum pwm_polarity polarity)
{
struct pwm_device *pwm;
unsigned int i;
int ret;
if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
- !chip->ops->enable || !chip->ops->disable)
+ !chip->ops->enable || !chip->ops->disable || !chip->npwm)
return -EINVAL;
mutex_lock(&pwm_lock);
pwm->chip = chip;
pwm->pwm = chip->base + i;
pwm->hwpwm = i;
+ pwm->polarity = polarity;
+ mutex_init(&pwm->lock);
radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
}
mutex_unlock(&pwm_lock);
return ret;
}
+EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
+
+/**
+ * pwmchip_add() - register a new PWM chip
+ * @chip: the PWM chip to add
+ *
+ * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
+ * will be used. The initial polarity for all channels is normal.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int pwmchip_add(struct pwm_chip *chip)
+{
+ return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
+}
EXPORT_SYMBOL_GPL(pwmchip_add);
/**
*
* Removes a PWM chip. This function may return busy if the PWM chip provides
* a PWM device that is still requested.
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwmchip_remove(struct pwm_chip *chip)
{
/**
* pwm_request() - request a PWM device
- * @pwm_id: global PWM device index
+ * @pwm: global PWM device index
* @label: PWM device label
*
* This function is deprecated, use pwm_get() instead.
+ *
+ * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
+ * failure.
*/
struct pwm_device *pwm_request(int pwm, const char *label)
{
* @index: per-chip index of the PWM to request
* @label: a literal description string of this PWM
*
- * Returns the PWM at the given index of the given PWM chip. A negative error
- * code is returned if the index is not valid for the specified PWM chip or
- * if the PWM device cannot be requested.
+ * Returns: A pointer to the PWM device at the given index of the given PWM
+ * chip. A negative error code is returned if the index is not valid for the
+ * specified PWM chip or if the PWM device cannot be requested.
*/
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
unsigned int index,
* @pwm: PWM device
* @duty_ns: "on" time (in nanoseconds)
* @period_ns: duration (in nanoseconds) of one cycle
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
* @pwm: PWM device
* @polarity: new polarity of the PWM signal
*
- * Note that the polarity cannot be configured while the PWM device is enabled
+ * Note that the polarity cannot be configured while the PWM device is
+ * enabled.
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
{
if (!pwm->chip->ops->set_polarity)
return -ENOSYS;
- if (test_bit(PWMF_ENABLED, &pwm->flags))
- return -EBUSY;
+ mutex_lock(&pwm->lock);
+
+ if (pwm_is_enabled(pwm)) {
+ err = -EBUSY;
+ goto unlock;
+ }
err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
if (err)
- return err;
+ goto unlock;
pwm->polarity = polarity;
- return 0;
+unlock:
+ mutex_unlock(&pwm->lock);
+ return err;
}
EXPORT_SYMBOL_GPL(pwm_set_polarity);
/**
* pwm_enable() - start a PWM output toggling
* @pwm: PWM device
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_enable(struct pwm_device *pwm)
{
- if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
- return pwm->chip->ops->enable(pwm->chip, pwm);
+ int err = 0;
- return pwm ? 0 : -EINVAL;
+ if (!pwm)
+ return -EINVAL;
+
+ mutex_lock(&pwm->lock);
+
+ if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+ err = pwm->chip->ops->enable(pwm->chip, pwm);
+ if (err)
+ clear_bit(PWMF_ENABLED, &pwm->flags);
+ }
+
+ mutex_unlock(&pwm->lock);
+
+ return err;
}
EXPORT_SYMBOL_GPL(pwm_enable);
* 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.
+ *
+ * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
+ * error code on failure.
*/
struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
{
* @table: array of consumers to register
* @num: number of consumers in table
*/
-void __init pwm_add_table(struct pwm_lookup *table, size_t num)
+void pwm_add_table(struct pwm_lookup *table, size_t num)
{
mutex_lock(&pwm_lookup_lock);
mutex_unlock(&pwm_lookup_lock);
}
+/**
+ * pwm_remove_table() - unregister PWM device consumers
+ * @table: array of consumers to unregister
+ * @num: number of consumers in table
+ */
+void pwm_remove_table(struct pwm_lookup *table, size_t num)
+{
+ mutex_lock(&pwm_lookup_lock);
+
+ while (num--) {
+ list_del(&table->list);
+ table++;
+ }
+
+ mutex_unlock(&pwm_lookup_lock);
+}
+
/**
* pwm_get() - look up and request a PWM device
* @dev: device for PWM consumer
*
* Once a PWM chip has been found the specified PWM device will be requested
* and is ready to be used.
+ *
+ * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
+ * error code on failure.
*/
struct pwm_device *pwm_get(struct device *dev, const char *con_id)
{
struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
const char *dev_id = dev ? dev_name(dev) : NULL;
struct pwm_chip *chip = NULL;
- unsigned int index = 0;
unsigned int best = 0;
- struct pwm_lookup *p;
+ struct pwm_lookup *p, *chosen = NULL;
unsigned int match;
/* look up via DT first */
}
if (match > best) {
- chip = pwmchip_find_by_name(p->provider);
- index = p->index;
+ chosen = p;
if (match != 3)
best = match;
}
}
- mutex_unlock(&pwm_lookup_lock);
+ if (!chosen) {
+ pwm = ERR_PTR(-ENODEV);
+ goto out;
+ }
- if (chip)
- pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id);
- if (IS_ERR(pwm))
- return pwm;
+ chip = pwmchip_find_by_name(chosen->provider);
+ if (!chip)
+ goto out;
- pwm_set_period(pwm, p->period);
- pwm_set_polarity(pwm, p->polarity);
+ pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
+ if (IS_ERR(pwm))
+ goto out;
+ pwm_set_period(pwm, chosen->period);
+ pwm_set_polarity(pwm, chosen->polarity);
+out:
+ mutex_unlock(&pwm_lookup_lock);
return pwm;
}
EXPORT_SYMBOL_GPL(pwm_get);
*
* This function performs like pwm_get() but the acquired PWM device will
* automatically be released on driver detach.
+ *
+ * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
+ * error code on failure.
*/
struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
{
*
* This function performs like of_pwm_get() but the acquired PWM device will
* automatically be released on driver detach.
+ *
+ * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
+ * error code on failure.
*/
struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
const char *con_id)
* pwm_can_sleep() - report whether PWM access will sleep
* @pwm: PWM device
*
- * It returns true if accessing the PWM can sleep, false otherwise.
+ * Returns: True if accessing the PWM can sleep, false otherwise.
*/
bool pwm_can_sleep(struct pwm_device *pwm)
{
if (test_bit(PWMF_REQUESTED, &pwm->flags))
seq_puts(s, " requested");
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
seq_puts(s, " enabled");
seq_puts(s, "\n");
return 0;
}
-
subsys_initcall(pwm_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
projects / karo-tx-linux.git / blobdiff