El Tue, Jun 28, 2011 at 12:02:47PM +0200 Sascha Hauer ha dit:

This patch adds framework support for PWM (pulse width modulation) devices.

[...]

[...]

+/**
+ * pwmchip_add() - register a new pwm
+ * @chip: the pwm
+ *
+ * register a new pwm. pwm->pwm_id must be initialized. if pwm_id < 0 then
+ * a dynamically assigned id will be used, otherwise the id specified,
+ */
+int pwmchip_add(struct pwm_chip *chip)
+{
+	struct pwm_device *pwm;
+	int ret = 0;
+
+	pwm = kzalloc(sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->chip = chip;
+
+	mutex_lock(&pwm_lock);
+
+	if (chip->pwm_id >= 0 && find_pwm(chip->pwm_id)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (chip->pwm_id < 0)
+		chip->pwm_id = next_pwm_id++;
+
+	list_add_tail(&pwm->node, &pwm_list);
+out:
+	mutex_unlock(&pwm_lock);
+
+	kfree(pwm);

as already pointed out by kurt, pwm should only be freed in case of an
error

+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pwmchip_add);
+
+/**
+ * pwmchip_remove() - remove a pwm
+ * @chip: the pwm
+ *
+ * remove a pwm. This function may return busy if the pwm is still requested.
+ */
+int pwmchip_remove(struct pwm_chip *chip)
+{
+	struct pwm_device *pwm;
+	int ret = 0;
+
+	mutex_lock(&pwm_lock);
+
+	pwm = find_pwm(chip->pwm_id);
+	if (!pwm) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	if (test_bit(FLAG_REQUESTED, &pwm->flags)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	list_del(&pwm->node);

  +	kfree(pwm);

+out:
+	mutex_unlock(&pwm_lock);
+
+	return ret;
+}

[...]

best regards

-- 
Matthias Kaehlcke
Embedded Linux Developer
Amsterdam

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                        (Nelson Mandela)
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