[PATCH 1/4] reset: Add reset_reset() and reset_reset_bulk() API

[Michal Simek]

Add reset_reset() and reset_reset_bulk() functions to the reset
controller API. These functions assert and then deassert reset signals
in a single call, providing a convenient way to pulse/toggle a reset
line.

This mirrors the Linux kernel's reset_control_reset() and
reset_control_bulk_reset() APIs. The new functions are useful for
drivers that need to cycle a reset line during initialization or
error recovery.

Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 drivers/reset/reset-uclass.c | 30 ++++++++++++++++++++++++++++++
 include/reset-uclass.h       | 11 +++++++++++
 include/reset.h              | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)

diff --git a/drivers/reset/reset-uclass.c b/drivers/reset/reset-uclass.c
index fe4cebf54f15..b26712abc366 100644
--- a/drivers/reset/reset-uclass.c
+++ b/drivers/reset/reset-uclass.c
@@ -225,6 +225,36 @@ int reset_deassert_bulk(struct reset_ctl_bulk *bulk)
 	return 0;
 }
 
+int reset_reset(struct reset_ctl *reset_ctl)
+{
+	struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
+	int ret;
+
+	debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
+
+	if (ops->rst_reset)
+		return ops->rst_reset(reset_ctl);
+
+	ret = reset_assert(reset_ctl);
+	if (ret < 0)
+		return ret;
+
+	return reset_deassert(reset_ctl);
+}
+
+int reset_reset_bulk(struct reset_ctl_bulk *bulk)
+{
+	int i, ret;
+
+	for (i = 0; i < bulk->count; i++) {
+		ret = reset_reset(&bulk->resets[i]);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
 int reset_status(struct reset_ctl *reset_ctl)
 {
 	struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
diff --git a/include/reset-uclass.h b/include/reset-uclass.h
index 9a0696dd1e3b..3ff665c947ea 100644
--- a/include/reset-uclass.h
+++ b/include/reset-uclass.h
@@ -76,6 +76,17 @@ struct reset_ops {
 	 * @return 0 if OK, or a negative error code.
 	 */
 	int (*rst_deassert)(struct reset_ctl *reset_ctl);
+	/**
+	 * rst_reset - Reset a HW module.
+	 *
+	 * This optional function triggers a reset pulse on the reset line,
+	 * asserting and then deasserting the reset signal. If not implemented,
+	 * the reset core will use rst_assert followed by rst_deassert.
+	 *
+	 * @reset_ctl:	The reset signal to pulse.
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*rst_reset)(struct reset_ctl *reset_ctl);
 	/**
 	 * rst_status - Check reset signal status.
 	 *
diff --git a/include/reset.h b/include/reset.h
index 036a786d2ace..cd10596825a3 100644
--- a/include/reset.h
+++ b/include/reset.h
@@ -320,6 +320,31 @@ int reset_deassert(struct reset_ctl *reset_ctl);
  */
 int reset_deassert_bulk(struct reset_ctl_bulk *bulk);
 
+/**
+ * reset_reset - Reset a HW module by asserting and deasserting a reset signal.
+ *
+ * This function will assert and then deassert the specified reset signal,
+ * thus resetting the affected HW module. This is a convenience function
+ * that combines reset_assert() and reset_deassert().
+ *
+ * @reset_ctl:	A reset control struct that was previously successfully
+ *		requested by reset_get_by_*().
+ * Return: 0 if OK, or a negative error code.
+ */
+int reset_reset(struct reset_ctl *reset_ctl);
+
+/**
+ * reset_reset_bulk - Reset all HW modules in a reset control bulk struct.
+ *
+ * This function will assert and then deassert all reset signals in the
+ * specified reset control bulk struct, thus resetting all affected HW modules.
+ *
+ * @bulk:	A reset control bulk struct that was previously successfully
+ *		requested by reset_get_bulk().
+ * Return: 0 if OK, or a negative error code.
+ */
+int reset_reset_bulk(struct reset_ctl_bulk *bulk);
+
 /**
  * rst_status - Check reset signal status.
  *
@@ -443,6 +468,16 @@ static inline int reset_deassert_bulk(struct reset_ctl_bulk *bulk)
 	return 0;
 }
 
+static inline int reset_reset(struct reset_ctl *reset_ctl)
+{
+	return 0;
+}
+
+static inline int reset_reset_bulk(struct reset_ctl_bulk *bulk)
+{
+	return 0;
+}
+
 static inline int reset_status(struct reset_ctl *reset_ctl)
 {
 	return -ENOTSUPP;
-- 
2.43.0