[RESEND RFC PATCH] reset: Add devm_reset_control_deassert helper

From: Prabhakar
Date: Wed Jun 05 2024 - 11:37:43 EST


From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

A typical code pattern for reset_control_deassert() call is to call it in
the _probe function and to call reset_control_assert() both from _probe
error path and from _remove function.

Add helper function to replace this bolierplate piece of code. Calling
devm_reset_control_deassert() removes the need for calling
reset_control_assert() both in the probe()'s error path and in the
remove() function.

Suggested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
drivers/reset/core.c | 22 ++++++++++++++++++++++
include/linux/reset.h | 6 ++++++
2 files changed, 28 insertions(+)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index dba74e857be6..a2a6eff8e599 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -592,6 +592,28 @@ int reset_control_deassert(struct reset_control *rstc)
}
EXPORT_SYMBOL_GPL(reset_control_deassert);

+static void reset_control_assert_action(void *rstc)
+{
+ reset_control_assert(rstc);
+}
+
+/**
+ * devm_reset_control_deassert - devres-enabled version of reset_control_deassert()
+ * @dev: device that requests the reset control
+ * @rstc: reset controller
+ */
+int devm_reset_control_deassert(struct device *dev, struct reset_control *rstc)
+{
+ int ret;
+
+ ret = reset_control_deassert(rstc);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, reset_control_assert_action, rstc);
+}
+EXPORT_SYMBOL_GPL(devm_reset_control_deassert);
+
/**
* reset_control_bulk_deassert - deasserts the reset lines in reverse order
* @num_rstcs: number of entries in rstcs array
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 514ddf003efc..e41e752ba098 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -31,6 +31,7 @@ int reset_control_reset(struct reset_control *rstc);
int reset_control_rearm(struct reset_control *rstc);
int reset_control_assert(struct reset_control *rstc);
int reset_control_deassert(struct reset_control *rstc);
+int devm_reset_control_deassert(struct device *dev, struct reset_control *rstc);
int reset_control_status(struct reset_control *rstc);
int reset_control_acquire(struct reset_control *rstc);
void reset_control_release(struct reset_control *rstc);
@@ -91,6 +92,11 @@ static inline int reset_control_deassert(struct reset_control *rstc)
return 0;
}

+static inline int devm_reset_control_deassert(struct device *dev, struct reset_control *rstc)
+{
+ return 0;
+}
+
static inline int reset_control_status(struct reset_control *rstc)
{
return 0;
--
2.34.1