reset: Provide new devm_reset helpers for get and deassert reset control

[PATCH RFC] reset: Provide new devm_reset helpers for get and deassert reset control

Posted by Yuesong Li 1 year, 5 months ago

When a driver wants to get reset control and deassert it,this
helper will handle the return value of these function, also it
will register a devres so that when the device been detached, the
reset control will be assert.

Signed-off-by: Yuesong Li <liyuesong@vivo.com>
---
 include/linux/reset.h | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/include/linux/reset.h b/include/linux/reset.h
index 514ddf003efc..d7e02968b63b 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -806,6 +806,35 @@ devm_reset_control_get_shared_by_index(struct device *dev, int index)
 	return __devm_reset_control_get(dev, NULL, index, true, false, false);
 }
 
+/**
+ * devm_reset_control_get_deassert - resource managed
+ * @dev: device to be reset by the controller
+ * @index: index of the reset controller
+ *
+ * A helper function to automatically handle return value of
+ * devm_reset_control_get_exclusive() and reset_control_deassert().
+ */
+static struct reset_control *devm_reset_control_get_deassert(
+			  struct device *dev, const char *id)
+{
+	int ret;
+	struct reset_control *reset;
+
+	reset = devm_reset_control_get_exclusive(dev, id);
+	if (IS_ERR(reset))
+		return reset;
+
+	ret = reset_control_deassert(reset);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = devm_add_action_or_reset(dev, (void *)reset_control_assert, (void *)reset);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return reset;
+}
+
 /*
  * TEMPORARY calls to use during transition:
  *
-- 
2.34.1

Re: [PATCH RFC] reset: Provide new devm_reset helpers for get and deassert reset control

Posted by Yuesong Li 1 year, 5 months ago


On 2024/8/30 11:33, Yuesong Li wrote:
> When a driver wants to get reset control and deassert it,this
> helper will handle the return value of these function, also it
> will register a devres so that when the device been detached, the
> reset control will be assert.
> 
> Signed-off-by: Yuesong Li <liyuesong@vivo.com>
> ---
>   include/linux/reset.h | 29 +++++++++++++++++++++++++++++
>   1 file changed, 29 insertions(+)
> 
> diff --git a/include/linux/reset.h b/include/linux/reset.h
> index 514ddf003efc..d7e02968b63b 100644
> --- a/include/linux/reset.h
> +++ b/include/linux/reset.h
> @@ -806,6 +806,35 @@ devm_reset_control_get_shared_by_index(struct device *dev, int index)
>   	return __devm_reset_control_get(dev, NULL, index, true, false, false);
>   }
>   
> +/**
> + * devm_reset_control_get_deassert - resource managed
> + * @dev: device to be reset by the controller
> + * @index: index of the reset controller
> + *
> + * A helper function to automatically handle return value of
> + * devm_reset_control_get_exclusive() and reset_control_deassert().
> + */
> +static struct reset_control *devm_reset_control_get_deassert(
> +			  struct device *dev, const char *id)
> +{
> +	int ret;
> +	struct reset_control *reset;
> +
> +	reset = devm_reset_control_get_exclusive(dev, id);
> +	if (IS_ERR(reset))
> +		return reset;
> +
> +	ret = reset_control_deassert(reset);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	ret = devm_add_action_or_reset(dev, (void *)reset_control_assert, (void *)reset);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return reset;
> +}
> +
>   /*
>    * TEMPORARY calls to use during transition:
>    *

Please ignore this patch, I did not use clang to check the compile 
process. This patch is meant to simplify a common pattern appears in 
more than 10 files. For example in
"drivers/thermal/sun8i_thermal.c" line 393-401
But to pass the complier test, we need to include other header which 
does not make sense. So drop this patch.

Re: [PATCH RFC] reset: Provide new devm_reset helpers for get and deassert reset control

Posted by Philipp Zabel 1 year, 5 months ago

On Mo, 2024-09-02 at 17:52 +0800, Yuesong Li wrote:
> 
> On 2024/8/30 11:33, Yuesong Li wrote:
> > When a driver wants to get reset control and deassert it,this
> > helper will handle the return value of these function, also it
> > will register a devres so that when the device been detached, the
> > reset control will be assert.
> > 
> > Signed-off-by: Yuesong Li <liyuesong@vivo.com>

Could you have a look at the pre-deasserted / auto-reasserting reset
control series [1] and see if that would fit your use case?

[1] https://lore.kernel.org/all/20240621-reset-get-deasserted-v1-0-94ee76fb7b7d@pengutronix.de/

regards
Philipp

Re: [PATCH RFC] reset: Provide new devm_reset helpers for get and deassert reset control

Posted by Yuesong Li 1 year, 5 months ago


On 2024/9/2 18:44, Philipp Zabel wrote:
> On Mo, 2024-09-02 at 17:52 +0800, Yuesong Li wrote:
>>
>> On 2024/8/30 11:33, Yuesong Li wrote:
>>> When a driver wants to get reset control and deassert it,this
>>> helper will handle the return value of these function, also it
>>> will register a devres so that when the device been detached, the
>>> reset control will be assert.
>>>
>>> Signed-off-by: Yuesong Li <liyuesong@vivo.com>
> 
> Could you have a look at the pre-deasserted / auto-reasserting reset
> control series [1] and see if that would fit your use case?
> 
> [1] https://lore.kernel.org/all/20240621-reset-get-deasserted-v1-0-94ee76fb7b7d@pengutronix.de/
> 
> regards
> Philipp

Thanks for reaching out, this patch fit my case exactly.

Best regards,
Yuesong