Re: [PATCH v4 1/5] regulator: Allow regulators to verify enabled during enable()
On Tue 02 Jun 03:09 PDT 2020, Sumit Semwal wrote:
> Some regulators might need to verify that they have indeed been enabled
> after the enable() call is made and enable_time delay has passed.
>
> This is implemented by repeatedly checking is_enabled() upto
> poll_enabled_time, waiting for the already calculated enable delay in
> each iteration.
>
> Signed-off-by: Sumit Semwal
> --
> v2: Address review comments, including swapping enable_time and
> poll_enabled_time.
> ---
> drivers/regulator/core.c | 58 +++-
> include/linux/regulator/driver.h | 5 +++
> 2 files changed, 62 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 7486f6e4e613..d9ab888da95f 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -2347,6 +2347,32 @@ static void _regulator_enable_delay(unsigned int delay)
> udelay(us);
> }
>
> +/* _regulator_check_status_enabled
Please make all your kerneldoc follow:
https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation
> + *
> + * returns:
> + * 1 if status shows regulator is in enabled state
> + * 0 if not enabled state
> + * else, error value as received from ops->get_status()
> + */
> +static inline int _regulator_check_status_enabled(struct regulator_dev *rdev)
> +{
> + int ret = rdev->desc->ops->get_status(rdev);
> +
> + if (ret < 0) {
> + rdev_info(rdev, "get_status returned error: %d\n", ret);
> + return ret;
> + }
> +
> + switch (ret) {
> + case REGULATOR_STATUS_OFF:
> + case REGULATOR_STATUS_ERROR:
> + case REGULATOR_STATUS_UNDEFINED:
> + return 0;
> + default:
> + return 1;
> + }
> +}
> +
> static int _regulator_do_enable(struct regulator_dev *rdev)
> {
> int ret, delay;
> @@ -2407,7 +2433,37 @@ static int _regulator_do_enable(struct regulator_dev
> *rdev)
>* together. */
> trace_regulator_enable_delay(rdev_get_name(rdev));
>
> - _regulator_enable_delay(delay);
> + /* If poll_enabled_time is set, poll upto the delay calculated
> + * above, delaying poll_enabled_time uS to check if the regulator
> + * actually got enabled.
> + * If the regulator isn't enabled after enable_delay has
> + * expired, return -ETIMEDOUT.
> + */
> + if (rdev->desc->poll_enabled_time) {
> + unsigned int time_remaining = delay;
> +
> + while (time_remaining > 0) {
> + _regulator_enable_delay(rdev->desc->poll_enabled_time);
> +
> + if (rdev->desc->ops->get_status) {
> + ret = _regulator_check_status_enabled(rdev);
> + if (ret < 0)
> + return ret;
> + else if (ret)
> + break;
> + } else if (rdev->desc->ops->is_enabled(rdev))
> + break;
> +
> + time_remaining -= rdev->desc->poll_enabled_time;
> + }
> +
> + if (time_remaining <= 0) {
> + rdev_err(rdev, "Enabled check failed.\n");
> + return -ETIMEDOUT;
> + }
> + } else {
> + _regulator_enable_delay(delay);
> + }
>
> trace_regulator_enable_complete(rdev_get_name(rdev));
>
> diff --git a/include/linux/regulator/driver.h
> b/include/linux/regulator/driver.h
> index 29d920516e0b..bb50e943010f 100644
> --- a/include/linux/regulator/driver.h
> +++ b/include/linux/regulator/driver.h
> @@ -322,6 +322,9 @@ enum regulator_type {
> * @enable_time: Time taken for initial enable of regulator (in uS).
> * @off_on_delay: guard time (in uS), before re-enabling a regulator
> *
> + * @poll_enabled_time: Maximum time (in uS) to poll if the regulator is
> + * actually enabled, after enable() call
I read this as "how long should we stay in the poll loop". I think it
would be better describes as something like "The polling interval to use
while checking that the regulator was actually enabled".
Regards,
Bjorn
> + *
> * @of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard
> mode
> */
> struct regulator_desc {
> @@ -389,6 +392,8 @@ struct regulator_desc {
>
> unsigned int off_on_delay;
>
> + unsigned int poll_enabled_time;
> +
> unsigned int (*of_map_mode)(unsigned int mode);
> };
>
> --
> 2.26.2
>
Re: [PATCH v4 1/5] regulator: Allow regulators to verify enabled during enable()
Hi Mark,
Thanks for the review!
On Tue, 2 Jun 2020 at 16:54, Mark Brown wrote:
>
> On Tue, Jun 02, 2020 at 03:39:20PM +0530, Sumit Semwal wrote:
>
> > +
> > + if (time_remaining <= 0) {
> > + rdev_err(rdev, "Enabled check failed.\n");
> > + return -ETIMEDOUT;
>
> s/failed/timed out/
Ack
>
> > + * @poll_enabled_time: Maximum time (in uS) to poll if the regulator is
> > + * actually enabled, after enable() call
> > + *
>
> This comment needs updating to reflect the new implementation.
Yes, I will update.
Best,
Sumit.
Re: [PATCH v4 1/5] regulator: Allow regulators to verify enabled during enable()
On Tue, Jun 02, 2020 at 03:39:20PM +0530, Sumit Semwal wrote:
> +
> + if (time_remaining <= 0) {
> + rdev_err(rdev, "Enabled check failed.\n");
> + return -ETIMEDOUT;
s/failed/timed out/
> + * @poll_enabled_time: Maximum time (in uS) to poll if the regulator is
> + * actually enabled, after enable() call
> + *
This comment needs updating to reflect the new implementation.
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[PATCH v4 1/5] regulator: Allow regulators to verify enabled during enable()
Some regulators might need to verify that they have indeed been enabled
after the enable() call is made and enable_time delay has passed.
This is implemented by repeatedly checking is_enabled() upto
poll_enabled_time, waiting for the already calculated enable delay in
each iteration.
Signed-off-by: Sumit Semwal
--
v2: Address review comments, including swapping enable_time and
poll_enabled_time.
---
drivers/regulator/core.c | 58 +++-
include/linux/regulator/driver.h | 5 +++
2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 7486f6e4e613..d9ab888da95f 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2347,6 +2347,32 @@ static void _regulator_enable_delay(unsigned int delay)
udelay(us);
}
+/* _regulator_check_status_enabled
+ *
+ * returns:
+ * 1 if status shows regulator is in enabled state
+ * 0 if not enabled state
+ * else, error value as received from ops->get_status()
+ */
+static inline int _regulator_check_status_enabled(struct regulator_dev *rdev)
+{
+ int ret = rdev->desc->ops->get_status(rdev);
+
+ if (ret < 0) {
+ rdev_info(rdev, "get_status returned error: %d\n", ret);
+ return ret;
+ }
+
+ switch (ret) {
+ case REGULATOR_STATUS_OFF:
+ case REGULATOR_STATUS_ERROR:
+ case REGULATOR_STATUS_UNDEFINED:
+ return 0;
+ default:
+ return 1;
+ }
+}
+
static int _regulator_do_enable(struct regulator_dev *rdev)
{
int ret, delay;
@@ -2407,7 +2433,37 @@ static int _regulator_do_enable(struct regulator_dev
*rdev)
* together. */
trace_regulator_enable_delay(rdev_get_name(rdev));
- _regulator_enable_delay(delay);
+ /* If poll_enabled_time is set, poll upto the delay calculated
+* above, delaying poll_enabled_time uS to check if the regulator
+* actually got enabled.
+* If the regulator isn't enabled after enable_delay has
+* expired, return -ETIMEDOUT.
+*/
+ if (rdev->desc->poll_enabled_time) {
+ unsigned int time_remaining = delay;
+
+ while (time_remaining > 0) {
+ _regulator_enable_delay(rdev->desc->poll_enabled_time);
+
+ if (rdev->desc->ops->get_status) {
+ ret = _regulator_check_status_enabled(rdev);
+ if (ret < 0)
+ return ret;
+ else if (ret)
+ break;
+ } else if (rdev->desc->ops->is_enabled(rdev))
+ break;
+
+ time_remaining -= rdev->desc->poll_enabled_time;
+ }
+
+ if (time_remaining <= 0) {
+ rdev_err(rdev, "Enabled check failed.\n");
+ return -ETIMEDOUT;
+ }
+ } else {
+ _regulator_enable_delay(delay);
+ }
trace_regulator_enable_complete(rdev_get_name(rdev));
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 29d920516e0b..bb50e943010f 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -322,6 +322,9 @@ enum regulator_type {
* @enable_time: Time taken for initial enable of regulator (in uS).
* @off_on_delay: guard time (in uS), before re-enabling a regulator
*
+ * @poll_enabled_time: Maximum time (in uS) to poll if the regulator is
+ * actually enabled, after enable() call
+ *
* @of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard
mode
*/
struct regulator_desc {
@@ -389,6 +392,8 @@ struct regulator_desc {
unsigned int off_on_delay;
+ unsigned int poll_enabled_time;
+
unsigned int (*of_map_mode)(unsigned int mode);
};
--
2.26.2
