2015-07-14 08:00:14

by Vaibhav Jain

[permalink] [raw]
Subject: [PATCH] rtc/rtc-opal: Enable alarms only when opal supports tpo

rtc-opal driver provides support for rtc alarms via
timed-power-on(tpo). However some Power platforms like BML use a fake
rtc clock and don't support tpo. Such platforms are indicated by the
missing 'has-tpo' property in the device tree.

Current implementation however enables callback for
rtc_class_ops.read/set alarm irrespective of the tpo support from the
platform. This results in a failed opal call when kernel tries to read
an existing alarms via opal_get_tpo_time during rtc device registration.

This patch fixes this issue by setting opal_rtc_ops.read/set_alarm
callback pointers only when tpo is supported.

Acked-by: Michael Neuling <[email protected]>
Acked-by: Neelesh Gupta <[email protected]>
Signed-off-by: Vaibhav Jain <[email protected]>
---
drivers/rtc/rtc-opal.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index 7061dca..1125641 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -190,11 +190,9 @@ exit:
return rc;
}

-static const struct rtc_class_ops opal_rtc_ops = {
+static struct rtc_class_ops opal_rtc_ops = {
.read_time = opal_get_rtc_time,
.set_time = opal_set_rtc_time,
- .read_alarm = opal_get_tpo_time,
- .set_alarm = opal_set_tpo_time,
};

static int opal_rtc_probe(struct platform_device *pdev)
@@ -202,8 +200,11 @@ static int opal_rtc_probe(struct platform_device *pdev)
struct rtc_device *rtc;

if (pdev->dev.of_node && of_get_property(pdev->dev.of_node, "has-tpo",
- NULL))
+ NULL)) {
device_set_wakeup_capable(&pdev->dev, true);
+ opal_rtc_ops.read_alarm = opal_get_tpo_time;
+ opal_rtc_ops.set_alarm = opal_set_tpo_time;
+ }

rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops,
THIS_MODULE);
--
2.2.1


2015-07-15 04:09:24

by Stewart Smith

[permalink] [raw]
Subject: Re: [PATCH] rtc/rtc-opal: Enable alarms only when opal supports tpo

Vaibhav Jain <[email protected]> writes:
> rtc-opal driver provides support for rtc alarms via
> timed-power-on(tpo). However some Power platforms like BML use a fake
> rtc clock and don't support tpo. Such platforms are indicated by the
> missing 'has-tpo' property in the device tree.
>
> Current implementation however enables callback for
> rtc_class_ops.read/set alarm irrespective of the tpo support from the
> platform. This results in a failed opal call when kernel tries to read
> an existing alarms via opal_get_tpo_time during rtc device registration.
>
> This patch fixes this issue by setting opal_rtc_ops.read/set_alarm
> callback pointers only when tpo is supported.
>
> Acked-by: Michael Neuling <[email protected]>
> Acked-by: Neelesh Gupta <[email protected]>
> Signed-off-by: Vaibhav Jain <[email protected]>

Acked-by: Stewart Smith <[email protected]>

FWIW I'm updating OPAL docs with this. The TPO calls aren't actually
documented :(

In future, it'd be great if there was an accompanying skiboot patch
updating the documentation there too.

2015-07-22 17:11:25

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [PATCH] rtc/rtc-opal: Enable alarms only when opal supports tpo

On 14/07/2015 at 13:28:28 +0530, Vaibhav Jain wrote :
> rtc-opal driver provides support for rtc alarms via
> timed-power-on(tpo). However some Power platforms like BML use a fake
> rtc clock and don't support tpo. Such platforms are indicated by the
> missing 'has-tpo' property in the device tree.
>
> Current implementation however enables callback for
> rtc_class_ops.read/set alarm irrespective of the tpo support from the
> platform. This results in a failed opal call when kernel tries to read
> an existing alarms via opal_get_tpo_time during rtc device registration.
>
> This patch fixes this issue by setting opal_rtc_ops.read/set_alarm
> callback pointers only when tpo is supported.
>
> Acked-by: Michael Neuling <[email protected]>
> Acked-by: Neelesh Gupta <[email protected]>
> Signed-off-by: Vaibhav Jain <[email protected]>
> ---
> drivers/rtc/rtc-opal.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
Applied, thanks.

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com