Device's clocks need to be enabled always at probing time
if !CONFIG_PM_RUNTIME - in that way, device will become accesible
and, later, its clocks can be disabled/enabled during system
suspend/resume by using pm_clk_suspend/pm_clk_resume APIs.
But now, the clocks management code doesn't enable clocks when
clocks are being registered per-device by using pm_clk_add/_clk().
So, update pm_clk_acquire(), which is called from pm_clk_add/_clk(),
to enable clock always if !CONFIG_PM_RUNTIME.
Also, Platform PM domains drivers will not have to add code like below
each time they need to handle the case when !CONFIG_PM_RUNTIME [1 - 3]:
if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {
ret = pm_clk_resume(dev);
if (ret) {
dev_err(dev, "pm_clk_resume failed %d\n", ret);
goto clk_err;
};
}
[1] https://lkml.org/lkml/2014/10/3/306
[2] https://lkml.org/lkml/2014/10/16/305
[3] https://lkml.org/lkml/2014/10/20/249
CC: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
CC: Kevin Hilman <khilman@xxxxxxxxxx>
CC: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
CC: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
CC: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
CC: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
CC: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
Hi,
I marked it as RFC, because:
Generic clock manipulation PM callbacks can be used for any device
for which list of clocks need to be maintained - and it doesn't mean
that this framework need to be always connected to GPD/Runtime PM or
used during suspend resume. Also, for DT-use case - it doesn't perform
any actions (except clk_prepare) on clocks by itself and only
by request from framework's consumer.
For example, it can be reused by Power domain/controller drivers like:
- Rockchip RK3288 PM Domain (https://lkml.org/lkml/2014/11/6/30)
- IMX.6 PU power domain (http://www.spinics.net/lists/arm-kernel/msg360709.html)
to maintain list of clocks for GPD itself and these clocks should not
be enabled by default, because they are used to power on/off Power domain
in a specific way:
- enable all clocks assigned to PD
- power on/off PD
- disable all clocks assigned to PD.
After this patch it will be impossible to reuse Generic clock manipulation PM
callbacks in cases described above.
drivers/base/power/clock_ops.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index b32b5d4..36cdff7 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -69,6 +69,10 @@ static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
ce->status = PCE_STATUS_ACQUIRED;
dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
}
+
+ if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {
+ __pm_clk_enable(dev, ce);
+ }
}
static int __pm_clk_add(struct device *dev, const char *con_id,
--
1.9.1
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