[PATCH RFC 07/27] PM / Domains: Read domain residency from DT
Lina Iyer
lina.iyer at linaro.org
Tue Nov 17 14:37:31 PST 2015
Domains that have expensive suspend resume operations, may require a
certain amount of time be spent in an idle state to reap the power
saving benefit. Such domains, may provide the residency requirement for
a domain state.
Read the residency for a domain state from the DT. A domain governor may
use this information in determining the state for the domain.
Cc: Axel Haslam <ahaslam at baylibre.com>
Cc: Marc Titinger <mtitinger at baylibre.com>
Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
---
Documentation/devicetree/bindings/power/power_domain.txt | 7 +++++++
drivers/base/power/domain.c | 6 ++++++
include/linux/pm_domain.h | 1 +
3 files changed, 14 insertions(+)
diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
index ecfaf44..d71da29 100644
--- a/Documentation/devicetree/bindings/power/power_domain.txt
+++ b/Documentation/devicetree/bindings/power/power_domain.txt
@@ -67,6 +67,13 @@ have the following properties -
If omitted, this is assumed to be equal to:
entry-latency-us + exit-latency-us
+ - residency-us:
+ Usage: Optional
+ Value type: <prop-encoded-array>
+ Definition: A u32 value representing the time for which a
+ domain must be idle in the state to reap power saving benefits
+ of entering the state.
+
- state-param:
Usage: Optional
Value type: <prop-encoded-array>
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 9a0df09..abc81bd 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1245,6 +1245,7 @@ static int genpd_alloc_states_data(struct generic_pm_domain *genpd,
st[i].power_on_latency_ns;
genpd->states[i].power_off_latency_ns =
st[i].power_off_latency_ns;
+ genpd->states[i].residency_ns = st[i].residency_ns;
genpd->states[i].param = st[i].param;
}
@@ -1513,6 +1514,7 @@ static int of_get_genpd_power_state(struct genpd_power_state *genpd_state,
const struct of_device_id *match_id;
int err = 0;
u32 latency;
+ u32 residency;
u32 param;
match_id = of_match_node(power_state_match, state_node);
@@ -1554,6 +1556,10 @@ static int of_get_genpd_power_state(struct genpd_power_state *genpd_state,
return -EINVAL;
}
+ err = of_property_read_u32(state_node, "residency-us", &residency);
+ if (!err)
+ genpd_state->residency_ns = 1000 * residency;
+
err = of_property_read_u32(state_node, "state-param", ¶m);
if (!err)
genpd_state->param = param;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 108a4b3..fed024a 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -41,6 +41,7 @@ struct genpd_power_state {
char *name;
s64 power_off_latency_ns;
s64 power_on_latency_ns;
+ s64 residency_ns;
u32 param;
};
--
2.1.4
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