Madhusudhan wrote:
-----Original Message-----
From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap-
owner@xxxxxxxxxxxxxxx] On Behalf Of Adrian Hunter
Sent: Tuesday, July 28, 2009 5:39 AM
To: Andrew Morton
Cc: Jarkko Lavinen; Adrian Hunter; linux-omap Mailing List; Pierre Ossman;
Denis Karpov; Matt Fleming; lkml
Subject: [PATCH V2 4/32] mmc: add ability to save power by powering off
cards
From e6355578d082d94707c8fda1e1342c478019b5c8 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Mon, 11 May 2009 12:20:57 +0300
Subject: [PATCH] mmc: add ability to save power by powering off cards
Power can be saved by powering off cards that are not
in use. This is similar to suspend / resume except
it is under the control of the driver, and does not
require any power management support. It can only
be used when the driver can monitor whether the card
is removed, otherwise it is unsafe. This is possible
because, unlike suspend, the driver still receives
card detect and / or cover switch interrupts.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/core.c | 34 ++++++++++++++++++++++++++++++++++
drivers/mmc/core/core.h | 2 ++
drivers/mmc/core/mmc.c | 11 +++++++++++
drivers/mmc/core/sd.c | 11 +++++++++++
include/linux/mmc/host.h | 3 +++
5 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index bab5015..39f7bd1 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1145,6 +1145,40 @@ void mmc_stop_host(struct mmc_host *host)
mmc_power_off(host);
}
+void mmc_power_save_host(struct mmc_host *host)
+{
+ mmc_bus_get(host);
+
+ if (!host->bus_ops || host->bus_dead || !host->bus_ops-
power_restore) {
+ mmc_bus_put(host);
+ return;
+ }
+
+ if (host->bus_ops->power_save)
+ host->bus_ops->power_save(host);
+
+ mmc_bus_put(host);
+
+ mmc_power_off(host);
+}
+EXPORT_SYMBOL(mmc_power_save_host);
+
+void mmc_power_restore_host(struct mmc_host *host)
+{
+ mmc_bus_get(host);
+
+ if (!host->bus_ops || host->bus_dead || !host->bus_ops-
power_restore) {
+ mmc_bus_put(host);
+ return;
+ }
+
+ mmc_power_up(host);
+ host->bus_ops->power_restore(host);
+
+ mmc_bus_put(host);
+}
+EXPORT_SYMBOL(mmc_power_restore_host);
+
Who calls these exported functions " mmc_power_save_host" and "
mmc_power_restore_host"?
The present design has the host driver calling them i.e. for us it
is omap_hsmmc. See the "support for deeper power saving states"
patch.
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
