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authorAdrian Hunter <adrian.hunter@nokia.com>2009-09-22 16:44:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-23 07:39:33 -0700
commiteae1aeeed852aae37621b82a9e7f6c05096a18fd (patch)
tree6a1b108032a5cf08ccfa6fffa29c81cccbe8c82d /drivers/mmc
parent9feae246963c648b212abad0f0eb8938de5f5fe5 (diff)
downloadop-kernel-dev-eae1aeeed852aae37621b82a9e7f6c05096a18fd.zip
op-kernel-dev-eae1aeeed852aae37621b82a9e7f6c05096a18fd.tar.gz
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@nokia.com> Acked-by: Matt Fleming <matt@console-pimps.org> Cc: Ian Molton <ian@mnementh.co.uk> Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com> Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com> Cc: Denis Karpov <ext-denis.2.karpov@nokia.com> Cc: Pierre Ossman <pierre@ossman.eu> Cc: Philip Langdale <philipl@overt.org> Cc: "Madhusudhan" <madhu.cr@ti.com> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/core/core.c34
-rw-r--r--drivers/mmc/core/core.h2
-rw-r--r--drivers/mmc/core/mmc.c11
-rw-r--r--drivers/mmc/core/sd.c11
4 files changed, 58 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 02f2b18..be1fc01 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1151,6 +1151,40 @@ 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);
+
#ifdef CONFIG_PM
/**
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index c819eff..f7eb4c4 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -20,6 +20,8 @@ struct mmc_bus_ops {
void (*detect)(struct mmc_host *);
void (*suspend)(struct mmc_host *);
void (*resume)(struct mmc_host *);
+ void (*power_save)(struct mmc_host *);
+ void (*power_restore)(struct mmc_host *);
};
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 995db18..27e842d 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -549,6 +549,14 @@ static void mmc_resume(struct mmc_host *host)
}
+static void mmc_power_restore(struct mmc_host *host)
+{
+ host->card->state &= ~MMC_STATE_HIGHSPEED;
+ mmc_claim_host(host);
+ mmc_init_card(host, host->ocr, host->card);
+ mmc_release_host(host);
+}
+
#ifdef CONFIG_MMC_UNSAFE_RESUME
static const struct mmc_bus_ops mmc_ops = {
@@ -556,6 +564,7 @@ static const struct mmc_bus_ops mmc_ops = {
.detect = mmc_detect,
.suspend = mmc_suspend,
.resume = mmc_resume,
+ .power_restore = mmc_power_restore,
};
static void mmc_attach_bus_ops(struct mmc_host *host)
@@ -570,6 +579,7 @@ static const struct mmc_bus_ops mmc_ops = {
.detect = mmc_detect,
.suspend = NULL,
.resume = NULL,
+ .power_restore = mmc_power_restore,
};
static const struct mmc_bus_ops mmc_ops_unsafe = {
@@ -577,6 +587,7 @@ static const struct mmc_bus_ops mmc_ops_unsafe = {
.detect = mmc_detect,
.suspend = mmc_suspend,
.resume = mmc_resume,
+ .power_restore = mmc_power_restore,
};
static void mmc_attach_bus_ops(struct mmc_host *host)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 92fa9dc..222a609 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -603,6 +603,14 @@ static void mmc_sd_resume(struct mmc_host *host)
}
+static void mmc_sd_power_restore(struct mmc_host *host)
+{
+ host->card->state &= ~MMC_STATE_HIGHSPEED;
+ mmc_claim_host(host);
+ mmc_sd_init_card(host, host->ocr, host->card);
+ mmc_release_host(host);
+}
+
#ifdef CONFIG_MMC_UNSAFE_RESUME
static const struct mmc_bus_ops mmc_sd_ops = {
@@ -610,6 +618,7 @@ static const struct mmc_bus_ops mmc_sd_ops = {
.detect = mmc_sd_detect,
.suspend = mmc_sd_suspend,
.resume = mmc_sd_resume,
+ .power_restore = mmc_sd_power_restore,
};
static void mmc_sd_attach_bus_ops(struct mmc_host *host)
@@ -624,6 +633,7 @@ static const struct mmc_bus_ops mmc_sd_ops = {
.detect = mmc_sd_detect,
.suspend = NULL,
.resume = NULL,
+ .power_restore = mmc_sd_power_restore,
};
static const struct mmc_bus_ops mmc_sd_ops_unsafe = {
@@ -631,6 +641,7 @@ static const struct mmc_bus_ops mmc_sd_ops_unsafe = {
.detect = mmc_sd_detect,
.suspend = mmc_sd_suspend,
.resume = mmc_sd_resume,
+ .power_restore = mmc_sd_power_restore,
};
static void mmc_sd_attach_bus_ops(struct mmc_host *host)
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