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authorChris Blair <chris.blair@stericsson.com>2011-11-08 08:54:46 +0000
committerLinus Walleij <linus.walleij@linaro.org>2011-12-01 17:16:08 +0100
commit53e4acea0e819a6a8513e10a0773f2259ede0481 (patch)
tree621636e14849593e0d2381ee20124309ac624713 /drivers/spi
parentspi/pl022: disable the PL022 block when unused (diff)
downloadlinux-dev-53e4acea0e819a6a8513e10a0773f2259ede0481.tar.xz
linux-dev-53e4acea0e819a6a8513e10a0773f2259ede0481.zip
spi/pl022: add support for pm_runtime autosuspend
Adds support for configuring the spi bus to use autosuspend for runtime power management. This can reduce the latency in starting an spi transfer by not suspending the device immediately following completion of a transfer. If another transfer then takes place before the autosuspend timeout, the call to resume the device can return immediately rather than needing to risk sleeping in order to resume the device. Reviewed-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Chris Blair <chris.blair@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-pl022.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 82a929f916fd..13988a3024bb 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -1516,7 +1516,13 @@ static void pump_messages(struct work_struct *work)
/* nothing more to do - disable spi/ssp and power off */
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
- pm_runtime_put(&pl022->adev->dev);
+
+ if (pl022->master_info->autosuspend_delay > 0) {
+ pm_runtime_mark_last_busy(&pl022->adev->dev);
+ pm_runtime_put_autosuspend(&pl022->adev->dev);
+ } else {
+ pm_runtime_put(&pl022->adev->dev);
+ }
}
pl022->busy = false;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
@@ -2247,7 +2253,17 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
dev_dbg(dev, "probe succeeded\n");
/* let runtime pm put suspend */
- pm_runtime_put(dev);
+ if (platform_info->autosuspend_delay > 0) {
+ dev_info(&adev->dev,
+ "will use autosuspend for runtime pm, delay %dms\n",
+ platform_info->autosuspend_delay);
+ pm_runtime_set_autosuspend_delay(dev,
+ platform_info->autosuspend_delay);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_put_autosuspend(dev);
+ } else {
+ pm_runtime_put(dev);
+ }
return 0;
err_spi_register: