[PATCH 3/6] spi/pl022: disable the PL022 block when unused

[PATCH 3/6] spi/pl022: disable the PL022 block when unused

[Linus Walleij]

From: Virupax Sadashivpetimath <virupax.sadashivpetimath-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>

Make sure we clear the enable bit when the block is not used.
This will save some energy in certain hardware versions.

Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/spi/spi-pl022.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 305f2ba..fa3eaae 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -512,6 +512,11 @@ static void giveback(struct pl022 *pl022)
 	msg->state = NULL;
 	if (msg->complete)
 		msg->complete(msg->context);
+
+	/* disable the SPI/SSP operation */
+	writew((readw(SSP_CR1(pl022->virtbase)) &
+		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
 	/* This message is completed, so let's turn off the clocks & power */
 	pm_runtime_put(&pl022->adev->dev);
 }
-- 
1.7.3.2


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Re: [PATCH 3/6] spi/pl022: disable the PL022 block when unused

[Viresh Kumar]

On 11/9/2011 4:09 PM, Linus WALLEIJ wrote:
> From: Virupax Sadashivpetimath <virupax.sadashivpetimath-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
> 
> Make sure we clear the enable bit when the block is not used.
> This will save some energy in certain hardware versions.
> 
> Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
> Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> ---
>  drivers/spi/spi-pl022.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 305f2ba..fa3eaae 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -512,6 +512,11 @@ static void giveback(struct pl022 *pl022)
>  	msg->state = NULL;
>  	if (msg->complete)
>  		msg->complete(msg->context);
> +
> +	/* disable the SPI/SSP operation */
> +	writew((readw(SSP_CR1(pl022->virtbase)) &
> +		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
> +
>  	/* This message is completed, so let's turn off the clocks & power */
>  	pm_runtime_put(&pl022->adev->dev);
>  }

Reviewed-by: Viresh Kumar <viresh.kumar-qxv4g6HH51o@public.gmane.org>

-- 
viresh

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