[PATCH 2/3] spi/pl022: disable the PL022 block when unused

[PATCH 2/3] 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 |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 91700bb..0a1d8ed 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -513,7 +513,12 @@ static void giveback(struct pl022 *pl022)
 	msg->state = NULL;
 	if (msg->complete)
 		msg->complete(msg->context);
-	/* This message is completed, so let's turn off the clocks & power */
+
+	/* 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 clock! */
 	clk_disable(pl022->clk);
 	amba_pclk_disable(pl022->adev);
 	amba_vcore_disable(pl022->adev);
-- 
1.7.3.2


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Re: [PATCH 2/3] spi/pl022: disable the PL022 block when unused

[Viresh Kumar]

On 10/17/2011 6:42 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 |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 91700bb..0a1d8ed 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -513,7 +513,12 @@ static void giveback(struct pl022 *pl022)
>  	msg->state = NULL;
>  	if (msg->complete)
>  		msg->complete(msg->context);
> -	/* This message is completed, so let's turn off the clocks & power */
> +
> +	/* 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 clock! */
>  	clk_disable(pl022->clk);
>  	amba_pclk_disable(pl022->adev);
>  	amba_vcore_disable(pl022->adev);

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

-- 
viresh

------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure contains a
definitive record of customers, application performance, security
threats, fraudulent activity and more. Splunk takes this data and makes
sense of it. Business sense. IT sense. Common sense.
http://p.sf.net/sfu/splunk-d2d-oct

Re: [PATCH 2/3] spi/pl022: disable the PL022 block when unused

[Russell King - ARM Linux]

On Tue, Oct 18, 2011 at 02:43:27PM +0530, Viresh Kumar wrote:
> On 10/17/2011 6:42 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 |    7 ++++++-
> >  1 files changed, 6 insertions(+), 1 deletions(-)
> > 
> > diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> > index 91700bb..0a1d8ed 100644
> > --- a/drivers/spi/spi-pl022.c
> > +++ b/drivers/spi/spi-pl022.c
> > @@ -513,7 +513,12 @@ static void giveback(struct pl022 *pl022)
> >  	msg->state = NULL;
> >  	if (msg->complete)
> >  		msg->complete(msg->context);
> > -	/* This message is completed, so let's turn off the clocks & power */
> > +
> > +	/* 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 clock! */
> >  	clk_disable(pl022->clk);
> >  	amba_pclk_disable(pl022->adev);
> >  	amba_vcore_disable(pl022->adev);
> 
> Reviewed-by: Viresh Kumar <viresh.kumar-qxv4g6HH51o@public.gmane.org>

Note that I have some changes around here in my amba branch (which are
dependent on other changes I have for the primecell runtime pm.)

------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure contains a
definitive record of customers, application performance, security
threats, fraudulent activity and more. Splunk takes this data and makes
sense of it. Business sense. IT sense. Common sense.
http://p.sf.net/sfu/splunk-d2d-oct