From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH 3/6] spi/pl022: disable the PL022 block when unused Date: Wed, 9 Nov 2011 16:23:24 +0530 Message-ID: <4EBA5BA4.8030504@st.com> References: <1320835146-31268-1-git-send-email-linus.walleij@stericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Linus Walleij , Shiraz HASHIM , Virupax SADASHIVPETIMATH , "spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" To: Linus WALLEIJ Return-path: In-Reply-To: <1320835146-31268-1-git-send-email-linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On 11/9/2011 4:09 PM, Linus WALLEIJ wrote: > From: Virupax Sadashivpetimath > > 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 > Signed-off-by: Linus Walleij > --- > 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 ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1