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

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Submitter Linus Walleij
Subject [2/3] spi/pl022: disable the PL022 block when unused
Date Oct. 17, 2011, 1:12 p.m.
List thread <1318857154-32160-1-git-send-email-linus.walleij@stericsson.com>
Project Linux SPI core/device drivers discussion
State Superseded
Last updated Nov. 24, 2011, 4:19 p.m.
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Comments

Linus Walleij - Oct. 17, 2011, 1:12 p.m.
From: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>

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@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/spi/spi-pl022.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

Patch

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);