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From: Anton Vorontsov <avorontsov@ru.mvista.com>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org,
	Andrew Morton <akpm@linux-foundation.org>,
	David Brownell <dbrownell@users.sourceforge.net>,
	linux-kernel@vger.kernel.org,
	spi-devel-general@lists.sourceforge.net
Subject: [PATCH 3/9] spi_mpc83xx: Add small delay after asserting chip-select line
Date: Fri, 1 May 2009 03:48:24 +0400	[thread overview]
Message-ID: <20090430234824.GC7901@oksana.dev.rtsoft.ru> (raw)
In-Reply-To: <20090430234739.GA27709@oksana.dev.rtsoft.ru>

This is needed for some underlaying GPIO controllers that may be
a bit slow, or if chip-select signal need some time to stabilize.

For what it's worth, we already have the similar delay for
chip-select de-assertion case.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---
 drivers/spi/spi_mpc83xx.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 08b49d2..d378d5e 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -383,8 +383,10 @@ static void mpc83xx_spi_work(struct work_struct *work)
 					break;
 			}
 
-			if (cs_change)
+			if (cs_change) {
 				mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
+				ndelay(nsecs);
+			}
 			cs_change = t->cs_change;
 			if (t->len)
 				status = mpc83xx_spi_bufs(spi, t);
-- 
1.6.2.2

  parent reply	other threads:[~2009-04-30 23:48 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-30 23:47 [PATCH 0/9] Some work for spi_mpc83xx driver, spi-mmc support for MPC8610HPCD Anton Vorontsov
2009-04-30 23:48 ` [PATCH 1/9] spi_mpc83xx: Handles other Freescale processors Anton Vorontsov
2009-04-30 23:48 ` [PATCH 2/9] spi_mpc83xx: Quieten down the "Requested speed is too low" message Anton Vorontsov
2009-04-30 23:48 ` Anton Vorontsov [this message]
2009-04-30 23:48 ` [PATCH 4/9] powerpc/86xx: Add MMC SPI support for MPC8610HPCD boards Anton Vorontsov
2009-04-30 23:48 ` [PATCH 5/9] spi_mpc83xx: Fix checkpatch issues Anton Vorontsov
2009-04-30 23:48 ` [PATCH 6/9] spi_mpc83xx: Split mpc83xx_spi_work() into two routines Anton Vorontsov
2009-04-30 23:48 ` [PATCH 7/9] spi_mpc83xx: Remove dead code Anton Vorontsov
2009-04-30 23:48 ` [PATCH 8/9] spi_mpc83xx: Rename spi_83xx.c to spi_8xxx.c Anton Vorontsov
2009-04-30 23:48 ` [PATCH 9/9] spi_mpc8xxx: s/83xx/8xxx/g Anton Vorontsov
2009-05-01 21:42   ` [spi-devel-general] " Grant Likely
2009-05-04 20:53   ` Andrew Morton
2009-05-04 23:36     ` Anton Vorontsov
2009-05-04 20:55 ` [PATCH 0/9] Some work for spi_mpc83xx driver, spi-mmc support for MPC8610HPCD Andrew Morton
2009-05-04 23:36   ` Anton Vorontsov

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