From 5afbf098d171664695db2a7e828e8d96871a01e1 Mon Sep 17 00:00:00 2001
From: Anton Vorontsov <avorontsov@ru.mvista.com>
Date: Thu, 18 Jun 2009 16:49:01 -0700
Subject: [PATCH] spi_mpc83xx: add small delay after asserting chip-select line
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>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/spi/spi_mpc83xx.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 4988230a7e0c..6e0232e65a38 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);
--
2.20.1