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| author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2009-06-19 01:49:01 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-20 01:46:04 +0200 |
| commit | 5afbf098d171664695db2a7e828e8d96871a01e1 (patch) | |
| tree | 99e46bb86d1cecd144612d82667ef87cc2c79115 /drivers/spi/spi_mpc83xx.c | |
| parent | spi_mpc83xx: quieten down the "Requested speed is too low" message (diff) | |
| download | linux-5afbf098d171664695db2a7e828e8d96871a01e1.tar.xz linux-5afbf098d171664695db2a7e828e8d96871a01e1.zip | |
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>
Diffstat (limited to 'drivers/spi/spi_mpc83xx.c')
| -rw-r--r-- | 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 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); |