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spi_mpc83xx: fix clockrate calculation for low speed 

Commit a61f5345 (spi_mpc83xx clockrate fixes) broke clockrate calculation
for low speeds.  SPMODE_DIV16 should be set if the divider is higher than
64, not only if the divider gets clipped to 1024.

Furthermore, the clipping check was off by a factor 16 as well.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Korsgaard 2008-09-13 02:33:14 -07:00 committed by Linus Torvalds
parent d7a3e4959c
commit 53604dbe13
1 changed files with 5 additions and 8 deletions
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13
drivers/spi/spi_mpc83xx.c
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@ -267,16 +267,13 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
cs->hw_mode |= SPMODE_LEN(bits_per_word);
if ((mpc83xx_spi->spibrg / hz) > 64) {
cs->hw_mode |= SPMODE_DIV16;
pm = mpc83xx_spi->spibrg / (hz * 64);
if (pm > 16) {
cs->hw_mode |= SPMODE_DIV16;
pm /= 16;
if (pm > 16) {
dev_err(&spi->dev, "Requested speed is too "
"low: %d Hz. Will use %d Hz instead.\n",
hz, mpc83xx_spi->spibrg / 1024);
pm = 16;
}
dev_err(&spi->dev, "Requested speed is too "
"low: %d Hz. Will use %d Hz instead.\n",
hz, mpc83xx_spi->spibrg / 1024);
pm = 16;
}
} else
pm = mpc83xx_spi->spibrg / (hz * 4);