aboutsummaryrefslogtreecommitdiff
path: root/drivers/spi
diff options
context:
space:
mode:
authorRussell King <rmk@dyn-67.arm.linux.org.uk>2009-09-12 12:04:37 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-09-12 12:04:37 +0100
commit87d721ad7a37b7650dd710c88dd5c6a5bf9fe996 (patch)
tree869d633803eb7c429624d3bd16a6117816849763 /drivers/spi
parentddd559b13f6d2fe3ad68c4b3f5235fd3c2eae4e3 (diff)
parentb7cfda9fc3d7aa60cffab5367f2a72a4a70060cd (diff)
Merge branch 'master' into devel
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi_s3c24xx.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c
index e0d44af4745..3f3119d760d 100644
--- a/drivers/spi/spi_s3c24xx.c
+++ b/drivers/spi/spi_s3c24xx.c
@@ -111,29 +111,32 @@ static int s3c24xx_spi_setupxfer(struct spi_device *spi,
unsigned int bpw;
unsigned int hz;
unsigned int div;
+ unsigned long clk;
bpw = t ? t->bits_per_word : spi->bits_per_word;
hz = t ? t->speed_hz : spi->max_speed_hz;
+ if (!bpw)
+ bpw = 8;
+
+ if (!hz)
+ hz = spi->max_speed_hz;
+
if (bpw != 8) {
dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
return -EINVAL;
}
- div = clk_get_rate(hw->clk) / hz;
-
- /* is clk = pclk / (2 * (pre+1)), or is it
- * clk = (pclk * 2) / ( pre + 1) */
-
- div /= 2;
-
- if (div > 0)
- div -= 1;
+ clk = clk_get_rate(hw->clk);
+ div = DIV_ROUND_UP(clk, hz * 2) - 1;
if (div > 255)
div = 255;
- dev_dbg(&spi->dev, "setting pre-scaler to %d (hz %d)\n", div, hz);
+ dev_dbg(&spi->dev, "setting pre-scaler to %d (wanted %d, got %ld)\n",
+ div, hz, clk / (2 * (div + 1)));
+
+
writeb(div, hw->regs + S3C2410_SPPRE);
spin_lock(&hw->bitbang.lock);