spi_mpc83xx: fix clockrate calculation for low speed
Peter Korsgaard [Sat, 13 Sep 2008 09:33:14 +0000 (02:33 -0700)]
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>

drivers/spi/spi_mpc83xx.c

index 070c621..ab7ee44 100644 (file)
@@ -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);