ARM: 6981/2: mmci: adjust calculation of f_min
authorLinus Walleij <linus.walleij@linaro.org>
Fri, 8 Jul 2011 08:57:15 +0000 (09:57 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Tue, 19 Jul 2011 15:04:35 +0000 (16:04 +0100)
The ARM version maximum clock divider is 512 whereas for the ST
variants it's 257. Let's use DIV_ROUND_UP() for both cases so we
can see clearly what's going on here.

[Use DIV_ROUND_UP to clarify elder code]

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
drivers/mmc/host/mmci.c

index 7721de9..c471cdb 100644 (file)
@@ -1061,7 +1061,15 @@ static int __devinit mmci_probe(struct amba_device *dev,
        }
 
        mmc->ops = &mmci_ops;
-       mmc->f_min = (host->mclk + 511) / 512;
+       /*
+        * The ARM and ST versions of the block have slightly different
+        * clock divider equations which means that the minimum divider
+        * differs too.
+        */
+       if (variant->st_clkdiv)
+               mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
+       else
+               mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
        /*
         * If the platform data supplies a maximum operating
         * frequency, this takes precedence. Else, we fall back