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mmci: adjust calculation of f_min

Message ID 1310070455-26418-1-git-send-email-linus.walleij@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Linus Walleij July 7, 2011, 8:27 p.m. UTC 
From: Ulf Hansson <ulf.hansson@stericsson.com>

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.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
[Use DIV_ROUND_UP to clarify elder code]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)
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Patch

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index fe14072..50f4f77 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1063,7 +1063,15 @@  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