From: Tony Prisk Date: Thu, 27 Dec 2012 00:14:30 +0000 (+1300) Subject: clk: vt8500: Fix device clock divisor calculations X-Git-Tag: next-20130218~5^2~16 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=72480014b8;p=karo-tx-linux.git clk: vt8500: Fix device clock divisor calculations When calculating device clock divisor values in set_rate and round_rate, we do a simple integer divide. If parent_rate / rate has a fraction, this is dropped which results in the device clock being set too high. This patch corrects the problem by adding 1 to the calculated divisor if the division would have had a decimal result. Signed-off-by: Tony Prisk Signed-off-by: Mike Turquette --- diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c index 0cb26bef427d..3306c2b1906c 100644 --- a/drivers/clk/clk-vt8500.c +++ b/drivers/clk/clk-vt8500.c @@ -123,6 +123,10 @@ static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate, struct clk_device *cdev = to_clk_device(hw); u32 divisor = *prate / rate; + /* If prate / rate would be decimal, incr the divisor */ + if (rate * divisor < *prate) + divisor++; + /* * If this is a request for SDMMC we have to adjust the divisor * when >31 to use the fixed predivisor @@ -141,6 +145,10 @@ static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate, u32 divisor = parent_rate / rate; unsigned long flags = 0; + /* If prate / rate would be decimal, incr the divisor */ + if (rate * divisor < *prate) + divisor++; + if (divisor == cdev->div_mask + 1) divisor = 0;