From 5c894cd1c89fc10907febd93e6ef35cd3c65e25e Mon Sep 17 00:00:00 2001 From: Pavel Pisa Date: Wed, 6 Dec 2006 17:08:27 +0100 Subject: [ARM] 3990/1: i.MX/MX1 more precise PLL decode The future high resolution support inclusion utilizes imx_decode_pll() in timer base frequency computation. This use requires more precise computation without discarding 10 bits by shifting left. Signed-off-by: Pavel Pisa Acked-by: Sascha Hauer Signed-off-by: Russell King --- arch/arm/mach-imx/generic.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm/mach-imx/generic.c b/arch/arm/mach-imx/generic.c index 12ea58a3b84..b5aa49d00ca 100644 --- a/arch/arm/mach-imx/generic.c +++ b/arch/arm/mach-imx/generic.c @@ -104,6 +104,9 @@ EXPORT_SYMBOL(imx_gpio_mode); */ static unsigned int imx_decode_pll(unsigned int pll) { + unsigned long long ll; + unsigned long quot; + u32 mfi = (pll >> 10) & 0xf; u32 mfn = pll & 0x3ff; u32 mfd = (pll >> 16) & 0x3ff; @@ -112,7 +115,11 @@ static unsigned int imx_decode_pll(unsigned int pll) mfi = mfi <= 5 ? 5 : mfi; - return (2 * (f_ref>>10) * ( (mfi<<10) + (mfn<<10) / (mfd+1) )) / (pd+1); + ll = 2 * (unsigned long long)f_ref * ( (mfi<<16) + (mfn<<16) / (mfd+1) ); + quot = (pd+1) * (1<<16); + ll += quot / 2; + do_div(ll, quot); + return (unsigned int) ll; } unsigned int imx_get_system_clk(void) -- cgit v1.2.3