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authorPavel Pisa <ppisa@pikron.com>2006-12-06 11:08:27 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-12-07 11:24:15 -0500
commit5c894cd1c89fc10907febd93e6ef35cd3c65e25e (patch)
treea7be88236384910ee326402748f1cafd64b9b5ca /arch/arm/mach-imx
parent9073341c2ba5d5e77b3d05d84cf9e3a16e8a7902 (diff)
[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 <pisa@cmp.felk.cvut.cz> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-imx')
-rw-r--r--arch/arm/mach-imx/generic.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm/mach-imx/generic.c b/arch/arm/mach-imx/generic.c
index 12ea58a3b84f..b5aa49d00ca3 100644
--- a/arch/arm/mach-imx/generic.c
+++ b/arch/arm/mach-imx/generic.c
@@ -104,6 +104,9 @@ EXPORT_SYMBOL(imx_gpio_mode);
104 */ 104 */
105static unsigned int imx_decode_pll(unsigned int pll) 105static unsigned int imx_decode_pll(unsigned int pll)
106{ 106{
107 unsigned long long ll;
108 unsigned long quot;
109
107 u32 mfi = (pll >> 10) & 0xf; 110 u32 mfi = (pll >> 10) & 0xf;
108 u32 mfn = pll & 0x3ff; 111 u32 mfn = pll & 0x3ff;
109 u32 mfd = (pll >> 16) & 0x3ff; 112 u32 mfd = (pll >> 16) & 0x3ff;
@@ -112,7 +115,11 @@ static unsigned int imx_decode_pll(unsigned int pll)
112 115
113 mfi = mfi <= 5 ? 5 : mfi; 116 mfi = mfi <= 5 ? 5 : mfi;
114 117
115 return (2 * (f_ref>>10) * ( (mfi<<10) + (mfn<<10) / (mfd+1) )) / (pd+1); 118 ll = 2 * (unsigned long long)f_ref * ( (mfi<<16) + (mfn<<16) / (mfd+1) );
119 quot = (pd+1) * (1<<16);
120 ll += quot / 2;
121 do_div(ll, quot);
122 return (unsigned int) ll;
116} 123}
117 124
118unsigned int imx_get_system_clk(void) 125unsigned int imx_get_system_clk(void)