From: Willy Tarreau Date: Sat, 9 Feb 2008 22:24:08 +0000 (+0100) Subject: x86: GEODE fix MFGPT input clock value X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=36445cf30686b9ea4ddf71f28057e4dd07db0e2d;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git x86: GEODE fix MFGPT input clock value The GEODE MFGPT code assumed that 32kHz was 32000 Hz while the boards run on a 32.768 kHz digital watch crystal. In practise, it will not change the timer's frequency as the skew was only 2.4%, but it should provide more accurate intervals. Signed-off-by: Willy Tarreau Signed-off-by: Andres Salomon Signed-off-by: Jordan Crouse Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c index 9146b2de1698..586228140b9e 100644 --- a/arch/x86/kernel/mfgpt_32.c +++ b/arch/x86/kernel/mfgpt_32.c @@ -12,21 +12,20 @@ */ /* - * We are using the 32Khz input clock - its the only one that has the + * We are using the 32.768kHz input clock - it's the only one that has the * ranges we find desirable. The following table lists the suitable - * divisors and the associated hz, minimum interval - * and the maximum interval: + * divisors and the associated Hz, minimum interval and the maximum interval: * - * Divisor Hz Min Delta (S) Max Delta (S) - * 1 32000 .0005 2.048 - * 2 16000 .001 4.096 - * 4 8000 .002 8.192 - * 8 4000 .004 16.384 - * 16 2000 .008 32.768 - * 32 1000 .016 65.536 - * 64 500 .032 131.072 - * 128 250 .064 262.144 - * 256 125 .128 524.288 + * Divisor Hz Min Delta (s) Max Delta (s) + * 1 32768 .00048828125 2.000 + * 2 16384 .0009765625 4.000 + * 4 8192 .001953125 8.000 + * 8 4096 .00390625 16.000 + * 16 2048 .0078125 32.000 + * 32 1024 .015625 64.000 + * 64 512 .03125 128.000 + * 128 256 .0625 256.000 + * 256 128 .125 512.000 */ #include @@ -45,7 +44,7 @@ static struct mfgpt_timer_t { #define MFGPT_DIVISOR 16 #define MFGPT_SCALE 4 /* divisor = 2^(scale) */ -#define MFGPT_HZ (32000 / MFGPT_DIVISOR) +#define MFGPT_HZ (32768 / MFGPT_DIVISOR) #define MFGPT_PERIODIC (MFGPT_HZ / HZ) #ifdef CONFIG_GEODE_MFGPT_TIMER