diff options
Diffstat (limited to 'arch/arm/mach-pxa/pxa25x.c')
-rw-r--r-- | arch/arm/mach-pxa/pxa25x.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/pxa25x.c b/arch/arm/mach-pxa/pxa25x.c new file mode 100644 index 000000000000..e887b7175ef3 --- /dev/null +++ b/arch/arm/mach-pxa/pxa25x.c @@ -0,0 +1,104 @@ +/* + * linux/arch/arm/mach-pxa/pxa25x.c + * + * Author: Nicolas Pitre + * Created: Jun 15, 2001 + * Copyright: MontaVista Software Inc. + * + * Code specific to PXA21x/25x/26x variants. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Since this file should be linked before any other machine specific file, + * the __initcall() here will be executed first. This serves as default + * initialization stuff for PXA machines which can be overridden later if + * need be. + */ +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/pm.h> + +#include <asm/hardware.h> +#include <asm/arch/pxa-regs.h> + +#include "generic.h" + +/* + * Various clock factors driven by the CCCR register. + */ + +/* Crystal Frequency to Memory Frequency Multiplier (L) */ +static unsigned char L_clk_mult[32] = { 0, 27, 32, 36, 40, 45, 0, }; + +/* Memory Frequency to Run Mode Frequency Multiplier (M) */ +static unsigned char M_clk_mult[4] = { 0, 1, 2, 4 }; + +/* Run Mode Frequency to Turbo Mode Frequency Multiplier (N) */ +/* Note: we store the value N * 2 here. */ +static unsigned char N2_clk_mult[8] = { 0, 0, 2, 3, 4, 0, 6, 0 }; + +/* Crystal clock */ +#define BASE_CLK 3686400 + +/* + * Get the clock frequency as reflected by CCCR and the turbo flag. + * We assume these values have been applied via a fcs. + * If info is not 0 we also display the current settings. + */ +unsigned int get_clk_frequency_khz(int info) +{ + unsigned long cccr, turbo; + unsigned int l, L, m, M, n2, N; + + cccr = CCCR; + asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (turbo) ); + + l = L_clk_mult[(cccr >> 0) & 0x1f]; + m = M_clk_mult[(cccr >> 5) & 0x03]; + n2 = N2_clk_mult[(cccr >> 7) & 0x07]; + + L = l * BASE_CLK; + M = m * L; + N = n2 * M / 2; + + if(info) + { + L += 5000; + printk( KERN_INFO "Memory clock: %d.%02dMHz (*%d)\n", + L / 1000000, (L % 1000000) / 10000, l ); + M += 5000; + printk( KERN_INFO "Run Mode clock: %d.%02dMHz (*%d)\n", + M / 1000000, (M % 1000000) / 10000, m ); + N += 5000; + printk( KERN_INFO "Turbo Mode clock: %d.%02dMHz (*%d.%d, %sactive)\n", + N / 1000000, (N % 1000000) / 10000, n2 / 2, (n2 % 2) * 5, + (turbo & 1) ? "" : "in" ); + } + + return (turbo & 1) ? (N/1000) : (M/1000); +} + +EXPORT_SYMBOL(get_clk_frequency_khz); + +/* + * Return the current memory clock frequency in units of 10kHz + */ +unsigned int get_memclk_frequency_10khz(void) +{ + return L_clk_mult[(CCCR >> 0) & 0x1f] * BASE_CLK / 10000; +} + +EXPORT_SYMBOL(get_memclk_frequency_10khz); + +/* + * Return the current LCD clock frequency in units of 10kHz + */ +unsigned int get_lcdclk_frequency_10khz(void) +{ + return get_memclk_frequency_10khz(); +} + +EXPORT_SYMBOL(get_lcdclk_frequency_10khz); |