2 * linux/arch/arm/mach-pxa/pxa25x.c
4 * Author: Nicolas Pitre
5 * Created: Jun 15, 2001
6 * Copyright: MontaVista Software Inc.
8 * Code specific to PXA21x/25x/26x variants.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
14 * Since this file should be linked before any other machine specific file,
15 * the __initcall() here will be executed first. This serves as default
16 * initialization stuff for PXA machines which can be overridden later if
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/init.h>
24 #include <asm/hardware.h>
25 #include <asm/arch/pxa-regs.h>
30 * Various clock factors driven by the CCCR register.
33 /* Crystal Frequency to Memory Frequency Multiplier (L) */
34 static unsigned char L_clk_mult
[32] = { 0, 27, 32, 36, 40, 45, 0, };
36 /* Memory Frequency to Run Mode Frequency Multiplier (M) */
37 static unsigned char M_clk_mult
[4] = { 0, 1, 2, 4 };
39 /* Run Mode Frequency to Turbo Mode Frequency Multiplier (N) */
40 /* Note: we store the value N * 2 here. */
41 static unsigned char N2_clk_mult
[8] = { 0, 0, 2, 3, 4, 0, 6, 0 };
44 #define BASE_CLK 3686400
47 * Get the clock frequency as reflected by CCCR and the turbo flag.
48 * We assume these values have been applied via a fcs.
49 * If info is not 0 we also display the current settings.
51 unsigned int get_clk_frequency_khz(int info
)
53 unsigned long cccr
, turbo
;
54 unsigned int l
, L
, m
, M
, n2
, N
;
57 asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (turbo
) );
59 l
= L_clk_mult
[(cccr
>> 0) & 0x1f];
60 m
= M_clk_mult
[(cccr
>> 5) & 0x03];
61 n2
= N2_clk_mult
[(cccr
>> 7) & 0x07];
70 printk( KERN_INFO
"Memory clock: %d.%02dMHz (*%d)\n",
71 L
/ 1000000, (L
% 1000000) / 10000, l
);
73 printk( KERN_INFO
"Run Mode clock: %d.%02dMHz (*%d)\n",
74 M
/ 1000000, (M
% 1000000) / 10000, m
);
76 printk( KERN_INFO
"Turbo Mode clock: %d.%02dMHz (*%d.%d, %sactive)\n",
77 N
/ 1000000, (N
% 1000000) / 10000, n2
/ 2, (n2
% 2) * 5,
78 (turbo
& 1) ? "" : "in" );
81 return (turbo
& 1) ? (N
/1000) : (M
/1000);
84 EXPORT_SYMBOL(get_clk_frequency_khz
);
87 * Return the current memory clock frequency in units of 10kHz
89 unsigned int get_memclk_frequency_10khz(void)
91 return L_clk_mult
[(CCCR
>> 0) & 0x1f] * BASE_CLK
/ 10000;
94 EXPORT_SYMBOL(get_memclk_frequency_10khz
);
97 * Return the current LCD clock frequency in units of 10kHz
99 unsigned int get_lcdclk_frequency_10khz(void)
101 return get_memclk_frequency_10khz();
104 EXPORT_SYMBOL(get_lcdclk_frequency_10khz
);