2 * linux/arch/arm/mach-pxa/pxa27x.c
4 * Author: Nicolas Pitre
5 * Created: Nov 05, 2002
6 * Copyright: MontaVista Software Inc.
8 * Code specific to PXA27x aka Bulverde.
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 #include <linux/config.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
20 #include <asm/hardware.h>
24 /* Crystal clock : 13-MHZ*/
25 #define BASE_CLK 13000000
28 * Get the clock frequency as reflected by CCSR and the turbo flag.
29 * We assume these values have been applied via a fcs.
30 * If info is not 0 we also display the current settings.
32 * For more details, refer to Bulverde Manual, section 3.8.2.1
34 unsigned int get_clk_frequency_khz( int info)
36 unsigned long ccsr, turbo, b, ht;
37 unsigned int l, L, m, M, n2, N, S, cccra;
40 cccra = CCCR & (0x1 << 25);
42 /* Read clkcfg register: it has turbo, b, half-turbo (and f) */
43 asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (turbo) );
44 b = (turbo & (0x1 << 3));
45 ht = (turbo & (0x1 << 2));
50 /* The calculation from the Yellow Book is incorrect:
51 it says M=4 for L=21-30 (which is easy to calculate
52 by subtracting 1 and then dividing by 10, but not
53 with 31, so we'll do it manually */
68 printk( KERN_INFO "Run Mode clock: %d.%02dMHz (*%d)\n",
69 L / 1000000, (L % 1000000) / 10000, l );
70 printk( KERN_INFO "Memory clock: %d.%02dMHz (/%d)\n",
71 M / 1000000, (M % 1000000) / 10000, m );
72 printk( KERN_INFO "Turbo Mode clock: %d.%02dMHz (*%d.%d, %sactive)\n",
73 N / 1000000, (N % 1000000)/10000, n2 / 2, (n2 % 2)*5,
74 (turbo & 1) ? "" : "in" );
75 printk( KERN_INFO "System bus clock: %d.%02dMHz \n",
76 S / 1000000, (S % 1000000) / 10000 );
79 return (turbo & 1) ? (N/1000) : (L/1000);
83 * Return the current mem clock frequency in units of 10kHz as
84 * reflected by CCCR[A], B, and L
86 unsigned int get_lclk_frequency_10khz(void)
88 unsigned long ccsr, clkcfg, b;
89 unsigned int l, L, m, M, cccra;
91 cccra = CCCR & (0x1 << 25);
93 /* Read clkcfg register to obtain b */
94 asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg) );
95 b = (clkcfg & (0x1 << 3));
100 /* The calculation from the Yellow Book is incorrect:
101 it says M=4 for L=21-30 (which is easy to calculate
102 by subtracting 1 and then dividing by 10, but not
103 with 31, so we'll do it manually */
118 EXPORT_SYMBOL(get_clk_frequency_khz);
119 EXPORT_SYMBOL(get_lclk_frequency_10khz);