xref: /openbmc/linux/arch/arm/mach-pxa/pxa25x.c (revision 64c70b1c)
1 /*
2  *  linux/arch/arm/mach-pxa/pxa25x.c
3  *
4  *  Author:	Nicolas Pitre
5  *  Created:	Jun 15, 2001
6  *  Copyright:	MontaVista Software Inc.
7  *
8  * Code specific to PXA21x/25x/26x variants.
9  *
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.
13  *
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
17  * need be.
18  */
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/pm.h>
23 
24 #include <asm/hardware.h>
25 #include <asm/arch/pxa-regs.h>
26 
27 #include "generic.h"
28 
29 /*
30  * Various clock factors driven by the CCCR register.
31  */
32 
33 /* Crystal Frequency to Memory Frequency Multiplier (L) */
34 static unsigned char L_clk_mult[32] = { 0, 27, 32, 36, 40, 45, 0, };
35 
36 /* Memory Frequency to Run Mode Frequency Multiplier (M) */
37 static unsigned char M_clk_mult[4] = { 0, 1, 2, 4 };
38 
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 };
42 
43 /* Crystal clock */
44 #define BASE_CLK	3686400
45 
46 /*
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.
50  */
51 unsigned int get_clk_frequency_khz(int info)
52 {
53 	unsigned long cccr, turbo;
54 	unsigned int l, L, m, M, n2, N;
55 
56 	cccr = CCCR;
57 	asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (turbo) );
58 
59 	l  =  L_clk_mult[(cccr >> 0) & 0x1f];
60 	m  =  M_clk_mult[(cccr >> 5) & 0x03];
61 	n2 = N2_clk_mult[(cccr >> 7) & 0x07];
62 
63 	L = l * BASE_CLK;
64 	M = m * L;
65 	N = n2 * M / 2;
66 
67 	if(info)
68 	{
69 		L += 5000;
70 		printk( KERN_INFO "Memory clock: %d.%02dMHz (*%d)\n",
71 			L / 1000000, (L % 1000000) / 10000, l );
72 		M += 5000;
73 		printk( KERN_INFO "Run Mode clock: %d.%02dMHz (*%d)\n",
74 			M / 1000000, (M % 1000000) / 10000, m );
75 		N += 5000;
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" );
79 	}
80 
81 	return (turbo & 1) ? (N/1000) : (M/1000);
82 }
83 
84 EXPORT_SYMBOL(get_clk_frequency_khz);
85 
86 /*
87  * Return the current memory clock frequency in units of 10kHz
88  */
89 unsigned int get_memclk_frequency_10khz(void)
90 {
91 	return L_clk_mult[(CCCR >> 0) & 0x1f] * BASE_CLK / 10000;
92 }
93 
94 EXPORT_SYMBOL(get_memclk_frequency_10khz);
95 
96 /*
97  * Return the current LCD clock frequency in units of 10kHz
98  */
99 unsigned int get_lcdclk_frequency_10khz(void)
100 {
101 	return get_memclk_frequency_10khz();
102 }
103 
104 EXPORT_SYMBOL(get_lcdclk_frequency_10khz);
105 
106 #ifdef CONFIG_PM
107 
108 int pxa_cpu_pm_prepare(suspend_state_t state)
109 {
110 	switch (state) {
111 	case PM_SUSPEND_MEM:
112 		break;
113 	default:
114 		return -EINVAL;
115 	}
116 
117 	return 0;
118 }
119 
120 void pxa_cpu_pm_enter(suspend_state_t state)
121 {
122 	extern void pxa_cpu_suspend(unsigned int);
123 	extern void pxa_cpu_resume(void);
124 
125 	CKEN = 0;
126 
127 	switch (state) {
128 	case PM_SUSPEND_MEM:
129 		/* set resume return address */
130 		PSPR = virt_to_phys(pxa_cpu_resume);
131 		pxa_cpu_suspend(PWRMODE_SLEEP);
132 		break;
133 	}
134 }
135 
136 #endif
137