linux/arch/arm/mach-pxa/pxa27x.c
Todd Poynor 26705ca46b [PATCH] ARM: 2781/2: PXA27x Standby mode take 2
Patch from Todd Poynor

Add support for PXA27x Standby mode, a low-power mode that retains CPU
and some peripheral state (the existing "sleep" mode is a power-power
mode that retains less state). Activated via:
echo -n standby > /sys/power/state
From: David Burrage and Todd Poynor

Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-01 11:27:05 +01:00

207 lines
4.5 KiB
C

/*
* linux/arch/arm/mach-pxa/pxa27x.c
*
* Author: Nicolas Pitre
* Created: Nov 05, 2002
* Copyright: MontaVista Software Inc.
*
* Code specific to PXA27x aka Bulverde.
*
* 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.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/arch/pxa-regs.h>
#include "generic.h"
/* Crystal clock: 13MHz */
#define BASE_CLK 13000000
/*
* Get the clock frequency as reflected by CCSR 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 ccsr, clkcfg;
unsigned int l, L, m, M, n2, N, S;
int cccr_a, t, ht, b;
ccsr = CCSR;
cccr_a = CCCR & (1 << 25);
/* Read clkcfg register: it has turbo, b, half-turbo (and f) */
asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg) );
t = clkcfg & (1 << 1);
ht = clkcfg & (1 << 2);
b = clkcfg & (1 << 3);
l = ccsr & 0x1f;
n2 = (ccsr>>7) & 0xf;
m = (l <= 10) ? 1 : (l <= 20) ? 2 : 4;
L = l * BASE_CLK;
N = (L * n2) / 2;
M = (!cccr_a) ? (L/m) : ((b) ? L : (L/2));
S = (b) ? L : (L/2);
if (info) {
printk( KERN_INFO "Run Mode clock: %d.%02dMHz (*%d)\n",
L / 1000000, (L % 1000000) / 10000, l );
printk( KERN_INFO "Turbo Mode clock: %d.%02dMHz (*%d.%d, %sactive)\n",
N / 1000000, (N % 1000000)/10000, n2 / 2, (n2 % 2)*5,
(t) ? "" : "in" );
printk( KERN_INFO "Memory clock: %d.%02dMHz (/%d)\n",
M / 1000000, (M % 1000000) / 10000, m );
printk( KERN_INFO "System bus clock: %d.%02dMHz \n",
S / 1000000, (S % 1000000) / 10000 );
}
return (t) ? (N/1000) : (L/1000);
}
/*
* Return the current mem clock frequency in units of 10kHz as
* reflected by CCCR[A], B, and L
*/
unsigned int get_memclk_frequency_10khz(void)
{
unsigned long ccsr, clkcfg;
unsigned int l, L, m, M;
int cccr_a, b;
ccsr = CCSR;
cccr_a = CCCR & (1 << 25);
/* Read clkcfg register: it has turbo, b, half-turbo (and f) */
asm( "mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg) );
b = clkcfg & (1 << 3);
l = ccsr & 0x1f;
m = (l <= 10) ? 1 : (l <= 20) ? 2 : 4;
L = l * BASE_CLK;
M = (!cccr_a) ? (L/m) : ((b) ? L : (L/2));
return (M / 10000);
}
/*
* Return the current LCD clock frequency in units of 10kHz as
*/
unsigned int get_lcdclk_frequency_10khz(void)
{
unsigned long ccsr;
unsigned int l, L, k, K;
ccsr = CCSR;
l = ccsr & 0x1f;
k = (l <= 7) ? 1 : (l <= 16) ? 2 : 4;
L = l * BASE_CLK;
K = L / k;
return (K / 10000);
}
EXPORT_SYMBOL(get_clk_frequency_khz);
EXPORT_SYMBOL(get_memclk_frequency_10khz);
EXPORT_SYMBOL(get_lcdclk_frequency_10khz);
#ifdef CONFIG_PM
int pxa_cpu_pm_prepare(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_MEM:
case PM_SUSPEND_STANDBY:
return 0;
default:
return -EINVAL;
}
}
void pxa_cpu_pm_enter(suspend_state_t state)
{
extern void pxa_cpu_standby(void);
extern void pxa_cpu_suspend(unsigned int);
extern void pxa_cpu_resume(void);
if (state == PM_SUSPEND_STANDBY)
CKEN = CKEN22_MEMC | CKEN9_OSTIMER | CKEN16_LCD |CKEN0_PWM0;
else
CKEN = CKEN22_MEMC | CKEN9_OSTIMER;
/* ensure voltage-change sequencer not initiated, which hangs */
PCFR &= ~PCFR_FVC;
/* Clear edge-detect status register. */
PEDR = 0xDF12FE1B;
switch (state) {
case PM_SUSPEND_STANDBY:
pxa_cpu_standby();
break;
case PM_SUSPEND_MEM:
/* set resume return address */
PSPR = virt_to_phys(pxa_cpu_resume);
pxa_cpu_suspend(3);
break;
}
}
#endif
/*
* device registration specific to PXA27x.
*/
static u64 pxa27x_dmamask = 0xffffffffUL;
static struct resource pxa27x_ohci_resources[] = {
[0] = {
.start = 0x4C000000,
.end = 0x4C00ff6f,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_USBH1,
.end = IRQ_USBH1,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device ohci_device = {
.name = "pxa27x-ohci",
.id = -1,
.dev = {
.dma_mask = &pxa27x_dmamask,
.coherent_dma_mask = 0xffffffff,
},
.num_resources = ARRAY_SIZE(pxa27x_ohci_resources),
.resource = pxa27x_ohci_resources,
};
static struct platform_device *devices[] __initdata = {
&ohci_device,
};
static int __init pxa27x_init(void)
{
return platform_add_devices(devices, ARRAY_SIZE(devices));
}
subsys_initcall(pxa27x_init);