linux/arch/arm/mach-at91/cpuidle.c
Arnd Bergmann f5fa4098c3 ARM: at91: suspend both memory controllers on at91sam9263
For the past three years, we have had a #warning in
mach-at91 about the sdram_selfrefresh_enable or
at91sam9_standby functions possibly not working on
at91sam9263. In the meantime a function was added
to do the right thing on at91sam9g45, which looks like
it should also work on '9263.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[nicolas.ferre@atmel.com: remove paragraph in commit message]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-04-18 16:31:02 +02:00

83 lines
2.0 KiB
C

/*
* based on arch/arm/mach-kirkwood/cpuidle.c
*
* CPU idle support for AT91 SoC
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* The cpu idle uses wait-for-interrupt and RAM self refresh in order
* to implement two idle states -
* #1 wait-for-interrupt
* #2 wait-for-interrupt and RAM self refresh
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/cpuidle.h>
#include <linux/io.h>
#include <linux/export.h>
#include <asm/proc-fns.h>
#include <asm/cpuidle.h>
#include <mach/cpu.h>
#include "pm.h"
#define AT91_MAX_STATES 2
static DEFINE_PER_CPU(struct cpuidle_device, at91_cpuidle_device);
/* Actual code that puts the SoC in different idle states */
static int at91_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
if (cpu_is_at91rm9200())
at91rm9200_standby();
else if (cpu_is_at91sam9g45())
at91sam9g45_standby();
else if (cpu_is_at91sam9263())
at91sam9263_standby();
else
at91sam9_standby();
return index;
}
static struct cpuidle_driver at91_idle_driver = {
.name = "at91_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
.states[0] = ARM_CPUIDLE_WFI_STATE,
.states[1] = {
.enter = at91_enter_idle,
.exit_latency = 10,
.target_residency = 100000,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "RAM_SR",
.desc = "WFI and DDR Self Refresh",
},
.state_count = AT91_MAX_STATES,
};
/* Initialize CPU idle by registering the idle states */
static int at91_init_cpuidle(void)
{
struct cpuidle_device *device;
device = &per_cpu(at91_cpuidle_device, smp_processor_id());
device->state_count = AT91_MAX_STATES;
cpuidle_register_driver(&at91_idle_driver);
if (cpuidle_register_device(device)) {
printk(KERN_ERR "at91_init_cpuidle: Failed registering\n");
return -EIO;
}
return 0;
}
device_initcall(at91_init_cpuidle);