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/*
* arch/arm/mach-kirkwood/cpuidle.c
*
* CPU idle Marvell Kirkwood SoCs
*
* 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 DDR self refresh in order
* to implement two idle states -
* #1 wait-for-interrupt
* #2 wait-for-interrupt and DDR 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/kirkwood.h>
#define KIRKWOOD_MAX_STATES 2
/* Actual code that puts the SoC in different idle states */
static int kirkwood_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
writel(0x7, DDR_OPERATION_BASE);
cpu_do_idle();
return index;
}
static struct cpuidle_driver kirkwood_idle_driver = {
.name = "kirkwood_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
.states[0] = ARM_CPUIDLE_WFI_STATE,
.states[1] = {
.enter = kirkwood_enter_idle,
.exit_latency = 10,
.target_residency = 100000,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "DDR SR",
.desc = "WFI and DDR Self Refresh",
},
.state_count = KIRKWOOD_MAX_STATES,
};
static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device);
/* Initialize CPU idle by registering the idle states */
static int kirkwood_init_cpuidle(void)
{
struct cpuidle_device *device;
device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id());
device->state_count = KIRKWOOD_MAX_STATES;
cpuidle_register_driver(&kirkwood_idle_driver);
if (cpuidle_register_device(device)) {
pr_err("kirkwood_init_cpuidle: Failed registering\n");
return -EIO;
}
return 0;
}
device_initcall(kirkwood_init_cpuidle);
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