74 lines
1.9 KiB
C
74 lines
1.9 KiB
C
/*
|
|
* 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)) {
|
|
printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n");
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(kirkwood_init_cpuidle);
|