63 lines
1.5 KiB
C
63 lines
1.5 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/*
|
||
|
|
* based on arch/arm/mach-kirkwood/cpuidle.c
|
||
|
|
*
|
||
|
|
* CPU idle support for AT91 SoC
|
||
|
|
*
|
||
|
|
* 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/cpuidle.h>
|
||
|
|
|
||
|
|
#define AT91_MAX_STATES 2
|
||
|
|
|
||
|
|
static void (*at91_standby)(void);
|
||
|
|
|
||
|
|
/* 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)
|
||
|
|
{
|
||
|
|
at91_standby();
|
||
|
|
return index;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct cpuidle_driver at91_idle_driver = {
|
||
|
|
.name = "at91_idle",
|
||
|
|
.owner = THIS_MODULE,
|
||
|
|
.states[0] = ARM_CPUIDLE_WFI_STATE,
|
||
|
|
.states[1] = {
|
||
|
|
.enter = at91_enter_idle,
|
||
|
|
.exit_latency = 10,
|
||
|
|
.target_residency = 10000,
|
||
|
|
.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_cpuidle_probe(struct platform_device *dev)
|
||
|
|
{
|
||
|
|
at91_standby = (void *)(dev->dev.platform_data);
|
||
|
|
|
||
|
|
return cpuidle_register(&at91_idle_driver, NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct platform_driver at91_cpuidle_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = "cpuidle-at91",
|
||
|
|
},
|
||
|
|
.probe = at91_cpuidle_probe,
|
||
|
|
};
|
||
|
|
builtin_platform_driver(at91_cpuidle_driver);
|