linux/drivers/cpuidle/cpuidle-kirkwood.c
Thomas Gleixner 3bb165608e treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 2)
Based on the normalized pattern:

    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

extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10 14:51:35 +02:00

82 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* CPU idle Marvell Kirkwood SoCs
*
* 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
*
* Maintainer: Jason Cooper <jason@lakedaemon.net>
* Maintainer: Andrew Lunn <andrew@lunn.ch>
*/
#include <linux/kernel.h>
#include <linux/module.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 KIRKWOOD_MAX_STATES 2
static void __iomem *ddr_operation_base;
/* 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,
.states[0] = ARM_CPUIDLE_WFI_STATE,
.states[1] = {
.enter = kirkwood_enter_idle,
.exit_latency = 10,
.target_residency = 100000,
.name = "DDR SR",
.desc = "WFI and DDR Self Refresh",
},
.state_count = KIRKWOOD_MAX_STATES,
};
/* Initialize CPU idle by registering the idle states */
static int kirkwood_cpuidle_probe(struct platform_device *pdev)
{
ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(ddr_operation_base))
return PTR_ERR(ddr_operation_base);
return cpuidle_register(&kirkwood_idle_driver, NULL);
}
static int kirkwood_cpuidle_remove(struct platform_device *pdev)
{
cpuidle_unregister(&kirkwood_idle_driver);
return 0;
}
static struct platform_driver kirkwood_cpuidle_driver = {
.probe = kirkwood_cpuidle_probe,
.remove = kirkwood_cpuidle_remove,
.driver = {
.name = "kirkwood_cpuidle",
},
};
module_platform_driver(kirkwood_cpuidle_driver);
MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
MODULE_DESCRIPTION("Kirkwood cpu idle driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:kirkwood-cpuidle");