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/*
* 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
*
* 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/proc-fns.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,
.flags = CPUIDLE_FLAG_TIME_VALID,
.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)
{
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL)
return -EINVAL;
ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
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",
.owner = THIS_MODULE,
},
};
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");
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