[linux-2.6-block.git] / drivers / cpuidle / cpuidle-kirkwood.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");
Commit	Line	Data
3bb16560	1	// SPDX-License-Identifier: GPL-2.0-only
e50b6bef	2	/*
e50b6bef RK	3	* CPU idle Marvell Kirkwood SoCs
e50b6bef RK	4	*
e50b6bef RK	5	* The cpu idle uses wait-for-interrupt and DDR self refresh in order
	6	* to implement two idle states -
	7	* #1 wait-for-interrupt
	8	* #2 wait-for-interrupt and DDR self refresh
a8e39c35 DL	9	*
	10	* Maintainer: Jason Cooper <jason@lakedaemon.net>
	11	* Maintainer: Andrew Lunn <andrew@lunn.ch>
e50b6bef RK	12	*/
	13
	14	#include <linux/kernel.h>
9cfc94eb	15	#include <linux/module.h>
e50b6bef RK	16	#include <linux/init.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/cpuidle.h>
	19	#include <linux/io.h>
dc28094b	20	#include <linux/export.h>
b334648d	21	#include <asm/cpuidle.h>
e50b6bef RK	22
	23	#define KIRKWOOD_MAX_STATES 2
	24
9cfc94eb AL	25	static void __iomem *ddr_operation_base;
9cfc94eb AL	26
e50b6bef RK	27	/* Actual code that puts the SoC in different idle states */
e50b6bef RK	28	static int kirkwood_enter_idle(struct cpuidle_device *dev,
9cfc94eb	29	struct cpuidle_driver *drv,
e978aa7d	30	int index)
e50b6bef	31	{
9cfc94eb	32	writel(0x7, ddr_operation_base);
b334648d	33	cpu_do_idle();
e978aa7d DD	34
e978aa7d DD	35	return index;
e50b6bef RK	36	}
e50b6bef RK	37
b334648d RL	38	static struct cpuidle_driver kirkwood_idle_driver = {
	39	.name = "kirkwood_idle",
	40	.owner = THIS_MODULE,
b334648d RL	41	.states[0] = ARM_CPUIDLE_WFI_STATE,
	42	.states[1] = {
	43	.enter = kirkwood_enter_idle,
	44	.exit_latency = 10,
	45	.target_residency = 100000,
b334648d RL	46	.name = "DDR SR",
	47	.desc = "WFI and DDR Self Refresh",
	48	},
	49	.state_count = KIRKWOOD_MAX_STATES,
	50	};
b334648d	51
e50b6bef	52	/* Initialize CPU idle by registering the idle states */
9cfc94eb	53	static int kirkwood_cpuidle_probe(struct platform_device *pdev)
e50b6bef	54	{
85c3ebd4	55	ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
488540bf SMP	56	if (IS_ERR(ddr_operation_base))
488540bf SMP	57	return PTR_ERR(ddr_operation_base);
e50b6bef	58
30dc72c6	59	return cpuidle_register(&kirkwood_idle_driver, NULL);
e50b6bef RK	60	}
e50b6bef RK	61
75d6137d	62	static int kirkwood_cpuidle_remove(struct platform_device *pdev)
9cfc94eb	63	{
30dc72c6	64	cpuidle_unregister(&kirkwood_idle_driver);
9cfc94eb AL	65	return 0;
	66	}
	67
	68	static struct platform_driver kirkwood_cpuidle_driver = {
	69	.probe = kirkwood_cpuidle_probe,
	70	.remove = kirkwood_cpuidle_remove,
	71	.driver = {
	72	.name = "kirkwood_cpuidle",
9cfc94eb AL	73	},
	74	};
	75
	76	module_platform_driver(kirkwood_cpuidle_driver);
	77
	78	MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
	79	MODULE_DESCRIPTION("Kirkwood cpu idle driver");
	80	MODULE_LICENSE("GPL v2");
	81	MODULE_ALIAS("platform:kirkwood-cpuidle");