[linux-2.6-block.git] / arch / arm / mach-davinci / cpuidle.c

/*
 * CPU idle for DaVinci SoCs
 *
 * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/
 *
 * Derived from Marvell Kirkwood CPU idle code
 * (arch/arm/mach-kirkwood/cpuidle.c)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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/cpuidle.h>
#include <mach/ddr2.h>

#define DAVINCI_CPUIDLE_MAX_STATES	2

static DEFINE_PER_CPU(struct cpuidle_device, davinci_cpuidle_device);
static void __iomem *ddr2_reg_base;
static bool ddr2_pdown;

static void davinci_save_ddr_power(int enter, bool pdown)
{
	u32 val;

	val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET);

	if (enter) {
		if (pdown)
			val |= DDR2_SRPD_BIT;
		else
			val &= ~DDR2_SRPD_BIT;
		val |= DDR2_LPMODEN_BIT;
	} else {
		val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT);
	}

	__raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET);
}

/* Actual code that puts the SoC in different idle states */
static int davinci_enter_idle(struct cpuidle_device *dev,
				struct cpuidle_driver *drv,
						int index)
{
	davinci_save_ddr_power(1, ddr2_pdown);

	index = cpuidle_wrap_enter(dev,	drv, index,
				arm_cpuidle_simple_enter);

	davinci_save_ddr_power(0, ddr2_pdown);

	return index;
}

static struct cpuidle_driver davinci_idle_driver = {
	.name			= "cpuidle-davinci",
	.owner			= THIS_MODULE,
	.en_core_tk_irqen	= 1,
	.states[0]		= ARM_CPUIDLE_WFI_STATE,
	.states[1]		= {
		.enter			= davinci_enter_idle,
		.exit_latency		= 10,
		.target_residency	= 100000,
		.flags			= CPUIDLE_FLAG_TIME_VALID,
		.name			= "DDR SR",
		.desc			= "WFI and DDR Self Refresh",
	},
	.state_count = DAVINCI_CPUIDLE_MAX_STATES,
};

static int __init davinci_cpuidle_probe(struct platform_device *pdev)
{
	int ret;
	struct cpuidle_device *device;
	struct davinci_cpuidle_config *pdata = pdev->dev.platform_data;

	device = &per_cpu(davinci_cpuidle_device, smp_processor_id());

	if (!pdata) {
		dev_err(&pdev->dev, "cannot get platform data\n");
		return -ENOENT;
	}

	ddr2_reg_base = pdata->ddr2_ctlr_base;

	ddr2_pdown = pdata->ddr2_pdown;

	ret = cpuidle_register_driver(&davinci_idle_driver);
	if (ret) {
		dev_err(&pdev->dev, "failed to register driver\n");
		return ret;
	}

	ret = cpuidle_register_device(device);
	if (ret) {
		dev_err(&pdev->dev, "failed to register device\n");
		cpuidle_unregister_driver(&davinci_idle_driver);
		return ret;
	}

	return 0;
}

static struct platform_driver davinci_cpuidle_driver = {
	.driver = {
		.name	= "cpuidle-davinci",
		.owner	= THIS_MODULE,
	},
};

static int __init davinci_cpuidle_init(void)
{
	return platform_driver_probe(&davinci_cpuidle_driver,
						davinci_cpuidle_probe);
}
device_initcall(davinci_cpuidle_init);
Commit	Line	Data
a6c0f6ec SN	1	/*
	2	* CPU idle for DaVinci SoCs
	3	*
	4	* Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/
	5	*
	6	* Derived from Marvell Kirkwood CPU idle code
	7	* (arch/arm/mach-kirkwood/cpuidle.c)
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/cpuidle.h>
	18	#include <linux/io.h>
dc28094b	19	#include <linux/export.h>
a6c0f6ec	20	#include <asm/proc-fns.h>
19976c2a	21	#include <asm/cpuidle.h>
a6c0f6ec SN	22
a6c0f6ec SN	23	#include <mach/cpuidle.h>
0020afb3	24	#include <mach/ddr2.h>
a6c0f6ec SN	25
	26	#define DAVINCI_CPUIDLE_MAX_STATES 2
	27
a6c0f6ec SN	28	static DEFINE_PER_CPU(struct cpuidle_device, davinci_cpuidle_device);
a6c0f6ec SN	29	static void __iomem *ddr2_reg_base;
5af4a21c	30	static bool ddr2_pdown;
a6c0f6ec	31
a6c0f6ec SN	32	static void davinci_save_ddr_power(int enter, bool pdown)
	33	{
	34	u32 val;
	35
	36	val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET);
	37
	38	if (enter) {
	39	if (pdown)
	40	val \|= DDR2_SRPD_BIT;
	41	else
	42	val &= ~DDR2_SRPD_BIT;
	43	val \|= DDR2_LPMODEN_BIT;
	44	} else {
	45	val &= ~(DDR2_SRPD_BIT \| DDR2_LPMODEN_BIT);
	46	}
	47
	48	__raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET);
	49	}
	50
8d60143a DL	51	/* Actual code that puts the SoC in different idle states */
	52	static int davinci_enter_idle(struct cpuidle_device *dev,
	53	struct cpuidle_driver *drv,
	54	int index)
	55	{
36ce8d4f	56	davinci_save_ddr_power(1, ddr2_pdown);
8d60143a DL	57
	58	index = cpuidle_wrap_enter(dev, drv, index,
	59	arm_cpuidle_simple_enter);
	60
36ce8d4f	61	davinci_save_ddr_power(0, ddr2_pdown);
8d60143a DL	62
	63	return index;
	64	}
	65
	66	static struct cpuidle_driver davinci_idle_driver = {
	67	.name = "cpuidle-davinci",
	68	.owner = THIS_MODULE,
	69	.en_core_tk_irqen = 1,
	70	.states[0] = ARM_CPUIDLE_WFI_STATE,
	71	.states[1] = {
	72	.enter = davinci_enter_idle,
	73	.exit_latency = 10,
	74	.target_residency = 100000,
	75	.flags = CPUIDLE_FLAG_TIME_VALID,
	76	.name = "DDR SR",
	77	.desc = "WFI and DDR Self Refresh",
	78	},
	79	.state_count = DAVINCI_CPUIDLE_MAX_STATES,
	80	};
	81
a6c0f6ec SN	82	static int __init davinci_cpuidle_probe(struct platform_device *pdev)
	83	{
	84	int ret;
	85	struct cpuidle_device *device;
	86	struct davinci_cpuidle_config *pdata = pdev->dev.platform_data;
a6c0f6ec SN	87
	88	device = &per_cpu(davinci_cpuidle_device, smp_processor_id());
	89
	90	if (!pdata) {
	91	dev_err(&pdev->dev, "cannot get platform data\n");
	92	return -ENOENT;
	93	}
	94
948c66df	95	ddr2_reg_base = pdata->ddr2_ctlr_base;
a6c0f6ec	96
5af4a21c	97	ddr2_pdown = pdata->ddr2_pdown;
a6c0f6ec	98
46bcfad7 DD	99	ret = cpuidle_register_driver(&davinci_idle_driver);
	100	if (ret) {
	101	dev_err(&pdev->dev, "failed to register driver\n");
	102	return ret;
	103	}
a6c0f6ec SN	104
	105	ret = cpuidle_register_device(device);
	106	if (ret) {
	107	dev_err(&pdev->dev, "failed to register device\n");
948c66df SN	108	cpuidle_unregister_driver(&davinci_idle_driver);
948c66df SN	109	return ret;
a6c0f6ec SN	110	}
	111
	112	return 0;
a6c0f6ec SN	113	}
	114
	115	static struct platform_driver davinci_cpuidle_driver = {
	116	.driver = {
	117	.name = "cpuidle-davinci",
	118	.owner = THIS_MODULE,
	119	},
	120	};
	121
	122	static int __init davinci_cpuidle_init(void)
	123	{
	124	return platform_driver_probe(&davinci_cpuidle_driver,
	125	davinci_cpuidle_probe);
	126	}
	127	device_initcall(davinci_cpuidle_init);
	128