103 строки
2.3 KiB
C
103 строки
2.3 KiB
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/cpuidle.h>
|
|
|
|
#include "cpuidle.h"
|
|
#include "ddr2.h"
|
|
|
|
#define DAVINCI_CPUIDLE_MAX_STATES 2
|
|
|
|
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);
|
|
cpu_do_idle();
|
|
davinci_save_ddr_power(0, ddr2_pdown);
|
|
|
|
return index;
|
|
}
|
|
|
|
static struct cpuidle_driver davinci_idle_driver = {
|
|
.name = "cpuidle-davinci",
|
|
.owner = THIS_MODULE,
|
|
.states[0] = ARM_CPUIDLE_WFI_STATE,
|
|
.states[1] = {
|
|
.enter = davinci_enter_idle,
|
|
.exit_latency = 10,
|
|
.target_residency = 10000,
|
|
.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)
|
|
{
|
|
struct davinci_cpuidle_config *pdata = pdev->dev.platform_data;
|
|
|
|
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;
|
|
|
|
return cpuidle_register(&davinci_idle_driver, NULL);
|
|
}
|
|
|
|
static struct platform_driver davinci_cpuidle_driver = {
|
|
.driver = {
|
|
.name = "cpuidle-davinci",
|
|
},
|
|
};
|
|
|
|
static int __init davinci_cpuidle_init(void)
|
|
{
|
|
return platform_driver_probe(&davinci_cpuidle_driver,
|
|
davinci_cpuidle_probe);
|
|
}
|
|
device_initcall(davinci_cpuidle_init);
|
|
|