linux/arch/arm/mach-davinci/cpuidle.c
Sekhar Nori 948c66df0d davinci: cpuidle: move mapping of DDR2 controller registers out of driver
When suspend is supported, both cpuidle and suspend code
need to work on DDR2 registers. Instead of mapping the
DDR2 registers twice, do it once outside of cpuidle
driver and let cpuidle driver get the virtual base address
of DDR2 registers.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2010-02-04 13:29:38 -08:00

170 lines
4.2 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 <asm/proc-fns.h>
#include <mach/cpuidle.h>
#include <mach/memory.h>
#define DAVINCI_CPUIDLE_MAX_STATES 2
struct davinci_ops {
void (*enter) (u32 flags);
void (*exit) (u32 flags);
u32 flags;
};
/* fields in davinci_ops.flags */
#define DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN BIT(0)
static struct cpuidle_driver davinci_idle_driver = {
.name = "cpuidle-davinci",
.owner = THIS_MODULE,
};
static DEFINE_PER_CPU(struct cpuidle_device, davinci_cpuidle_device);
static void __iomem *ddr2_reg_base;
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);
}
static void davinci_c2state_enter(u32 flags)
{
davinci_save_ddr_power(1, !!(flags & DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN));
}
static void davinci_c2state_exit(u32 flags)
{
davinci_save_ddr_power(0, !!(flags & DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN));
}
static struct davinci_ops davinci_states[DAVINCI_CPUIDLE_MAX_STATES] = {
[1] = {
.enter = davinci_c2state_enter,
.exit = davinci_c2state_exit,
},
};
/* Actual code that puts the SoC in different idle states */
static int davinci_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct davinci_ops *ops = cpuidle_get_statedata(state);
struct timeval before, after;
int idle_time;
local_irq_disable();
do_gettimeofday(&before);
if (ops && ops->enter)
ops->enter(ops->flags);
/* Wait for interrupt state */
cpu_do_idle();
if (ops && ops->exit)
ops->exit(ops->flags);
do_gettimeofday(&after);
local_irq_enable();
idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
(after.tv_usec - before.tv_usec);
return idle_time;
}
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;
ret = cpuidle_register_driver(&davinci_idle_driver);
if (ret) {
dev_err(&pdev->dev, "failed to register driver\n");
return ret;
}
/* Wait for interrupt state */
device->states[0].enter = davinci_enter_idle;
device->states[0].exit_latency = 1;
device->states[0].target_residency = 10000;
device->states[0].flags = CPUIDLE_FLAG_TIME_VALID;
strcpy(device->states[0].name, "WFI");
strcpy(device->states[0].desc, "Wait for interrupt");
/* Wait for interrupt and DDR self refresh state */
device->states[1].enter = davinci_enter_idle;
device->states[1].exit_latency = 10;
device->states[1].target_residency = 10000;
device->states[1].flags = CPUIDLE_FLAG_TIME_VALID;
strcpy(device->states[1].name, "DDR SR");
strcpy(device->states[1].desc, "WFI and DDR Self Refresh");
if (pdata->ddr2_pdown)
davinci_states[1].flags |= DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN;
cpuidle_set_statedata(&device->states[1], &davinci_states[1]);
device->state_count = DAVINCI_CPUIDLE_MAX_STATES;
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);