68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/*
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* based on arch/arm/mach-kirkwood/cpuidle.c
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*
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* CPU idle support for AT91 SoC
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*
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* The cpu idle uses wait-for-interrupt and RAM self refresh in order
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* to implement two idle states -
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* #1 wait-for-interrupt
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* #2 wait-for-interrupt and RAM self refresh
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/cpuidle.h>
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#include <linux/io.h>
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#include <linux/export.h>
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#include <asm/proc-fns.h>
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#include <asm/cpuidle.h>
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#define AT91_MAX_STATES 2
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static void (*at91_standby)(void);
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/* Actual code that puts the SoC in different idle states */
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static int at91_enter_idle(struct cpuidle_device *dev,
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struct cpuidle_driver *drv,
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int index)
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{
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at91_standby();
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return index;
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}
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static struct cpuidle_driver at91_idle_driver = {
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.name = "at91_idle",
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.owner = THIS_MODULE,
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.states[0] = ARM_CPUIDLE_WFI_STATE,
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.states[1] = {
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.enter = at91_enter_idle,
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.exit_latency = 10,
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.target_residency = 10000,
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.name = "RAM_SR",
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.desc = "WFI and DDR Self Refresh",
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},
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.state_count = AT91_MAX_STATES,
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};
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/* Initialize CPU idle by registering the idle states */
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static int at91_cpuidle_probe(struct platform_device *dev)
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{
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at91_standby = (void *)(dev->dev.platform_data);
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return cpuidle_register(&at91_idle_driver, NULL);
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}
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static struct platform_driver at91_cpuidle_driver = {
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.driver = {
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.name = "cpuidle-at91",
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},
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.probe = at91_cpuidle_probe,
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};
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module_platform_driver(at91_cpuidle_driver);
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