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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * based on arch/arm/mach-kirkwood/cpuidle.c4 *5 * CPU idle support for AT91 SoC6 *7 * The cpu idle uses wait-for-interrupt and RAM self refresh in order8 * to implement two idle states -9 * #1 wait-for-interrupt10 * #2 wait-for-interrupt and RAM self refresh11 */12 13#include <linux/kernel.h>14#include <linux/init.h>15#include <linux/platform_device.h>16#include <linux/cpuidle.h>17#include <linux/io.h>18#include <linux/export.h>19#include <asm/cpuidle.h>20 21#define AT91_MAX_STATES 222 23static void (*at91_standby)(void);24 25/* Actual code that puts the SoC in different idle states */26static int at91_enter_idle(struct cpuidle_device *dev,27 struct cpuidle_driver *drv,28 int index)29{30 at91_standby();31 return index;32}33 34static struct cpuidle_driver at91_idle_driver = {35 .name = "at91_idle",36 .owner = THIS_MODULE,37 .states[0] = ARM_CPUIDLE_WFI_STATE,38 .states[1] = {39 .enter = at91_enter_idle,40 .exit_latency = 10,41 .target_residency = 10000,42 .name = "RAM_SR",43 .desc = "WFI and DDR Self Refresh",44 },45 .state_count = AT91_MAX_STATES,46};47 48/* Initialize CPU idle by registering the idle states */49static int at91_cpuidle_probe(struct platform_device *dev)50{51 at91_standby = (void *)(dev->dev.platform_data);52 53 return cpuidle_register(&at91_idle_driver, NULL);54}55 56static struct platform_driver at91_cpuidle_driver = {57 .driver = {58 .name = "cpuidle-at91",59 },60 .probe = at91_cpuidle_probe,61};62builtin_platform_driver(at91_cpuidle_driver);63