2 * Copyright (C) 2014 Freescale Semiconductor, Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/cpuidle.h>
10 #include <linux/cpu_pm.h>
11 #include <linux/module.h>
12 #include <asm/cacheflush.h>
13 #include <asm/cpuidle.h>
14 #include <asm/suspend.h>
19 static int imx6sx_idle_finish(unsigned long val)
22 * for Cortex-A7 which has an internal L2
23 * cache, need to flush it before powering
24 * down ARM platform, since flushing L1 cache
25 * here again has very small overhead, compared
26 * to adding conditional code for L2 cache type,
27 * just call flush_cache_all() is fine.
35 static int imx6sx_enter_wait(struct cpuidle_device *dev,
36 struct cpuidle_driver *drv, int index)
38 imx6_set_lpm(WAIT_UNCLOCKED);
45 imx6_enable_rbc(true);
46 imx_gpc_set_arm_power_in_lpm(true);
47 imx_set_cpu_jump(0, v7_cpu_resume);
48 /* Need to notify there is a cpu pm operation. */
50 cpu_cluster_pm_enter();
52 cpu_suspend(0, imx6sx_idle_finish);
54 cpu_cluster_pm_exit();
56 imx_gpc_set_arm_power_in_lpm(false);
57 imx6_enable_rbc(false);
63 imx6_set_lpm(WAIT_CLOCKED);
68 static struct cpuidle_driver imx6sx_cpuidle_driver = {
69 .name = "imx6sx_cpuidle",
73 ARM_CPUIDLE_WFI_STATE,
77 .target_residency = 75,
78 .flags = CPUIDLE_FLAG_TIMER_STOP,
79 .enter = imx6sx_enter_wait,
83 /* WAIT + ARM power off */
86 * ARM gating 31us * 5 + RBC clear 65us
87 * and some margin for SW execution, here set it
91 .target_residency = 500,
92 .flags = CPUIDLE_FLAG_TIMER_STOP,
93 .enter = imx6sx_enter_wait,
94 .name = "LOW-POWER-IDLE",
95 .desc = "ARM power off",
99 .safe_state_index = 0,
102 int __init imx6sx_cpuidle_init(void)
104 imx6_set_int_mem_clk_lpm(true);
105 imx6_enable_rbc(false);
106 imx_gpc_set_l2_mem_power_in_lpm(false);
108 * set ARM power up/down timing to the fastest,
109 * sw2iso and sw can be set to one 32K cycle = 31us
110 * except for power up sw2iso which need to be
111 * larger than LDO ramp up time.
113 imx_gpc_set_arm_power_up_timing(0xf, 1);
114 imx_gpc_set_arm_power_down_timing(1, 1);
116 return cpuidle_register(&imx6sx_cpuidle_driver, NULL);