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Diffstat (limited to 'arch/arm/mach-imx/cpuidle-imx6sx.c')
-rw-r--r--arch/arm/mach-imx/cpuidle-imx6sx.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
new file mode 100644
index 000000000..3708a71f3
--- /dev/null
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * 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/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+#include <asm/cpuidle.h>
+#include <asm/suspend.h>
+
+#include "common.h"
+#include "cpuidle.h"
+#include "hardware.h"
+
+static int imx6sx_idle_finish(unsigned long val)
+{
+ /*
+ * for Cortex-A7 which has an internal L2
+ * cache, need to flush it before powering
+ * down ARM platform, since flushing L1 cache
+ * here again has very small overhead, compared
+ * to adding conditional code for L2 cache type,
+ * just call flush_cache_all() is fine.
+ */
+ flush_cache_all();
+ cpu_do_idle();
+
+ return 0;
+}
+
+static int imx6sx_enter_wait(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ imx6_set_lpm(WAIT_UNCLOCKED);
+
+ switch (index) {
+ case 1:
+ cpu_do_idle();
+ break;
+ case 2:
+ imx6_enable_rbc(true);
+ imx_gpc_set_arm_power_in_lpm(true);
+ imx_set_cpu_jump(0, v7_cpu_resume);
+ /* Need to notify there is a cpu pm operation. */
+ cpu_pm_enter();
+ cpu_cluster_pm_enter();
+
+ cpu_suspend(0, imx6sx_idle_finish);
+
+ cpu_cluster_pm_exit();
+ cpu_pm_exit();
+ imx_gpc_set_arm_power_in_lpm(false);
+ imx6_enable_rbc(false);
+ break;
+ default:
+ break;
+ }
+
+ imx6_set_lpm(WAIT_CLOCKED);
+
+ return index;
+}
+
+static struct cpuidle_driver imx6sx_cpuidle_driver = {
+ .name = "imx6sx_cpuidle",
+ .owner = THIS_MODULE,
+ .states = {
+ /* WFI */
+ ARM_CPUIDLE_WFI_STATE,
+ /* WAIT */
+ {
+ .exit_latency = 50,
+ .target_residency = 75,
+ .flags = CPUIDLE_FLAG_TIMER_STOP,
+ .enter = imx6sx_enter_wait,
+ .name = "WAIT",
+ .desc = "Clock off",
+ },
+ /* WAIT + ARM power off */
+ {
+ /*
+ * ARM gating 31us * 5 + RBC clear 65us
+ * and some margin for SW execution, here set it
+ * to 300us.
+ */
+ .exit_latency = 300,
+ .target_residency = 500,
+ .flags = CPUIDLE_FLAG_TIMER_STOP,
+ .enter = imx6sx_enter_wait,
+ .name = "LOW-POWER-IDLE",
+ .desc = "ARM power off",
+ },
+ },
+ .state_count = 3,
+ .safe_state_index = 0,
+};
+
+int __init imx6sx_cpuidle_init(void)
+{
+ imx6_set_int_mem_clk_lpm(true);
+ imx6_enable_rbc(false);
+ imx_gpc_set_l2_mem_power_in_lpm(false);
+ /*
+ * set ARM power up/down timing to the fastest,
+ * sw2iso and sw can be set to one 32K cycle = 31us
+ * except for power up sw2iso which need to be
+ * larger than LDO ramp up time.
+ */
+ imx_gpc_set_arm_power_up_timing(cpu_is_imx6sx() ? 0xf : 0x2, 1);
+ imx_gpc_set_arm_power_down_timing(1, 1);
+
+ return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
+}