ARM: imx: add cpuidle support for i.mx6sl

Add cpuidle support for i.MX6SL, currently only support
two cpuidle levels(ARM wfi and WAIT mode), and add software
workaround for WAIT mode errata as below:

ERR005311 CCM: After exit from WAIT mode, unwanted interrupt(s) taken
          during WAIT mode entry process could cause cache memory
          corruption.

Software workaround:
    To prevent this issue from occurring, software should ensure that
the ARM to IPG clock ratio is less than 12:5 (that is < 2.4x), before
entering WAIT mode.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/cpuidle.h b/arch/arm/mach-imx/cpuidle.h
index 786f98ecc145..24e33670417c 100644
--- a/arch/arm/mach-imx/cpuidle.h
+++ b/arch/arm/mach-imx/cpuidle.h
@@ -13,6 +13,7 @@
 #ifdef CONFIG_CPU_IDLE
 extern int imx5_cpuidle_init(void);
 extern int imx6q_cpuidle_init(void);
+extern int imx6sl_cpuidle_init(void);
 #else
 static inline int imx5_cpuidle_init(void)
 {
@@ -22,4 +23,8 @@ static inline int imx6q_cpuidle_init(void)
 {
         return 0;
 }
+static inline int imx6sl_cpuidle_init(void)
+{
+        return 0;
+}
 #endif