[PATCH V3] ARM: imx: add cpuidle support for i.mx6ul

[Anson Huang]

This patch adds cpuidle support for i.MX6UL,
it shares cpuidle driver with i.MX6SX, total
3 levels of cpuidle are supported as below:

1. ARM WFI;
2. SOC in WAIT mode;
3. SOC in WAIT mode + ARM power off.

Signed-off-by: Anson Huang <b20788 at freescale.com>
---
I am NOT sure if using cpu_is_xxx() here to distinguish i.MX6UL
from i.MX6SX is good enough, as I saw many other patches
are trying to avoid using such cpu_is_xxx() API.

Obviously we have many other ways to identify if the ARM core
is a Cortex-A9 or Cortex-A7, they have different L2 cache implemented,
so cache operation is different.

Please advise if you have better idea about this point, thanks!

 arch/arm/mach-imx/cpuidle-imx6sx.c | 8 +++++++-
 arch/arm/mach-imx/mach-imx6ul.c    | 9 +++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
index 3c6672b..e1ce40c 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ * Copyright (C) 2014-2015 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
@@ -9,14 +9,20 @@
 #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)
 {
+	/* flush internal L2 cache if necessary */
+	if (cpu_is_imx6ul())
+		flush_cache_all();
+
 	cpu_do_idle();
 
 	return 0;
diff --git a/arch/arm/mach-imx/mach-imx6ul.c b/arch/arm/mach-imx/mach-imx6ul.c
index f206506..3fe37ab 100644
--- a/arch/arm/mach-imx/mach-imx6ul.c
+++ b/arch/arm/mach-imx/mach-imx6ul.c
@@ -11,6 +11,7 @@
 #include <asm/mach/map.h>
 
 #include "common.h"
+#include "cpuidle.h"
 
 static void __init imx6ul_init_machine(void)
 {
@@ -29,6 +30,13 @@ static void __init imx6ul_init_irq(void)
 	imx_init_revision_from_anatop();
 	imx_src_init();
 	irqchip_init();
+	imx6_pm_ccm_init("fsl,imx6ul-ccm");
+}
+
+static void __init imx6ul_init_late(void)
+{
+	/* share cpuidle driver with i.MX6SX */
+	imx6sx_cpuidle_init();
 }
 
 static const char *imx6ul_dt_compat[] __initconst = {
@@ -40,4 +48,5 @@ DT_MACHINE_START(IMX6UL, "Freescale i.MX6 Ultralite (Device Tree)")
 	.init_irq	= imx6ul_init_irq,
 	.init_machine	= imx6ul_init_machine,
 	.dt_compat	= imx6ul_dt_compat,
+	.init_late	= imx6ul_init_late,
 MACHINE_END
-- 
1.9.1