MLK-13441-17 ARM: imx: add cpuidle support for i.mx7ulp

Add i.MX7ULP cpuidle support, 3 levels idle as below:

1. patial stop mode 3;
2. patial stop mode 2;
3. patial stop mode 1.

PSTOP1 - Partial Stop with system and bus clock disabled
PSTOP2 - Partial Stop with system clock disabled and bus clock enabled
PSTOP3 - Partial Stop with system clock enabled and bus clock enabled

All drivers has DMA function need to add pm_qos
API to prevent cpuidle from entering PSTOP 1/2.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/cpuidle-imx7ulp.c b/arch/arm/mach-imx/cpuidle-imx7ulp.c
new file mode 100644
index 000000000000..924a19c16321
--- /dev/null
+++ b/arch/arm/mach-imx/cpuidle-imx7ulp.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2016 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/module.h>
+#include <asm/cpuidle.h>
+
+#include "common.h"
+#include "cpuidle.h"
+#include "hardware.h"
+
+static int imx7ulp_enter_wait(struct cpuidle_device *dev,
+			    struct cpuidle_driver *drv, int index)
+{
+	if (index == 1)
+		imx7ulp_set_lpm(WAIT);
+	else
+		imx7ulp_set_lpm(STOP);
+
+	cpu_do_idle();
+
+	imx7ulp_set_lpm(RUN);
+
+	return index;
+}
+
+static struct cpuidle_driver imx7ulp_cpuidle_driver = {
+	.name = "imx7ulp_cpuidle",
+	.owner = THIS_MODULE,
+	.states = {
+		/* WFI */
+		ARM_CPUIDLE_WFI_STATE,
+		/* WAIT */
+		{
+			.exit_latency = 50,
+			.target_residency = 75,
+			.enter = imx7ulp_enter_wait,
+			.name = "WAIT",
+			.desc = "PSTOP2",
+		},
+		/* STOP */
+		{
+			.exit_latency = 100,
+			.target_residency = 150,
+			.enter = imx7ulp_enter_wait,
+			.name = "STOP",
+			.desc = "PSTOP1",
+		},
+	},
+	.state_count = 3,
+	.safe_state_index = 0,
+};
+
+int __init imx7ulp_cpuidle_init(void)
+{
+	return cpuidle_register(&imx7ulp_cpuidle_driver, NULL);
+}