[U-Boot] [PATCH V2 3/3] imx: mx7: psci: add system power off support

[Anson Huang]

Add i.MX7 PSCI system power off support, linux
kernel can use "poweroff" command to power off
system via SNVS, PMIC power will be disabled.

Signed-off-by: Anson Huang <Anson.Huang at nxp.com>
---
changes since v1:
	use "bl" instead of "b" as we need the call to return back.
 arch/arm/mach-imx/mx7/psci-mx7.c | 18 ++++++++++++++++++
 arch/arm/mach-imx/mx7/psci.S     |  7 +++++++
 2 files changed, 25 insertions(+)

diff --git a/arch/arm/mach-imx/mx7/psci-mx7.c b/arch/arm/mach-imx/mx7/psci-mx7.c
index 66f6db6..0e515f0 100644
--- a/arch/arm/mach-imx/mx7/psci-mx7.c
+++ b/arch/arm/mach-imx/mx7/psci-mx7.c
@@ -26,6 +26,12 @@
 #define BP_SRC_A7RCR0_A7_CORE_RESET0	0
 #define BP_SRC_A7RCR1_A7_CORE1_ENABLE	1
 
+#define SNVS_LPCR		0x38
+#define BP_SNVS_LPCR_DP_EN	0x20
+#define BP_SNVS_LPCR_TOP	0x40
+
+#define CCM_CCGR_SNVS		0x4250
+
 static inline void imx_gpcv2_set_m_core_pgc(bool enable, u32 offset)
 {
 	writel(enable, GPC_IPS_BASE_ADDR + offset);
@@ -79,3 +85,15 @@ __secure void imx_system_reset(void)
 {
 	writew(1 << 2, WDOG1_BASE_ADDR);
 }
+
+__secure void imx_system_off(void)
+{
+	u32 val;
+
+	/* make sure SNVS clock is enabled */
+	writel(0x3, CCM_BASE_ADDR + CCM_CCGR_SNVS);
+
+	val = readl(SNVS_BASE_ADDR + SNVS_LPCR);
+	val |= BP_SNVS_LPCR_DP_EN | BP_SNVS_LPCR_TOP;
+	writel(val, SNVS_BASE_ADDR + SNVS_LPCR);
+}
diff --git a/arch/arm/mach-imx/mx7/psci.S b/arch/arm/mach-imx/mx7/psci.S
index e23db24..bc2cd8a 100644
--- a/arch/arm/mach-imx/mx7/psci.S
+++ b/arch/arm/mach-imx/mx7/psci.S
@@ -50,4 +50,11 @@ psci_system_reset:
 2: 	wfi
 	b 2b
 
+.globl psci_system_off
+psci_system_off:
+	bl	imx_system_off
+
+3: 	wfi
+	b 3b
+
 	.popsection
-- 
1.9.1