imx: mx7: add system suspend/resume support
This patch adds system suspend/resume support,
when linux kernel enters deep sleep mode, SoC will go
into below mode:
- CA7 platform goes into STOP mode;
- SoC goes into DSM mode;
- DDR goes into self-refresh mode;
- CPU0/SCU will be powered down.
When wake up event arrives:
- SoC DSM mdoe exits;
- CA7 platform exit STOP mode, SCU/CPU0 power up;
- Invalidate L1 cache;
- DDR exit self-refresh mode;
- Do secure monitor mode related initialization;
- Jump to linux kernel resume entry.
Belwo is the log of 1 iteration of system suspend/resume:
[ 338.824862] PM: suspend entry (deep)
[ 338.828853] PM: Syncing filesystems ... done.
[ 338.834433] Freezing user space processes ... (elapsed 0.001 seconds) done.
[ 338.842939] OOM killer disabled.
[ 338.846182] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[ 338.869717] PM: suspend devices took 0.010 seconds
[ 338.877846] Disabling non-boot CPUs ...
[ 338.960301] Retrying again to check for CPU kill
[ 338.964953] CPU1 killed.
[ 338.968104] Enabling non-boot CPUs ...
[ 338.973598] CPU1 is up
[ 339.267155] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
[ 339.275833] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
[ 339.284158] mmc1: queuing unknown CIS tuple 0x80 (6 bytes)
[ 339.385065] PM: resume devices took 0.400 seconds
[ 339.389836] OOM killer enabled.
[ 339.392986] Restarting tasks ... done.
[ 339.398990] PM: suspend exit
The resume entry function has to initialize stack pointer before calling
C code, otherwise there will be an external abort occur, in additional,
invalidate L1 cache must be done in secure section as well, so this
patch also adds assembly code back and keep it as simple as possible.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Stefan Agner <stefan@agner.ch>
Tested-by: Stefan Agner <stefan@agner.ch>
diff --git a/arch/arm/mach-imx/mx7/psci-suspend.S b/arch/arm/mach-imx/mx7/psci-suspend.S
new file mode 100644
index 0000000..a21403f
--- /dev/null
+++ b/arch/arm/mach-imx/mx7/psci-suspend.S
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2018 NXP
+ */
+
+#include <config.h>
+#include <linux/linkage.h>
+
+#include <asm/armv7.h>
+#include <asm/psci.h>
+
+ .pushsection ._secure.text, "ax"
+
+ .arch_extension sec
+
+.globl v7_invalidate_l1
+v7_invalidate_l1:
+ mov r0, #0
+ mcr p15, 2, r0, c0, c0, 0
+ mrc p15, 1, r0, c0, c0, 0
+
+ movw r1, #0x7fff
+ and r2, r1, r0, lsr #13
+
+ movw r1, #0x3ff
+
+ and r3, r1, r0, lsr #3 @ NumWays - 1
+ add r2, r2, #1 @ NumSets
+
+ and r0, r0, #0x7
+ add r0, r0, #4 @ SetShift
+
+ clz r1, r3 @ WayShift
+ add r4, r3, #1 @ NumWays
+1:
+ sub r2, r2, #1 @ NumSets--
+ mov r3, r4 @ Temp = NumWays
+2:
+ subs r3, r3, #1 @ Temp--
+ mov r5, r3, lsl r1
+ mov r6, r2, lsl r0
+ orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
+ mcr p15, 0, r5, c7, c6, 2
+ bgt 2b
+ cmp r2, #0
+ bgt 1b
+ dsb st
+ isb
+ mov pc, lr
+
+.globl psci_system_resume
+psci_system_resume:
+ mov sp, r0
+
+ /* invalidate L1 I-cache first */
+ mov r6, #0x0
+ mcr p15, 0, r6, c7, c5, 0
+ mcr p15, 0, r6, c7, c5, 6
+ /* enable the Icache and branch prediction */
+ mov r6, #0x1800
+ mcr p15, 0, r6, c1, c0, 0
+ isb
+
+ bl v7_invalidate_l1
+ b imx_system_resume
+
+ .popsection