sh: SuperH Mobile suspend support

This patch contains CONFIG_SUSPEND support to the SuperH
architecture. If enabled, SuperH Mobile processors will
register their suspend callbacks during boot.

To suspend, use "echo mem > /sys/power/state". To allow
wakeup, make sure "/sys/device/platform/../power/wakeup"
contains "enabled". Additional per-device driver patches
are most likely needed.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 125 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/sh4a/sleep-sh_mobile.S b/arch/sh/kernel/cpu/sh4a/sleep-sh_mobile.S
new file mode 100644
index 00000000000..5d888ef53d8
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4a/sleep-sh_mobile.S
@@ -0,0 +1,125 @@
+/*
+ * arch/sh/kernel/cpu/sh4a/sleep-sh_mobile.S
+ *
+ * Sleep mode and Standby modes support for SuperH Mobile
+ *
+ *  Copyright (C) 2009 Magnus Damm
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/sys.h>
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/suspend.h>
+
+/* manage self-refresh and enter standby mode.
+ * this code will be copied to on-chip memory and executed from there.
+ */
+
+	.balign 	4096,0,4096
+ENTRY(sh_mobile_standby)
+	mov	r4, r0
+
+	tst	#SUSP_SH_SF, r0
+	bt	skip_set_sf
+
+	/* SDRAM: disable power down and put in self-refresh mode */
+	mov.l	1f, r4
+	mov.l	2f, r1
+	mov.l	@r4, r2
+	or	r1, r2
+	mov.l   3f, r3
+	and	r3, r2
+	mov.l	r2, @r4
+
+skip_set_sf:
+	tst	#SUSP_SH_SLEEP, r0
+	bt	test_standby
+
+	/* set mode to "sleep mode" */
+	bra	do_sleep
+	 mov	#0x00, r1
+
+test_standby:
+	tst	#SUSP_SH_STANDBY, r0
+	bt	test_rstandby
+
+	/* set mode to "software standby mode" */
+	bra	do_sleep
+	 mov	#0x80, r1
+
+test_rstandby:
+	tst	#SUSP_SH_RSTANDBY, r0
+	bt	test_ustandby
+
+	/* set mode to "r-standby mode" */
+	bra	do_sleep
+	 mov	#0x20, r1
+
+test_ustandby:
+	tst	#SUSP_SH_USTANDBY, r0
+	bt	done_sleep
+
+	/* set mode to "u-standby mode" */
+	mov	#0x10, r1
+
+	/* fall-through */
+
+do_sleep:
+	/* setup and enter selected standby mode */
+	mov.l	5f, r4
+	mov.l	r1, @r4
+	sleep
+
+done_sleep:
+	/* reset standby mode to sleep mode */
+	mov.l	5f, r4
+	mov	#0x00, r1
+	mov.l	r1, @r4
+
+	tst	#SUSP_SH_SF, r0
+	bt	skip_restore_sf
+
+	/* SDRAM: set auto-refresh mode */
+	mov.l	1f, r4
+	mov.l	@r4, r2
+	mov.l   4f, r3
+	and	r3, r2
+	mov.l	r2, @r4
+	mov.l	6f, r4
+	mov.l	7f, r1
+	mov.l	8f, r2
+	mov.l	@r4, r3
+	mov	#-1, r4
+	add	r4, r3
+	or	r2, r3
+	mov.l	r3, @r1
+skip_restore_sf:
+	rts
+	 nop
+
+	.balign 4
+1:	.long	0xfe400008 /* SDCR0 */
+2:	.long	0x00000400
+3:	.long	0xffff7fff
+4:	.long	0xfffffbff
+5:	.long	0xa4150020 /* STBCR */
+6:	.long   0xfe40001c /* RTCOR */
+7:	.long   0xfe400018 /* RTCNT */
+8:	.long   0xa55a0000
+
+/* interrupt vector @ 0x600 */
+	.balign 	0x400,0,0x400
+	.long	0xdeadbeef
+	.balign 	0x200,0,0x200
+	/* sh7722 will end up here in sleep mode */
+	rte
+	 nop
+sh_mobile_standby_end:
+
+ENTRY(sh_mobile_standby_size)
+	.long sh_mobile_standby_end - sh_mobile_standby