linux/arch/sh/kernel/cpu/shmobile/sleep.S
Magnus Damm 309214af53 sh: rework SuperH Mobile sleep code exception handling
This patch updates the exception handling in the sleep code
for SuperH Mobile. With the patch applied the sleep code
always rewrites the VBR and resumes from the exception vector,
re-initializes hardware and jumps straight to the original
interrupt vector.

Tested on sh7722 and sh7724 with "Sleep Mode", "Sleep Mode + SF"
and "Software Standby Mode + SF" with CONFIG_SUSPEND.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-18 10:17:29 +09:00

247 lines
4.3 KiB
ArmAsm

/*
* 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>
/*
* Kernel mode register usage, see entry.S:
* k0 scratch
* k1 scratch
* k4 scratch
*/
#define k0 r0
#define k1 r1
#define k4 r4
/* 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)
/* save original vbr */
stc vbr, r1
mova saved_vbr, r0
mov.l r1, @r0
/* point vbr to our on-chip memory page */
ldc r5, vbr
/* save return address */
mova saved_spc, r0
sts pr, r5
mov.l r5, @r0
/* save sr */
mova saved_sr, r0
stc sr, r5
mov.l r5, @r0
/* save mode flags */
mova saved_mode, r0
mov.l r4, @r0
/* put mode flags in r0 */
mov r4, r0
tst #SUSP_SH_SF, r0
bt skip_set_sf
#ifdef CONFIG_CPU_SUBTYPE_SH7724
/* DBSC: put memory in self-refresh mode */
mov.l dben_reg, r4
mov.l dben_data0, r1
mov.l r1, @r4
mov.l dbrfpdn0_reg, r4
mov.l dbrfpdn0_data0, r1
mov.l r1, @r4
mov.l dbcmdcnt_reg, r4
mov.l dbcmdcnt_data0, r1
mov.l r1, @r4
mov.l dbcmdcnt_reg, r4
mov.l dbcmdcnt_data1, r1
mov.l r1, @r4
mov.l dbrfpdn0_reg, r4
mov.l dbrfpdn0_data1, r1
mov.l r1, @r4
#else
/* SBSC: 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
#endif
skip_set_sf:
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 force_sleep
/* set mode to "u-standby mode" */
bra do_sleep
mov #0x10, r1
force_sleep:
/* set mode to "sleep mode" */
mov #0x00, r1
do_sleep:
/* setup and enter selected standby mode */
mov.l 5f, r4
mov.l r1, @r4
again:
sleep
bra again
nop
restore_jump_vbr:
/* setup spc with return address to c code */
mov.l saved_spc, k0
ldc k0, spc
/* restore vbr */
mov.l saved_vbr, k0
ldc k0, vbr
/* setup ssr with saved sr */
mov.l saved_sr, k0
ldc k0, ssr
/* get mode flags */
mov.l saved_mode, k0
done_sleep:
/* reset standby mode to sleep mode */
mov.l 5f, k4
mov #0x00, k1
mov.l k1, @k4
tst #SUSP_SH_SF, k0
bt skip_restore_sf
#ifdef CONFIG_CPU_SUBTYPE_SH7724
/* DBSC: put memory in auto-refresh mode */
mov.l dbrfpdn0_reg, k4
mov.l dbrfpdn0_data0, k1
mov.l k1, @k4
nop /* sleep 140 ns */
nop
nop
nop
mov.l dbcmdcnt_reg, k4
mov.l dbcmdcnt_data0, k1
mov.l k1, @k4
mov.l dbcmdcnt_reg, k4
mov.l dbcmdcnt_data1, k1
mov.l k1, @k4
mov.l dben_reg, k4
mov.l dben_data1, k1
mov.l k1, @k4
mov.l dbrfpdn0_reg, k4
mov.l dbrfpdn0_data2, k1
mov.l k1, @k4
#else
/* SBSC: set auto-refresh mode */
mov.l 1f, k4
mov.l @k4, k0
mov.l 4f, k1
and k1, k0
mov.l k0, @k4
mov.l 6f, k4
mov.l 8f, k0
mov.l @k4, k1
mov #-1, k4
add k4, k1
or k1, k0
mov.l 7f, k1
mov.l k0, @k1
#endif
skip_restore_sf:
/* jump to vbr vector */
mov.l saved_vbr, k0
mov.l offset_vbr, k4
add k4, k0
jmp @k0
nop
.balign 4
saved_mode: .long 0
saved_spc: .long 0
saved_sr: .long 0
saved_vbr: .long 0
offset_vbr: .long 0x600
#ifdef CONFIG_CPU_SUBTYPE_SH7724
dben_reg: .long 0xfd000010 /* DBEN */
dben_data0: .long 0
dben_data1: .long 1
dbrfpdn0_reg: .long 0xfd000040 /* DBRFPDN0 */
dbrfpdn0_data0: .long 0
dbrfpdn0_data1: .long 1
dbrfpdn0_data2: .long 0x00010000
dbcmdcnt_reg: .long 0xfd000014 /* DBCMDCNT */
dbcmdcnt_data0: .long 2
dbcmdcnt_data1: .long 4
#else
1: .long 0xfe400008 /* SDCR0 */
2: .long 0x00000400
3: .long 0xffff7fff
4: .long 0xfffffbff
#endif
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
bra restore_jump_vbr
nop
sh_mobile_standby_end:
ENTRY(sh_mobile_standby_size)
.long sh_mobile_standby_end - sh_mobile_standby