/*
* Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/linkage.h>
#define M4IF_MCR0_OFFSET (0x008C)
#define M4IF_MCR0_FDVFS (0x1 << 11)
#define M4IF_MCR0_FDVACK (0x1 << 27)
.align 3
/*
* ==================== low level suspend ====================
*
* On entry
* r0: pm_info structure address;
*
* suspend ocram space layout:
* ======================== high address ======================
* .
* .
* .
* ^
* ^
* ^
* imx53_suspend code
* PM_INFO structure(imx53_suspend_info)
* ======================== low address =======================
*/
/* Offsets of members of struct imx53_suspend_info */
#define SUSPEND_INFO_MX53_M4IF_V_OFFSET 0x0
#define SUSPEND_INFO_MX53_IOMUXC_V_OFFSET 0x4
#define SUSPEND_INFO_MX53_IO_COUNT_OFFSET 0x8
#define SUSPEND_INFO_MX53_IO_STATE_OFFSET 0xc
ENTRY(imx53_suspend)
stmfd sp!, {r4,r5,r6,r7}
/* Save pad config */
ldr r1, [r0, #SUSPEND_INFO_MX53_IO_COUNT_OFFSET]
cmp r1, #0
beq skip_pad_conf_1
add r2, r0, #SUSPEND_INFO_MX53_IO_STATE_OFFSET
ldr r3, [r0, #SUSPEND_INFO_MX53_IOMUXC_V_OFFSET]
1:
ldr r5, [r2], #12 /* IOMUXC register offset */
ldr r6, [r3, r5] /* current value */
str r6, [r2], #4 /* save area */
subs r1, r1, #1
bne 1b
skip_pad_conf_1:
/* Set FDVFS bit of M4IF_MCR0 to request DDR to enter self-refresh */
ldr r1, [r0, #SUSPEND_INFO_MX53_M4IF_V_OFFSET]
ldr r2,[r1, #M4IF_MCR0_OFFSET]
orr r2, r2, #M4IF_MCR0_FDVFS
str r2,[r1, #M4IF_MCR0_OFFSET]
/* Poll FDVACK bit of M4IF_MCR to wait for DDR to enter self-refresh */
wait_sr_ack:
ldr r2,[r1, #M4IF_MCR0_OFFSET]
ands r2, r2, #M4IF_MCR0_FDVACK
beq wait_sr_ack
/* Set pad config */
ldr r1, [r0, #SUSPEND_INFO_MX53_IO_COUNT_OFFSET]
cmp r1, #0
beq skip_pad_conf_2
add r2, r0, #SUSPEND_INFO_MX53_IO_STATE_OFFSET
ldr r3, [r0, #SUSPEND_INFO_MX53_IOMUXC_V_OFFSET]
2:
ldr r5, [r2], #4 /* IOMUXC register offset */
ldr r6, [r2], #4 /* clear */
ldr r7, [r3, r5]
bic r7, r7, r6
ldr r6, [r2], #8 /* set */
orr r7, r7, r6
str r7, [r3, r5]
subs r1, r1, #1
bne 2b
skip_pad_conf_2:
/* Zzz, enter stop mode */
wfi
nop
nop
nop
nop
/* Restore pad config */
ldr r1, [r0, #SUSPEND_INFO_MX53_IO_COUNT_OFFSET]
cmp r1, #0
beq skip_pad_conf_3
add r2, r0, #SUSPEND_INFO_MX53_IO_STATE_OFFSET
ldr r3, [r0, #SUSPEND_INFO_MX53_IOMUXC_V_OFFSET]
3:
ldr r5, [r2], #12 /* IOMUXC register offset */
ldr r6, [r2], #4 /* saved value */
str r6, [r3, r5]
subs r1, r1, #1
bne 3b
skip_pad_conf_3:
/* Clear FDVFS bit of M4IF_MCR0 to request DDR to exit self-refresh */
ldr r1, [r0, #SUSPEND_INFO_MX53_M4IF_V_OFFSET]
ldr r2,[r1, #M4IF_MCR0_OFFSET]
bic r2, r2, #M4IF_MCR0_FDVFS
str r2,[r1, #M4IF_MCR0_OFFSET]
/* Poll FDVACK bit of M4IF_MCR to wait for DDR to exit self-refresh */
wait_ar_ack:
ldr r2,[r1, #M4IF_MCR0_OFFSET]
ands r2, r2, #M4IF_MCR0_FDVACK
bne wait_ar_ack
/* Restore registers */
ldmfd sp!, {r4,r5,r6,r7}
mov pc, lr
ENDPROC(imx53_suspend)
ENTRY(imx53_suspend_sz)
.word . - imx53_suspend
