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-rw-r--r--arch/arm/mach-imx/suspend-imx53.S139
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/suspend-imx53.S b/arch/arm/mach-imx/suspend-imx53.S
new file mode 100644
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--- /dev/null
+++ b/arch/arm/mach-imx/suspend-imx53.S
@@ -0,0 +1,139 @@
+/*
+ * 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