1 files changed, 361 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S
new file mode 100644
index 000000000000..20048ff05739
--- /dev/null
+++ b/arch/arm/mach-imx/suspend-imx6.S
@@ -0,0 +1,361 @@
+/*
+ * Copyright 2014 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>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
+#include "hardware.h"
+
+/*
+ * ==================== low level suspend ====================
+ *
+ * Better to follow below rules to use ARM registers:
+ * r0: pm_info structure address;
+ * r1 ~ r4: for saving pm_info members;
+ * r5 ~ r10: free registers;
+ * r11: io base address.
+ *
+ * suspend ocram space layout:
+ * ======================== high address ======================
+ *                              .
+ *                              .
+ *                              .
+ *                              ^
+ *                              ^
+ *                              ^
+ *                      imx6_suspend code
+ *              PM_INFO structure(imx6_cpu_pm_info)
+ * ======================== low address =======================
+ */
+
+/*
+ * Below offsets are based on struct imx6_cpu_pm_info
+ * which defined in arch/arm/mach-imx/pm-imx6q.c, this
+ * structure contains necessary pm info for low level
+ * suspend related code.
+ */
+#define PM_INFO_PBASE_OFFSET                    0x0
+#define PM_INFO_RESUME_ADDR_OFFSET              0x4
+#define PM_INFO_CPU_TYPE_OFFSET                 0x8
+#define PM_INFO_PM_INFO_SIZE_OFFSET             0xC
+#define PM_INFO_MX6Q_MMDC_P_OFFSET              0x10
+#define PM_INFO_MX6Q_MMDC_V_OFFSET              0x14
+#define PM_INFO_MX6Q_SRC_P_OFFSET               0x18
+#define PM_INFO_MX6Q_SRC_V_OFFSET               0x1C
+#define PM_INFO_MX6Q_IOMUXC_P_OFFSET            0x20
+#define PM_INFO_MX6Q_IOMUXC_V_OFFSET            0x24
+#define PM_INFO_MX6Q_CCM_P_OFFSET               0x28
+#define PM_INFO_MX6Q_CCM_V_OFFSET               0x2C
+#define PM_INFO_MX6Q_GPC_P_OFFSET               0x30
+#define PM_INFO_MX6Q_GPC_V_OFFSET               0x34
+#define PM_INFO_MX6Q_L2_P_OFFSET                0x38
+#define PM_INFO_MX6Q_L2_V_OFFSET                0x3C
+#define PM_INFO_MMDC_IO_NUM_OFFSET              0x40
+#define PM_INFO_MMDC_IO_VAL_OFFSET              0x44
+
+#define MX6Q_SRC_GPR1   0x20
+#define MX6Q_SRC_GPR2   0x24
+#define MX6Q_MMDC_MAPSR 0x404
+#define MX6Q_MMDC_MPDGCTRL0     0x83c
+#define MX6Q_GPC_IMR1   0x08
+#define MX6Q_GPC_IMR2   0x0c
+#define MX6Q_GPC_IMR3   0x10
+#define MX6Q_GPC_IMR4   0x14
+#define MX6Q_CCM_CCR    0x0
+
+        .align 3
+
+        .macro  sync_l2_cache
+
+        /* sync L2 cache to drain L2's buffers to DRAM. */
+#ifdef CONFIG_CACHE_L2X0
+        ldr     r11, [r0, #PM_INFO_MX6Q_L2_V_OFFSET]
+        mov     r6, #0x0
+        str     r6, [r11, #L2X0_CACHE_SYNC]
+1:
+        ldr     r6, [r11, #L2X0_CACHE_SYNC]
+        ands    r6, r6, #0x1
+        bne     1b
+#endif
+
+        .endm
+
+        .macro  resume_mmdc
+
+        /* restore MMDC IO */
+        cmp     r5, #0x0
+        ldreq   r11, [r0, #PM_INFO_MX6Q_IOMUXC_V_OFFSET]
+        ldrne   r11, [r0, #PM_INFO_MX6Q_IOMUXC_P_OFFSET]
+
+        ldr     r6, [r0, #PM_INFO_MMDC_IO_NUM_OFFSET]
+        ldr     r7, =PM_INFO_MMDC_IO_VAL_OFFSET
+        add     r7, r7, r0
+1:
+        ldr     r8, [r7], #0x4
+        ldr     r9, [r7], #0x4
+        str     r9, [r11, r8]
+        subs    r6, r6, #0x1
+        bne     1b
+
+        cmp     r5, #0x0
+        ldreq   r11, [r0, #PM_INFO_MX6Q_MMDC_V_OFFSET]
+        ldrne   r11, [r0, #PM_INFO_MX6Q_MMDC_P_OFFSET]
+
+        cmp     r3, #MXC_CPU_IMX6SL
+        bne     4f
+
+        /* reset read FIFO, RST_RD_FIFO */
+        ldr     r7, =MX6Q_MMDC_MPDGCTRL0
+        ldr     r6, [r11, r7]
+        orr     r6, r6, #(1 << 31)
+        str     r6, [r11, r7]
+2:
+        ldr     r6, [r11, r7]
+        ands    r6, r6, #(1 << 31)
+        bne     2b
+
+        /* reset FIFO a second time */
+        ldr     r6, [r11, r7]
+        orr     r6, r6, #(1 << 31)
+        str     r6, [r11, r7]
+3:
+        ldr     r6, [r11, r7]
+        ands    r6, r6, #(1 << 31)
+        bne     3b
+4:
+        /* let DDR out of self-refresh */
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        bic     r7, r7, #(1 << 21)
+        str     r7, [r11, #MX6Q_MMDC_MAPSR]
+5:
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        ands    r7, r7, #(1 << 25)
+        bne     5b
+
+        /* enable DDR auto power saving */
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        bic     r7, r7, #0x1
+        str     r7, [r11, #MX6Q_MMDC_MAPSR]
+
+        .endm
+
+ENTRY(imx6_suspend)
+        ldr     r1, [r0, #PM_INFO_PBASE_OFFSET]
+        ldr     r2, [r0, #PM_INFO_RESUME_ADDR_OFFSET]
+        ldr     r3, [r0, #PM_INFO_CPU_TYPE_OFFSET]
+        ldr     r4, [r0, #PM_INFO_PM_INFO_SIZE_OFFSET]
+
+        /*
+         * counting the resume address in iram
+         * to set it in SRC register.
+         */
+        ldr     r6, =imx6_suspend
+        ldr     r7, =resume
+        sub     r7, r7, r6
+        add     r8, r1, r4
+        add     r9, r8, r7
+
+        /*
+         * make sure TLB contain the addr we want,
+         * as we will access them after MMDC IO floated.
+         */
+
+        ldr     r11, [r0, #PM_INFO_MX6Q_CCM_V_OFFSET]
+        ldr     r6, [r11, #0x0]
+        ldr     r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
+        ldr     r6, [r11, #0x0]
+
+        /* use r11 to store the IO address */
+        ldr     r11, [r0, #PM_INFO_MX6Q_SRC_V_OFFSET]
+        /* store physical resume addr and pm_info address. */
+        str     r9, [r11, #MX6Q_SRC_GPR1]
+        str     r1, [r11, #MX6Q_SRC_GPR2]
+
+        /* need to sync L2 cache before DSM. */
+        sync_l2_cache
+
+        ldr     r11, [r0, #PM_INFO_MX6Q_MMDC_V_OFFSET]
+        /*
+         * put DDR explicitly into self-refresh and
+         * disable automatic power savings.
+         */
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        orr     r7, r7, #0x1
+        str     r7, [r11, #MX6Q_MMDC_MAPSR]
+
+        /* make the DDR explicitly enter self-refresh. */
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        orr     r7, r7, #(1 << 21)
+        str     r7, [r11, #MX6Q_MMDC_MAPSR]
+
+poll_dvfs_set:
+        ldr     r7, [r11, #MX6Q_MMDC_MAPSR]
+        ands    r7, r7, #(1 << 25)
+        beq     poll_dvfs_set
+
+        ldr     r11, [r0, #PM_INFO_MX6Q_IOMUXC_V_OFFSET]
+        ldr     r6, =0x0
+        ldr     r7, [r0, #PM_INFO_MMDC_IO_NUM_OFFSET]
+        ldr     r8, =PM_INFO_MMDC_IO_VAL_OFFSET
+        add     r8, r8, r0
+        /* i.MX6SL's last 3 IOs need special setting */
+        cmp     r3, #MXC_CPU_IMX6SL
+        subeq   r7, r7, #0x3
+set_mmdc_io_lpm:
+        ldr     r9, [r8], #0x8
+        str     r6, [r11, r9]
+        subs    r7, r7, #0x1
+        bne     set_mmdc_io_lpm
+
+        cmp     r3, #MXC_CPU_IMX6SL
+        bne     set_mmdc_io_lpm_done
+        ldr     r6, =0x1000
+        ldr     r9, [r8], #0x8
+        str     r6, [r11, r9]
+        ldr     r9, [r8], #0x8
+        str     r6, [r11, r9]
+        ldr     r6, =0x80000
+        ldr     r9, [r8]
+        str     r6, [r11, r9]
+set_mmdc_io_lpm_done:
+
+        /*
+         * mask all GPC interrupts before
+         * enabling the RBC counters to
+         * avoid the counter starting too
+         * early if an interupt is already
+         * pending.
+         */
+        ldr     r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
+        ldr     r6, [r11, #MX6Q_GPC_IMR1]
+        ldr     r7, [r11, #MX6Q_GPC_IMR2]
+        ldr     r8, [r11, #MX6Q_GPC_IMR3]
+        ldr     r9, [r11, #MX6Q_GPC_IMR4]
+
+        ldr     r10, =0xffffffff
+        str     r10, [r11, #MX6Q_GPC_IMR1]
+        str     r10, [r11, #MX6Q_GPC_IMR2]
+        str     r10, [r11, #MX6Q_GPC_IMR3]
+        str     r10, [r11, #MX6Q_GPC_IMR4]
+
+        /*
+         * enable the RBC bypass counter here
+         * to hold off the interrupts. RBC counter
+         * = 32 (1ms), Minimum RBC delay should be
+         * 400us for the analog LDOs to power down.
+         */
+        ldr     r11, [r0, #PM_INFO_MX6Q_CCM_V_OFFSET]
+        ldr     r10, [r11, #MX6Q_CCM_CCR]
+        bic     r10, r10, #(0x3f << 21)
+        orr     r10, r10, #(0x20 << 21)
+        str     r10, [r11, #MX6Q_CCM_CCR]
+
+        /* enable the counter. */
+        ldr     r10, [r11, #MX6Q_CCM_CCR]
+        orr     r10, r10, #(0x1 << 27)
+        str     r10, [r11, #MX6Q_CCM_CCR]
+
+        /* unmask all the GPC interrupts. */
+        ldr     r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
+        str     r6, [r11, #MX6Q_GPC_IMR1]
+        str     r7, [r11, #MX6Q_GPC_IMR2]
+        str     r8, [r11, #MX6Q_GPC_IMR3]
+        str     r9, [r11, #MX6Q_GPC_IMR4]
+
+        /*
+         * now delay for a short while (3usec)
+         * ARM is at 1GHz at this point
+         * so a short loop should be enough.
+         * this delay is required to ensure that
+         * the RBC counter can start counting in
+         * case an interrupt is already pending
+         * or in case an interrupt arrives just
+         * as ARM is about to assert DSM_request.
+         */
+        ldr     r6, =2000
+rbc_loop:
+        subs    r6, r6, #0x1
+        bne     rbc_loop
+
+        /* Zzz, enter stop mode */
+        wfi
+        nop
+        nop
+        nop
+        nop
+
+        /*
+         * run to here means there is pending
+         * wakeup source, system should auto
+         * resume, we need to restore MMDC IO first
+         */
+        mov     r5, #0x0
+        resume_mmdc
+
+        /* return to suspend finish */
+        mov     pc, lr
+
+resume:
+        /* 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
+
+        /* get physical resume address from pm_info. */
+        ldr     lr, [r0, #PM_INFO_RESUME_ADDR_OFFSET]
+        /* clear core0's entry and parameter */
+        ldr     r11, [r0, #PM_INFO_MX6Q_SRC_P_OFFSET]
+        mov     r7, #0x0
+        str     r7, [r11, #MX6Q_SRC_GPR1]
+        str     r7, [r11, #MX6Q_SRC_GPR2]
+
+        ldr     r3, [r0, #PM_INFO_CPU_TYPE_OFFSET]
+        mov     r5, #0x1
+        resume_mmdc
+
+        mov     pc, lr
+ENDPROC(imx6_suspend)
+
+/*
+ * The following code must assume it is running from physical address
+ * where absolute virtual addresses to the data section have to be
+ * turned into relative ones.
+ */
+
+#ifdef CONFIG_CACHE_L2X0
+        .macro  pl310_resume
+        adr     r0, l2x0_saved_regs_offset
+        ldr     r2, [r0]
+        add     r2, r2, r0
+        ldr     r0, [r2, #L2X0_R_PHY_BASE]      @ get physical base of l2x0
+        ldr     r1, [r2, #L2X0_R_AUX_CTRL]      @ get aux_ctrl value
+        str     r1, [r0, #L2X0_AUX_CTRL]        @ restore aux_ctrl
+        mov     r1, #0x1
+        str     r1, [r0, #L2X0_CTRL]            @ re-enable L2
+        .endm
+
+l2x0_saved_regs_offset:
+        .word   l2x0_saved_regs - .
+
+#else
+        .macro  pl310_resume
+        .endm
+#endif
+
+ENTRY(v7_cpu_resume)
+        bl      v7_invalidate_l1
+        pl310_resume
+        b       cpu_resume
+ENDPROC(v7_cpu_resume)