diff options
Diffstat (limited to 'arch/arm/mach-imx/suspend-imx6.S')
| -rw-r--r-- | arch/arm/mach-imx/suspend-imx6.S | 336 |
1 files changed, 336 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 000000000..99d2e2960 --- /dev/null +++ b/arch/arm/mach-imx/suspend-imx6.S @@ -0,0 +1,336 @@ +/* + * 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/assembler.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_DDR_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 + .arm + + .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] + teq r11, #0 + beq 6f + mov r6, #0x0 + str r6, [r11, #L2X0_CACHE_SYNC] +1: + ldr r6, [r11, #L2X0_CACHE_SYNC] + ands r6, r6, #0x1 + bne 1b +6: +#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, #IMX_DDR_TYPE_LPDDR2 + 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_DDR_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] + ldr r11, [r0, #PM_INFO_MX6Q_IOMUXC_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 + /* LPDDR2's last 3 IOs need special setting */ + cmp r3, #IMX_DDR_TYPE_LPDDR2 + 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, #IMX_DDR_TYPE_LPDDR2 + 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 */ + ret 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_DDR_TYPE_OFFSET] + mov r5, #0x1 + resume_mmdc + + ret lr +ENDPROC(imx6_suspend) |