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|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Low level suspend code for AM43XX SoCs
*
* Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
* Dave Gerlach, Vaibhav Bedia
*/
#include <generated/ti-pm-asm-offsets.h>
#include <linux/linkage.h>
#include <linux/ti-emif-sram.h>
#include <linux/platform_data/pm33xx.h>
#include <asm/assembler.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/memory.h>
#include "cm33xx.h"
#include "common.h"
#include "iomap.h"
#include "omap-secure.h"
#include "omap44xx.h"
#include "prm33xx.h"
#include "prcm43xx.h"
/* replicated define because linux/bitops.h cannot be included in assembly */
#define BIT(nr) (1 << (nr))
#define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED 0x00030000
#define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE 0x0003
#define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE 0x0002
#define AM43XX_EMIF_POWEROFF_ENABLE 0x1
#define AM43XX_EMIF_POWEROFF_DISABLE 0x0
#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP 0x1
#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO 0x3
#define AM43XX_CM_BASE 0x44DF0000
#define AM43XX_CM_REGADDR(inst, reg) \
AM33XX_L4_WK_IO_ADDRESS(AM43XX_CM_BASE + (inst) + (reg))
#define AM43XX_CM_MPU_CLKSTCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
AM43XX_CM_MPU_MPU_CDOFFS)
#define AM43XX_CM_MPU_MPU_CLKCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
AM43XX_CM_MPU_MPU_CLKCTRL_OFFSET)
#define AM43XX_CM_PER_EMIF_CLKCTRL AM43XX_CM_REGADDR(AM43XX_CM_PER_INST, \
AM43XX_CM_PER_EMIF_CLKCTRL_OFFSET)
#define AM43XX_PRM_EMIF_CTRL_OFFSET 0x0030
#define RTC_SECONDS_REG 0x0
#define RTC_PMIC_REG 0x98
#define RTC_PMIC_POWER_EN BIT(16)
#define RTC_PMIC_EXT_WAKEUP_STS BIT(12)
#define RTC_PMIC_EXT_WAKEUP_POL BIT(4)
#define RTC_PMIC_EXT_WAKEUP_EN BIT(0)
.arm
.arch armv7-a
.arch_extension sec
.align 3
ENTRY(am43xx_do_wfi)
stmfd sp!, {r4 - r11, lr} @ save registers on stack
/* Save wfi_flags arg to data space */
mov r4, r0
adr r3, am43xx_pm_ro_sram_data
ldr r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
str r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
#ifdef CONFIG_CACHE_L2X0
/* Retrieve l2 cache virt address BEFORE we shut off EMIF */
ldr r1, get_l2cache_base
blx r1
mov r8, r0
#endif
/* Only flush cache is we know we are losing MPU context */
tst r4, #WFI_FLAG_FLUSH_CACHE
beq cache_skip_flush
/*
* Flush all data from the L1 and L2 data cache before disabling
* SCTLR.C bit.
*/
ldr r1, kernel_flush
blx r1
/*
* Clear the SCTLR.C bit to prevent further data cache
* allocation. Clearing SCTLR.C would make all the data accesses
* strongly ordered and would not hit the cache.
*/
mrc p15, 0, r0, c1, c0, 0
bic r0, r0, #(1 << 2) @ Disable the C bit
mcr p15, 0, r0, c1, c0, 0
isb
dsb
/*
* Invalidate L1 and L2 data cache.
*/
ldr r1, kernel_flush
blx r1
#ifdef CONFIG_CACHE_L2X0
/*
* Clean and invalidate the L2 cache.
*/
#ifdef CONFIG_PL310_ERRATA_727915
mov r0, #0x03
mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
dsb
smc #0
dsb
#endif
mov r0, r8
adr r4, am43xx_pm_ro_sram_data
ldr r3, [r4, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
mov r2, r0
ldr r0, [r2, #L2X0_AUX_CTRL]
str r0, [r3, #AMX3_PM_L2_AUX_CTRL_VAL_OFFSET]
ldr r0, [r2, #L310_PREFETCH_CTRL]
str r0, [r3, #AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET]
ldr r0, l2_val
str r0, [r2, #L2X0_CLEAN_INV_WAY]
wait:
ldr r0, [r2, #L2X0_CLEAN_INV_WAY]
ldr r1, l2_val
ands r0, r0, r1
bne wait
#ifdef CONFIG_PL310_ERRATA_727915
mov r0, #0x00
mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
dsb
smc #0
dsb
#endif
l2x_sync:
mov r0, r8
mov r2, r0
mov r0, #0x0
str r0, [r2, #L2X0_CACHE_SYNC]
sync:
ldr r0, [r2, #L2X0_CACHE_SYNC]
ands r0, r0, #0x1
bne sync
#endif
/* Restore wfi_flags */
adr r3, am43xx_pm_ro_sram_data
ldr r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
ldr r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
cache_skip_flush:
/*
* If we are trying to enter RTC+DDR mode we must perform
* a read from the rtc address space to ensure translation
* presence in the TLB to avoid page table walk after DDR
* is unavailable.
*/
tst r4, #WFI_FLAG_RTC_ONLY
beq skip_rtc_va_refresh
adr r3, am43xx_pm_ro_sram_data
ldr r1, [r3, #AMX3_PM_RTC_BASE_VIRT_OFFSET]
ldr r0, [r1]
skip_rtc_va_refresh:
/* Check if we want self refresh */
tst r4, #WFI_FLAG_SELF_REFRESH
beq emif_skip_enter_sr
adr r9, am43xx_emif_sram_table
ldr r3, [r9, #EMIF_PM_ENTER_SR_OFFSET]
blx r3
emif_skip_enter_sr:
/* Only necessary if PER is losing context */
tst r4, #WFI_FLAG_SAVE_EMIF
beq emif_skip_save
ldr r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET]
blx r3
emif_skip_save:
/* Only can disable EMIF if we have entered self refresh */
tst r4, #WFI_FLAG_SELF_REFRESH
beq emif_skip_disable
/* Disable EMIF */
ldr r1, am43xx_virt_emif_clkctrl
ldr r2, [r1]
bic r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
str r2, [r1]
wait_emif_disable:
ldr r2, [r1]
mov r3, #AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED
cmp r2, r3
bne wait_emif_disable
emif_skip_disable:
tst r4, #WFI_FLAG_RTC_ONLY
beq skip_rtc_only
adr r3, am43xx_pm_ro_sram_data
ldr r1, [r3, #AMX3_PM_RTC_BASE_VIRT_OFFSET]
ldr r0, [r1, #RTC_PMIC_REG]
orr r0, r0, #RTC_PMIC_POWER_EN
orr r0, r0, #RTC_PMIC_EXT_WAKEUP_STS
orr r0, r0, #RTC_PMIC_EXT_WAKEUP_EN
orr r0, r0, #RTC_PMIC_EXT_WAKEUP_POL
str r0, [r1, #RTC_PMIC_REG]
ldr r0, [r1, #RTC_PMIC_REG]
/* Wait for 2 seconds to lose power */
mov r3, #2
ldr r2, [r1, #RTC_SECONDS_REG]
rtc_loop:
ldr r0, [r1, #RTC_SECONDS_REG]
cmp r0, r2
beq rtc_loop
mov r2, r0
subs r3, r3, #1
bne rtc_loop
b re_enable_emif
skip_rtc_only:
tst r4, #WFI_FLAG_WAKE_M3
beq wkup_m3_skip
/*
* For the MPU WFI to be registered as an interrupt
* to WKUP_M3, MPU_CLKCTRL.MODULEMODE needs to be set
* to DISABLED
*/
ldr r1, am43xx_virt_mpu_clkctrl
ldr r2, [r1]
bic r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
str r2, [r1]
/*
* Put MPU CLKDM to SW_SLEEP
*/
ldr r1, am43xx_virt_mpu_clkstctrl
mov r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP
str r2, [r1]
wkup_m3_skip:
/*
* Execute a barrier instruction to ensure that all cache,
* TLB and branch predictor maintenance operations issued
* have completed.
*/
dsb
dmb
/*
* Execute a WFI instruction and wait until the
* STANDBYWFI output is asserted to indicate that the
* CPU is in idle and low power state. CPU can specualatively
* prefetch the instructions so add NOPs after WFI. Sixteen
* NOPs as per Cortex-A9 pipeline.
*/
wfi
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
/* We come here in case of an abort due to a late interrupt */
ldr r1, am43xx_virt_mpu_clkstctrl
mov r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
str r2, [r1]
/* Set MPU_CLKCTRL.MODULEMODE back to ENABLE */
ldr r1, am43xx_virt_mpu_clkctrl
mov r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
str r2, [r1]
re_enable_emif:
/* Re-enable EMIF */
ldr r1, am43xx_virt_emif_clkctrl
mov r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
str r2, [r1]
wait_emif_enable:
ldr r3, [r1]
cmp r2, r3
bne wait_emif_enable
tst r4, #WFI_FLAG_FLUSH_CACHE
beq cache_skip_restore
/*
* Set SCTLR.C bit to allow data cache allocation
*/
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #(1 << 2) @ Enable the C bit
mcr p15, 0, r0, c1, c0, 0
isb
cache_skip_restore:
/* Only necessary if PER is losing context */
tst r4, #WFI_FLAG_SELF_REFRESH
beq emif_skip_exit_sr_abt
adr r9, am43xx_emif_sram_table
ldr r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
blx r1
emif_skip_exit_sr_abt:
/* Let the suspend code know about the abort */
mov r0, #1
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
ENDPROC(am43xx_do_wfi)
.align
ENTRY(am43xx_resume_offset)
.word . - am43xx_do_wfi
ENTRY(am43xx_resume_from_deep_sleep)
/* Set MPU CLKSTCTRL to HW AUTO so that CPUidle works properly */
ldr r1, am43xx_virt_mpu_clkstctrl
mov r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
str r2, [r1]
/* For AM43xx, use EMIF power down until context is restored */
ldr r2, am43xx_phys_emif_poweroff
mov r1, #AM43XX_EMIF_POWEROFF_ENABLE
str r1, [r2, #0x0]
/* Re-enable EMIF */
ldr r1
|