linux_dsm_epyc7002/arch/arm/mach-at91/pm_suspend.S
Claudiu Beznea 9f7195da31 power: reset: at91-poweroff: switch to slow clock before shutdown
The SAMA5D2 NRST input signal is resynchronized with the SLCK clock and it
can take up to 2 SLCK cycles (about 90us) for the internal reset to be
effective. During this delay, the VDDCORE current consumption may still be
high (application-dependent) with the VDDCORE regulator already OFF. Under
such conditions, VDDCORE may operate below its operating range leading to
potential register corruption.

To prevent such situation, it is recommended to decrease significantly the
power consumption of the device once the voltage regulator is  turned-off.
This can be achieved by operating the device at a much lower low frequency.

To solve this switch the master clock to slock clock just before writing
shutdown command to shutdown controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Suggested-by: Patrice Vilchez <patrice.vilchez@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2018-09-16 12:31:48 +02:00

481 lines
9.6 KiB
ArmAsm

/*
* arch/arm/mach-at91/pm_slow_clock.S
*
* Copyright (C) 2006 Savin Zlobec
*
* AT91SAM9 support:
* Copyright (C) 2007 Anti Sullin <anti.sullin@artecdesign.ee>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/linkage.h>
#include <linux/clk/at91_pmc.h>
#include "pm.h"
#include "generated/at91_pm_data-offsets.h"
#define SRAMC_SELF_FRESH_ACTIVE 0x01
#define SRAMC_SELF_FRESH_EXIT 0x00
pmc .req r0
tmp1 .req r4
tmp2 .req r5
/*
* Wait until master clock is ready (after switching master clock source)
*/
.macro wait_mckrdy
1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MCKRDY
beq 1b
.endm
/*
* Wait until master oscillator has stabilized.
*/
.macro wait_moscrdy
1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MOSCS
beq 1b
.endm
/*
* Wait for main oscillator selection is done
*/
.macro wait_moscsels
1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MOSCSELS
beq 1b
.endm
/*
* Wait until PLLA has locked.
*/
.macro wait_pllalock
1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKA
beq 1b
.endm
/*
* Put the processor to enter the idle state
*/
.macro at91_cpu_idle
#if defined(CONFIG_CPU_V7)
mov tmp1, #AT91_PMC_PCK
str tmp1, [pmc, #AT91_PMC_SCDR]
dsb
wfi @ Wait For Interrupt
#else
mcr p15, 0, tmp1, c7, c0, 4
#endif
.endm
.text
.arm
/*
* void at91_suspend_sram_fn(struct at91_pm_data*)
* @input param:
* @r0: base address of struct at91_pm_data
*/
/* at91_pm_suspend_in_sram must be 8-byte aligned per the requirements of fncpy() */
.align 3
ENTRY(at91_pm_suspend_in_sram)
/* Save registers on stack */
stmfd sp!, {r4 - r12, lr}
/* Drain write buffer */
mov tmp1, #0
mcr p15, 0, tmp1, c7, c10, 4
ldr tmp1, [r0, #PM_DATA_PMC]
str tmp1, .pmc_base
ldr tmp1, [r0, #PM_DATA_RAMC0]
str tmp1, .sramc_base
ldr tmp1, [r0, #PM_DATA_RAMC1]
str tmp1, .sramc1_base
ldr tmp1, [r0, #PM_DATA_MEMCTRL]
str tmp1, .memtype
ldr tmp1, [r0, #PM_DATA_MODE]
str tmp1, .pm_mode
/* Both ldrne below are here to preload their address in the TLB */
ldr tmp1, [r0, #PM_DATA_SHDWC]
str tmp1, .shdwc
cmp tmp1, #0
ldrne tmp2, [tmp1, #0]
ldr tmp1, [r0, #PM_DATA_SFRBU]
str tmp1, .sfr
cmp tmp1, #0
ldrne tmp2, [tmp1, #0x10]
/* Active the self-refresh mode */
mov r0, #SRAMC_SELF_FRESH_ACTIVE
bl at91_sramc_self_refresh
ldr r0, .pm_mode
cmp r0, #AT91_PM_STANDBY
beq standby
cmp r0, #AT91_PM_BACKUP
beq backup_mode
bl at91_ulp_mode
b exit_suspend
standby:
/* Wait for interrupt */
ldr pmc, .pmc_base
at91_cpu_idle
b exit_suspend
backup_mode:
bl at91_backup_mode
b exit_suspend
exit_suspend:
/* Exit the self-refresh mode */
mov r0, #SRAMC_SELF_FRESH_EXIT
bl at91_sramc_self_refresh
/* Restore registers, and return */
ldmfd sp!, {r4 - r12, pc}
ENDPROC(at91_pm_suspend_in_sram)
ENTRY(at91_backup_mode)
/* Switch the master clock source to slow clock. */
ldr pmc, .pmc_base
ldr tmp1, [pmc, #AT91_PMC_MCKR]
bic tmp1, tmp1, #AT91_PMC_CSS
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
/*BUMEN*/
ldr r0, .sfr
mov tmp1, #0x1
str tmp1, [r0, #0x10]
/* Shutdown */
ldr r0, .shdwc
mov tmp1, #0xA5000000
add tmp1, tmp1, #0x1
str tmp1, [r0, #0]
ENDPROC(at91_backup_mode)
.macro at91_pm_ulp0_mode
ldr pmc, .pmc_base
/* Turn off the crystal oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
bic tmp1, tmp1, #AT91_PMC_MOSCEN
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
/* Wait for interrupt */
at91_cpu_idle
/* Turn on the crystal oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_MOSCEN
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_moscrdy
.endm
/**
* Note: This procedure only applies on the platform which uses
* the external crystal oscillator as a main clock source.
*/
.macro at91_pm_ulp1_mode
ldr pmc, .pmc_base
/* Switch the main clock source to 12-MHz RC oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
bic tmp1, tmp1, #AT91_PMC_MOSCSEL
bic tmp1, tmp1, #AT91_PMC_KEY_MASK
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_moscsels
/* Disable the crystal oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
bic tmp1, tmp1, #AT91_PMC_MOSCEN
bic tmp1, tmp1, #AT91_PMC_KEY_MASK
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
/* Switch the master clock source to main clock */
ldr tmp1, [pmc, #AT91_PMC_MCKR]
bic tmp1, tmp1, #AT91_PMC_CSS
orr tmp1, tmp1, #AT91_PMC_CSS_MAIN
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
/* Enter the ULP1 mode by set WAITMODE bit in CKGR_MOR */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_WAITMODE
bic tmp1, tmp1, #AT91_PMC_KEY_MASK
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_mckrdy
/* Enable the crystal oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_MOSCEN
bic tmp1, tmp1, #AT91_PMC_KEY_MASK
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_moscrdy
/* Switch the master clock source to slow clock */
ldr tmp1, [pmc, #AT91_PMC_MCKR]
bic tmp1, tmp1, #AT91_PMC_CSS
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
/* Switch main clock source to crystal oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_MOSCSEL
bic tmp1, tmp1, #AT91_PMC_KEY_MASK
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_moscsels
/* Switch the master clock source to main clock */
ldr tmp1, [pmc, #AT91_PMC_MCKR]
bic tmp1, tmp1, #AT91_PMC_CSS
orr tmp1, tmp1, #AT91_PMC_CSS_MAIN
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
.endm
ENTRY(at91_ulp_mode)
ldr pmc, .pmc_base
/* Save Master clock setting */
ldr tmp1, [pmc, #AT91_PMC_MCKR]
str tmp1, .saved_mckr
/*
* Set the Master clock source to slow clock
*/
bic tmp1, tmp1, #AT91_PMC_CSS
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
/* Save PLLA setting and disable it */
ldr tmp1, [pmc, #AT91_CKGR_PLLAR]
str tmp1, .saved_pllar
mov tmp1, #AT91_PMC_PLLCOUNT
orr tmp1, tmp1, #(1 << 29) /* bit 29 always set */
str tmp1, [pmc, #AT91_CKGR_PLLAR]
ldr r0, .pm_mode
cmp r0, #AT91_PM_ULP1
beq ulp1_mode
at91_pm_ulp0_mode
b ulp_exit
ulp1_mode:
at91_pm_ulp1_mode
b ulp_exit
ulp_exit:
ldr pmc, .pmc_base
/* Restore PLLA setting */
ldr tmp1, .saved_pllar
str tmp1, [pmc, #AT91_CKGR_PLLAR]
tst tmp1, #(AT91_PMC_MUL & 0xff0000)
bne 3f
tst tmp1, #(AT91_PMC_MUL & ~0xff0000)
beq 4f
3:
wait_pllalock
4:
/*
* Restore master clock setting
*/
ldr tmp1, .saved_mckr
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
mov pc, lr
ENDPROC(at91_ulp_mode)
/*
* void at91_sramc_self_refresh(unsigned int is_active)
*
* @input param:
* @r0: 1 - active self-refresh mode
* 0 - exit self-refresh mode
* register usage:
* @r1: memory type
* @r2: base address of the sram controller
*/
ENTRY(at91_sramc_self_refresh)
ldr r1, .memtype
ldr r2, .sramc_base
cmp r1, #AT91_MEMCTRL_MC
bne ddrc_sf
/*
* at91rm9200 Memory controller
*/
/*
* For exiting the self-refresh mode, do nothing,
* automatically exit the self-refresh mode.
*/
tst r0, #SRAMC_SELF_FRESH_ACTIVE
beq exit_sramc_sf
/* Active SDRAM self-refresh mode */
mov r3, #1
str r3, [r2, #AT91_MC_SDRAMC_SRR]
b exit_sramc_sf
ddrc_sf:
cmp r1, #AT91_MEMCTRL_DDRSDR
bne sdramc_sf
/*
* DDR Memory controller
*/
tst r0, #SRAMC_SELF_FRESH_ACTIVE
beq ddrc_exit_sf
/* LPDDR1 --> force DDR2 mode during self-refresh */
ldr r3, [r2, #AT91_DDRSDRC_MDR]
str r3, .saved_sam9_mdr
bic r3, r3, #~AT91_DDRSDRC_MD
cmp r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
ldreq r3, [r2, #AT91_DDRSDRC_MDR]
biceq r3, r3, #AT91_DDRSDRC_MD
orreq r3, r3, #AT91_DDRSDRC_MD_DDR2
streq r3, [r2, #AT91_DDRSDRC_MDR]
/* Active DDRC self-refresh mode */
ldr r3, [r2, #AT91_DDRSDRC_LPR]
str r3, .saved_sam9_lpr
bic r3, r3, #AT91_DDRSDRC_LPCB
orr r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
str r3, [r2, #AT91_DDRSDRC_LPR]
/* If using the 2nd ddr controller */
ldr r2, .sramc1_base
cmp r2, #0
beq no_2nd_ddrc
ldr r3, [r2, #AT91_DDRSDRC_MDR]
str r3, .saved_sam9_mdr1
bic r3, r3, #~AT91_DDRSDRC_MD
cmp r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
ldreq r3, [r2, #AT91_DDRSDRC_MDR]
biceq r3, r3, #AT91_DDRSDRC_MD
orreq r3, r3, #AT91_DDRSDRC_MD_DDR2
streq r3, [r2, #AT91_DDRSDRC_MDR]
/* Active DDRC self-refresh mode */
ldr r3, [r2, #AT91_DDRSDRC_LPR]
str r3, .saved_sam9_lpr1
bic r3, r3, #AT91_DDRSDRC_LPCB
orr r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
str r3, [r2, #AT91_DDRSDRC_LPR]
no_2nd_ddrc:
b exit_sramc_sf
ddrc_exit_sf:
/* Restore MDR in case of LPDDR1 */
ldr r3, .saved_sam9_mdr
str r3, [r2, #AT91_DDRSDRC_MDR]
/* Restore LPR on AT91 with DDRAM */
ldr r3, .saved_sam9_lpr
str r3, [r2, #AT91_DDRSDRC_LPR]
/* If using the 2nd ddr controller */
ldr r2, .sramc1_base
cmp r2, #0
ldrne r3, .saved_sam9_mdr1
strne r3, [r2, #AT91_DDRSDRC_MDR]
ldrne r3, .saved_sam9_lpr1
strne r3, [r2, #AT91_DDRSDRC_LPR]
b exit_sramc_sf
/*
* SDRAMC Memory controller
*/
sdramc_sf:
tst r0, #SRAMC_SELF_FRESH_ACTIVE
beq sdramc_exit_sf
/* Active SDRAMC self-refresh mode */
ldr r3, [r2, #AT91_SDRAMC_LPR]
str r3, .saved_sam9_lpr
bic r3, r3, #AT91_SDRAMC_LPCB
orr r3, r3, #AT91_SDRAMC_LPCB_SELF_REFRESH
str r3, [r2, #AT91_SDRAMC_LPR]
sdramc_exit_sf:
ldr r3, .saved_sam9_lpr
str r3, [r2, #AT91_SDRAMC_LPR]
exit_sramc_sf:
mov pc, lr
ENDPROC(at91_sramc_self_refresh)
.pmc_base:
.word 0
.sramc_base:
.word 0
.sramc1_base:
.word 0
.shdwc:
.word 0
.sfr:
.word 0
.memtype:
.word 0
.pm_mode:
.word 0
.saved_mckr:
.word 0
.saved_pllar:
.word 0
.saved_sam9_lpr:
.word 0
.saved_sam9_lpr1:
.word 0
.saved_sam9_mdr:
.word 0
.saved_sam9_mdr1:
.word 0
ENTRY(at91_pm_suspend_in_sram_sz)
.word .-at91_pm_suspend_in_sram