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linux/arch/arm/mach-at91/pm_slowclock.S
Wenyou Yang 23be4be5a6 ARM: at91/pm: standby mode uses same sram function as suspend to memory mode 
To simply the PM code, the suspend to standby mode uses same sram function
as the suspend to memory mode, running in the internal SRAM, instead of the
respective code for each mode.

For the suspend to standby mode, the master clock doesn't switch to the slow
clock, and PLLA and the main oscillator doesn't turn off as well.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2015-03-13 13:34:53 +01:00

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/*
* 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 <mach/hardware.h>
#include <mach/at91_ramc.h>
#include "pm.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 until PLLA has locked.
*/
.macro wait_pllalock
1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKA
beq 1b
.endm
.text
.arm
/* void at91_slow_clock(void __iomem *pmc, void __iomem *sdramc,
* void __iomem *ramc1, int memctrl)
*/
ENTRY(at91_slow_clock)
/* Save registers on stack */
stmfd sp!, {r4 - r12, lr}
/*
* Register usage:
* R0 = Base address of AT91_PMC
* R1 = Base address of RAM Controller (SDRAM, DDRSDR, or AT91_SYS)
* R2 = Base address of second RAM Controller or 0 if not present
* R3 = Memory controller
* R4 = temporary register
* R5 = temporary register
*/
/* Drain write buffer */
mov tmp1, #0
mcr p15, 0, tmp1, c7, c10, 4
str r0, .pmc_base
str r1, .sramc_base
str r2, .sramc1_base
and r0, r3, #AT91_PM_MEMTYPE_MASK
str r0, .memtype
lsr r0, r3, #AT91_PM_MODE_OFFSET
and r0, r0, #AT91_PM_MODE_MASK
str r0, .pm_mode
/* Active the self-refresh mode */
mov r0, #SRAMC_SELF_FRESH_ACTIVE
bl at91_sramc_self_refresh
ldr r0, .pm_mode
tst r0, #AT91_PM_SLOW_CLOCK
beq skip_disable_main_clock
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]
/* Turn off the main 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]
skip_disable_main_clock:
ldr pmc, .pmc_base
/* Wait for interrupt */
mcr p15, 0, tmp1, c7, c0, 4
ldr r0, .pm_mode
tst r0, #AT91_PM_SLOW_CLOCK
beq skip_enable_main_clock
ldr pmc, .pmc_base
/* Turn on the main 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
/* 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
skip_enable_main_clock:
/* 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_slow_clock)
/*
* 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, #AT91RM9200_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
.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_slow_clock_sz)
.word .-at91_slow_clock
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