linux/arch/arm/mach-at91/pm_slowclock.S
Jean-Christophe PLAGNIOL-VILLARD 1e3ce2b854 ARN: at91: introduce SOC_AT91xxx define to allow to compile SoC core support
We can now compile all SoC core support together and DT boards.
We still can not compile together the non DT board.
So We keep the ARCH_AT91xxx for the non DT board and for backward defconfig
compatibility. This will enable the plaform_device ressources.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2012-04-17 14:47:21 +02:00

332 lines
6.6 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 <mach/hardware.h>
#include <mach/at91_pmc.h>
#include <mach/at91_ramc.h>
#ifdef CONFIG_SOC_AT91SAM9263
/*
* FIXME either or both the SDRAM controllers (EB0, EB1) might be in use;
* handle those cases both here and in the Suspend-To-RAM support.
*/
#warning Assuming EB1 SDRAM controller is *NOT* used
#endif
/*
* When SLOWDOWN_MASTER_CLOCK is defined we will also slow down the Master
* clock during suspend by adjusting its prescalar and divisor.
* NOTE: This hasn't been shown to be stable on SAM9s; and on the RM9200 there
* are errata regarding adjusting the prescalar and divisor.
*/
#undef SLOWDOWN_MASTER_CLOCK
#define MCKRDY_TIMEOUT 1000
#define MOSCRDY_TIMEOUT 1000
#define PLLALOCK_TIMEOUT 1000
#define PLLBLOCK_TIMEOUT 1000
pmc .req r0
sdramc .req r1
ramc1 .req r2
memctrl .req r3
tmp1 .req r4
tmp2 .req r5
/*
* Wait until master clock is ready (after switching master clock source)
*/
.macro wait_mckrdy
mov tmp2, #MCKRDY_TIMEOUT
1: sub tmp2, tmp2, #1
cmp tmp2, #0
beq 2f
ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MCKRDY
beq 1b
2:
.endm
/*
* Wait until master oscillator has stabilized.
*/
.macro wait_moscrdy
mov tmp2, #MOSCRDY_TIMEOUT
1: sub tmp2, tmp2, #1
cmp tmp2, #0
beq 2f
ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MOSCS
beq 1b
2:
.endm
/*
* Wait until PLLA has locked.
*/
.macro wait_pllalock
mov tmp2, #PLLALOCK_TIMEOUT
1: sub tmp2, tmp2, #1
cmp tmp2, #0
beq 2f
ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKA
beq 1b
2:
.endm
/*
* Wait until PLLB has locked.
*/
.macro wait_pllblock
mov tmp2, #PLLBLOCK_TIMEOUT
1: sub tmp2, tmp2, #1
cmp tmp2, #0
beq 2f
ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKB
beq 1b
2:
.endm
.text
/* 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
cmp memctrl, #AT91_MEMCTRL_MC
bne ddr_sr_enable
/*
* at91rm9200 Memory controller
*/
/* Put SDRAM in self-refresh mode */
mov tmp1, #1
str tmp1, [sdramc, #AT91RM9200_SDRAMC_SRR]
b sdr_sr_done
/*
* DDRSDR Memory controller
*/
ddr_sr_enable:
cmp memctrl, #AT91_MEMCTRL_DDRSDR
bne sdr_sr_enable
/* prepare for DDRAM self-refresh mode */
ldr tmp1, [sdramc, #AT91_DDRSDRC_LPR]
str tmp1, .saved_sam9_lpr
bic tmp1, #AT91_DDRSDRC_LPCB
orr tmp1, #AT91_DDRSDRC_LPCB_SELF_REFRESH
/* figure out if we use the second ram controller */
cmp ramc1, #0
ldrne tmp2, [ramc1, #AT91_DDRSDRC_LPR]
strne tmp2, .saved_sam9_lpr1
bicne tmp2, #AT91_DDRSDRC_LPCB
orrne tmp2, #AT91_DDRSDRC_LPCB_SELF_REFRESH
/* Enable DDRAM self-refresh mode */
str tmp1, [sdramc, #AT91_DDRSDRC_LPR]
strne tmp2, [ramc1, #AT91_DDRSDRC_LPR]
b sdr_sr_done
/*
* SDRAMC Memory controller
*/
sdr_sr_enable:
/* Enable SDRAM self-refresh mode */
ldr tmp1, [sdramc, #AT91_SDRAMC_LPR]
str tmp1, .saved_sam9_lpr
bic tmp1, #AT91_SDRAMC_LPCB
orr tmp1, #AT91_SDRAMC_LPCB_SELF_REFRESH
str tmp1, [sdramc, #AT91_SDRAMC_LPR]
sdr_sr_done:
/* 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
#ifdef SLOWDOWN_MASTER_CLOCK
/*
* Set the Master Clock PRES and MDIV fields.
*
* See AT91RM9200 errata #27 and #28 for details.
*/
mov tmp1, #0
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
#endif
/* 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]
/* Save PLLB setting and disable it */
ldr tmp1, [pmc, #AT91_CKGR_PLLBR]
str tmp1, .saved_pllbr
mov tmp1, #AT91_PMC_PLLCOUNT
str tmp1, [pmc, #AT91_CKGR_PLLBR]
/* Turn off the main oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
bic tmp1, tmp1, #AT91_PMC_MOSCEN
str tmp1, [pmc, #AT91_CKGR_MOR]
/* Wait for interrupt */
mcr p15, 0, tmp1, c7, c0, 4
/* Turn on the main oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_MOSCEN
str tmp1, [pmc, #AT91_CKGR_MOR]
wait_moscrdy
/* Restore PLLB setting */
ldr tmp1, .saved_pllbr
str tmp1, [pmc, #AT91_CKGR_PLLBR]
tst tmp1, #(AT91_PMC_MUL & 0xff0000)
bne 1f
tst tmp1, #(AT91_PMC_MUL & ~0xff0000)
beq 2f
1:
wait_pllblock
2:
/* 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:
#ifdef SLOWDOWN_MASTER_CLOCK
/*
* First set PRES if it was not 0,
* than set CSS and MDIV fields.
*
* See AT91RM9200 errata #27 and #28 for details.
*/
ldr tmp1, .saved_mckr
tst tmp1, #AT91_PMC_PRES
beq 2f
and tmp1, tmp1, #AT91_PMC_PRES
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
#endif
/*
* Restore master clock setting
*/
2: ldr tmp1, .saved_mckr
str tmp1, [pmc, #AT91_PMC_MCKR]
wait_mckrdy
/*
* at91rm9200 Memory controller
* Do nothing - self-refresh is automatically disabled.
*/
cmp memctrl, #AT91_MEMCTRL_MC
beq ram_restored
/*
* DDRSDR Memory controller
*/
cmp memctrl, #AT91_MEMCTRL_DDRSDR
bne sdr_en_restore
/* Restore LPR on AT91 with DDRAM */
ldr tmp1, .saved_sam9_lpr
str tmp1, [sdramc, #AT91_DDRSDRC_LPR]
/* if we use the second ram controller */
cmp ramc1, #0
ldrne tmp2, .saved_sam9_lpr1
strne tmp2, [ramc1, #AT91_DDRSDRC_LPR]
b ram_restored
/*
* SDRAMC Memory controller
*/
sdr_en_restore:
/* Restore LPR on AT91 with SDRAM */
ldr tmp1, .saved_sam9_lpr
str tmp1, [sdramc, #AT91_SDRAMC_LPR]
ram_restored:
/* Restore registers, and return */
ldmfd sp!, {r4 - r12, pc}
.saved_mckr:
.word 0
.saved_pllar:
.word 0
.saved_pllbr:
.word 0
.saved_sam9_lpr:
.word 0
.saved_sam9_lpr1:
.word 0
ENTRY(at91_slow_clock_sz)
.word .-at91_slow_clock