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linux/arch/arm/mach-at91/pm_slowclock.S
Nicolas Ferre 7dca3343fc ARM: 6185/1: AT91: PM: dual ram controller support 
This rework allows to address tow memory controllers. AT91SAM9263 and
AT91SAM9G45 family have tow SDRAM or DDR/SDRAM controllers. Power management
should take care of this.
This patch modify the way RAM IP header files are implemented to allow
access to registers of both controllers ; it also adds some macros.

We also modify the power management files to use those modified header files.
Slow clock (assembly) and regular power management functions are synchronized
for setting of RAM self-refresh procedure:
(lpr & ~AT91_DDRSDRC_LPCB) | AT91_DDRSDRC_LPCB_SELF_REFRESH

Note that AT91RM9200 is not impacted by this modification.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-09 12:31:50 +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 <mach/hardware.h>
#include <mach/at91_pmc.h>
#if defined(CONFIG_ARCH_AT91RM9200)
#include <mach/at91rm9200_mc.h>
#elif defined(CONFIG_ARCH_AT91CAP9)
#include <mach/at91cap9_ddrsdr.h>
#elif defined(CONFIG_ARCH_AT91SAM9G45)
#include <mach/at91sam9_ddrsdr.h>
#else
#include <mach/at91sam9_sdramc.h>
#endif
#ifdef CONFIG_ARCH_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
/*
* Wait until master clock is ready (after switching master clock source)
*/
.macro wait_mckrdy
mov r4, #MCKRDY_TIMEOUT
1: sub r4, r4, #1
cmp r4, #0
beq 2f
ldr r3, [r1, #(AT91_PMC_SR - AT91_PMC)]
tst r3, #AT91_PMC_MCKRDY
beq 1b
2:
.endm
/*
* Wait until master oscillator has stabilized.
*/
.macro wait_moscrdy
mov r4, #MOSCRDY_TIMEOUT
1: sub r4, r4, #1
cmp r4, #0
beq 2f
ldr r3, [r1, #(AT91_PMC_SR - AT91_PMC)]
tst r3, #AT91_PMC_MOSCS
beq 1b
2:
.endm
/*
* Wait until PLLA has locked.
*/
.macro wait_pllalock
mov r4, #PLLALOCK_TIMEOUT
1: sub r4, r4, #1
cmp r4, #0
beq 2f
ldr r3, [r1, #(AT91_PMC_SR - AT91_PMC)]
tst r3, #AT91_PMC_LOCKA
beq 1b
2:
.endm
/*
* Wait until PLLB has locked.
*/
.macro wait_pllblock
mov r4, #PLLBLOCK_TIMEOUT
1: sub r4, r4, #1
cmp r4, #0
beq 2f
ldr r3, [r1, #(AT91_PMC_SR - AT91_PMC)]
tst r3, #AT91_PMC_LOCKB
beq 1b
2:
.endm
.text
ENTRY(at91_slow_clock)
/* Save registers on stack */
stmfd sp!, {r0 - r12, lr}
/*
* Register usage:
* R1 = Base address of AT91_PMC
* R2 = Base address of RAM Controller (SDRAM, DDRSDR, or AT91_SYS)
* R3 = temporary register
* R4 = temporary register
* R5 = Base address of second RAM Controller or 0 if not present
*/
ldr r1, .at91_va_base_pmc
ldr r2, .at91_va_base_sdramc
ldr r5, .at91_va_base_ramc1
/* Drain write buffer */
mcr p15, 0, r0, c7, c10, 4
#ifdef CONFIG_ARCH_AT91RM9200
/* Put SDRAM in self-refresh mode */
mov r3, #1
str r3, [r2, #AT91_SDRAMC_SRR]
#elif defined(CONFIG_ARCH_AT91CAP9) \
|| defined(CONFIG_ARCH_AT91SAM9G45)
/* prepare for DDRAM self-refresh mode */
ldr r3, [r2, #AT91_DDRSDRC_LPR]
str r3, .saved_sam9_lpr
bic r3, #AT91_DDRSDRC_LPCB
orr r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
/* figure out if we use the second ram controller */
cmp r5, #0
ldrne r4, [r5, #AT91_DDRSDRC_LPR]
strne r4, .saved_sam9_lpr1
bicne r4, #AT91_DDRSDRC_LPCB
orrne r4, #AT91_DDRSDRC_LPCB_SELF_REFRESH
/* Enable DDRAM self-refresh mode */
str r3, [r2, #AT91_DDRSDRC_LPR]
strne r4, [r5, #AT91_DDRSDRC_LPR]
#else
/* Enable SDRAM self-refresh mode */
ldr r3, [r2, #AT91_SDRAMC_LPR]
str r3, .saved_sam9_lpr
bic r3, #AT91_SDRAMC_LPCB
orr r3, #AT91_SDRAMC_LPCB_SELF_REFRESH
str r3, [r2, #AT91_SDRAMC_LPR]
#endif
/* Save Master clock setting */
ldr r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)]
str r3, .saved_mckr
/*
* Set the Master clock source to slow clock
*/
bic r3, r3, #AT91_PMC_CSS
str r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)]
wait_mckrdy
#ifdef SLOWDOWN_MASTER_CLOCK
/*
* Set the Master Clock PRES and MDIV fields.
*
* See AT91RM9200 errata #27 and #28 for details.
*/
mov r3, #0
str r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)]
wait_mckrdy
#endif
/* Save PLLA setting and disable it */
ldr r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)]
str r3, .saved_pllar
mov r3, #AT91_PMC_PLLCOUNT
orr r3, r3, #(1 << 29) /* bit 29 always set */
str r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)]
/* Save PLLB setting and disable it */
ldr r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)]
str r3, .saved_pllbr
mov r3, #AT91_PMC_PLLCOUNT
str r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)]
/* Turn off the main oscillator */
ldr r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)]
bic r3, r3, #AT91_PMC_MOSCEN
str r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)]
/* Wait for interrupt */
mcr p15, 0, r0, c7, c0, 4
/* Turn on the main oscillator */
ldr r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)]
orr r3, r3, #AT91_PMC_MOSCEN
str r3, [r1, #(AT91_CKGR_MOR - AT91_PMC)]
wait_moscrdy
/* Restore PLLB setting */
ldr r3, .saved_pllbr
str r3, [r1, #(AT91_CKGR_PLLBR - AT91_PMC)]
tst r3, #(AT91_PMC_MUL & 0xff0000)
bne 1f
tst r3, #(AT91_PMC_MUL & ~0xff0000)
beq 2f
1:
wait_pllblock
2:
/* Restore PLLA setting */
ldr r3, .saved_pllar
str r3, [r1, #(AT91_CKGR_PLLAR - AT91_PMC)]
tst r3, #(AT91_PMC_MUL & 0xff0000)
bne 3f
tst r3, #(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 r3, .saved_mckr
tst r3, #AT91_PMC_PRES
beq 2f
and r3, r3, #AT91_PMC_PRES
str r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)]
wait_mckrdy
#endif
/*
* Restore master clock setting
*/
2: ldr r3, .saved_mckr
str r3, [r1, #(AT91_PMC_MCKR - AT91_PMC)]
wait_mckrdy
#ifdef CONFIG_ARCH_AT91RM9200
/* Do nothing - self-refresh is automatically disabled. */
#elif defined(CONFIG_ARCH_AT91CAP9) \
|| defined(CONFIG_ARCH_AT91SAM9G45)
/* Restore LPR on AT91 with DDRAM */
ldr r3, .saved_sam9_lpr
str r3, [r2, #AT91_DDRSDRC_LPR]
/* if we use the second ram controller */
cmp r5, #0
ldrne r4, .saved_sam9_lpr1
strne r4, [r5, #AT91_DDRSDRC_LPR]
#else
/* Restore LPR on AT91 with SDRAM */
ldr r3, .saved_sam9_lpr
str r3, [r2, #AT91_SDRAMC_LPR]
#endif
/* Restore registers, and return */
ldmfd sp!, {r0 - r12, pc}
.saved_mckr:
.word 0
.saved_pllar:
.word 0
.saved_pllbr:
.word 0
.saved_sam9_lpr:
.word 0
.saved_sam9_lpr1:
.word 0
.at91_va_base_pmc:
.word AT91_VA_BASE_SYS + AT91_PMC
#ifdef CONFIG_ARCH_AT91RM9200
.at91_va_base_sdramc:
.word AT91_VA_BASE_SYS
#elif defined(CONFIG_ARCH_AT91CAP9) \
|| defined(CONFIG_ARCH_AT91SAM9G45)
.at91_va_base_sdramc:
.word AT91_VA_BASE_SYS + AT91_DDRSDRC0
#else
.at91_va_base_sdramc:
.word AT91_VA_BASE_SYS + AT91_SDRAMC0
#endif
.at91_va_base_ramc1:
#if defined(CONFIG_ARCH_AT91SAM9G45)
.word AT91_VA_BASE_SYS + AT91_DDRSDRC1
#else
.word 0
#endif
ENTRY(at91_slow_clock_sz)
.word .-at91_slow_clock
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