/* cmode.S: clock mode management
|
*
|
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
* Written by David Woodhouse (dwmw2@infradead.org)
|
*
|
* This program is free software; you can redistribute it and/or
|
* modify it under the terms of the GNU General Public License
|
* as published by the Free Software Foundation; either version
|
* 2 of the License, or (at your option) any later version.
|
*
|
*/
|
|
#include <linux/sys.h>
|
#include <linux/linkage.h>
|
#include <asm/setup.h>
|
#include <asm/segment.h>
|
#include <asm/ptrace.h>
|
#include <asm/errno.h>
|
#include <asm/cache.h>
|
#include <asm/spr-regs.h>
|
|
#define __addr_MASK 0xfeff9820 /* interrupt controller mask */
|
|
#define __addr_SDRAMC 0xfe000400 /* SDRAM controller regs */
|
#define SDRAMC_DSTS 0x28 /* SDRAM status */
|
#define SDRAMC_DSTS_SSI 0x00000001 /* indicates that the SDRAM is in self-refresh mode */
|
#define SDRAMC_DRCN 0x30 /* SDRAM refresh control */
|
#define SDRAMC_DRCN_SR 0x00000001 /* transition SDRAM into self-refresh mode */
|
#define __addr_CLKC 0xfeff9a00
|
#define CLKC_SWCMODE 0x00000008
|
#define __addr_LEDS 0xe1200004
|
|
.macro li v r
|
sethi.p %hi(\v),\r
|
setlo %lo(\v),\r
|
.endm
|
|
.text
|
.balign 4
|
|
|
###############################################################################
|
#
|
# Change CMODE
|
# - void frv_change_cmode(int cmode)
|
#
|
###############################################################################
|
.globl frv_change_cmode
|
.type frv_change_cmode,@function
|
|
.macro LEDS v
|
#ifdef DEBUG_CMODE
|
setlos #~\v,gr10
|
sti gr10,@(gr11,#0)
|
membar
|
#endif
|
.endm
|
|
frv_change_cmode:
|
movsg lr,gr9
|
#ifdef DEBUG_CMODE
|
li __addr_LEDS,gr11
|
#endif
|
dcef @(gr0,gr0),#1
|
|
# Shift argument left by 24 bits to fit in SWCMODE register later.
|
slli gr8,#24,gr8
|
|
# (1) Set '0' in the PSR.ET bit, and prohibit interrupts.
|
movsg psr,gr14
|
andi gr14,#~PSR_ET,gr3
|
movgs gr3,psr
|
|
#if 0 // Fujitsu recommend to skip this and will update docs.
|
# (2) Set '0' to all bits of the MASK register of the interrupt
|
# controller, and mask interrupts.
|
li __addr_MASK,gr12
|
ldi @(gr12,#0),gr13
|
li 0xffff0000,gr4
|
sti gr4,@(gr12,#0)
|
#endif
|
|
# (3) Stop the transfer function of DMAC. Stop all the bus masters
|
# to access SDRAM and the internal resources.
|
|
# (already done by caller)
|
|
# (4) Preload a series of following instructions to the instruction
|
# cache.
|
li #__cmode_icache_lock_start,gr3
|
li #__cmode_icache_lock_end,gr4
|
|
1: icpl gr3,gr0,#1
|
addi gr3,#L1_CACHE_BYTES,gr3
|
cmp gr4,gr3,icc0
|
bhi icc0,#0,1b
|
|
# Set up addresses in regs for later steps.
|
setlos SDRAMC_DRCN_SR,gr3
|
li __addr_SDRAMC,gr4
|
li __addr_CLKC,gr5
|
ldi @(gr5,#0),gr6
|
li #0x80000000,gr7
|
or gr6,gr7,gr6
|
|
bra __cmode_icache_lock_start
|
|
.balign L1_CACHE_BYTES
|
__cmode_icache_lock_start:
|
|
# (5) Flush the content of all caches by the DCEF instruction.
|
dcef @(gr0,gr0),#1
|
|
# (6) Execute loading the dummy for SDRAM.
|
ldi @(gr9,#0),gr0
|
|
# (7) Set '1' to the DRCN.SR bit, and change SDRAM to the
|
# self-refresh mode. Execute the dummy load to all memory
|
# devices set to cacheable on the external bus side in parallel
|
# with this.
|
sti gr3,@(gr4,#SDRAMC_DRCN)
|
|
# (8) Execute memory barrier instruction (MEMBAR).
|
membar
|
|
# (9) Read the DSTS register repeatedly until '1' stands in the
|
# DSTS.SSI field.
|
1: ldi @(gr4,#SDRAMC_DSTS),gr3
|
andicc gr3,#SDRAMC_DSTS_SSI,gr3,icc0
|
beq icc0,#0,1b
|
|
# (10) Execute memory barrier instruction (MEMBAR).
|
membar
|
|
#if 1
|
# (11) Set the value of CMODE that you want to change to
|
# SWCMODE.SWCM[3:0].
|
sti gr8,@(gr5,#CLKC_SWCMODE)
|
|
# (12) Set '1' to the CLKC.SWEN bit. In that case, do not change
|
# fields other than SWEN of the CLKC register.
|
sti gr6,@(gr5,#0)
|
#endif
|
# (13) Execute the instruction just after the memory barrier
|
# instruction that executes the self-loop 256 times. (Meanwhile,
|
# the CMODE switch is done.)
|
membar
|
setlos #256,gr7
|
2: subicc gr7,#1,gr7,icc0
|
bne icc0,#2,2b
|
|
LEDS 0x36
|
|
# (14) Release the self-refresh of SDRAM.
|
sti gr0,@(gr4,#SDRAMC_DRCN)
|
|
# Wait for it...
|
3: ldi @(gr4,#SDRAMC_DSTS),gr3
|
andicc gr3,#SDRAMC_DSTS_SSI,gr3,icc0
|
bne icc0,#2,3b
|
|
#if 0
|
li 0x0100000,gr10
|
4: subicc gr10,#1,gr10,icc0
|
|
bne icc0,#0,4b
|
#endif
|
|
__cmode_icache_lock_end:
|
|
li #__cmode_icache_lock_start,gr3
|
li #__cmode_icache_lock_end,gr4
|
|
4: icul gr3
|
addi gr3,#L1_CACHE_BYTES,gr3
|
cmp gr4,gr3,icc0
|
bhi icc0,#0,4b
|
|
#if 0 // Fujitsu recommend to skip this and will update docs.
|
# (15) Release the interrupt mask setting of the MASK register of
|
# the interrupt controller if necessary.
|
sti gr13,@(gr12,#0)
|
#endif
|
# (16) Set 1' in the PSR.ET bit, and permit interrupt.
|
movgs gr14,psr
|
|
bralr
|
|
.size frv_change_cmode, .-frv_change_cmode
|
