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