Initial import

1 files changed, 189 insertions, 0 deletions

diff --git a/arch/frv/kernel/cmode.S b/arch/frv/kernel/cmode.S
new file mode 100644
index 000000000..53deeb5d7
--- /dev/null
+++ b/arch/frv/kernel/cmode.S
@@ -0,0 +1,189 @@
+/* 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