1 files changed, 190 insertions, 0 deletions

diff --git a/arch/frv/kernel/cmode.S b/arch/frv/kernel/cmode.S
new file mode 100644
index 000000000000..6591e6a37ae9
--- /dev/null
+++ b/arch/frv/kernel/cmode.S
@@ -0,0 +1,190 @@
+/* cmode.S: clock mode management
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Woodhouse (dwmw2@redhat.com)
+ *
+ * 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/config.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