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authorJesper Nilsson <jespern@stork.se.axis.com>2007-11-29 17:11:23 +0100
committerJesper Nilsson <jesper.nilsson@axis.com>2008-02-08 11:06:23 +0100
commit035e111f9a9b29843bc899f03d56f19d94bebb53 (patch)
treecb46b3c0eb6d9f2cc915522153454d3acaa7fcda /arch/cris/arch-v32/mach-fs/dram_init.S
parent6107c61fd3e6b47106b078db1726ad814564efef (diff)
CRIS v32: Add new machine dependent files for Etrax-FS and Artpec-3.
The two chips are somewhat different, and needs different handling. Adds handing of the dma, dram initialization, hardware settings, io, memory arbiter and pinmux Also moves the dma, dram initialization and io from CRIS v32 common files.
Diffstat (limited to 'arch/cris/arch-v32/mach-fs/dram_init.S')
-rw-r--r--arch/cris/arch-v32/mach-fs/dram_init.S116
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/mach-fs/dram_init.S b/arch/cris/arch-v32/mach-fs/dram_init.S
new file mode 100644
index 000000000000..6fbad336527b
--- /dev/null
+++ b/arch/cris/arch-v32/mach-fs/dram_init.S
@@ -0,0 +1,116 @@
+/*
+ * DRAM/SDRAM initialization - alter with care
+ * This file is intended to be included from other assembler files
+ *
+ * Note: This file may not modify r8 or r9 because they are used to
+ * carry information from the decompresser to the kernel
+ *
+ * Copyright (C) 2000-2007 Axis Communications AB
+ *
+ * Authors: Mikael Starvik <starvik@axis.com>
+ */
+
+/* Just to be certain the config file is included, we include it here
+ * explicitely instead of depending on it being included in the file that
+ * uses this code.
+ */
+
+#include <hwregs/asm/reg_map_asm.h>
+#include <hwregs/asm/bif_core_defs_asm.h>
+
+ ;; WARNING! The registers r8 and r9 are used as parameters carrying
+ ;; information from the decompressor (if the kernel was compressed).
+ ;; They should not be used in the code below.
+
+ ; Refer to BIF MDS for a description of SDRAM initialization
+
+ ; Bank configuration
+ move.d REG_ADDR(bif_core, regi_bif_core, rw_sdram_cfg_grp0), $r0
+ move.d CONFIG_ETRAX_SDRAM_GRP0_CONFIG, $r1
+ move.d $r1, [$r0]
+ move.d REG_ADDR(bif_core, regi_bif_core, rw_sdram_cfg_grp1), $r0
+ move.d CONFIG_ETRAX_SDRAM_GRP1_CONFIG, $r1
+ move.d $r1, [$r0]
+
+ ; Calculate value of mrs_data
+ ; CAS latency = 2 && bus_width = 32 => 0x40
+ ; CAS latency = 3 && bus_width = 32 => 0x60
+ ; CAS latency = 2 && bus_width = 16 => 0x20
+ ; CAS latency = 3 && bus_width = 16 => 0x30
+
+ ; Check if value is already supplied in kernel config
+ move.d CONFIG_ETRAX_SDRAM_COMMAND, $r2
+ bne _set_timing
+ nop
+
+ move.d 0x40, $r4 ; Assume 32 bits and CAS latency = 2
+ move.d CONFIG_ETRAX_SDRAM_TIMING, $r1
+ and.d 0x07, $r1 ; Get CAS latency
+ cmpq 2, $r1 ; CL = 2 ?
+ beq _bw_check
+ nop
+ move.d 0x60, $r4
+
+_bw_check:
+ ; Assume that group 0 width is equal to group 1. This assumption
+ ; is wrong for a group 1 only hardware (such as the grand old
+ ; StorPoint+).
+ move.d CONFIG_ETRAX_SDRAM_GRP0_CONFIG, $r1
+ and.d 0x200, $r1 ; DRAM width is bit 9
+ beq _set_timing
+ lslq 2, $r4 ; mrs_data starts at bit 2
+ lsrq 1, $r4 ; 16 bits. Shift down value.
+
+ ; Set timing parameters (refresh off to avoid Guinness TR 83)
+_set_timing:
+ move.d CONFIG_ETRAX_SDRAM_TIMING, $r1
+ and.d ~(3 << reg_bif_core_rw_sdram_timing___ref___lsb), $r1
+ move.d REG_ADDR(bif_core, regi_bif_core, rw_sdram_timing), $r0
+ move.d $r1, [$r0]
+
+ ; Issue NOP command
+ move.d REG_ADDR(bif_core, regi_bif_core, rw_sdram_cmd), $r5
+ moveq regk_bif_core_nop, $r1
+ move.d $r1, [$r5]
+
+ ; Wait 200us
+ move.d 10000, $r2
+1: bne 1b
+ subq 1, $r2
+
+ ; Issue initialization command sequence
+ lapc _sdram_commands_start, $r2
+ lapc _sdram_commands_end, $r3
+1: clear.d $r6
+ move.b [$r2+], $r6 ; Load command
+ or.d $r4, $r6 ; Add calculated mrs
+ move.d $r6, [$r5] ; Write rw_sdram_cmd
+ ; Wait 80 ns between each command
+ move.d 4000, $r7
+2: bne 2b
+ subq 1, $r7
+ cmp.d $r2, $r3 ; Last command?
+ bne 1b
+ nop
+
+ ; Start refresh
+ move.d CONFIG_ETRAX_SDRAM_TIMING, $r1
+ move.d REG_ADDR(bif_core, regi_bif_core, rw_sdram_timing), $r0
+ move.d $r1, [$r0]
+
+ ; Initialization finished
+ ba _sdram_commands_end
+ nop
+
+_sdram_commands_start:
+ .byte regk_bif_core_pre ; Precharge
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_ref ; refresh
+ .byte regk_bif_core_mrs ; mrs
+_sdram_commands_end: