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path: root/drivers/acorn/block/fd1772dma.S
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Diffstat (limited to 'drivers/acorn/block/fd1772dma.S')
-rw-r--r--drivers/acorn/block/fd1772dma.S100
1 files changed, 100 insertions, 0 deletions
diff --git a/drivers/acorn/block/fd1772dma.S b/drivers/acorn/block/fd1772dma.S
new file mode 100644
index 00000000000..7964435443e
--- /dev/null
+++ b/drivers/acorn/block/fd1772dma.S
@@ -0,0 +1,100 @@
+#include <asm/hardware.h>
+
+@ Code for DMA with the 1772 fdc
+.text
+
+
+ .global fdc1772_dataaddr
+fdc1772_fiqdata:
+@ Number of bytes left to DMA
+ .global fdc1772_bytestogo
+fdc1772_bytestogo:
+ .word 0
+@ Place to put/get data from in DMA
+ .global fdc1772_dataaddr
+fdc1772_dataaddr:
+ .word 0
+
+ .global fdc1772_fdc_int_done
+fdc1772_fdc_int_done:
+ .word 0
+ .global fdc1772_comendstatus
+fdc1772_comendstatus:
+ .word 0
+
+@ We hang this off DMA channel 1
+ .global fdc1772_comendhandler
+fdc1772_comendhandler:
+ mov r8,#IOC_BASE
+ ldrb r9,[r8,#0x34] @ IOC FIQ status
+ tst r9,#2
+ subeqs pc,r14,#4 @ should I leave a space here
+ orr r9,r8,#0x10000 @ FDC base
+ adr r8,fdc1772_fdc_int_done
+ ldrb r10,[r9,#0] @ FDC status
+ mov r9,#1 @ Got a FIQ flag
+ stmia r8,{r9,r10}
+ subs pc,r14,#4
+
+
+ .global fdc1772_dma_read
+fdc1772_dma_read:
+ mov r8,#IOC_BASE
+ ldrb r9,[r8,#0x34] @ IOC FIQ status
+ tst r9,#1
+ beq fdc1772_dma_read_notours
+ orr r8,r8,#0x10000 @ FDC base
+ ldrb r10,[r8,#0xc] @ Read from FDC data reg (also clears interrupt)
+ ldmia r11,{r8,r9}
+ subs r8,r8,#1 @ One less byte to go
+ @ If there was somewhere for this data to go then store it and update pointers
+ strplb r10,[r9],#1 @ Store the data and increment the pointer
+ stmplia r11,{r8,r9} @ Update count/pointers
+ @ Handle any other interrupts if there are any
+fdc1772_dma_read_notours:
+ @ Cant branch because this code has been copied down to the FIQ vector
+ ldr pc,[pc,#-4]
+ .word fdc1772_comendhandler
+ .global fdc1772_dma_read_end
+fdc1772_dma_read_end:
+
+ .global fdc1772_dma_write
+fdc1772_dma_write:
+ mov r8,#IOC_BASE
+ ldrb r9,[r8,#0x34] @ IOC FIQ status
+ tst r9,#1
+ beq fdc1772_dma_write_notours
+ orr r8,r8,#0x10000 @ FDC base
+ ldmia r11,{r9,r10}
+ subs r9,r9,#1 @ One less byte to go
+ @ If there really is some data then get it, store it and update count
+ ldrplb r12,[r10],#1
+ strplb r12,[r8,#0xc] @ write it to FDC data reg
+ stmplia r11,{r9,r10} @ Update count and pointer - should clear interrupt
+ @ Handle any other interrupts
+fdc1772_dma_write_notours:
+ @ Cant branch because this code has been copied down to the FIQ vector
+ ldr pc,[pc,#-4]
+ .word fdc1772_comendhandler
+
+ .global fdc1772_dma_write_end
+fdc1772_dma_write_end:
+
+
+@ Setup the FIQ R11 to point to the data and store the count, address
+@ for this dma
+@ R0=count
+@ R1=address
+ .global fdc1772_setupdma
+fdc1772_setupdma:
+ @ The big job is flipping in and out of FIQ mode
+ adr r2,fdc1772_fiqdata @ This is what we really came here for
+ stmia r2,{r0,r1}
+ mov r3, pc
+ teqp pc,#0x0c000001 @ Disable FIQs, IRQs and switch to FIQ mode
+ mov r0,r0 @ NOP
+ mov r11,r2
+ teqp r3,#0 @ Normal mode
+ mov r0,r0 @ NOP
+ mov pc,r14
+