patch-2.1.101 linux/drivers/acorn/block/fd1772dma.S

• Lines: 101
• Date: Fri May 8 00:42:38 1998
• Orig file: v2.1.100/linux/drivers/acorn/block/fd1772dma.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.100/linux/drivers/acorn/block/fd1772dma.S linux/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
+