arch/arm/mach-s3c2410/include/mach/entry-macro.S

   1 /*
   2  * arch/arm/mach-s3c2410/include/mach/entry-macro.S
   3  *
   4  * Low-level IRQ helper macros for S3C2410-based platforms
   5  *
   6  * This file is licensed under  the terms of the GNU General Public
   7  * License version 2. This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9 */
  10
  11 /* We have a problem that the INTOFFSET register does not always
  12  * show one interrupt. Occasionally we get two interrupts through
  13  * the prioritiser, and this causes the INTOFFSET register to show
  14  * what looks like the logical-or of the two interrupt numbers.
  15  *
  16  * Thanks to Klaus, Shannon, et al for helping to debug this problem
  17 */
  18
  19 #define INTPND          (0x10)
  20 #define INTOFFSET       (0x14)
  21
  22 #include <mach/hardware.h>
  23 #include <asm/irq.h>
  24
  25         .macro  get_irqnr_preamble, base, tmp
  26         .endm
  27
  28         .macro  arch_ret_to_user, tmp1, tmp2
  29         .endm
  30
  31         .macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
  32
  33                 mov     \base, #S3C24XX_VA_IRQ
  34
  35                 @@ try the interrupt offset register, since it is there
  36
  37                 ldr     \irqstat, [ \base, #INTPND ]
  38                 teq     \irqstat, #0
  39                 beq     1002f
  40                 ldr     \irqnr, [ \base, #INTOFFSET ]
  41                 mov     \tmp, #1
  42                 tst     \irqstat, \tmp, lsl \irqnr
  43                 bne     1001f
  44
  45                 @@ the number specified is not a valid irq, so try
  46                 @@ and work it out for ourselves
  47
  48                 mov     \irqnr, #0              @@ start here
  49
  50                 @@ work out which irq (if any) we got
  51
  52                 movs    \tmp, \irqstat, lsl#16
  53                 addeq   \irqnr, \irqnr, #16
  54                 moveq   \irqstat, \irqstat, lsr#16
  55                 tst     \irqstat, #0xff
  56                 addeq   \irqnr, \irqnr, #8
  57                 moveq   \irqstat, \irqstat, lsr#8
  58                 tst     \irqstat, #0xf
  59                 addeq   \irqnr, \irqnr, #4
  60                 moveq   \irqstat, \irqstat, lsr#4
  61                 tst     \irqstat, #0x3
  62                 addeq   \irqnr, \irqnr, #2
  63                 moveq   \irqstat, \irqstat, lsr#2
  64                 tst     \irqstat, #0x1
  65                 addeq   \irqnr, \irqnr, #1
  66
  67                 @@ we have the value
  68 1001:
  69                 adds    \irqnr, \irqnr, #IRQ_EINT0
  70 1002:
  71                 @@ exit here, Z flag unset if IRQ
  72
  73         .endm
  74
  75                 /* currently don't need an disable_fiq macro */
  76
  77                 .macro  disable_fiq
  78                 .endm