arch/arm/kernel/dma-riscstation.c

   1 /*
   2  *  linux/arch/arm/kernel/dma-riscstation.c
   3  *
   4  *  Copyright (C) 1998 Russell King
   5  *  Copyright (C) 2002 Ben Dooks / Simtec Electronics
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  *  DMA functions specific to RiscStatiun architecture
  12  *
  13  * sliced down version of the RiscPC DMA code by RMK
  14  */
  15 #include <linux/sched.h>
  16 #include <linux/slab.h>
  17 #include <linux/mman.h>
  18 #include <linux/init.h>
  19 #include <linux/pci.h>
  20
  21 #include <asm/page.h>
  22 #include <asm/dma.h>
  23 #include <asm/fiq.h>
  24 #include <asm/io.h>
  25 #include <asm/irq.h>
  26 #include <asm/hardware.h>
  27 #include <asm/uaccess.h>
  28
  29 #include <asm/mach/dma.h>
  30 #include <asm/hardware/iomd.h>
  31
  32 static struct fiq_handler fh = {
  33         name: "floppydma"
  34 };
  35
  36 static void floppy_enable_dma(dmach_t channel, dma_t *dma)
  37 {
  38         void *fiqhandler_start;
  39         unsigned int fiqhandler_length;
  40         struct pt_regs regs;
  41
  42         if (dma->dma_mode == DMA_MODE_READ) {
  43                 extern unsigned char floppy_fiqin_start, floppy_fiqin_end;
  44                 fiqhandler_start = &floppy_fiqin_start;
  45                 fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start;
  46         } else {
  47                 extern unsigned char floppy_fiqout_start, floppy_fiqout_end;
  48                 fiqhandler_start = &floppy_fiqout_start;
  49                 fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start;
  50         }
  51
  52         regs.ARM_r9  = dma->buf.length;
  53         regs.ARM_r10 = (unsigned long)dma->buf.address;
  54         regs.ARM_fp  = FLOPPYDMA_BASE;
  55
  56         if (claim_fiq(&fh)) {
  57                 printk("floppydma: couldn't claim FIQ.\n");
  58                 return;
  59         }
  60
  61         set_fiq_handler(fiqhandler_start, fiqhandler_length);
  62         set_fiq_regs(&regs);
  63         enable_fiq(dma->dma_irq);
  64 }
  65
  66 static void floppy_disable_dma(dmach_t channel, dma_t *dma)
  67 {
  68         disable_fiq(dma->dma_irq);
  69         release_fiq(&fh);
  70 }
  71
  72 static int floppy_get_residue(dmach_t channel, dma_t *dma)
  73 {
  74         struct pt_regs regs;
  75         get_fiq_regs(&regs);
  76         return regs.ARM_r9;
  77 }
  78
  79 static struct dma_ops floppy_dma_ops = {
  80         type:           "FIQDMA",
  81         enable:         floppy_enable_dma,
  82         disable:        floppy_disable_dma,
  83         residue:        floppy_get_residue,
  84 };
  85
  86 /*
  87  * This is virtual DMA - we don't need anything here.
  88  */
  89 static void sound_enable_disable_dma(dmach_t channel, dma_t *dma)
  90 {
  91 }
  92
  93 static struct dma_ops sound_dma_ops = {
  94         type:           "VIRTUAL",
  95         enable:         sound_enable_disable_dma,
  96         disable:        sound_enable_disable_dma,
  97 };
  98
  99 void __init arch_dma_init(dma_t *dma)
 100 {
 101 #if 0
 102         iomd_writeb(0, IOMD_IO0CR);
 103         iomd_writeb(0, IOMD_IO1CR);
 104         iomd_writeb(0, IOMD_IO2CR);
 105         iomd_writeb(0, IOMD_IO3CR);
 106
 107         iomd_writeb(0xa0, IOMD_DMATCR);
 108 #endif
 109
 110         dma[DMA_VIRTUAL_FLOPPY].dma_irq = FIQ_FLOPPYDATA;
 111         dma[DMA_VIRTUAL_FLOPPY].d_ops   = &floppy_dma_ops;
 112         dma[DMA_VIRTUAL_SOUND].d_ops    = &sound_dma_ops;
 113 }