drivers/firewire/fw-iso.c

   1 /*
   2  * Isochronous IO functionality
   3  *
   4  * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/dma-mapping.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/mm.h>
  26
  27 #include "fw-transaction.h"
  28 #include "fw-topology.h"
  29 #include "fw-device.h"
  30
  31 int
  32 fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
  33                    int page_count, enum dma_data_direction direction)
  34 {
  35         int i, j, retval = -ENOMEM;
  36         dma_addr_t address;
  37
  38         buffer->page_count = page_count;
  39         buffer->direction = direction;
  40
  41         buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
  42                                 GFP_KERNEL);
  43         if (buffer->pages == NULL)
  44                 goto out;
  45
  46         for (i = 0; i < buffer->page_count; i++) {
  47                 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
  48                 if (buffer->pages[i] == NULL)
  49                         goto out_pages;
  50
  51                 address = dma_map_page(card->device, buffer->pages[i],
  52                                        0, PAGE_SIZE, direction);
  53                 if (dma_mapping_error(address)) {
  54                         __free_page(buffer->pages[i]);
  55                         goto out_pages;
  56                 }
  57                 set_page_private(buffer->pages[i], address);
  58         }
  59
  60         return 0;
  61
  62  out_pages:
  63         for (j = 0; j < i; j++) {
  64                 address = page_private(buffer->pages[j]);
  65                 dma_unmap_page(card->device, address,
  66                                PAGE_SIZE, DMA_TO_DEVICE);
  67                 __free_page(buffer->pages[j]);
  68         }
  69         kfree(buffer->pages);
  70  out:
  71         buffer->pages = NULL;
  72         return retval;
  73 }
  74
  75 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
  76 {
  77         unsigned long uaddr;
  78         int i, retval;
  79
  80         uaddr = vma->vm_start;
  81         for (i = 0; i < buffer->page_count; i++) {
  82                 retval = vm_insert_page(vma, uaddr, buffer->pages[i]);
  83                 if (retval)
  84                         return retval;
  85                 uaddr += PAGE_SIZE;
  86         }
  87
  88         return 0;
  89 }
  90
  91 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
  92                            struct fw_card *card)
  93 {
  94         int i;
  95         dma_addr_t address;
  96
  97         for (i = 0; i < buffer->page_count; i++) {
  98                 address = page_private(buffer->pages[i]);
  99                 dma_unmap_page(card->device, address,
 100                                PAGE_SIZE, DMA_TO_DEVICE);
 101                 __free_page(buffer->pages[i]);
 102         }
 103
 104         kfree(buffer->pages);
 105         buffer->pages = NULL;
 106 }
 107
 108 struct fw_iso_context *
 109 fw_iso_context_create(struct fw_card *card, int type,
 110                       int channel, int speed, size_t header_size,
 111                       fw_iso_callback_t callback, void *callback_data)
 112 {
 113         struct fw_iso_context *ctx;
 114
 115         ctx = card->driver->allocate_iso_context(card, type, header_size);
 116         if (IS_ERR(ctx))
 117                 return ctx;
 118
 119         ctx->card = card;
 120         ctx->type = type;
 121         ctx->channel = channel;
 122         ctx->speed = speed;
 123         ctx->header_size = header_size;
 124         ctx->callback = callback;
 125         ctx->callback_data = callback_data;
 126
 127         return ctx;
 128 }
 129 EXPORT_SYMBOL(fw_iso_context_create);
 130
 131 void fw_iso_context_destroy(struct fw_iso_context *ctx)
 132 {
 133         struct fw_card *card = ctx->card;
 134
 135         card->driver->free_iso_context(ctx);
 136 }
 137 EXPORT_SYMBOL(fw_iso_context_destroy);
 138
 139 int
 140 fw_iso_context_start(struct fw_iso_context *ctx, int cycle, int sync, int tags)
 141 {
 142         return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
 143 }
 144 EXPORT_SYMBOL(fw_iso_context_start);
 145
 146 int
 147 fw_iso_context_queue(struct fw_iso_context *ctx,
 148                      struct fw_iso_packet *packet,
 149                      struct fw_iso_buffer *buffer,
 150                      unsigned long payload)
 151 {
 152         struct fw_card *card = ctx->card;
 153
 154         return card->driver->queue_iso(ctx, packet, buffer, payload);
 155 }
 156 EXPORT_SYMBOL(fw_iso_context_queue);
 157
 158 int
 159 fw_iso_context_stop(struct fw_iso_context *ctx)
 160 {
 161         return ctx->card->driver->stop_iso(ctx);
 162 }
 163 EXPORT_SYMBOL(fw_iso_context_stop);