drivers/firewire/fw-iso.c

   1 /*                                              -*- c-basic-offset: 8 -*-
   2  *
   3  * fw-iso.c - Isochronous IO
   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 static int
  32 setup_iso_buffer(struct fw_iso_context *ctx, size_t size,
  33                  enum dma_data_direction direction)
  34 {
  35         struct page *page;
  36         int i, j;
  37         void *p;
  38
  39         ctx->buffer_size = PAGE_ALIGN(size);
  40         if (size == 0)
  41                 return 0;
  42
  43         ctx->buffer = vmalloc_32_user(ctx->buffer_size);
  44         if (ctx->buffer == NULL)
  45                 goto fail_buffer_alloc;
  46
  47         ctx->page_count = ctx->buffer_size >> PAGE_SHIFT;
  48         ctx->pages =
  49             kzalloc(ctx->page_count * sizeof(ctx->pages[0]), GFP_KERNEL);
  50         if (ctx->pages == NULL)
  51                 goto fail_pages_alloc;
  52
  53         p = ctx->buffer;
  54         for (i = 0; i < ctx->page_count; i++, p += PAGE_SIZE) {
  55                 page = vmalloc_to_page(p);
  56                 ctx->pages[i] = dma_map_page(ctx->card->device,
  57                                              page, 0, PAGE_SIZE, direction);
  58                 if (dma_mapping_error(ctx->pages[i]))
  59                         goto fail_mapping;
  60         }
  61
  62         return 0;
  63
  64  fail_mapping:
  65         for (j = 0; j < i; j++)
  66                 dma_unmap_page(ctx->card->device, ctx->pages[j],
  67                                PAGE_SIZE, DMA_TO_DEVICE);
  68  fail_pages_alloc:
  69         vfree(ctx->buffer);
  70  fail_buffer_alloc:
  71         return -ENOMEM;
  72 }
  73
  74 static void destroy_iso_buffer(struct fw_iso_context *ctx)
  75 {
  76         int i;
  77
  78         for (i = 0; i < ctx->page_count; i++)
  79                 dma_unmap_page(ctx->card->device, ctx->pages[i],
  80                                PAGE_SIZE, DMA_TO_DEVICE);
  81
  82         kfree(ctx->pages);
  83         vfree(ctx->buffer);
  84 }
  85
  86 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, int type,
  87                                              size_t buffer_size,
  88                                              fw_iso_callback_t callback,
  89                                              void *callback_data)
  90 {
  91         struct fw_iso_context *ctx;
  92         int retval;
  93
  94         ctx = card->driver->allocate_iso_context(card, type);
  95         if (IS_ERR(ctx))
  96                 return ctx;
  97
  98         ctx->card = card;
  99         ctx->type = type;
 100         ctx->callback = callback;
 101         ctx->callback_data = callback_data;
 102
 103         retval = setup_iso_buffer(ctx, buffer_size, DMA_TO_DEVICE);
 104         if (retval < 0) {
 105                 card->driver->free_iso_context(ctx);
 106                 return ERR_PTR(retval);
 107         }
 108
 109         return ctx;
 110 }
 111 EXPORT_SYMBOL(fw_iso_context_create);
 112
 113 void fw_iso_context_destroy(struct fw_iso_context *ctx)
 114 {
 115         struct fw_card *card = ctx->card;
 116
 117         destroy_iso_buffer(ctx);
 118
 119         card->driver->free_iso_context(ctx);
 120 }
 121 EXPORT_SYMBOL(fw_iso_context_destroy);
 122
 123 int
 124 fw_iso_context_send(struct fw_iso_context *ctx,
 125                     int channel, int speed, int cycle)
 126 {
 127         ctx->channel = channel;
 128         ctx->speed = speed;
 129
 130         return ctx->card->driver->send_iso(ctx, cycle);
 131 }
 132 EXPORT_SYMBOL(fw_iso_context_send);
 133
 134 int
 135 fw_iso_context_queue(struct fw_iso_context *ctx,
 136                      struct fw_iso_packet *packet, void *payload)
 137 {
 138         struct fw_card *card = ctx->card;
 139
 140         return card->driver->queue_iso(ctx, packet, payload);
 141 }
 142 EXPORT_SYMBOL(fw_iso_context_queue);