LXR linux/sound/pci/asihpi/hpios.c

   1/******************************************************************************
   2
   3    AudioScience HPI driver
   4    Copyright (C) 1997-2012  AudioScience Inc. <support@audioscience.com>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of version 2 of the GNU General Public License as
   8    published by the Free Software Foundation;
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19HPI Operating System function implementation for Linux
  20
  21(C) Copyright AudioScience Inc. 1997-2003
  22******************************************************************************/
  23#define SOURCEFILE_NAME "hpios.c"
  24#include "hpi_internal.h"
  25#include "hpidebug.h"
  26#include <linux/delay.h>
  27#include <linux/sched.h>
  28
  29void hpios_delay_micro_seconds(u32 num_micro_sec)
  30{
  31        if ((usecs_to_jiffies(num_micro_sec) > 1) && !in_interrupt()) {
  32                /* MUST NOT SCHEDULE IN INTERRUPT CONTEXT! */
  33                schedule_timeout_uninterruptible(usecs_to_jiffies
  34                        (num_micro_sec));
  35        } else if (num_micro_sec <= 2000)
  36                udelay(num_micro_sec);
  37        else
  38                mdelay(num_micro_sec / 1000);
  39
  40}
  41
  42/** Allocate an area of locked memory for bus master DMA operations.
  43
  44If allocation fails, return 1, and *pMemArea.size = 0
  45*/
  46u16 hpios_locked_mem_alloc(struct consistent_dma_area *p_mem_area, u32 size,
  47        struct pci_dev *pdev)
  48{
  49        /*?? any benefit in using managed dmam_alloc_coherent? */
  50        p_mem_area->vaddr =
  51                dma_alloc_coherent(&pdev->dev, size, &p_mem_area->dma_handle,
  52                GFP_DMA32 | GFP_KERNEL);
  53
  54        if (p_mem_area->vaddr) {
  55                HPI_DEBUG_LOG(DEBUG, "allocated %d bytes, dma 0x%x vma %p\n",
  56                        size, (unsigned int)p_mem_area->dma_handle,
  57                        p_mem_area->vaddr);
  58                p_mem_area->pdev = &pdev->dev;
  59                p_mem_area->size = size;
  60                return 0;
  61        } else {
  62                HPI_DEBUG_LOG(WARNING,
  63                        "failed to allocate %d bytes locked memory\n", size);
  64                p_mem_area->size = 0;
  65                return 1;
  66        }
  67}
  68
  69u16 hpios_locked_mem_free(struct consistent_dma_area *p_mem_area)
  70{
  71        if (p_mem_area->size) {
  72                dma_free_coherent(p_mem_area->pdev, p_mem_area->size,
  73                        p_mem_area->vaddr, p_mem_area->dma_handle);
  74                HPI_DEBUG_LOG(DEBUG, "freed %lu bytes, dma 0x%x vma %p\n",
  75                        (unsigned long)p_mem_area->size,
  76                        (unsigned int)p_mem_area->dma_handle,
  77                        p_mem_area->vaddr);
  78                p_mem_area->size = 0;
  79                return 0;
  80        } else {
  81                return 1;
  82        }
  83}
  84