kernel/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
  19 HPI 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
  29 void 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
  44 If allocation fails, return 1, and *pMemArea.size = 0
  45 */
  46 u16 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
  69 u16 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 }