linux/sound/pci/asihpi/hpios.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/******************************************************************************
   3
   4    AudioScience HPI driver
   5    Copyright (C) 1997-2012  AudioScience Inc. <support@audioscience.com>
   6
   7
   8HPI Operating System function implementation for Linux
   9
  10(C) Copyright AudioScience Inc. 1997-2003
  11******************************************************************************/
  12#define SOURCEFILE_NAME "hpios.c"
  13#include "hpi_internal.h"
  14#include "hpidebug.h"
  15#include <linux/delay.h>
  16#include <linux/sched.h>
  17
  18void hpios_delay_micro_seconds(u32 num_micro_sec)
  19{
  20        if ((usecs_to_jiffies(num_micro_sec) > 1) && !in_interrupt()) {
  21                /* MUST NOT SCHEDULE IN INTERRUPT CONTEXT! */
  22                schedule_timeout_uninterruptible(usecs_to_jiffies
  23                        (num_micro_sec));
  24        } else if (num_micro_sec <= 2000)
  25                udelay(num_micro_sec);
  26        else
  27                mdelay(num_micro_sec / 1000);
  28
  29}
  30
  31/** Allocate an area of locked memory for bus master DMA operations.
  32
  33If allocation fails, return 1, and *pMemArea.size = 0
  34*/
  35u16 hpios_locked_mem_alloc(struct consistent_dma_area *p_mem_area, u32 size,
  36        struct pci_dev *pdev)
  37{
  38        /*?? any benefit in using managed dmam_alloc_coherent? */
  39        p_mem_area->vaddr =
  40                dma_alloc_coherent(&pdev->dev, size, &p_mem_area->dma_handle,
  41                GFP_KERNEL);
  42
  43        if (p_mem_area->vaddr) {
  44                HPI_DEBUG_LOG(DEBUG, "allocated %d bytes, dma 0x%x vma %p\n",
  45                        size, (unsigned int)p_mem_area->dma_handle,
  46                        p_mem_area->vaddr);
  47                p_mem_area->pdev = &pdev->dev;
  48                p_mem_area->size = size;
  49                return 0;
  50        } else {
  51                HPI_DEBUG_LOG(WARNING,
  52                        "failed to allocate %d bytes locked memory\n", size);
  53                p_mem_area->size = 0;
  54                return 1;
  55        }
  56}
  57
  58u16 hpios_locked_mem_free(struct consistent_dma_area *p_mem_area)
  59{
  60        if (p_mem_area->size) {
  61                dma_free_coherent(p_mem_area->pdev, p_mem_area->size,
  62                        p_mem_area->vaddr, p_mem_area->dma_handle);
  63                HPI_DEBUG_LOG(DEBUG, "freed %lu bytes, dma 0x%x vma %p\n",
  64                        (unsigned long)p_mem_area->size,
  65                        (unsigned int)p_mem_area->dma_handle,
  66                        p_mem_area->vaddr);
  67                p_mem_area->size = 0;
  68                return 0;
  69        } else {
  70                return 1;
  71        }
  72}
  73