xref: /linux/sound/pci/asihpi/hpios.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 }
84