projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * ISA DMA support functions | |
| c1017a4c | 3 | * Copyright (c) by Jaroslav Kysela <[email protected]> |
| 1da177e4 LT |
4 | * |
| 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 | |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 19 | * | |
| 20 | */ | |
| 21 | ||
| 22 | /* | |
| 23 | * Defining following add some delay. Maybe this helps for some broken | |
| 24 | * ISA DMA controllers. | |
| 25 | */ | |
| 26 | ||
| 27 | #undef HAVE_REALLY_SLOW_DMA_CONTROLLER | |
| 28 | ||
| 29 | #include <sound/driver.h> | |
| 30 | #include <sound/core.h> | |
| 31 | #include <asm/dma.h> | |
| 32 | ||
| 33 | /** | |
| 34 | * snd_dma_program - program an ISA DMA transfer | |
| 35 | * @dma: the dma number | |
| 36 | * @addr: the physical address of the buffer | |
| 37 | * @size: the DMA transfer size | |
| 38 | * @mode: the DMA transfer mode, DMA_MODE_XXX | |
| 39 | * | |
| 40 | * Programs an ISA DMA transfer for the given buffer. | |
| 41 | */ | |
| 42 | void snd_dma_program(unsigned long dma, | |
| 43 | unsigned long addr, unsigned int size, | |
| 44 | unsigned short mode) | |
| 45 | { | |
| 46 | unsigned long flags; | |
| 47 | ||
| 48 | flags = claim_dma_lock(); | |
| 49 | disable_dma(dma); | |
| 50 | clear_dma_ff(dma); | |
| 51 | set_dma_mode(dma, mode); | |
| 52 | set_dma_addr(dma, addr); | |
| 53 | set_dma_count(dma, size); | |
| 54 | if (!(mode & DMA_MODE_NO_ENABLE)) | |
| 55 | enable_dma(dma); | |
| 56 | release_dma_lock(flags); | |
| 57 | } | |
| 58 | ||
| c0d3fb39 TI |
59 | EXPORT_SYMBOL(snd_dma_program); |
| 60 | ||
| 1da177e4 LT |
61 | /** |
| 62 | * snd_dma_disable - stop the ISA DMA transfer | |
| 63 | * @dma: the dma number | |
| 64 | * | |
| 65 | * Stops the ISA DMA transfer. | |
| 66 | */ | |
| 67 | void snd_dma_disable(unsigned long dma) | |
| 68 | { | |
| 69 | unsigned long flags; | |
| 70 | ||
| 71 | flags = claim_dma_lock(); | |
| 72 | clear_dma_ff(dma); | |
| 73 | disable_dma(dma); | |
| 74 | release_dma_lock(flags); | |
| 75 | } | |
| 76 | ||
| c0d3fb39 TI |
77 | EXPORT_SYMBOL(snd_dma_disable); |
| 78 | ||
| 1da177e4 LT |
79 | /** |
| 80 | * snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes | |
| 81 | * @dma: the dma number | |
| 82 | * @size: the dma transfer size | |
| 83 | * | |
| 84 | * Returns the current pointer in DMA tranfer buffer in bytes | |
| 85 | */ | |
| 86 | unsigned int snd_dma_pointer(unsigned long dma, unsigned int size) | |
| 87 | { | |
| 88 | unsigned long flags; | |
| 89 | unsigned int result; | |
| 90 | ||
| 91 | flags = claim_dma_lock(); | |
| 92 | clear_dma_ff(dma); | |
| 93 | if (!isa_dma_bridge_buggy) | |
| 94 | disable_dma(dma); | |
| 95 | result = get_dma_residue(dma); | |
| 96 | if (!isa_dma_bridge_buggy) | |
| 97 | enable_dma(dma); | |
| 98 | release_dma_lock(flags); | |
| 99 | #ifdef CONFIG_SND_DEBUG | |
| 100 | if (result > size) | |
| 101 | snd_printk(KERN_ERR "pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size); | |
| 102 | #endif | |
| 103 | if (result >= size || result == 0) | |
| 104 | return 0; | |
| 105 | else | |
| 106 | return size - result; | |
| 107 | } | |
| c0d3fb39 TI |
108 | |
| 109 | EXPORT_SYMBOL(snd_dma_pointer); |