/* * ISA DMA support functions * Copyright (c) by Jaroslav Kysela * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ /* * Defining following add some delay. Maybe this helps for some broken * ISA DMA controllers. */ #undef HAVE_REALLY_SLOW_DMA_CONTROLLER #include #include #include /** * snd_dma_program - program an ISA DMA transfer * @dma: the dma number * @addr: the physical address of the buffer * @size: the DMA transfer size * @mode: the DMA transfer mode, DMA_MODE_XXX * * Programs an ISA DMA transfer for the given buffer. */ void snd_dma_program(unsigned long dma, unsigned long addr, unsigned int size, unsigned short mode) { unsigned long flags; flags = claim_dma_lock(); disable_dma(dma); clear_dma_ff(dma); set_dma_mode(dma, mode); set_dma_addr(dma, addr); set_dma_count(dma, size); if (!(mode & DMA_MODE_NO_ENABLE)) enable_dma(dma); release_dma_lock(flags); } EXPORT_SYMBOL(snd_dma_program); /** * snd_dma_disable - stop the ISA DMA transfer * @dma: the dma number * * Stops the ISA DMA transfer. */ void snd_dma_disable(unsigned long dma) { unsigned long flags; flags = claim_dma_lock(); clear_dma_ff(dma); disable_dma(dma); release_dma_lock(flags); } EXPORT_SYMBOL(snd_dma_disable); /** * snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes * @dma: the dma number * @size: the dma transfer size * * Return: The current pointer in DMA transfer buffer in bytes. */ unsigned int snd_dma_pointer(unsigned long dma, unsigned int size) { unsigned long flags; unsigned int result, result1; flags = claim_dma_lock(); clear_dma_ff(dma); if (!isa_dma_bridge_buggy) disable_dma(dma); result = get_dma_residue(dma); /* * HACK - read the counter again and choose higher value in order to * avoid reading during counter lower byte roll over if the * isa_dma_bridge_buggy is set. */ result1 = get_dma_residue(dma); if (!isa_dma_bridge_buggy) enable_dma(dma); release_dma_lock(flags); if (unlikely(result < result1)) result = result1; #ifdef CONFIG_SND_DEBUG if (result > size) pr_err("ALSA: pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size); #endif if (result >= size || result == 0) return 0; else return size - result; } EXPORT_SYMBOL(snd_dma_pointer); ools/perf/ui/hist.c

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