| /* |
| * Helper functions for indirect PCM data transfer to a simple FIFO in |
| * hardware (small, no possibility to read "hardware io position", |
| * updating position done by interrupt, ...) |
| * |
| * Copyright (c) by 2007 Joachim Foerster <JOFT@gmx.de> |
| * |
| * Based on "pcm-indirect.h" (alsa-driver-1.0.13) by |
| * |
| * Copyright (c) by Takashi Iwai <tiwai@suse.de> |
| * Jaroslav Kysela <perex@suse.cz> |
| * |
| * 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., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #ifndef __SOUND_PCM_INDIRECT2_H |
| #define __SOUND_PCM_INDIRECT2_H |
| |
| /* struct snd_pcm_substream, struct snd_pcm_runtime, snd_pcm_uframes_t */ |
| #include <sound/pcm.h> |
| |
| /* Debug options for code which may be removed completely in a final version */ |
| #ifdef CONFIG_SND_DEBUG |
| #define SND_PCM_INDIRECT2_STAT /* turn on some "statistics" about the |
| * process of copying bytes from the |
| * intermediate buffer to the hardware |
| * fifo and the other way round |
| */ |
| #endif |
| |
| struct snd_pcm_indirect2 { |
| unsigned int hw_buffer_size; /* Byte size of hardware buffer */ |
| int hw_ready; /* playback: 1 = hw fifo has room left, |
| * 0 = hw fifo is full |
| */ |
| unsigned int min_multiple; |
| int min_periods; /* counts number of min. periods until |
| * min_multiple is reached |
| */ |
| int min_period_count; /* counts bytes to count number of |
| * min. periods |
| */ |
| |
| unsigned int sw_buffer_size; /* Byte size of software buffer */ |
| |
| /* sw_data: position in intermediate buffer, where we will read (or |
| * write) from/to next time (to transfer data to/from HW) |
| */ |
| unsigned int sw_data; /* Offset to next dst (or src) in sw |
| * ring buffer |
| */ |
| /* easiest case (playback): |
| * sw_data is nearly the same as ~ runtime->control->appl_ptr, with the |
| * exception that sw_data is "behind" by the number if bytes ALSA wrote |
| * to the intermediate buffer last time. |
| * A call to ack() callback synchronizes both indirectly. |
| */ |
| |
| /* We have no real sw_io pointer here. Usually sw_io is pointing to the |
| * current playback/capture position _inside_ the hardware. Devices |
| * with plain FIFOs often have no possibility to publish this position. |
| * So we say: if sw_data is updated, that means bytes were copied to |
| * the hardware, we increase sw_io by that amount, because there have |
| * to be as much bytes which were played. So sw_io will stay behind |
| * sw_data all the time and has to converge to sw_data at the end of |
| * playback. |
| */ |
| unsigned int sw_io; /* Current software pointer in bytes */ |
| |
| /* sw_ready: number of bytes ALSA copied to the intermediate buffer, so |
| * it represents the number of bytes which wait for transfer to the HW |
| */ |
| int sw_ready; /* Bytes ready to be transferred to/from hw */ |
| |
| /* appl_ptr: last known position of ALSA (where ALSA is going to write |
| * next time into the intermediate buffer |
| */ |
| snd_pcm_uframes_t appl_ptr; /* Last seen appl_ptr */ |
| |
| unsigned int bytes2hw; |
| int check_alignment; |
| |
| #ifdef SND_PCM_INDIRECT2_STAT |
| unsigned int zeros2hw; |
| unsigned int mul_elapsed; |
| unsigned int mul_elapsed_real; |
| unsigned long firstbytetime; |
| unsigned long lastbytetime; |
| unsigned long firstzerotime; |
| unsigned int byte_sizes[64]; |
| unsigned int zero_sizes[64]; |
| unsigned int min_adds[8]; |
| unsigned int mul_adds[8]; |
| unsigned int zero_times[3750]; /* = 15s */ |
| unsigned int zero_times_saved; |
| unsigned int zero_times_notsaved; |
| unsigned int irq_occured; |
| unsigned int pointer_calls; |
| unsigned int lastdifftime; |
| #endif |
| }; |
| |
| typedef size_t (*snd_pcm_indirect2_copy_t) (struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec, |
| size_t bytes); |
| typedef size_t (*snd_pcm_indirect2_zero_t) (struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec); |
| |
| #ifdef SND_PCM_INDIRECT2_STAT |
| void snd_pcm_indirect2_stat(struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec); |
| #endif |
| |
| snd_pcm_uframes_t |
| snd_pcm_indirect2_pointer(struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec); |
| void |
| snd_pcm_indirect2_playback_interrupt(struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec, |
| snd_pcm_indirect2_copy_t copy, |
| snd_pcm_indirect2_zero_t zero); |
| void |
| snd_pcm_indirect2_capture_interrupt(struct snd_pcm_substream *substream, |
| struct snd_pcm_indirect2 *rec, |
| snd_pcm_indirect2_copy_t copy, |
| snd_pcm_indirect2_zero_t null); |
| |
| #endif /* __SOUND_PCM_INDIRECT2_H */ |