[linux.git] / sound / drivers / pcm-indirect2.h

/*
 * 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 <[email protected]>
 *
 *  Based on "pcm-indirect.h" (alsa-driver-1.0.13) by
 *
 *  Copyright (c) by Takashi Iwai <[email protected]>
 *                   Jaroslav Kysela <[email protected]>
 *
 *   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 */
Commit	Line	Data
a9f00d8d JF	1	/*
	2	* Helper functions for indirect PCM data transfer to a simple FIFO in
	3	* hardware (small, no possibility to read "hardware io position",
	4	* updating position done by interrupt, ...)
	5	*
	6	* Copyright (c) by 2007 Joachim Foerster <[email protected]>
	7	*
	8	* Based on "pcm-indirect.h" (alsa-driver-1.0.13) by
	9	*
	10	* Copyright (c) by Takashi Iwai <[email protected]>
	11	* Jaroslav Kysela <[email protected]>
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2 of the License, or
	16	* (at your option) any later version.
	17	*
	18	* This program is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	* GNU General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU General Public License
	24	* along with this program; if not, write to the Free Software
	25	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	26	*/
	27
	28	#ifndef __SOUND_PCM_INDIRECT2_H
	29	#define __SOUND_PCM_INDIRECT2_H
	30
	31	/* struct snd_pcm_substream, struct snd_pcm_runtime, snd_pcm_uframes_t */
	32	#include <sound/pcm.h>
	33
	34	/* Debug options for code which may be removed completely in a final version */
	35	#ifdef CONFIG_SND_DEBUG
	36	#define SND_PCM_INDIRECT2_STAT /* turn on some "statistics" about the
	37	* process of copying bytes from the
	38	* intermediate buffer to the hardware
	39	* fifo and the other way round
	40	*/
	41	#endif
	42
	43	struct snd_pcm_indirect2 {
	44	unsigned int hw_buffer_size; /* Byte size of hardware buffer */
	45	int hw_ready; /* playback: 1 = hw fifo has room left,
	46	* 0 = hw fifo is full
	47	*/
	48	unsigned int min_multiple;
	49	int min_periods; /* counts number of min. periods until
	50	* min_multiple is reached
	51	*/
	52	int min_period_count; /* counts bytes to count number of
	53	* min. periods
	54	*/
	55
	56	unsigned int sw_buffer_size; /* Byte size of software buffer */
	57
	58	/* sw_data: position in intermediate buffer, where we will read (or
	59	* write) from/to next time (to transfer data to/from HW)
	60	*/
	61	unsigned int sw_data; /* Offset to next dst (or src) in sw
	62	* ring buffer
	63	*/
	64	/* easiest case (playback):
65	* sw_data is nearly the same as ~ runtime->control->appl_ptr, with the
66	* exception that sw_data is "behind" by the number if bytes ALSA wrote
67	* to the intermediate buffer last time.
68	* A call to ack() callback synchronizes both indirectly.
69	*/
70
71	/* We have no real sw_io pointer here. Usually sw_io is pointing to the
72	* current playback/capture position _inside_ the hardware. Devices
73	* with plain FIFOs often have no possibility to publish this position.
74	* So we say: if sw_data is updated, that means bytes were copied to
75	* the hardware, we increase sw_io by that amount, because there have
76	* to be as much bytes which were played. So sw_io will stay behind
77	* sw_data all the time and has to converge to sw_data at the end of
78	* playback.
79	*/
80	unsigned int sw_io; /* Current software pointer in bytes */
81
82	/* sw_ready: number of bytes ALSA copied to the intermediate buffer, so
83	* it represents the number of bytes which wait for transfer to the HW
84	*/
85	int sw_ready; /* Bytes ready to be transferred to/from hw */
86
87	/* appl_ptr: last known position of ALSA (where ALSA is going to write
88	* next time into the intermediate buffer
89	*/
90	snd_pcm_uframes_t appl_ptr; /* Last seen appl_ptr */
91
92	unsigned int bytes2hw;
93	int check_alignment;
94
95	#ifdef SND_PCM_INDIRECT2_STAT
96	unsigned int zeros2hw;
97	unsigned int mul_elapsed;
98	unsigned int mul_elapsed_real;
99	unsigned long firstbytetime;
100	unsigned long lastbytetime;
101	unsigned long firstzerotime;
102	unsigned int byte_sizes[64];
103	unsigned int zero_sizes[64];
104	unsigned int min_adds[8];
105	unsigned int mul_adds[8];
106	unsigned int zero_times[3750]; /* = 15s */
107	unsigned int zero_times_saved;
108	unsigned int zero_times_notsaved;
109	unsigned int irq_occured;
110	unsigned int pointer_calls;
111	unsigned int lastdifftime;
112	#endif
113	};
114
115	typedef size_t (snd_pcm_indirect2_copy_t) (struct snd_pcm_substream substream,
116	struct snd_pcm_indirect2 *rec,
117	size_t bytes);
118	typedef size_t (snd_pcm_indirect2_zero_t) (struct snd_pcm_substream substream,
119	struct snd_pcm_indirect2 *rec);
120
121	#ifdef SND_PCM_INDIRECT2_STAT
122	void snd_pcm_indirect2_stat(struct snd_pcm_substream *substream,
123	struct snd_pcm_indirect2 *rec);
124	#endif
125
126	snd_pcm_uframes_t
127	snd_pcm_indirect2_pointer(struct snd_pcm_substream *substream,
128	struct snd_pcm_indirect2 *rec);
129	void
130	snd_pcm_indirect2_playback_interrupt(struct snd_pcm_substream *substream,
131	struct snd_pcm_indirect2 *rec,
132	snd_pcm_indirect2_copy_t copy,
133	snd_pcm_indirect2_zero_t zero);
134	void
135	snd_pcm_indirect2_capture_interrupt(struct snd_pcm_substream *substream,
136	struct snd_pcm_indirect2 *rec,
137	snd_pcm_indirect2_copy_t copy,
138	snd_pcm_indirect2_zero_t null);
139
140	#endif /* __SOUND_PCM_INDIRECT2_H */