/*
   *  PCM Interface - misc routines

   *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>

   *
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Library 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 Library General Public License for more details.
   *
   *   You should have received a copy of the GNU Library General Public
   *   License along with this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */
    

  #include <linux/time.h>
  #include <sound/core.h>
  #include <sound/pcm.h>
  #define SND_PCM_FORMAT_UNKNOWN (-1)
  
  /* NOTE: "signed" prefix must be given below since the default char is
   *       unsigned on some architectures!
   */
  struct pcm_format_data {
  	unsigned char width;	/* bit width */
  	unsigned char phys;	/* physical bit width */
  	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
  	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
  	unsigned char silence[8];	/* silence data to fill */
  };
  
  static struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = {
  	[SNDRV_PCM_FORMAT_S8] = {
  		.width = 8, .phys = 8, .le = -1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U8] = {
  		.width = 8, .phys = 8, .le = -1, .signd = 0,
  		.silence = { 0x80 },
  	},
  	[SNDRV_PCM_FORMAT_S16_LE] = {
  		.width = 16, .phys = 16, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S16_BE] = {
  		.width = 16, .phys = 16, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U16_LE] = {
  		.width = 16, .phys = 16, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x80 },
  	},
  	[SNDRV_PCM_FORMAT_U16_BE] = {
  		.width = 16, .phys = 16, .le = 0, .signd = 0,
  		.silence = { 0x80, 0x00 },
  	},
  	[SNDRV_PCM_FORMAT_S24_LE] = {
  		.width = 24, .phys = 32, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S24_BE] = {
  		.width = 24, .phys = 32, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U24_LE] = {
  		.width = 24, .phys = 32, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x00, 0x80 },
  	},
  	[SNDRV_PCM_FORMAT_U24_BE] = {
  		.width = 24, .phys = 32, .le = 0, .signd = 0,

  		.silence = { 0x00, 0x80, 0x00, 0x00 },

  	},
  	[SNDRV_PCM_FORMAT_S32_LE] = {
  		.width = 32, .phys = 32, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S32_BE] = {
  		.width = 32, .phys = 32, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U32_LE] = {
  		.width = 32, .phys = 32, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x00, 0x00, 0x80 },
  	},
  	[SNDRV_PCM_FORMAT_U32_BE] = {
  		.width = 32, .phys = 32, .le = 0, .signd = 0,
  		.silence = { 0x80, 0x00, 0x00, 0x00 },
  	},
  	[SNDRV_PCM_FORMAT_FLOAT_LE] = {
  		.width = 32, .phys = 32, .le = 1, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_FLOAT_BE] = {
  		.width = 32, .phys = 32, .le = 0, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
  		.width = 64, .phys = 64, .le = 1, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
  		.width = 64, .phys = 64, .le = 0, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
  		.width = 32, .phys = 32, .le = 1, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
  		.width = 32, .phys = 32, .le = 0, .signd = -1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_MU_LAW] = {
  		.width = 8, .phys = 8, .le = -1, .signd = -1,
  		.silence = { 0x7f },
  	},
  	[SNDRV_PCM_FORMAT_A_LAW] = {
  		.width = 8, .phys = 8, .le = -1, .signd = -1,
  		.silence = { 0x55 },
  	},
  	[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
  		.width = 4, .phys = 4, .le = -1, .signd = -1,
  		.silence = {},
  	},
  	/* FIXME: the following three formats are not defined properly yet */
  	[SNDRV_PCM_FORMAT_MPEG] = {
  		.le = -1, .signd = -1,
  	},
  	[SNDRV_PCM_FORMAT_GSM] = {
  		.le = -1, .signd = -1,
  	},
  	[SNDRV_PCM_FORMAT_SPECIAL] = {
  		.le = -1, .signd = -1,
  	},
  	[SNDRV_PCM_FORMAT_S24_3LE] = {
  		.width = 24, .phys = 24, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S24_3BE] = {
  		.width = 24, .phys = 24, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U24_3LE] = {
  		.width = 24, .phys = 24, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x00, 0x80 },
  	},
  	[SNDRV_PCM_FORMAT_U24_3BE] = {
  		.width = 24, .phys = 24, .le = 0, .signd = 0,
  		.silence = { 0x80, 0x00, 0x00 },
  	},
  	[SNDRV_PCM_FORMAT_S20_3LE] = {
  		.width = 20, .phys = 24, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S20_3BE] = {
  		.width = 20, .phys = 24, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U20_3LE] = {
  		.width = 20, .phys = 24, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x00, 0x08 },
  	},
  	[SNDRV_PCM_FORMAT_U20_3BE] = {
  		.width = 20, .phys = 24, .le = 0, .signd = 0,
  		.silence = { 0x08, 0x00, 0x00 },
  	},
  	[SNDRV_PCM_FORMAT_S18_3LE] = {
  		.width = 18, .phys = 24, .le = 1, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_S18_3BE] = {
  		.width = 18, .phys = 24, .le = 0, .signd = 1,
  		.silence = {},
  	},
  	[SNDRV_PCM_FORMAT_U18_3LE] = {
  		.width = 18, .phys = 24, .le = 1, .signd = 0,
  		.silence = { 0x00, 0x00, 0x02 },
  	},
  	[SNDRV_PCM_FORMAT_U18_3BE] = {
  		.width = 18, .phys = 24, .le = 0, .signd = 0,
  		.silence = { 0x02, 0x00, 0x00 },
  	},
  };
  
  
  /**
   * snd_pcm_format_signed - Check the PCM format is signed linear
   * @format: the format to check
   *
   * Returns 1 if the given PCM format is signed linear, 0 if unsigned
   * linear, and a negative error code for non-linear formats.
   */
  int snd_pcm_format_signed(snd_pcm_format_t format)
  {
  	int val;
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return -EINVAL;
  	if ((val = pcm_formats[format].signd) < 0)
  		return -EINVAL;
  	return val;
  }

  EXPORT_SYMBOL(snd_pcm_format_signed);

  /**
   * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
   * @format: the format to check
   *
   * Returns 1 if the given PCM format is unsigned linear, 0 if signed
   * linear, and a negative error code for non-linear formats.
   */
  int snd_pcm_format_unsigned(snd_pcm_format_t format)
  {
  	int val;
  
  	val = snd_pcm_format_signed(format);
  	if (val < 0)
  		return val;
  	return !val;
  }

  EXPORT_SYMBOL(snd_pcm_format_unsigned);

  /**
   * snd_pcm_format_linear - Check the PCM format is linear
   * @format: the format to check
   *
   * Returns 1 if the given PCM format is linear, 0 if not.
   */
  int snd_pcm_format_linear(snd_pcm_format_t format)
  {
  	return snd_pcm_format_signed(format) >= 0;
  }

  EXPORT_SYMBOL(snd_pcm_format_linear);

  /**
   * snd_pcm_format_little_endian - Check the PCM format is little-endian
   * @format: the format to check
   *
   * Returns 1 if the given PCM format is little-endian, 0 if
   * big-endian, or a negative error code if endian not specified.
   */
  int snd_pcm_format_little_endian(snd_pcm_format_t format)
  {
  	int val;
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return -EINVAL;
  	if ((val = pcm_formats[format].le) < 0)
  		return -EINVAL;
  	return val;
  }

  EXPORT_SYMBOL(snd_pcm_format_little_endian);

  /**
   * snd_pcm_format_big_endian - Check the PCM format is big-endian
   * @format: the format to check
   *
   * Returns 1 if the given PCM format is big-endian, 0 if
   * little-endian, or a negative error code if endian not specified.
   */
  int snd_pcm_format_big_endian(snd_pcm_format_t format)
  {
  	int val;
  
  	val = snd_pcm_format_little_endian(format);
  	if (val < 0)
  		return val;
  	return !val;
  }

  EXPORT_SYMBOL(snd_pcm_format_big_endian);

  /**

   * snd_pcm_format_width - return the bit-width of the format
   * @format: the format to check
   *
   * Returns the bit-width of the format, or a negative error code
   * if unknown format.
   */
  int snd_pcm_format_width(snd_pcm_format_t format)
  {
  	int val;
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return -EINVAL;
  	if ((val = pcm_formats[format].width) == 0)
  		return -EINVAL;
  	return val;
  }

  EXPORT_SYMBOL(snd_pcm_format_width);

  /**
   * snd_pcm_format_physical_width - return the physical bit-width of the format
   * @format: the format to check
   *
   * Returns the physical bit-width of the format, or a negative error code
   * if unknown format.
   */
  int snd_pcm_format_physical_width(snd_pcm_format_t format)
  {
  	int val;
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return -EINVAL;
  	if ((val = pcm_formats[format].phys) == 0)
  		return -EINVAL;
  	return val;
  }

  EXPORT_SYMBOL(snd_pcm_format_physical_width);

  /**
   * snd_pcm_format_size - return the byte size of samples on the given format
   * @format: the format to check

   * @samples: sampling rate

   *
   * Returns the byte size of the given samples for the format, or a
   * negative error code if unknown format.
   */
  ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
  {
  	int phys_width = snd_pcm_format_physical_width(format);
  	if (phys_width < 0)
  		return -EINVAL;
  	return samples * phys_width / 8;
  }

  EXPORT_SYMBOL(snd_pcm_format_size);

  /**
   * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
   * @format: the format to check
   *
   * Returns the format pattern to fill or NULL if error.
   */
  const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
  {
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return NULL;
  	if (! pcm_formats[format].phys)
  		return NULL;
  	return pcm_formats[format].silence;
  }

  EXPORT_SYMBOL(snd_pcm_format_silence_64);

  /**
   * snd_pcm_format_set_silence - set the silence data on the buffer
   * @format: the PCM format
   * @data: the buffer pointer
   * @samples: the number of samples to set silence
   *
   * Sets the silence data on the buffer for the given samples.
   *
   * Returns zero if successful, or a negative error code on failure.
   */
  int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
  {
  	int width;
  	unsigned char *dst, *pat;
  
  	if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
  		return -EINVAL;
  	if (samples == 0)
  		return 0;
  	width = pcm_formats[format].phys; /* physical width */
  	pat = pcm_formats[format].silence;
  	if (! width)
  		return -EINVAL;
  	/* signed or 1 byte data */
  	if (pcm_formats[format].signd == 1 || width <= 8) {
  		unsigned int bytes = samples * width / 8;
  		memset(data, *pat, bytes);
  		return 0;
  	}
  	/* non-zero samples, fill using a loop */
  	width /= 8;
  	dst = data;
  #if 0
  	while (samples--) {
  		memcpy(dst, pat, width);
  		dst += width;
  	}
  #else
  	/* a bit optimization for constant width */
  	switch (width) {
  	case 2:
  		while (samples--) {
  			memcpy(dst, pat, 2);
  			dst += 2;
  		}
  		break;
  	case 3:
  		while (samples--) {
  			memcpy(dst, pat, 3);
  			dst += 3;
  		}
  		break;
  	case 4:
  		while (samples--) {
  			memcpy(dst, pat, 4);
  			dst += 4;
  		}
  		break;
  	case 8:
  		while (samples--) {
  			memcpy(dst, pat, 8);
  			dst += 8;
  		}
  		break;
  	}
  #endif
  	return 0;
  }

  EXPORT_SYMBOL(snd_pcm_format_set_silence);

  /**
   * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
   * @runtime: the runtime instance
   *
   * Determines the rate_min and rate_max fields from the rates bits of
   * the given runtime->hw.
   *
   * Returns zero if successful.
   */

  int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)

  {

  	int i;

  	for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {

  		if (runtime->hw.rates & (1 << i)) {

  			runtime->hw.rate_min = snd_pcm_known_rates.list[i];

  			break;
  		}
  	}

  	for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {

  		if (runtime->hw.rates & (1 << i)) {

  			runtime->hw.rate_max = snd_pcm_known_rates.list[i];

  			break;
  		}
  	}
  	return 0;
  }

  
  EXPORT_SYMBOL(snd_pcm_limit_hw_rates);

  
  /**
   * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
   * @rate: the sample rate to convert
   *
   * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
   * SNDRV_PCM_RATE_KNOT for an unknown rate.
   */
  unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
  {
  	unsigned int i;
  
  	for (i = 0; i < snd_pcm_known_rates.count; i++)
  		if (snd_pcm_known_rates.list[i] == rate)
  			return 1u << i;
  	return SNDRV_PCM_RATE_KNOT;
  }
  EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);