/**

 * \file control/tlv.c

 * \brief dB conversion functions from control TLV information

 * \author Takashi Iwai <tiwai@suse.de>

 * \date 2007

 */

/*

 *  Control Interface - dB conversion functions from control TLV information

 *

 *  Copyright (c) 2007 Takashi Iwai <tiwai@suse.de>

 *

 *

 *   This library is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU Lesser General Public License as

 *   published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

 *

 *   You should have received a copy of the GNU Lesser General Public

 *   License along with this library; if not, write to the Free Software

 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#ifndef HAVE_SOFT_FLOAT

#include <math.h>

#endif

#include "control_local.h"

#ifndef DOC_HIDDEN

/* convert to index of integer array */

#define int_index(size)	(((size) + sizeof(int) - 1) / sizeof(int))

/* max size of a TLV entry for dB information (including compound one) */

#define MAX_TLV_RANGE_SIZE	256

#endif

/**

 * \brief Parse TLV stream and retrieve dB information

 * \param tlv the TLV source

 * \param tlv_size the byte size of TLV source

 * \param db_tlvp the pointer stored the dB TLV information

 * \return the byte size of dB TLV information if found in the given

 *   TLV source, or a negative error code.

 *

 * This function parses the given TLV source and stores the TLV start

 * point if the TLV information regarding dB conversion is found.

 * The stored TLV pointer can be passed to the convesion functions

 * #snd_tlv_convert_to_dB(), #snd_tlv_convert_from_dB() and

 * #snd_tlv_get_dB_range().

 */

int snd_tlv_parse_dB_info(unsigned int *tlv,

			  unsigned int tlv_size,

			  unsigned int **db_tlvp)

{

	unsigned int type;

	unsigned int size;

	int err;

	*db_tlvp = NULL;

	type = tlv[SNDRV_CTL_TLVO_TYPE];

	size = tlv[SNDRV_CTL_TLVO_LEN];

	tlv_size -= 2 * sizeof(int);

	if (size > tlv_size) {

		SNDERR("TLV size error");

		return -EINVAL;

	}

	switch (type) {

	case SND_CTL_TLVT_CONTAINER:

		size = int_index(size) * sizeof(int);

		tlv += 2;

		while (size > 0) {

			unsigned int len;

			err = snd_tlv_parse_dB_info(tlv, size, db_tlvp);

			if (err < 0)

				return err; /* error */

			if (err > 0)

				return err; /* found */

			len = int_index(tlv[SNDRV_CTL_TLVO_LEN]) + 2;

			size -= len * sizeof(int);

			tlv += len;

		}

		break;

	case SND_CTL_TLVT_DB_SCALE:

	case SND_CTL_TLVT_DB_MINMAX:

	case SND_CTL_TLVT_DB_MINMAX_MUTE:

#ifndef HAVE_SOFT_FLOAT

	case SND_CTL_TLVT_DB_LINEAR:

#endif

	case SND_CTL_TLVT_DB_RANGE: {

		unsigned int minsize;

		if (type == SND_CTL_TLVT_DB_RANGE)

			minsize = 4 * sizeof(int);

		else

			minsize = 2 * sizeof(int);

		if (size < minsize) {

			SNDERR("Invalid dB_scale TLV size");

			return -EINVAL;

		}

		if (size > MAX_TLV_RANGE_SIZE) {

			SNDERR("Too big dB_scale TLV size: %d", size);

			return -EINVAL;

		}

		*db_tlvp = tlv;

		return size + sizeof(int) * 2;

	}

	default:

		break;

	}

	return -EINVAL; /* not found */

}

/**

 * \brief Get the dB min/max values

 * \param tlv the TLV source returned by #snd_tlv_parse_dB_info()

 * \param rangemin the minimum value of the raw volume

 * \param rangemax the maximum value of the raw volume

 * \param min the pointer to store the minimum dB value (in 0.01dB unit)

 * \param max the pointer to store the maximum dB value (in 0.01dB unit)

 * \return 0 if successful, or a negative error code

 */

int snd_tlv_get_dB_range(unsigned int *tlv, long rangemin, long rangemax,

			 long *min, long *max)

{

	int err;

	switch (tlv[SNDRV_CTL_TLVO_TYPE]) {

	case SND_CTL_TLVT_DB_RANGE: {

		unsigned int pos, len;

		len = int_index(tlv[SNDRV_CTL_TLVO_LEN]);

		if (len > MAX_TLV_RANGE_SIZE)

			return -EINVAL;

		pos = 2;

		while (pos + 4 <= len) {

			long rmin, rmax;

			long submin, submax;

			submin = (int)tlv[pos];

			submax = (int)tlv[pos + 1];

			if (rangemax < submax)

				submax = rangemax;

			err = snd_tlv_get_dB_range(tlv + pos + 2,

						   submin, submax,

						   &rmin, &rmax);

			if (err < 0)

				return err;

			if (pos > 2) {

				if (rmin < *min)

					*min = rmin;

				if (rmax > *max)

					*max = rmax;

			} else {

				*min = rmin;

				*max = rmax;

			}

			if (rangemax == submax)

				return 0;

			pos += int_index(tlv[pos + 3]) + 4;

		}

		return 0;

	}

	case SND_CTL_TLVT_DB_SCALE: {

		int step;

		if (tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] & 0x10000)

			*min = SND_CTL_TLV_DB_GAIN_MUTE;

		else

			*min = (int)tlv[SNDRV_CTL_TLVO_DB_SCALE_MIN];

		step = (tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] & 0xffff);

		*max = (int)tlv[SNDRV_CTL_TLVO_DB_SCALE_MIN] +

						step * (rangemax - rangemin);

		return 0;

	}

	case SND_CTL_TLVT_DB_MINMAX:

	case SND_CTL_TLVT_DB_LINEAR:

		*min = (int)tlv[SNDRV_CTL_TLVO_DB_LINEAR_MIN];

		*max = (int)tlv[SNDRV_CTL_TLVO_DB_LINEAR_MAX];

		return 0;

	case SND_CTL_TLVT_DB_MINMAX_MUTE:

		*min = SND_CTL_TLV_DB_GAIN_MUTE;

		*max = (int)tlv[SNDRV_CTL_TLVO_DB_MINMAX_MAX];

		return 0;

	}

	return -EINVAL;

}

/**

 * \brief Convert the given raw volume value to a dB gain

 * \param tlv the TLV source returned by #snd_tlv_parse_dB_info()

 * \param rangemin the minimum value of the raw volume

 * \param rangemax the maximum value of the raw volume

 * \param volume the raw volume value to convert

 * \param db_gain the dB gain (in 0.01dB unit)

 * \return 0 if successful, or a negative error code

 */

int snd_tlv_convert_to_dB(unsigned int *tlv, long rangemin, long rangemax,

			  long volume, long *db_gain)

{

	unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE];

	switch (type) {

	case SND_CTL_TLVT_DB_RANGE: {

		unsigned int pos, len;

		len = int_index(tlv[SNDRV_CTL_TLVO_LEN]);

		if (len > MAX_TLV_RANGE_SIZE)

			return -EINVAL;

		pos = 2;

		while (pos + 4 <= len) {

			rangemin = (int)tlv[pos];

			rangemax = (int)tlv[pos + 1];

			if (volume >= rangemin && volume <= rangemax)

				return snd_tlv_convert_to_dB(tlv + pos + 2,

							     rangemin, rangemax,

							     volume, db_gain);

			pos += int_index(tlv[pos + 3]) + 4;

		}

		return -EINVAL;

	}

	case SND_CTL_TLVT_DB_SCALE: {

		int min, step, mute;

		min = tlv[SNDRV_CTL_TLVO_DB_SCALE_MIN];

		step = (tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] & 0xffff);

		mute = (tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] >> 16) & 1;

		if (mute && volume <= rangemin)

			*db_gain = SND_CTL_TLV_DB_GAIN_MUTE;

		else

			*db_gain = (volume - rangemin) * step + min;

		return 0;

	}

	case SND_CTL_TLVT_DB_MINMAX:

	case SND_CTL_TLVT_DB_MINMAX_MUTE: {

		int mindb, maxdb;

		mindb = tlv[SNDRV_CTL_TLVO_DB_MINMAX_MIN];

		maxdb = tlv[SNDRV_CTL_TLVO_DB_MINMAX_MAX];

		if (volume <= rangemin || rangemax <= rangemin) {

			if (type == SND_CTL_TLVT_DB_MINMAX_MUTE)

				*db_gain = SND_CTL_TLV_DB_GAIN_MUTE;

			else

				*db_gain = mindb;

		} else if (volume >= rangemax)

			*db_gain = maxdb;

		else

			*db_gain = (maxdb - mindb) * (volume - rangemin) /

				(rangemax - rangemin) + mindb;

		return 0;

	}

#ifndef HAVE_SOFT_FLOAT

	case SND_CTL_TLVT_DB_LINEAR: {

		int mindb = tlv[SNDRV_CTL_TLVO_DB_LINEAR_MIN];

		int maxdb = tlv[SNDRV_CTL_TLVO_DB_LINEAR_MAX];

		if (volume <= rangemin || rangemax <= rangemin)

			*db_gain = mindb;

		else if (volume >= rangemax)

			*db_gain = maxdb;

		else {

			double val = (double)(volume - rangemin) /

				(double)(rangemax - rangemin);

			if (mindb <= SND_CTL_TLV_DB_GAIN_MUTE)

				*db_gain = (long)(100.0 * 20.0 * log10(val)) +

					maxdb;

			else {

				/* FIXME: precalculate and cache these values */

				double lmin = pow(10.0, mindb/2000.0);

				double lmax = pow(10.0, maxdb/2000.0);

				val = (lmax - lmin) * val + lmin;

				*db_gain = (long)(100.0 * 20.0 * log10(val));

			}

		}

		return 0;

	}

#endif

	}

	return -EINVAL;

}

/**

 * \brief Convert from dB gain to the corresponding raw value

 * \param tlv the TLV source returned by #snd_tlv_parse_dB_info()

 * \param rangemin the minimum value of the raw volume

 * \param rangemax the maximum value of the raw volume

 * \param db_gain the dB gain to convert (in 0.01dB unit)

 * \param value the pointer to store the converted raw volume value

 * \param xdir the direction for round-up. The value is round up

 *        when this is positive.

 * \return 0 if successful, or a negative error code

 */

int snd_tlv_convert_from_dB(unsigned int *tlv, long rangemin, long rangemax,

			    long db_gain, long *value, int xdir)

{

	unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE];

	switch (type) {

	case SND_CTL_TLVT_DB_RANGE: {

		long dbmin, dbmax, prev_submax;

		unsigned int pos, len;

		len = int_index(tlv[SNDRV_CTL_TLVO_LEN]);

		if (len < 6 || len > MAX_TLV_RANGE_SIZE)

			return -EINVAL;

		pos = 2;

		prev_submax = 0;

		while (pos + 4 <= len) {

			long submin, submax;

			submin = (int)tlv[pos];

			submax = (int)tlv[pos + 1];

			if (rangemax < submax)

				submax = rangemax;

			if (!snd_tlv_get_dB_range(tlv + pos + 2,

						  submin, submax,

						  &dbmin, &dbmax) &&

			    db_gain >= dbmin && db_gain <= dbmax)

				return snd_tlv_convert_from_dB(tlv + pos + 2,

							       submin, submax,

							       db_gain, value, xdir);

			else if (db_gain < dbmin) {

				*value = xdir > 0 || pos == 2 ? submin : prev_submax;

				return 0;

			}

			prev_submax = submax;

			if (rangemax == submax)

				break;

			pos += int_index(tlv[pos + 3]) + 4;

		}

		*value = prev_submax;

		return 0;

	}

	case SND_CTL_TLVT_DB_SCALE: {

		int min, step, max, mute;

		min = tlv[SNDRV_CTL_TLVO_DB_SCALE_MIN];

		step = tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] & 0xffff;

		mute = tlv[SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP] & 0x10000;

		max = min + (int)(step * (rangemax - rangemin));

		if (db_gain <= min)

			if (db_gain > SND_CTL_TLV_DB_GAIN_MUTE && xdir > 0 &&

			    mute)

				*value = rangemin + 1;

			else

				*value = rangemin;

		else if (db_gain >= max)

			*value = rangemax;

		else {

			long v = (db_gain - min) * (rangemax - rangemin);

			if (xdir > 0)

				v += (max - min) - 1;

			v = v / (max - min) + rangemin;

			*value = v;

		}

		return 0;

	}

	case SND_CTL_TLVT_DB_MINMAX:

	case SND_CTL_TLVT_DB_MINMAX_MUTE: {

		int min, max;

		min = tlv[SNDRV_CTL_TLVO_DB_MINMAX_MIN];

		max = tlv[SNDRV_CTL_TLVO_DB_MINMAX_MAX];

		if (db_gain <= min)

			if (db_gain > SND_CTL_TLV_DB_GAIN_MUTE && xdir > 0 &&

			    type == SND_CTL_TLVT_DB_MINMAX_MUTE)

				*value = rangemin + 1;

			else

				*value = rangemin;

		else if (db_gain >= max)

			*value = rangemax;

		else {

			long v = (db_gain - min) * (rangemax - rangemin);

			if (xdir > 0)

				v += (max - min) - 1;

			v = v / (max - min) + rangemin;

			*value = v;

		}

		return 0;

	}

#ifndef HAVE_SOFT_FLOAT

	case SND_CTL_TLVT_DB_LINEAR: {

		int min, max;

		min = tlv[SNDRV_CTL_TLVO_DB_LINEAR_MIN];

		max = tlv[SNDRV_CTL_TLVO_DB_LINEAR_MAX];

		if (db_gain <= min)

			*value = rangemin;

		else if (db_gain >= max)

			*value = rangemax;

		else {

			/* FIXME: precalculate and cache vmin and vmax */

			double vmin, vmax, v;

			vmin = (min <= SND_CTL_TLV_DB_GAIN_MUTE) ? 0.0 :

				pow(10.0,  (double)min / 2000.0);

			vmax = !max ? 1.0 : pow(10.0,  (double)max / 2000.0);

			v = pow(10.0, (double)db_gain / 2000.0);

			v = (v - vmin) * (rangemax - rangemin) / (vmax - vmin);

			if (xdir > 0)

				v = ceil(v);

			*value = (long)v + rangemin;

		}

		return 0;

	}

#endif

	default:

		break;

	}

	return -EINVAL;

}

#ifndef DOC_HIDDEN

#define TEMP_TLV_SIZE		4096

struct tlv_info {

	long minval, maxval;

	unsigned int *tlv;

	unsigned int buf[TEMP_TLV_SIZE];

};

#endif

static int get_tlv_info(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,

			struct tlv_info *rec)

{

	snd_ctl_elem_info_t info = {0};

	int err;

	snd_ctl_elem_info_set_id(&info, id);

	err = snd_ctl_elem_info(ctl, &info;;

	if (err < 0)

		return err;

	if (!snd_ctl_elem_info_is_tlv_readable(&info))

		return -EINVAL;

	if (snd_ctl_elem_info_get_type(&info) != SND_CTL_ELEM_TYPE_INTEGER)

		return -EINVAL;

	rec->minval = snd_ctl_elem_info_get_min(&info;;

	rec->maxval = snd_ctl_elem_info_get_max(&info;;

	err = snd_ctl_elem_tlv_read(ctl, id, rec->buf, sizeof(rec->buf));

	if (err < 0)

		return err;

	err = snd_tlv_parse_dB_info(rec->buf, sizeof(rec->buf), &rec->tlv);

	if (err < 0)

		return err;

	return 0;

}

/**

 * \brief Get the dB min/max values on the given control element

 * \param ctl the control handler

 * \param id the element id

 * \param min the pointer to store the minimum dB value (in 0.01dB unit)

 * \param max the pointer to store the maximum dB value (in 0.01dB unit)

 * \return 0 if successful, or a negative error code

 */

int snd_ctl_get_dB_range(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,

			 long *min, long *max)

{

	struct tlv_info info;

	int err;

	err = get_tlv_info(ctl, id, &info;;

	if (err < 0)

		return err;

	return snd_tlv_get_dB_range(info.tlv, info.minval, info.maxval,

				    min, max);

}

/**

 * \brief Convert the volume value to dB on the given control element

 * \param ctl the control handler

 * \param id the element id

 * \param volume the raw volume value to convert

 * \param db_gain the dB gain (in 0.01dB unit)

 * \return 0 if successful, or a negative error code

 */

int snd_ctl_convert_to_dB(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,

			  long volume, long *db_gain)

{

	struct tlv_info info;

	int err;

	err = get_tlv_info(ctl, id, &info;;

	if (err < 0)

		return err;

	return snd_tlv_convert_to_dB(info.tlv, info.minval, info.maxval,

				     volume, db_gain);

}

/**

 * \brief Convert from dB gain to the raw volume value on the given control element

 * \param ctl the control handler

 * \param id the element id

 * \param db_gain the dB gain to convert (in 0.01dB unit)

 * \param value the pointer to store the converted raw volume value

 * \param xdir the direction for round-up. The value is round up

 *        when this is positive.

 * \return 0 if successful, or a negative error code

 */

int snd_ctl_convert_from_dB(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,

			    long db_gain, long *value, int xdir)

{

	struct tlv_info info;

	int err;

	err = get_tlv_info(ctl, id, &info;;

	if (err < 0)

		return err;

	return snd_tlv_convert_from_dB(info.tlv, info.minval, info.maxval,

				       db_gain, value, xdir);

}