Commit fd3b3604 authored by Oleksandr Andrushchenko's avatar Oleksandr Andrushchenko Committed by Takashi Iwai
Browse files

ALSA: xen-front: Read sound driver configuration from Xen store 



Read configuration values from Xen store according
to xen/interface/io/sndif.h protocol:
  - introduce configuration structures for different
    components, e.g. sound card, device, stream
  - read PCM HW parameters, e.g rate, format etc.
  - detect stream type (capture/playback)
  - read device and card parameters

Signed-off-by: default avatarOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent cc3196ae

sound/xen/Makefile

+2 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0 OR MIT



snd_xen_front-objs := xen_snd_front.o

snd_xen_front-objs := xen_snd_front.o \

		      xen_snd_front_cfg.o



obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o

sound/xen/xen_snd_front.c

+7 −0
Original line number Diff line number Diff line
@@ -25,6 +25,13 @@ static void xen_snd_drv_fini(struct xen_snd_front_info *front_info) 


static int sndback_initwait(struct xen_snd_front_info *front_info)

{

	int num_streams;

	int ret;



	ret = xen_snd_front_cfg_card(front_info, &num_streams);

	if (ret < 0)

		return ret;



	return 0;

}

sound/xen/xen_snd_front.h

+4 −0
Original line number Diff line number Diff line
@@ -11,8 +11,12 @@ 
#ifndef __XEN_SND_FRONT_H

#define __XEN_SND_FRONT_H



#include "xen_snd_front_cfg.h"



struct xen_snd_front_info {

	struct xenbus_device *xb_dev;



	struct xen_front_cfg_card cfg;

};



#endif /* __XEN_SND_FRONT_H */

sound/xen/xen_snd_front_cfg.c

0 → 100644
+517 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0 OR MIT



/*

 * Xen para-virtual sound device

 *

 * Copyright (C) 2016-2018 EPAM Systems Inc.

 *

 * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

 */



#include <xen/xenbus.h>



#include <xen/interface/io/sndif.h>



#include "xen_snd_front.h"

#include "xen_snd_front_cfg.h"



/* Maximum number of supported streams. */

#define VSND_MAX_STREAM		8



struct cfg_hw_sample_rate {

	const char *name;

	unsigned int mask;

	unsigned int value;

};



static const struct cfg_hw_sample_rate CFG_HW_SUPPORTED_RATES[] = {

	{ .name = "5512",   .mask = SNDRV_PCM_RATE_5512,   .value = 5512 },

	{ .name = "8000",   .mask = SNDRV_PCM_RATE_8000,   .value = 8000 },

	{ .name = "11025",  .mask = SNDRV_PCM_RATE_11025,  .value = 11025 },

	{ .name = "16000",  .mask = SNDRV_PCM_RATE_16000,  .value = 16000 },

	{ .name = "22050",  .mask = SNDRV_PCM_RATE_22050,  .value = 22050 },

	{ .name = "32000",  .mask = SNDRV_PCM_RATE_32000,  .value = 32000 },

	{ .name = "44100",  .mask = SNDRV_PCM_RATE_44100,  .value = 44100 },

	{ .name = "48000",  .mask = SNDRV_PCM_RATE_48000,  .value = 48000 },

	{ .name = "64000",  .mask = SNDRV_PCM_RATE_64000,  .value = 64000 },

	{ .name = "96000",  .mask = SNDRV_PCM_RATE_96000,  .value = 96000 },

	{ .name = "176400", .mask = SNDRV_PCM_RATE_176400, .value = 176400 },

	{ .name = "192000", .mask = SNDRV_PCM_RATE_192000, .value = 192000 },

};



struct cfg_hw_sample_format {

	const char *name;

	u64 mask;

};



static const struct cfg_hw_sample_format CFG_HW_SUPPORTED_FORMATS[] = {

	{

		.name = XENSND_PCM_FORMAT_U8_STR,

		.mask = SNDRV_PCM_FMTBIT_U8

	},

	{

		.name = XENSND_PCM_FORMAT_S8_STR,

		.mask = SNDRV_PCM_FMTBIT_S8

	},

	{

		.name = XENSND_PCM_FORMAT_U16_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_U16_LE

	},

	{

		.name = XENSND_PCM_FORMAT_U16_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_U16_BE

	},

	{

		.name = XENSND_PCM_FORMAT_S16_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_S16_LE

	},

	{

		.name = XENSND_PCM_FORMAT_S16_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_S16_BE

	},

	{

		.name = XENSND_PCM_FORMAT_U24_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_U24_LE

	},

	{

		.name = XENSND_PCM_FORMAT_U24_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_U24_BE

	},

	{

		.name = XENSND_PCM_FORMAT_S24_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_S24_LE

	},

	{

		.name = XENSND_PCM_FORMAT_S24_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_S24_BE

	},

	{

		.name = XENSND_PCM_FORMAT_U32_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_U32_LE

	},

	{

		.name = XENSND_PCM_FORMAT_U32_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_U32_BE

	},

	{

		.name = XENSND_PCM_FORMAT_S32_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_S32_LE

	},

	{

		.name = XENSND_PCM_FORMAT_S32_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_S32_BE

	},

	{

		.name = XENSND_PCM_FORMAT_A_LAW_STR,

		.mask = SNDRV_PCM_FMTBIT_A_LAW

	},

	{

		.name = XENSND_PCM_FORMAT_MU_LAW_STR,

		.mask = SNDRV_PCM_FMTBIT_MU_LAW

	},

	{

		.name = XENSND_PCM_FORMAT_F32_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_FLOAT_LE

	},

	{

		.name = XENSND_PCM_FORMAT_F32_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_FLOAT_BE

	},

	{

		.name = XENSND_PCM_FORMAT_F64_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_FLOAT64_LE

	},

	{

		.name = XENSND_PCM_FORMAT_F64_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_FLOAT64_BE

	},

	{

		.name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR,

		.mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE

	},

	{

		.name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR,

		.mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE

	},

	{

		.name = XENSND_PCM_FORMAT_IMA_ADPCM_STR,

		.mask = SNDRV_PCM_FMTBIT_IMA_ADPCM

	},

	{

		.name = XENSND_PCM_FORMAT_MPEG_STR,

		.mask = SNDRV_PCM_FMTBIT_MPEG

	},

	{

		.name = XENSND_PCM_FORMAT_GSM_STR,

		.mask = SNDRV_PCM_FMTBIT_GSM

	},

};



static void cfg_hw_rates(char *list, unsigned int len,

			 const char *path, struct snd_pcm_hardware *pcm_hw)

{

	char *cur_rate;

	unsigned int cur_mask;

	unsigned int cur_value;

	unsigned int rates;

	unsigned int rate_min;

	unsigned int rate_max;

	int i;



	rates = 0;

	rate_min = -1;

	rate_max = 0;

	while ((cur_rate = strsep(&list, XENSND_LIST_SEPARATOR))) {

		for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_RATES); i++)

			if (!strncasecmp(cur_rate,

					 CFG_HW_SUPPORTED_RATES[i].name,

					 XENSND_SAMPLE_RATE_MAX_LEN)) {

				cur_mask = CFG_HW_SUPPORTED_RATES[i].mask;

				cur_value = CFG_HW_SUPPORTED_RATES[i].value;

				rates |= cur_mask;

				if (rate_min > cur_value)

					rate_min = cur_value;

				if (rate_max < cur_value)

					rate_max = cur_value;

			}

	}



	if (rates) {

		pcm_hw->rates = rates;

		pcm_hw->rate_min = rate_min;

		pcm_hw->rate_max = rate_max;

	}

}



static void cfg_formats(char *list, unsigned int len,

			const char *path, struct snd_pcm_hardware *pcm_hw)

{

	u64 formats;

	char *cur_format;

	int i;



	formats = 0;

	while ((cur_format = strsep(&list, XENSND_LIST_SEPARATOR))) {

		for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_FORMATS); i++)

			if (!strncasecmp(cur_format,

					 CFG_HW_SUPPORTED_FORMATS[i].name,

					 XENSND_SAMPLE_FORMAT_MAX_LEN))

				formats |= CFG_HW_SUPPORTED_FORMATS[i].mask;

	}



	if (formats)

		pcm_hw->formats = formats;

}



#define MAX_BUFFER_SIZE		(64 * 1024)

#define MIN_PERIOD_SIZE		64

#define MAX_PERIOD_SIZE		MAX_BUFFER_SIZE

#define USE_FORMATS		(SNDRV_PCM_FMTBIT_U8 | \

				 SNDRV_PCM_FMTBIT_S16_LE)

#define USE_RATE		(SNDRV_PCM_RATE_CONTINUOUS | \

				 SNDRV_PCM_RATE_8000_48000)

#define USE_RATE_MIN		5512

#define USE_RATE_MAX		48000

#define USE_CHANNELS_MIN	1

#define USE_CHANNELS_MAX	2

#define USE_PERIODS_MIN		2

#define USE_PERIODS_MAX		(MAX_BUFFER_SIZE / MIN_PERIOD_SIZE)



static const struct snd_pcm_hardware SND_DRV_PCM_HW_DEFAULT = {

	.info = (SNDRV_PCM_INFO_MMAP |

		 SNDRV_PCM_INFO_INTERLEAVED |

		 SNDRV_PCM_INFO_RESUME |

		 SNDRV_PCM_INFO_MMAP_VALID),

	.formats = USE_FORMATS,

	.rates = USE_RATE,

	.rate_min = USE_RATE_MIN,

	.rate_max = USE_RATE_MAX,

	.channels_min = USE_CHANNELS_MIN,

	.channels_max = USE_CHANNELS_MAX,

	.buffer_bytes_max = MAX_BUFFER_SIZE,

	.period_bytes_min = MIN_PERIOD_SIZE,

	.period_bytes_max = MAX_PERIOD_SIZE,

	.periods_min = USE_PERIODS_MIN,

	.periods_max = USE_PERIODS_MAX,

	.fifo_size = 0,

};



static void cfg_read_pcm_hw(const char *path,

			    struct snd_pcm_hardware *parent_pcm_hw,

			    struct snd_pcm_hardware *pcm_hw)

{

	char *list;

	int val;

	size_t buf_sz;

	unsigned int len;



	/* Inherit parent's PCM HW and read overrides from XenStore. */

	if (parent_pcm_hw)

		*pcm_hw = *parent_pcm_hw;

	else

		*pcm_hw = SND_DRV_PCM_HW_DEFAULT;



	val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MIN, 0);

	if (val)

		pcm_hw->channels_min = val;



	val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MAX, 0);

	if (val)

		pcm_hw->channels_max = val;



	list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_RATES, &len);

	if (!IS_ERR(list)) {

		cfg_hw_rates(list, len, path, pcm_hw);

		kfree(list);

	}



	list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_FORMATS, &len);

	if (!IS_ERR(list)) {

		cfg_formats(list, len, path, pcm_hw);

		kfree(list);

	}



	buf_sz = xenbus_read_unsigned(path, XENSND_FIELD_BUFFER_SIZE, 0);

	if (buf_sz)

		pcm_hw->buffer_bytes_max = buf_sz;



	/* Update configuration to match new values. */

	if (pcm_hw->channels_min > pcm_hw->channels_max)

		pcm_hw->channels_min = pcm_hw->channels_max;



	if (pcm_hw->rate_min > pcm_hw->rate_max)

		pcm_hw->rate_min = pcm_hw->rate_max;



	pcm_hw->period_bytes_max = pcm_hw->buffer_bytes_max;



	pcm_hw->periods_max = pcm_hw->period_bytes_max /

		pcm_hw->period_bytes_min;

}



static int cfg_get_stream_type(const char *path, int index,

			       int *num_pb, int *num_cap)

{

	char *str = NULL;

	char *stream_path;

	int ret;



	*num_pb = 0;

	*num_cap = 0;

	stream_path = kasprintf(GFP_KERNEL, "%s/%d", path, index);

	if (!stream_path) {

		ret = -ENOMEM;

		goto fail;

	}



	str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);

	if (IS_ERR(str)) {

		ret = PTR_ERR(str);

		goto fail;

	}



	if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,

			 sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {

		(*num_pb)++;

	} else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,

			      sizeof(XENSND_STREAM_TYPE_CAPTURE))) {

		(*num_cap)++;

	} else {

		ret = -EINVAL;

		goto fail;

	}

	ret = 0;



fail:

	kfree(stream_path);

	kfree(str);

	return ret;

}



static int cfg_stream(struct xen_snd_front_info *front_info,

		      struct xen_front_cfg_pcm_instance *pcm_instance,

		      const char *path, int index, int *cur_pb, int *cur_cap,

		      int *stream_cnt)

{

	char *str = NULL;

	char *stream_path;

	struct xen_front_cfg_stream *stream;

	int ret;



	stream_path = devm_kasprintf(&front_info->xb_dev->dev,

				     GFP_KERNEL, "%s/%d", path, index);

	if (!stream_path) {

		ret = -ENOMEM;

		goto fail;

	}



	str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);

	if (IS_ERR(str)) {

		ret = PTR_ERR(str);

		goto fail;

	}



	if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,

			 sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {

		stream = &pcm_instance->streams_pb[(*cur_pb)++];

	} else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,

			      sizeof(XENSND_STREAM_TYPE_CAPTURE))) {

		stream = &pcm_instance->streams_cap[(*cur_cap)++];

	} else {

		ret = -EINVAL;

		goto fail;

	}



	/* Get next stream index. */

	stream->index = (*stream_cnt)++;

	stream->xenstore_path = stream_path;

	/*

	 * Check XenStore if PCM HW configuration exists for this stream

	 * and update if so, e.g. we inherit all values from device's PCM HW,

	 * but can still override some of the values for the stream.

	 */

	cfg_read_pcm_hw(stream->xenstore_path,

			&pcm_instance->pcm_hw, &stream->pcm_hw);

	ret = 0;



fail:

	kfree(str);

	return ret;

}



static int cfg_device(struct xen_snd_front_info *front_info,

		      struct xen_front_cfg_pcm_instance *pcm_instance,

		      struct snd_pcm_hardware *parent_pcm_hw,

		      const char *path, int node_index, int *stream_cnt)

{

	char *str;

	char *device_path;

	int ret, i, num_streams;

	int num_pb, num_cap;

	int cur_pb, cur_cap;

	char node[3];



	device_path = kasprintf(GFP_KERNEL, "%s/%d", path, node_index);

	if (!device_path)

		return -ENOMEM;



	str = xenbus_read(XBT_NIL, device_path, XENSND_FIELD_DEVICE_NAME, NULL);

	if (!IS_ERR(str)) {

		strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));

		kfree(str);

	}



	pcm_instance->device_id = node_index;



	/*

	 * Check XenStore if PCM HW configuration exists for this device

	 * and update if so, e.g. we inherit all values from card's PCM HW,

	 * but can still override some of the values for the device.

	 */

	cfg_read_pcm_hw(device_path, parent_pcm_hw, &pcm_instance->pcm_hw);



	/* Find out how many streams were configured in Xen store. */

	num_streams = 0;

	do {

		snprintf(node, sizeof(node), "%d", num_streams);

		if (!xenbus_exists(XBT_NIL, device_path, node))

			break;



		num_streams++;

	} while (num_streams < VSND_MAX_STREAM);



	pcm_instance->num_streams_pb = 0;

	pcm_instance->num_streams_cap = 0;

	/* Get number of playback and capture streams. */

	for (i = 0; i < num_streams; i++) {

		ret = cfg_get_stream_type(device_path, i, &num_pb, &num_cap);

		if (ret < 0)

			goto fail;



		pcm_instance->num_streams_pb += num_pb;

		pcm_instance->num_streams_cap += num_cap;

	}



	if (pcm_instance->num_streams_pb) {

		pcm_instance->streams_pb =

				devm_kcalloc(&front_info->xb_dev->dev,

					     pcm_instance->num_streams_pb,

					     sizeof(struct xen_front_cfg_stream),

					     GFP_KERNEL);

		if (!pcm_instance->streams_pb) {

			ret = -ENOMEM;

			goto fail;

		}

	}



	if (pcm_instance->num_streams_cap) {

		pcm_instance->streams_cap =

				devm_kcalloc(&front_info->xb_dev->dev,

					     pcm_instance->num_streams_cap,

					     sizeof(struct xen_front_cfg_stream),

					     GFP_KERNEL);

		if (!pcm_instance->streams_cap) {

			ret = -ENOMEM;

			goto fail;

		}

	}



	cur_pb = 0;

	cur_cap = 0;

	for (i = 0; i < num_streams; i++) {

		ret = cfg_stream(front_info, pcm_instance, device_path, i,

				 &cur_pb, &cur_cap, stream_cnt);

		if (ret < 0)

			goto fail;

	}

	ret = 0;



fail:

	kfree(device_path);

	return ret;

}



int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,

			   int *stream_cnt)

{

	struct xenbus_device *xb_dev = front_info->xb_dev;

	struct xen_front_cfg_card *cfg = &front_info->cfg;

	int ret, num_devices, i;

	char node[3];



	*stream_cnt = 0;

	num_devices = 0;

	do {

		snprintf(node, sizeof(node), "%d", num_devices);

		if (!xenbus_exists(XBT_NIL, xb_dev->nodename, node))

			break;



		num_devices++;

	} while (num_devices < SNDRV_PCM_DEVICES);



	if (!num_devices) {

		dev_warn(&xb_dev->dev,

			 "No devices configured for sound card at %s\n",

			 xb_dev->nodename);

		return -ENODEV;

	}



	/* Start from default PCM HW configuration for the card. */

	cfg_read_pcm_hw(xb_dev->nodename, NULL, &cfg->pcm_hw);



	cfg->pcm_instances =

			devm_kcalloc(&front_info->xb_dev->dev, num_devices,

				     sizeof(struct xen_front_cfg_pcm_instance),

				     GFP_KERNEL);

	if (!cfg->pcm_instances)

		return -ENOMEM;



	for (i = 0; i < num_devices; i++) {

		ret = cfg_device(front_info, &cfg->pcm_instances[i],

				 &cfg->pcm_hw, xb_dev->nodename, i, stream_cnt);

		if (ret < 0)

			return ret;

	}

	cfg->num_pcm_instances = num_devices;

	return 0;

}

sound/xen/xen_snd_front_cfg.h

0 → 100644
+46 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 OR MIT */



/*

 * Xen para-virtual sound device

 *

 * Copyright (C) 2016-2018 EPAM Systems Inc.

 *

 * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

 */



#ifndef __XEN_SND_FRONT_CFG_H

#define __XEN_SND_FRONT_CFG_H



#include <sound/core.h>

#include <sound/pcm.h>



struct xen_snd_front_info;



struct xen_front_cfg_stream {

	int index;

	char *xenstore_path;

	struct snd_pcm_hardware pcm_hw;

};



struct xen_front_cfg_pcm_instance {

	char name[80];

	int device_id;

	struct snd_pcm_hardware pcm_hw;

	int  num_streams_pb;

	struct xen_front_cfg_stream *streams_pb;

	int  num_streams_cap;

	struct xen_front_cfg_stream *streams_cap;

};



struct xen_front_cfg_card {

	char name_short[32];

	char name_long[80];

	struct snd_pcm_hardware pcm_hw;

	int num_pcm_instances;

	struct xen_front_cfg_pcm_instance *pcm_instances;

};



int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,

			   int *stream_cnt);



#endif /* __XEN_SND_FRONT_CFG_H */

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