Recoded hwdep API to follow modern conf style.

Added hwdep configuration to alsa.conf.
Added documentation for hwdep interface.

src/hwdep/hwdep_hw.c

@@ -0,0 +1,180 @@
+/*
+ *  Hardware dependent Interface - main file for hardware access
+ *  Copyright (c) 2001 by Jaroslav Kysela <perex@suse.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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include "hwdep_local.h"
+
+#define SNDRV_FILE_HWDEP	"/dev/snd/hwC%iD%i"
+#define SNDRV_HWDEP_VERSION_MAX	SNDRV_PROTOCOL_VERSION(1, 0, 0)
+
+static int snd_hwdep_hw_close(snd_hwdep_t *hwdep)
+{
+	int res;
+	assert(hwdep);
+	res = close(hwdep->poll_fd) < 0 ? -errno : 0;
+	free(hwdep);
+	return res;
+}
+
+static int snd_hwdep_hw_nonblock(snd_hwdep_t *hwdep, int nonblock)
+{
+	long flags;
+	assert(hwdep);
+	if ((flags = fcntl(hwdep->poll_fd, F_GETFL)) < 0)
+		return -errno;
+	if (nonblock)
+		flags |= O_NONBLOCK;
+	else
+		flags &= ~O_NONBLOCK;
+	if (fcntl(hwdep->poll_fd, F_SETFL, flags) < 0)
+		return -errno;
+	return 0;
+}
+
+static int snd_hwdep_hw_info(snd_hwdep_t *hwdep, snd_hwdep_info_t *info)
+{
+	assert(hwdep && info);
+	if (ioctl(hwdep->poll_fd, SNDRV_HWDEP_IOCTL_INFO, info) < 0)
+		return -errno;
+	return 0;
+}
+
+static int snd_hwdep_hw_ioctl(snd_hwdep_t *hwdep, unsigned int request, void * arg)
+{
+	assert(hwdep);
+	if (ioctl(hwdep->poll_fd, request, arg) < 0)
+		return -errno;
+	return 0;
+}
+
+static ssize_t snd_hwdep_hw_write(snd_hwdep_t *hwdep, const void *buffer, size_t size)
+{
+	ssize_t result;
+	assert(hwdep && (buffer || size == 0));
+	result = write(hwdep->poll_fd, buffer, size);
+	if (result < 0)
+		return -errno;
+	return result;
+}
+
+static ssize_t snd_hwdep_hw_read(snd_hwdep_t *hwdep, void *buffer, size_t size)
+{
+	ssize_t result;
+	assert(hwdep && (buffer || size == 0));
+	result = read(hwdep->poll_fd, buffer, size);
+	if (result < 0)
+		return -errno;
+	return result;
+}
+
+static snd_hwdep_ops_t snd_hwdep_hw_ops = {
+	close: snd_hwdep_hw_close,
+	nonblock: snd_hwdep_hw_nonblock,
+	info: snd_hwdep_hw_info,
+	ioctl: snd_hwdep_hw_ioctl,
+	write: snd_hwdep_hw_write,
+	read: snd_hwdep_hw_read,
+};
+
+int snd_hwdep_hw_open(snd_hwdep_t **handle, const char *name, int card, int device, int mode)
+{
+	int fd, ver;
+	char filename[32];
+	snd_hwdep_t *hwdep;
+	assert(handle);
+
+	*handle = NULL;
+	
+	if (card < 0 || card >= 32)
+		return -EINVAL;
+	sprintf(filename, SNDRV_FILE_HWDEP, card, device);
+	if ((fd = open(filename, mode)) < 0) {
+		snd_card_load(card);
+		if ((fd = open(filename, mode)) < 0)
+			return -errno;
+	}
+	if (ioctl(fd, SNDRV_HWDEP_IOCTL_PVERSION, &ver) < 0) {
+		close(fd);
+		return -errno;
+	}
+	if (SNDRV_PROTOCOL_INCOMPATIBLE(ver, SNDRV_HWDEP_VERSION_MAX)) {
+		close(fd);
+		return -SND_ERROR_INCOMPATIBLE_VERSION;
+	}
+	hwdep = (snd_hwdep_t *) calloc(1, sizeof(snd_hwdep_t));
+	if (hwdep == NULL) {
+		close(fd);
+		return -ENOMEM;
+	}
+	hwdep->name = strdup(name);
+	hwdep->poll_fd = fd;
+	hwdep->mode = mode;
+	hwdep->type = SND_HWDEP_TYPE_HW;
+	hwdep->ops = &snd_hwdep_hw_ops;
+	*handle = hwdep;
+	return 0;
+}
+
+int _snd_hwdep_hw_open(snd_hwdep_t **hwdep, char *name,
+		       snd_config_t *root ATTRIBUTE_UNUSED,
+		       snd_config_t *conf, int mode)
+{
+	snd_config_iterator_t i, next;
+	long card = -1, device = 0;
+	const char *str;
+	int err;
+	snd_config_for_each(i, next, conf) {
+		snd_config_t *n = snd_config_iterator_entry(i);
+		const char *id = snd_config_get_id(n);
+		if (strcmp(id, "comment") == 0)
+			continue;
+		if (strcmp(id, "type") == 0)
+			continue;
+		if (strcmp(id, "card") == 0) {
+			err = snd_config_get_integer(n, &card);
+			if (err < 0) {
+				err = snd_config_get_string(n, &str);
+				if (err < 0)
+					return -EINVAL;
+				card = snd_card_get_index(str);
+				if (card < 0)
+					return card;
+			}
+			continue;
+		}
+		if (strcmp(id, "device") == 0) {
+			err = snd_config_get_integer(n, &device);
+			if (err < 0)
+				return err;
+			continue;
+		}
+		SNDERR("Unexpected field %s", id);
+		return -EINVAL;
+	}
+	if (card < 0)
+		return -EINVAL;
+	return snd_hwdep_hw_open(hwdep, name, card, device, mode);
+}