Fix alsa/sound/*.h for external programs

The recent update of sound/*.h to sync with the latest Linus uapi
files broke the build of alsa-tools programs.  These files used to be
a modified version of Linux sound/* header files, so that they could
be built without Linux headers.  The special prefix like __user and
other things were worked around there.

We may do that again, but a better approach is to fix those things in
Linux kernel uapi side, while we keep the minimal workaround in
alsa-lib such as the __u16 and co type definitions.

This patch is such an attempt, namely:
- Keep the original $LINUX/uapi/sound/*.h in include/sound/uapi
  directory
- The "fixes" are applied to some uapi headers, so that they don't
  contain Linux-specific prefix and use of opaque struct like
  snd_ctl_elem_id
- The uapi headers are included indirectly from include/sound/*.h
- Some headers have inclusion of type_compat.h for the Linux variable
  types and prefixes
- type_compat.h tries to use <linux/types.h> when __linux__ is
  defined, instead of the own conflicting definitions

The last type might need a bit more adjustment depending on the
compiler, but it can be fixed locally without disturbing else.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/uapi/tlv.h

@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ *   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.
+ */
+
+#ifndef __UAPI_SOUND_TLV_H
+#define __UAPI_SOUND_TLV_H
+
+#define SNDRV_CTL_TLVT_CONTAINER 0	/* one level down - group of TLVs */
+#define SNDRV_CTL_TLVT_DB_SCALE	1       /* dB scale */
+#define SNDRV_CTL_TLVT_DB_LINEAR 2	/* linear volume */
+#define SNDRV_CTL_TLVT_DB_RANGE 3	/* dB range container */
+#define SNDRV_CTL_TLVT_DB_MINMAX 4	/* dB scale with min/max */
+#define SNDRV_CTL_TLVT_DB_MINMAX_MUTE 5	/* dB scale with min/max with mute */
+
+/*
+ * channel-mapping TLV items
+ *  TLV length must match with num_channels
+ */
+#define SNDRV_CTL_TLVT_CHMAP_FIXED	0x101	/* fixed channel position */
+#define SNDRV_CTL_TLVT_CHMAP_VAR	0x102	/* channels freely swappable */
+#define SNDRV_CTL_TLVT_CHMAP_PAIRED	0x103	/* pair-wise swappable */
+
+/*
+ * TLV structure is right behind the struct snd_ctl_tlv:
+ *   unsigned int type  	- see SNDRV_CTL_TLVT_*
+ *   unsigned int length
+ *   .... data aligned to sizeof(unsigned int), use
+ *        block_length = (length + (sizeof(unsigned int) - 1)) &
+ *                       ~(sizeof(unsigned int) - 1)) ....
+ */
+#define SNDRV_CTL_TLVD_ITEM(type, ...) \
+	(type), SNDRV_CTL_TLVD_LENGTH(__VA_ARGS__), __VA_ARGS__
+#define SNDRV_CTL_TLVD_LENGTH(...) \
+	((unsigned int)sizeof((const unsigned int[]) { __VA_ARGS__ }))
+
+/* Accessor offsets for TLV data items */
+#define SNDRV_CTL_TLVO_TYPE		0
+#define SNDRV_CTL_TLVO_LEN		1
+
+#define SNDRV_CTL_TLVD_CONTAINER_ITEM(...) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_CONTAINER, __VA_ARGS__)
+#define SNDRV_CTL_TLVD_DECLARE_CONTAINER(name, ...) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_CONTAINER_ITEM(__VA_ARGS__) \
+	}
+
+#define SNDRV_CTL_TLVD_DB_SCALE_MASK	0xffff
+#define SNDRV_CTL_TLVD_DB_SCALE_MUTE	0x10000
+#define SNDRV_CTL_TLVD_DB_SCALE_ITEM(min, step, mute) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_SCALE, \
+			    (min), \
+			    ((step) & SNDRV_CTL_TLVD_DB_SCALE_MASK) | \
+			     ((mute) ? SNDRV_CTL_TLVD_DB_SCALE_MUTE : 0))
+#define SNDRV_CTL_TLVD_DECLARE_DB_SCALE(name, min, step, mute) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_SCALE_ITEM(min, step, mute) \
+	}
+
+/* Accessor offsets for min, mute and step items in dB scale type TLV */
+#define SNDRV_CTL_TLVO_DB_SCALE_MIN		2
+#define SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP	3
+
+/* dB scale specified with min/max values instead of step */
+#define SNDRV_CTL_TLVD_DB_MINMAX_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_MINMAX, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_MINMAX_MUTE, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DECLARE_DB_MINMAX(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_MINMAX_ITEM(min_dB, max_dB) \
+	}
+#define SNDRV_CTL_TLVD_DECLARE_DB_MINMAX_MUTE(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) \
+	}
+
+/* Accessor offsets for min, max items in db-minmax types of TLV. */
+#define SNDRV_CTL_TLVO_DB_MINMAX_MIN	2
+#define SNDRV_CTL_TLVO_DB_MINMAX_MAX	3
+
+/* linear volume between min_dB and max_dB (.01dB unit) */
+#define SNDRV_CTL_TLVD_DB_LINEAR_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_LINEAR, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DECLARE_DB_LINEAR(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_LINEAR_ITEM(min_dB, max_dB) \
+	}
+
+/* Accessor offsets for min, max items in db-linear type of TLV. */
+#define SNDRV_CTL_TLVO_DB_LINEAR_MIN	2
+#define SNDRV_CTL_TLVO_DB_LINEAR_MAX	3
+
+/* dB range container:
+ * Items in dB range container must be ordered by their values and by their
+ * dB values. This implies that larger values must correspond with larger
+ * dB values (which is also required for all other mixer controls).
+ */
+/* Each item is: <min> <max> <TLV> */
+#define SNDRV_CTL_TLVD_DB_RANGE_ITEM(...) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_RANGE, __VA_ARGS__)
+#define SNDRV_CTL_TLVD_DECLARE_DB_RANGE(name, ...) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_RANGE_ITEM(__VA_ARGS__) \
+	}
+
+#define SNDRV_CTL_TLVD_DB_GAIN_MUTE	-9999999
+
+#endif