ASoC: tegra: Add support for CIF programming

Audio Client Interface (CIF) is a proprietary interface employed to route
audio samples through Audio Hub (AHUB) components by inter connecting the
various modules.

This patch exports an inline function tegra_set_cif() which can be used,
for now, to program CIF on Tegra210 and later Tegra generations. Later it
can be extended to include helpers for legacy chips as well.
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/1595134890-16470-3-git-send-email-spujar@nvidia.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/tegra_cif.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * tegra_cif.h - TEGRA Audio CIF Programming
+ *
+ * Copyright (c) 2020 NVIDIA CORPORATION.  All rights reserved.
+ *
+ */
+
+#ifndef __TEGRA_CIF_H__
+#define __TEGRA_CIF_H__
+
+#include <linux/regmap.h>
+
+#define TEGRA_ACIF_CTRL_FIFO_TH_SHIFT		24
+#define TEGRA_ACIF_CTRL_AUDIO_CH_SHIFT		20
+#define TEGRA_ACIF_CTRL_CLIENT_CH_SHIFT		16
+#define TEGRA_ACIF_CTRL_AUDIO_BITS_SHIFT	12
+#define TEGRA_ACIF_CTRL_CLIENT_BITS_SHIFT	8
+#define TEGRA_ACIF_CTRL_EXPAND_SHIFT		6
+#define TEGRA_ACIF_CTRL_STEREO_CONV_SHIFT	4
+#define TEGRA_ACIF_CTRL_REPLICATE_SHIFT		3
+#define TEGRA_ACIF_CTRL_TRUNCATE_SHIFT		1
+#define TEGRA_ACIF_CTRL_MONO_CONV_SHIFT		0
+
+/* AUDIO/CLIENT_BITS values */
+#define TEGRA_ACIF_BITS_8			1
+#define TEGRA_ACIF_BITS_16			3
+#define TEGRA_ACIF_BITS_24			5
+#define TEGRA_ACIF_BITS_32			7
+
+#define TEGRA_ACIF_UPDATE_MASK			0x3ffffffb
+
+struct tegra_cif_conf {
+	unsigned int threshold;
+	unsigned int audio_ch;
+	unsigned int client_ch;
+	unsigned int audio_bits;
+	unsigned int client_bits;
+	unsigned int expand;
+	unsigned int stereo_conv;
+	unsigned int replicate;
+	unsigned int truncate;
+	unsigned int mono_conv;
+};
+
+static inline void tegra_set_cif(struct regmap *regmap, unsigned int reg,
+				 struct tegra_cif_conf *conf)
+{
+	unsigned int value;
+
+	value = (conf->threshold << TEGRA_ACIF_CTRL_FIFO_TH_SHIFT) |
+		((conf->audio_ch - 1) << TEGRA_ACIF_CTRL_AUDIO_CH_SHIFT) |
+		((conf->client_ch - 1) << TEGRA_ACIF_CTRL_CLIENT_CH_SHIFT) |
+		(conf->audio_bits << TEGRA_ACIF_CTRL_AUDIO_BITS_SHIFT) |
+		(conf->client_bits << TEGRA_ACIF_CTRL_CLIENT_BITS_SHIFT) |
+		(conf->expand << TEGRA_ACIF_CTRL_EXPAND_SHIFT) |
+		(conf->stereo_conv << TEGRA_ACIF_CTRL_STEREO_CONV_SHIFT) |
+		(conf->replicate << TEGRA_ACIF_CTRL_REPLICATE_SHIFT) |
+		(conf->truncate << TEGRA_ACIF_CTRL_TRUNCATE_SHIFT) |
+		(conf->mono_conv << TEGRA_ACIF_CTRL_MONO_CONV_SHIFT);
+
+	regmap_update_bits(regmap, reg, TEGRA_ACIF_UPDATE_MASK, value);
+}
+
+#endif