[alsa-devel] [PATCH v2 2/9] ASoC: tegra: add support for CIF programming

[Sameer Pujar]

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 a helper 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 at nvidia.com>
---
 sound/soc/tegra/Makefile    |  2 ++
 sound/soc/tegra/tegra_cif.c | 34 ++++++++++++++++++++++++++++++++
 sound/soc/tegra/tegra_cif.h | 47 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 sound/soc/tegra/tegra_cif.c
 create mode 100644 sound/soc/tegra/tegra_cif.h

diff --git a/sound/soc/tegra/Makefile b/sound/soc/tegra/Makefile
index c84f183..261aa21 100644
--- a/sound/soc/tegra/Makefile
+++ b/sound/soc/tegra/Makefile
@@ -8,9 +8,11 @@ snd-soc-tegra20-i2s-objs := tegra20_i2s.o
 snd-soc-tegra20-spdif-objs := tegra20_spdif.o
 snd-soc-tegra30-ahub-objs := tegra30_ahub.o
 snd-soc-tegra30-i2s-objs := tegra30_i2s.o
+snd-soc-tegra-cif-objs := tegra_cif.o
 
 obj-$(CONFIG_SND_SOC_TEGRA) += snd-soc-tegra-pcm.o
 obj-$(CONFIG_SND_SOC_TEGRA) += snd-soc-tegra-utils.o
+obj-$(CONFIG_SND_SOC_TEGRA) += snd-soc-tegra-cif.o
 obj-$(CONFIG_SND_SOC_TEGRA20_AC97) += snd-soc-tegra20-ac97.o
 obj-$(CONFIG_SND_SOC_TEGRA20_DAS) += snd-soc-tegra20-das.o
 obj-$(CONFIG_SND_SOC_TEGRA20_I2S) += snd-soc-tegra20-i2s.o
diff --git a/sound/soc/tegra/tegra_cif.c b/sound/soc/tegra/tegra_cif.c
new file mode 100644
index 0000000..242ae34
--- /dev/null
+++ b/sound/soc/tegra/tegra_cif.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * tegra_cif.c - Tegra Audio CIF Programming for AHUB modules
+ *
+ * Copyright (c) 2020 NVIDIA CORPORATION.  All rights reserved.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include "tegra_cif.h"
+
+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);
+}
+EXPORT_SYMBOL_GPL(tegra_set_cif);
+
+MODULE_DESCRIPTION("Tegra Audio Client Interface (ACIF) driver");
+MODULE_LICENSE("GPL v2");
diff --git a/sound/soc/tegra/tegra_cif.h b/sound/soc/tegra/tegra_cif.h
new file mode 100644
index 0000000..fb55812
--- /dev/null
+++ b/sound/soc/tegra/tegra_cif.h
@@ -0,0 +1,47 @@
+/* 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__
+
+#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;
+};
+
+void tegra_set_cif(struct regmap *regmap, unsigned int reg,
+		   struct tegra_cif_conf *conf);
+
+#endif
-- 
2.7.4