ASoC: tegra: Add Tegra210 based SFC driver

The Sampling Frequency Converter (SFC) converts the sampling frequency
of the input signal from one frequency to another. It supports sampling
frequency conversions of streams of up to two channels (stereo).

This patch registers SFC driver with ASoC framework. The component driver
exposes DAPM widgets, routes and kcontrols for the device. The DAI driver
exposes SFC interfaces, which can be used to connect different components
in the ASoC layer. Makefile and Kconfig support is added to allow build
the driver. It can be enabled in the DT via "nvidia,tegra210-sfc"
compatible binding.
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1631551342-25469-8-git-send-email-spujar@nvidia.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/Kconfig

@@ -117,6 +117,15 @@ config SND_SOC_TEGRA210_MVC
 	  per-stream volume control or for master volume control.
 	  Say Y or M if you want to add support for Tegra210 MVC module.
 
+config SND_SOC_TEGRA210_SFC
+	tristate "Tegra210 SFC module"
+	help
+	  Config to enable the Sampling Frequency Converter (SFC) which
+	  converts the sampling frequency of input signal to another
+	  frequency. It supports sampling frequency conversion of streams
+	  upto 2 channels (stereo).
+	  Say Y or M if you want to add support for Tegra210 SFC module.
+
 config SND_SOC_TEGRA_AUDIO_GRAPH_CARD
 	tristate "Audio Graph Card based Tegra driver"
 	depends on SND_AUDIO_GRAPH_CARD

sound/soc/tegra/Makefile

@@ -14,6 +14,7 @@ snd-soc-tegra210-i2s-objs := tegra210_i2s.o
 snd-soc-tegra186-dspk-objs := tegra186_dspk.o
 snd-soc-tegra210-admaif-objs := tegra210_admaif.o
 snd-soc-tegra210-mvc-objs := tegra210_mvc.o
+snd-soc-tegra210-sfc-objs := tegra210_sfc.o
 
 obj-$(CONFIG_SND_SOC_TEGRA) += snd-soc-tegra-pcm.o
 obj-$(CONFIG_SND_SOC_TEGRA20_AC97) += snd-soc-tegra20-ac97.o
@@ -28,6 +29,7 @@ obj-$(CONFIG_SND_SOC_TEGRA210_I2S) += snd-soc-tegra210-i2s.o
 obj-$(CONFIG_SND_SOC_TEGRA186_DSPK) += snd-soc-tegra186-dspk.o
 obj-$(CONFIG_SND_SOC_TEGRA210_ADMAIF) += snd-soc-tegra210-admaif.o
 obj-$(CONFIG_SND_SOC_TEGRA210_MVC) += snd-soc-tegra210-mvc.o
+obj-$(CONFIG_SND_SOC_TEGRA210_SFC) += snd-soc-tegra210-sfc.o
 
 # Tegra machine Support
 snd-soc-tegra-wm8903-objs := tegra_wm8903.o

sound/soc/tegra/tegra210_sfc.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * tegra210_sfc.h - Definitions for Tegra210 SFC driver
+ *
+ * Copyright (c) 2021 NVIDIA CORPORATION.  All rights reserved.
+ *
+ */
+
+#ifndef __TEGRA210_SFC_H__
+#define __TEGRA210_SFC_H__
+
+/*
+ * SFC_RX registers are with respect to XBAR.
+ * The data comes from XBAR to SFC.
+ */
+#define TEGRA210_SFC_RX_STATUS			0x0c
+#define TEGRA210_SFC_RX_INT_STATUS		0x10
+#define TEGRA210_SFC_RX_INT_MASK		0x14
+#define TEGRA210_SFC_RX_INT_SET			0x18
+#define TEGRA210_SFC_RX_INT_CLEAR		0x1c
+#define TEGRA210_SFC_RX_CIF_CTRL		0x20
+#define TEGRA210_SFC_RX_FREQ			0x24
+
+/*
+ * SFC_TX registers are with respect to XBAR.
+ * The data goes out of SFC.
+ */
+#define TEGRA210_SFC_TX_STATUS			0x4c
+#define TEGRA210_SFC_TX_INT_STATUS		0x50
+#define TEGRA210_SFC_TX_INT_MASK		0x54
+#define TEGRA210_SFC_TX_INT_SET			0x58
+#define TEGRA210_SFC_TX_INT_CLEAR		0x5c
+#define TEGRA210_SFC_TX_CIF_CTRL		0x60
+#define TEGRA210_SFC_TX_FREQ			0x64
+
+/* Register offsets from TEGRA210_SFC*_BASE */
+#define TEGRA210_SFC_ENABLE			0x80
+#define TEGRA210_SFC_SOFT_RESET			0x84
+#define TEGRA210_SFC_CG				0x88
+#define TEGRA210_SFC_STATUS			0x8c
+#define TEGRA210_SFC_INT_STATUS			0x90
+#define TEGRA210_SFC_COEF_RAM			0xbc
+#define TEGRA210_SFC_CFG_RAM_CTRL		0xc0
+#define TEGRA210_SFC_CFG_RAM_DATA		0xc4
+
+/* Fields in TEGRA210_SFC_ENABLE */
+#define TEGRA210_SFC_EN_SHIFT			0
+#define TEGRA210_SFC_EN				(1 << TEGRA210_SFC_EN_SHIFT)
+
+#define TEGRA210_SFC_NUM_RATES 12
+
+/* Fields in TEGRA210_SFC_COEF_RAM */
+#define TEGRA210_SFC_COEF_RAM_EN		BIT(0)
+
+#define TEGRA210_SFC_SOFT_RESET_EN              BIT(0)
+
+/* Coefficients */
+#define TEGRA210_SFC_COEF_RAM_DEPTH		64
+#define TEGRA210_SFC_RAM_CTRL_RW_WRITE		(1 << 14)
+#define TEGRA210_SFC_RAM_CTRL_ADDR_INIT_EN	(1 << 13)
+#define TEGRA210_SFC_RAM_CTRL_SEQ_ACCESS_EN	(1 << 12)
+
+
+enum tegra210_sfc_path {
+	SFC_RX_PATH,
+	SFC_TX_PATH,
+	SFC_PATHS,
+};
+
+struct tegra210_sfc {
+	unsigned int mono_to_stereo[SFC_PATHS];
+	unsigned int stereo_to_mono[SFC_PATHS];
+	unsigned int srate_out;
+	unsigned int srate_in;
+	struct regmap *regmap;
+};
+
+#endif