Add support for Fe-Pi audio sound card. (#1867)

Fe-Pi Audio Sound Card is based on NXP SGTL5000 codec.
Mechanical specification of the board is the same the Raspberry Pi Zero.
3.5mm jacks for Headphone/Mic, Line In, and Line Out.

Signed-off-by: Henry Kupis <fe-pi@cox.net>

arch/arm/boot/dts/overlays/Makefile

@@ -20,6 +20,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	dwc2.dtbo \
 	enc28j60.dtbo \
 	enc28j60-spi2.dtbo \
+	fe-pi-audio.dtbo \
 	gpio-ir.dtbo \
 	gpio-poweroff.dtbo \
 	hifiberry-amp.dtbo \

arch/arm/boot/dts/overlays/README

@@ -383,6 +383,12 @@ Params: int_pin                 GPIO used for INT (default 39)
         speed                   SPI bus speed (default 12000000)
 
 
+Name:   fe-pi-audio
+Info:   Configures the Fe-Pi Audio Sound Card
+Load:   dtoverlay=fe-pi-audio
+Params: <None>
+
+
 Name:   gpio-ir
 Info:   Use GPIO pin as rc-core style infrared receiver input. The rc-core-
         based gpio_ir_recv driver maps received keys directly to a

arch/arm/boot/dts/overlays/fe-pi-audio-overlay.dts

@@ -0,0 +1,70 @@
+// Definitions for Fe-Pi Audio
+/dts-v1/;
+/plugin/;
+
+/ {
+	compatible = "brcm,bcm2708";
+
+	fragment@0 {
+		target = <&clocks>;
+		__overlay__ {
+			sgtl5000_mclk: sgtl5000_mclk {
+				compatible = "fixed-clock";
+				#clock-cells = <0>;
+				clock-frequency = <12288000>;
+				clock-output-names = "sgtl5000-mclk";
+			};
+		};
+	};
+
+	fragment@1 {
+		target = <&soc>;
+		__overlay__ {
+			reg_1v8: reg_1v8@0 {
+				compatible = "regulator-fixed";
+				regulator-name = "1V8";
+				regulator-min-microvolt = <1800000>;
+				regulator-max-microvolt = <1800000>;
+				regulator-always-on;
+			};
+		};
+	};
+
+	fragment@2 {
+		target = <&i2c1>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "okay";
+
+			sgtl5000@0a {
+				#sound-dai-cells = <0>;
+				compatible = "fepi,sgtl5000";
+				reg = <0x0a>;
+				clocks = <&sgtl5000_mclk>;
+				micbias-resistor-k-ohms = <2>;
+				micbias-voltage-m-volts = <3000>;
+				VDDA-supply = <&vdd_3v3_reg>;
+				VDDIO-supply = <&vdd_3v3_reg>;
+				VDDD-supply = <&reg_1v8>;
+				status = "okay";
+			};
+		};
+	};
+
+	fragment@3 {
+		target = <&i2s>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment@4 {
+		target = <&sound>;
+		__overlay__ {
+			compatible = "fe-pi,fe-pi-audio";
+			i2s-controller = <&i2s>;
+			status = "okay";
+		};
+	};	
+};

arch/arm/configs/bcm2709_defconfig

@@ -891,6 +891,7 @@ CONFIG_SND_DIGIDAC1_SOUNDCARD=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO_V2=m
 CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC=m
+CONFIG_SND_BCM2708_SOC_FE_PI_AUDIO=m
 CONFIG_SND_PISOUND=m
 CONFIG_SND_SOC_ADAU1701=m
 CONFIG_SND_SOC_ADAU7002=m

arch/arm/configs/bcmrpi_defconfig

@@ -885,6 +885,7 @@ CONFIG_SND_DIGIDAC1_SOUNDCARD=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO_V2=m
 CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC=m
+CONFIG_SND_BCM2708_SOC_FE_PI_AUDIO=m
 CONFIG_SND_PISOUND=m
 CONFIG_SND_SOC_ADAU1701=m
 CONFIG_SND_SOC_ADAU7002=m

sound/soc/bcm/Kconfig

@@ -147,6 +147,13 @@ config SND_BCM2708_SOC_ALLO_PIANO_DAC
 	help
 	  Say Y or M if you want to add support for Allo Piano DAC.
 
+config SND_BCM2708_SOC_FE_PI_AUDIO
+	tristate "Support for Fe-Pi-Audio"
+	depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S
+	select SND_SOC_SGTL5000
+	help
+	  Say Y or M if you want to add support for Fe-Pi-Audio.
+
 config SND_PISOUND
 	tristate "Support for Blokas Labs pisound"
 	depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S

sound/soc/bcm/Makefile

@@ -28,6 +28,7 @@ snd-soc-dionaudio-loco-objs := dionaudio_loco.o
 snd-soc-dionaudio-loco-v2-objs := dionaudio_loco-v2.o
 snd-soc-allo-piano-dac-objs := allo-piano-dac.o
 snd-soc-pisound-objs := pisound.o
+snd-soc-fe-pi-audio-objs := fe-pi-audio.o
 
 obj-$(CONFIG_SND_BCM2708_SOC_ADAU1977_ADC) += snd-soc-adau1977-adc.o
 obj-$(CONFIG_SND_BCM2708_SOC_HIFIBERRY_AMP) += snd-soc-hifiberry-amp.o
@@ -48,3 +49,4 @@ obj-$(CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO) += snd-soc-dionaudio-loco.o
 obj-$(CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO_V2) += snd-soc-dionaudio-loco-v2.o
 obj-$(CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC) += snd-soc-allo-piano-dac.o
 obj-$(CONFIG_SND_PISOUND) += snd-soc-pisound.o
+obj-$(CONFIG_SND_BCM2708_SOC_FE_PI_AUDIO) += snd-soc-fe-pi-audio.o

sound/soc/bcm/fe-pi-audio.c

@@ -0,0 +1,158 @@
+/*
+ * ASoC Driver for Fe-Pi Audio Sound Card
+ *
+ * Author:	Henry Kupis <kuupaz@gmail.com>
+ *		Copyright 2016
+ *		based on code by Florian Meier <florian.meier@koalo.de>
+ *		based on code by Shawn Guo <shawn.guo@linaro.org>      
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+
+#include "../codecs/sgtl5000.h"
+
+static int snd_fe_pi_audio_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_card *card = rtd->card;
+	struct snd_soc_codec *codec = rtd->codec;
+
+	snd_soc_dapm_force_enable_pin(&card->dapm, "LO");
+	snd_soc_dapm_force_enable_pin(&card->dapm, "ADC");
+	snd_soc_dapm_force_enable_pin(&card->dapm, "DAC");
+	snd_soc_dapm_force_enable_pin(&card->dapm, "HP");
+	snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+			SGTL5000_VAG_POWERUP, SGTL5000_VAG_POWERUP);	
+
+	return 0;
+}
+
+static int snd_fe_pi_audio_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct device *dev = rtd->card->dev;
+	struct snd_soc_dai *codec_dai = rtd->codec_dai;
+
+	int ret;
+
+	/* Set SGTL5000's SYSCLK */
+	ret = snd_soc_dai_set_sysclk(codec_dai, SGTL5000_SYSCLK, 12288000, SND_SOC_CLOCK_IN);
+	if (ret) {
+		dev_err(dev, "could not set codec driver clock params\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+
+static struct snd_soc_ops snd_fe_pi_audio_ops = {
+	.hw_params = snd_fe_pi_audio_hw_params,
+};
+
+static struct snd_soc_dai_link snd_fe_pi_audio_dai[] = {
+	{
+		.name		= "FE-PI",
+		.stream_name	= "Fe-Pi HiFi",
+		.cpu_dai_name	= "bcm2708-i2s.0",
+		.codec_dai_name	= "sgtl5000",
+		.platform_name	= "bcm2708-i2s.0",
+		.codec_name	= "sgtl5000.1-000a",
+		.dai_fmt	= SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+					SND_SOC_DAIFMT_CBM_CFM,
+		.ops		= &snd_fe_pi_audio_ops,
+		.init		= snd_fe_pi_audio_init,
+	},
+};
+
+static const struct snd_soc_dapm_route fe_pi_audio_dapm_routes[] = {
+	{"ADC", NULL, "Mic Bias"},
+};
+
+
+static struct snd_soc_card fe_pi_audio = {
+	.name         = "Fe-Pi Audio",
+	.owner        = THIS_MODULE,
+	.dai_link     = snd_fe_pi_audio_dai,
+	.num_links    = ARRAY_SIZE(snd_fe_pi_audio_dai),
+
+	.dapm_routes = fe_pi_audio_dapm_routes,
+	.num_dapm_routes = ARRAY_SIZE(fe_pi_audio_dapm_routes),
+};
+
+static int snd_fe_pi_audio_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct snd_soc_card *card = &fe_pi_audio;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *i2s_node; 
+	struct snd_soc_dai_link *dai = &snd_fe_pi_audio_dai[0];
+
+	fe_pi_audio.dev = &pdev->dev;
+
+	i2s_node = of_parse_phandle(np, "i2s-controller", 0);
+	if (!i2s_node) {
+		dev_err(&pdev->dev, "i2s_node phandle missing or invalid\n");
+		return -EINVAL;
+	}
+
+	dai->cpu_dai_name = NULL;
+	dai->cpu_of_node = i2s_node;
+	dai->platform_name = NULL;
+	dai->platform_of_node = i2s_node;
+
+	of_node_put(i2s_node);
+
+	card->dev = &pdev->dev;
+	platform_set_drvdata(pdev, card);
+
+	ret = snd_soc_register_card(card);
+	if (ret && ret != -EPROBE_DEFER)
+		dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n", ret);
+
+	return ret;
+}
+
+static int snd_fe_pi_audio_remove(struct platform_device *pdev)
+{
+	return snd_soc_unregister_card(&fe_pi_audio);
+}
+
+static const struct of_device_id snd_fe_pi_audio_of_match[] = {
+	{ .compatible = "fe-pi,fe-pi-audio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, snd_fe_pi_audio_of_match);
+
+static struct platform_driver snd_fe_pi_audio_driver = {
+        .driver = {
+                .name   = "snd-fe-pi-audio",
+                .owner  = THIS_MODULE,
+                .of_match_table = snd_fe_pi_audio_of_match,
+        },
+        .probe          = snd_fe_pi_audio_probe,
+        .remove         = snd_fe_pi_audio_remove,
+};
+
+module_platform_driver(snd_fe_pi_audio_driver);
+
+MODULE_AUTHOR("Henry Kupis <fe-pi@cox.net>");
+MODULE_DESCRIPTION("ASoC Driver for Fe-Pi Audio");
+MODULE_LICENSE("GPL v2");