Initial commit of hifimems kernel module & device tree overlay

.gitignore

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+*.o
+.hifimems*
+*.ko
+*.dtbo
+*.mod.c
+Module*
+modules.order
+.tmp_versions/

Makefile

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+obj-m += hifimems-soundcard.o hifimems-codec.o
+SRC := $(shell pwd)
+
+all: devicetree
+ $(MAKE) -C $(KERNEL_SRC) M=$(SRC) modules
+
+modules_install: devicetree
+ $(MAKE) -C $(KERNEL_SRC) M=$(SRC) modules_install
+ cp hifimems-soundcard.dtbo /boot/overlays/
+
+clean: clean-local
+ $(MAKE) -C $(KERNEL_SRC) M=$(SRC) clean
+
+clean-local:
+ rm hifimems-soundcard.dtbo || true
+
+hifimems-soundcard.dtbo:
+ dtc -@ -I dts -O dtb -o hifimems-soundcard.dtbo hifimems-soundcard-overlay.dts
+
+devicetree: hifimems-soundcard.dtbo

README.md

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+# AoSC Driver Simple I2S Hifiberry and ICS43432 MEMS
+
+> Use Hifiberry-dac / Adafruit Speaker Bonnet and ICS43432 / SPH0645 I2S MEMS Mic simultaneously
+
+Tested with:
+ - [Adafruit I2S MEMS Microphone Breakout](https://www.adafruit.com/product/3421)
+ - [Adafruit I2S 3W Stereo Speaker Bonnet for Raspberry Pi](https://www.adafruit.com/product/3346)
+
+Based on googlevoicehat-{codec,soundcard}.c by Peter Malkin.
+
+## Install
+
+This was installed successfully on Linux 4.9.35+ on a Raspberry Pi Zero W
+
+```sh
+sudo apt-get install raspberrypi-kernel-headers
+
+git clone https://github.com/GothAck/hifimems-kmod
+cd hifimems-kmod
+
+make KERNEL_SRC=/lib/modules/$(uname -r)/build all
+sudo make KERNEL_SRC=/lib/modules/$(uname -r)/build modules_install
+```

hifimems-codec.c

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+/*
+ * Simple driver for Hifiberry and ICS43432 MEMS microphone compatible hardware
+ *
+ * Author: Greg Miell <[email protected]>
+ * Copyright 2017
+ * Based on googlevoicehat-codec.c by Peter Malkin
+ *
+ * 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/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/version.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+#include <sound/soc-dapm.h>
+
+static int hifimems_codec_probe(struct snd_soc_codec *codec) {
+ return 0;
+}
+
+static int hifimems_codec_remove(struct snd_soc_codec *codec) {
+ return 0;
+}
+
+static const struct snd_soc_dapm_widget hifimems_dapm_widgets[] = {
+ SND_SOC_DAPM_OUTPUT("Speaker"),
+};
+
+static const struct snd_soc_dapm_route hifimems_dapm_routes[] = {
+ {"Speaker", NULL, "Playback"},
+};
+
+static struct snd_soc_codec_driver hifimems_codec_driver = {
+ .probe = hifimems_codec_probe,
+ .remove = hifimems_codec_remove,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
+ .component_driver = {
+#endif
+ .dapm_widgets = hifimems_dapm_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(hifimems_dapm_widgets),
+ .dapm_routes = hifimems_dapm_routes,
+ .num_dapm_routes = ARRAY_SIZE(hifimems_dapm_routes),
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
+ },
+#endif
+};
+
+static struct snd_soc_dai_driver hifimems_dai = {
+ .name = "hifimems-hifi",
+ .capture = {.stream_name = "Capture",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_48000,
+ .formats = SNDRV_PCM_FMTBIT_S32_LE},
+ .playback = {.stream_name = "Playback",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_48000,
+ .formats = SNDRV_PCM_FMTBIT_S32_LE},
+ .symmetric_rates = 1};
+
+#ifdef CONFIG_OF
+static const struct of_device_id hifimems_ids[] = {
+ {
+ .compatible = "hifimems,hifimems",
+ },
+ {}};
+MODULE_DEVICE_TABLE(of, hifimems_ids);
+#endif
+
+static int hifimems_platform_probe(struct platform_device *pdev) {
+ return snd_soc_register_codec(&pdev->dev, &hifimems_codec_driver, &hifimems_dai, 1);
+}
+
+static int hifimems_platform_remove(struct platform_device *pdev) {
+ snd_soc_unregister_codec(&pdev->dev);
+ return 0;
+}
+
+static struct platform_driver hifimems_driver = {
+ .driver =
+ {
+ .name = "hifimems-codec", .of_match_table = of_match_ptr(hifimems_ids),
+ },
+ .probe = hifimems_platform_probe,
+ .remove = hifimems_platform_remove,
+};
+
+module_platform_driver(hifimems_driver);
+
+MODULE_DESCRIPTION("Simple I2S Hifiberry & ICS43432 MEMS Codec");
+MODULE_AUTHOR("Greg Miell <[email protected]>");
+MODULE_LICENSE("GPL v2");

hifimems-soundcard-overlay.dts

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+// Simple driver for Hifiberry and ICS43432 MEMS microphone compatible hardware
+/dts-v1/;
+/plugin/;
+
+/ {
+ compatible = "brcm,bcm2708";
+
+ fragment@0 {
+ target = <&i2s>;
+ __overlay__ {
+ status = "okay";
+ };
+ };
+
+ fragment@2 {
+ target-path = "/";
+ __overlay__ {
+ hifimems-codec {
+ #sound-dai-cells = <0>;
+ compatible = "hifimems,hifimems";
+ status = "okay";
+ };
+ };
+ };
+
+ fragment@3 {
+ target = <&sound>;
+ __overlay__ {
+ compatible = "hifimems,hifimems-soundcard";
+ i2s-controller = <&i2s>;
+ status = "okay";
+ };
+ };
+};

hifimems-soundcard.c

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+/*
+ * Simple driver for Hifiberry and ICS43432 MEMS microphone compatible hardware
+ *
+ * Author: Greg Miell <[email protected]>
+ * Copyright 2017
+ * Based on googlevoicehat-soundcard.c by Peter Malkin
+ *
+ * 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 <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+
+static int snd_rpi_hifimems_soundcard_init(struct snd_soc_pcm_runtime *rtd)
+{
+ return 0;
+}
+
+static int snd_rpi_hifimems_soundcard_hw_params(
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+
+ unsigned int sample_bits =
+ snd_pcm_format_physical_width(params_format(params));
+
+ return snd_soc_dai_set_bclk_ratio(cpu_dai, sample_bits * 2);
+}
+
+/* machine stream operations */
+static struct snd_soc_ops snd_rpi_hifimems_soundcard_ops = {
+ .hw_params = snd_rpi_hifimems_soundcard_hw_params,
+};
+
+static struct snd_soc_dai_link snd_rpi_hifimems_soundcard_dai[] = {
+{
+ .name = "I2S Hifiberry & ICS43432",
+ .stream_name = "I2S Hifiberry & ICS43432 Audio",
+ .cpu_dai_name = "bcm2708-i2s.0",
+ .codec_dai_name = "hifimems-hifi",
+ .platform_name = "bcm2708-i2s.0",
+ .codec_name = "hifimems-codec",
+ .dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+ SND_SOC_DAIFMT_CBS_CFS,
+ .ops = &snd_rpi_hifimems_soundcard_ops,
+ .init = snd_rpi_hifimems_soundcard_init,
+},
+};
+
+/* audio machine driver */
+static struct snd_soc_card snd_rpi_hifimems_soundcard = {
+ .name = "snd_rpi_hifimems_soundcard",
+ .owner = THIS_MODULE,
+ .dai_link = snd_rpi_hifimems_soundcard_dai,
+ .num_links = ARRAY_SIZE(snd_rpi_hifimems_soundcard_dai),
+};
+
+static int snd_rpi_hifimems_soundcard_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+
+ snd_rpi_hifimems_soundcard.dev = &pdev->dev;
+
+ if (pdev->dev.of_node) {
+ struct device_node *i2s_node;
+ struct snd_soc_dai_link *dai = &snd_rpi_hifimems_soundcard_dai[0];
+ i2s_node = of_parse_phandle(pdev->dev.of_node,
+ "i2s-controller", 0);
+
+ if (i2s_node) {
+ dai->cpu_dai_name = NULL;
+ dai->cpu_of_node = i2s_node;
+ dai->platform_name = NULL;
+ dai->platform_of_node = i2s_node;
+ }
+ }
+
+ ret = snd_soc_register_card(&snd_rpi_hifimems_soundcard);
+ if (ret)
+ dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n", ret);
+
+ return ret;
+}
+
+static int snd_rpi_hifimems_soundcard_remove(struct platform_device *pdev)
+{
+ return snd_soc_unregister_card(&snd_rpi_hifimems_soundcard);
+}
+
+static const struct of_device_id snd_rpi_hifimems_soundcard_of_match[] = {
+ { .compatible = "hifimems,hifimems-soundcard", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, snd_rpi_hifimems_soundcard_of_match);
+
+static struct platform_driver snd_rpi_hifimems_soundcard_driver = {
+ .driver = {
+ .name = "snd-hifimems-soundcard",
+ .owner = THIS_MODULE,
+ .of_match_table = snd_rpi_hifimems_soundcard_of_match,
+ },
+ .probe = snd_rpi_hifimems_soundcard_probe,
+ .remove = snd_rpi_hifimems_soundcard_remove,
+};
+
+module_platform_driver(snd_rpi_hifimems_soundcard_driver);
+
+MODULE_DESCRIPTION("AoSC Driver Simple I2S Hifiberry and ICS43432 MEMS");
+MODULE_AUTHOR("Greg Miell <[email protected]>");
+MODULE_LICENSE("GPL v2");