--- /dev/null
+/*
+ * Driver for the Google voiceHAT audio codec for Raspberry Pi.
+ *
+ * Author: Peter Malkin <petermalkin@google.com>
+ * Copyright 2016
+ *
+ * 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/gpio.h>
+#include <linux/gpio/consumer.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>
+
+#define ICS43432_RATE_MIN_HZ 7190 /* from data sheet */
+#define ICS43432_RATE_MAX_HZ 52800 /* from data sheet */
+/* Delay in enabling SDMODE after clock settles to remove pop */
+#define SDMODE_DELAY_MS 5
+
+struct voicehat_priv {
+ struct delayed_work enable_sdmode_work;
+ struct gpio_desc *sdmode_gpio;
+ unsigned long sdmode_delay_jiffies;
+};
+
+static void voicehat_enable_sdmode_work(struct work_struct *work)
+{
+ struct voicehat_priv *voicehat = container_of(work,
+ struct voicehat_priv,
+ enable_sdmode_work.work);
+ gpiod_set_value(voicehat->sdmode_gpio, 1);
+}
+
+static int voicehat_component_probe(struct snd_soc_component *component)
+{
+ struct voicehat_priv *voicehat =
+ snd_soc_component_get_drvdata(component);
+
+ voicehat->sdmode_gpio = devm_gpiod_get(component->dev, "sdmode",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(voicehat->sdmode_gpio)) {
+ dev_err(component->dev, "Unable to allocate GPIO pin\n");
+ return PTR_ERR(voicehat->sdmode_gpio);
+ }
+
+ INIT_DELAYED_WORK(&voicehat->enable_sdmode_work,
+ voicehat_enable_sdmode_work);
+ return 0;
+}
+
+static void voicehat_component_remove(struct snd_soc_component *component)
+{
+ struct voicehat_priv *voicehat =
+ snd_soc_component_get_drvdata(component);
+
+ cancel_delayed_work_sync(&voicehat->enable_sdmode_work);
+}
+
+static const struct snd_soc_dapm_widget voicehat_dapm_widgets[] = {
+ SND_SOC_DAPM_OUTPUT("Speaker"),
+};
+
+static const struct snd_soc_dapm_route voicehat_dapm_routes[] = {
+ {"Speaker", NULL, "HiFi Playback"},
+};
+
+static const struct snd_soc_component_driver voicehat_component_driver = {
+ .probe = voicehat_component_probe,
+ .remove = voicehat_component_remove,
+ .dapm_widgets = voicehat_dapm_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(voicehat_dapm_widgets),
+ .dapm_routes = voicehat_dapm_routes,
+ .num_dapm_routes = ARRAY_SIZE(voicehat_dapm_routes),
+};
+
+static int voicehat_daiops_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct snd_soc_component *component = dai->component;
+ struct voicehat_priv *voicehat =
+ snd_soc_component_get_drvdata(component);
+
+ if (voicehat->sdmode_delay_jiffies == 0)
+ return 0;
+
+ dev_dbg(dai->dev, "CMD %d", cmd);
+ dev_dbg(dai->dev, "Playback Active %d", dai->playback_active);
+ dev_dbg(dai->dev, "Capture Active %d", dai->capture_active);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ if (dai->playback_active) {
+ dev_info(dai->dev, "Enabling audio amp...\n");
+ queue_delayed_work(
+ system_power_efficient_wq,
+ &voicehat->enable_sdmode_work,
+ voicehat->sdmode_delay_jiffies);
+ }
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ if (dai->playback_active) {
+ cancel_delayed_work(&voicehat->enable_sdmode_work);
+ dev_info(dai->dev, "Disabling audio amp...\n");
+ gpiod_set_value(voicehat->sdmode_gpio, 0);
+ }
+ break;
+ }
+ return 0;
+}
+
+static const struct snd_soc_dai_ops voicehat_dai_ops = {
+ .trigger = voicehat_daiops_trigger,
+};
+
+static struct snd_soc_dai_driver voicehat_dai = {
+ .name = "voicehat-hifi",
+ .capture = {
+ .stream_name = "HiFi Capture",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_48000,
+ .formats = SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .playback = {
+ .stream_name = "HiFi Playback",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_48000,
+ .formats = SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .ops = &voicehat_dai_ops,
+ .symmetric_rates = 1
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id voicehat_ids[] = {
+ { .compatible = "google,voicehat", }, {}
+ };
+ MODULE_DEVICE_TABLE(of, voicehat_ids);
+#endif
+
+static int voicehat_platform_probe(struct platform_device *pdev)
+{
+ struct voicehat_priv *voicehat;
+ unsigned int sdmode_delay;
+ int ret;
+
+ voicehat = devm_kzalloc(&pdev->dev, sizeof(*voicehat), GFP_KERNEL);
+ if (!voicehat)
+ return -ENOMEM;
+
+ ret = device_property_read_u32(&pdev->dev, "voicehat_sdmode_delay",
+ &sdmode_delay);
+
+ if (ret) {
+ sdmode_delay = SDMODE_DELAY_MS;
+ dev_info(&pdev->dev,
+ "property 'voicehat_sdmode_delay' not found default 5 mS");
+ } else {
+ dev_info(&pdev->dev, "property 'voicehat_sdmode_delay' found delay= %d mS",
+ sdmode_delay);
+ }
+ voicehat->sdmode_delay_jiffies = msecs_to_jiffies(sdmode_delay);
+
+ dev_set_drvdata(&pdev->dev, voicehat);
+
+ return snd_soc_register_component(&pdev->dev,
+ &voicehat_component_driver,
+ &voicehat_dai,
+ 1);
+}
+
+static int voicehat_platform_remove(struct platform_device *pdev)
+{
+ snd_soc_unregister_component(&pdev->dev);
+ return 0;
+}
+
+static struct platform_driver voicehat_driver = {
+ .driver = {
+ .name = "voicehat-codec",
+ .of_match_table = of_match_ptr(voicehat_ids),
+ },
+ .probe = voicehat_platform_probe,
+ .remove = voicehat_platform_remove,
+};
+
+module_platform_driver(voicehat_driver);
+
+MODULE_DESCRIPTION("Google voiceHAT Codec driver");
+MODULE_AUTHOR("Peter Malkin <petermalkin@google.com>");
+MODULE_LICENSE("GPL v2");