greybus: gb-audio: Add integrated greybus audio driver
So here's the current greybus audio driver, which I
wanted to send out for more serious review and
consideration for merging.
I've tried to integrate much of the feedback from the
last round and most of the hotplug issues that I've found
have been resolved. I've tested this via gbsim, and the
Android ARA HAL layer seems to work with it.
Mark has also successfully played audio with this driver,
adding a few hacks to get the codec's i2c connection to
probe.
Current issues:
* Hotplug problem - When gbsim is killed, or the module
removed, the greybus driver gets stuck since the android
mediaserver process is holding the audio device open.
Killing the mediaserver allows things to clean up and
allows greybus to accept new gbsim connections. I have
a workaround patch to the soc-core.c logic which converts
the snd_card_free() call to snd_card_free_when_closed()
which allows the greybus connection cleanup to finish.
Remaining todos:
* Probably need to break apart the mgmt_setup function
to integrate better with the constraint logic. I took
a really basic stab at this, but more is probably
needed.
* Figure out how to properly find and tie in the
codec's I2C bus-id to the driver.
This code requires that the kernel support the following
config options, which I've enabled in a separate kernel
patch:
CONFIG_SND_SIMPLE_CARD
CONFIG_SND_SOC_SPDIF
CONFIG_SND_SOC_RT5645
I really can't calim to be the sole author of this, since
many many fixes and tweaks that have been folded in have
come from Mark Greer. His analsysis and debugging is really
what has made this dummy-framework driver evolve into an
actual audio driver. So much credit and thanks to Mark!
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/audio-dai.c b/drivers/staging/greybus/audio-dai.c
new file mode 100644
index 0000000..f2c8ca0
--- /dev/null
+++ b/drivers/staging/greybus/audio-dai.c
@@ -0,0 +1,103 @@
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/i2c.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/simple_card.h>
+#include "greybus.h"
+#include "gpbridge.h"
+#include "audio.h"
+
+/*
+ * This is the greybus cpu dai logic. It really doesn't do much
+ * other then provide the TRIGGER_START/STOP hooks that start
+ * and stop the timer sending audio data in the pcm logic.
+ */
+
+
+static int gb_dai_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct gb_snd *snd_dev;
+
+
+ snd_dev = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ gb_pcm_hrtimer_start(snd_dev);
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ gb_pcm_hrtimer_stop(snd_dev);
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * XXX This is annoying, if we don't have a set_fmt function
+ * the subsystem returns -ENOTSUPP, which causes applications
+ * to fail, so add a dummy function here.
+ */
+static int gb_dai_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+ return 0;
+}
+
+static const struct snd_soc_dai_ops gb_dai_ops = {
+ .trigger = gb_dai_trigger,
+ .set_fmt = gb_dai_set_fmt,
+};
+
+struct snd_soc_dai_driver gb_cpu_dai = {
+ .name = "gb-cpu-dai",
+ .playback = {
+ .rates = GB_RATES,
+ .formats = GB_FMTS,
+ .channels_min = 1,
+ .channels_max = 2,
+ },
+ .ops = &gb_dai_ops,
+};
+
+static const struct snd_soc_component_driver gb_soc_component = {
+ .name = "gb-component",
+};
+
+static int gb_plat_probe(struct platform_device *pdev)
+{
+ struct gb_snd *snd_dev;
+ int ret;
+
+ snd_dev = (struct gb_snd *)pdev->dev.platform_data;
+ dev_set_drvdata(&pdev->dev, snd_dev);
+
+ ret = snd_soc_register_component(&pdev->dev, &gb_soc_component,
+ &gb_cpu_dai, 1);
+ return ret;
+}
+
+static int gb_plat_remove(struct platform_device *pdev)
+{
+ snd_soc_unregister_component(&pdev->dev);
+ snd_soc_unregister_platform(&pdev->dev);
+ return 0;
+}
+
+struct platform_driver gb_audio_plat_driver = {
+ .driver = {
+ .name = "gb-dai-audio",
+ },
+ .probe = gb_plat_probe,
+ .remove = gb_plat_remove,
+};