ALSA: firewire-motu: add skeleton for Mark of the unicorn (MOTU) FireWire series

This commit adds an new driver for MOTU FireWire series. In this commit,
this driver just creates/removes card instance according to bus event.
More functionalities will be added in following commits.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/Kconfig

@@ -140,4 +140,14 @@ config SND_FIREWIRE_TASCAM
 	 To compile this driver as a module, choose M here: the module
 	 will be called snd-firewire-tascam.
 
+config SND_FIREWIRE_MOTU
+	tristate "Mark of the unicorn FireWire series support"
+	select SND_FIREWIRE_LIB
+	select SND_HWDEP
+	help
+	 Say Y here to enable support for FireWire devices which MOTU produced:
+
+	 To compile this driver as a module, choose M here: the module
+	 will be called snd-firewire-motu.
+
 endif # SND_FIREWIRE

sound/firewire/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_SND_FIREWORKS) += fireworks/
 obj-$(CONFIG_SND_BEBOB) += bebob/
 obj-$(CONFIG_SND_FIREWIRE_DIGI00X) += digi00x/
 obj-$(CONFIG_SND_FIREWIRE_TASCAM) += tascam/
+obj-$(CONFIG_SND_FIREWIRE_MOTU) += motu/

sound/firewire/motu/Makefile

+snd-firewire-motu-objs := motu.o
+obj-$(CONFIG_SND_FIREWIRE_MOTU) += snd-firewire-motu.o

sound/firewire/motu/motu.c

+/*
+ * motu.c - a part of driver for MOTU FireWire series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "motu.h"
+
+#define OUI_MOTU	0x0001f2
+
+MODULE_DESCRIPTION("MOTU FireWire driver");
+MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
+MODULE_LICENSE("GPL v2");
+
+static void name_card(struct snd_motu *motu)
+{
+	struct fw_device *fw_dev = fw_parent_device(motu->unit);
+	struct fw_csr_iterator it;
+	int key, val;
+	u32 version = 0;
+
+	fw_csr_iterator_init(&it, motu->unit->directory);
+	while (fw_csr_iterator_next(&it, &key, &val)) {
+		switch (key) {
+		case CSR_VERSION:
+			version = val;
+			break;
+		}
+	}
+
+	strcpy(motu->card->driver, "FW-MOTU");
+	snprintf(motu->card->longname, sizeof(motu->card->longname),
+		 "MOTU (version:%d), GUID %08x%08x at %s, S%d",
+		 version,
+		 fw_dev->config_rom[3], fw_dev->config_rom[4],
+		 dev_name(&motu->unit->device), 100 << fw_dev->max_speed);
+}
+
+static void motu_card_free(struct snd_card *card)
+{
+	struct snd_motu *motu = card->private_data;
+
+	fw_unit_put(motu->unit);
+
+	mutex_destroy(&motu->mutex);
+}
+
+static int motu_probe(struct fw_unit *unit,
+		      const struct ieee1394_device_id *entry)
+{
+	struct snd_card *card;
+	struct snd_motu *motu;
+	int err;
+
+	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE,
+			   sizeof(*motu), &card);
+	if (err < 0)
+		return err;
+
+	motu = card->private_data;
+	motu->card = card;
+	motu->unit = fw_unit_get(unit);
+	card->private_free = motu_card_free;
+
+	mutex_init(&motu->mutex);
+
+	name_card(motu);
+
+	err = snd_card_register(card);
+	if (err < 0)
+		goto error;
+
+	dev_set_drvdata(&unit->device, motu);
+
+	return 0;
+error:
+	snd_card_free(card);
+	return err;
+}
+
+static void motu_remove(struct fw_unit *unit)
+{
+	struct snd_motu *motu = dev_get_drvdata(&unit->device);
+
+	/* No need to wait for releasing card object in this context. */
+	snd_card_free_when_closed(motu->card);
+}
+
+static void motu_bus_update(struct fw_unit *unit)
+{
+	return;
+}
+
+#define SND_MOTU_DEV_ENTRY(model)			\
+{							\
+	.match_flags	= IEEE1394_MATCH_VENDOR_ID |	\
+			  IEEE1394_MATCH_MODEL_ID |	\
+			  IEEE1394_MATCH_SPECIFIER_ID,	\
+	.vendor_id	= OUI_MOTU,			\
+	.model_id	= model,			\
+	.specifier_id	= OUI_MOTU,			\
+}
+
+static const struct ieee1394_device_id motu_id_table[] = {
+	{ }
+};
+MODULE_DEVICE_TABLE(ieee1394, motu_id_table);
+
+static struct fw_driver motu_driver = {
+	.driver   = {
+		.owner	= THIS_MODULE,
+		.name	= KBUILD_MODNAME,
+		.bus	= &fw_bus_type,
+	},
+	.probe    = motu_probe,
+	.update   = motu_bus_update,
+	.remove   = motu_remove,
+	.id_table = motu_id_table,
+};
+
+static int __init alsa_motu_init(void)
+{
+	return driver_register(&motu_driver.driver);
+}
+
+static void __exit alsa_motu_exit(void)
+{
+	driver_unregister(&motu_driver.driver);
+}
+
+module_init(alsa_motu_init);
+module_exit(alsa_motu_exit);

sound/firewire/motu/motu.h

+/*
+ * motu.h - a part of driver for MOTU FireWire series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#ifndef SOUND_FIREWIRE_MOTU_H_INCLUDED
+#define SOUND_FIREWIRE_MOTU_H_INCLUDED
+
+#include <linux/device.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include <sound/control.h>
+#include <sound/core.h>
+
+struct snd_motu {
+	struct snd_card *card;
+	struct fw_unit *unit;
+	struct mutex mutex;
+};
+
+#endif