Initial import

1 files changed, 353 insertions, 0 deletions

diff --git a/sound/i2c/i2c.c b/sound/i2c/i2c.c
new file mode 100644
index 000000000..4677037f0
--- /dev/null
+++ b/sound/i2c/i2c.c
@@ -0,0 +1,353 @@
+/*
+ *   Generic i2c interface for ALSA
+ *
+ *   (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
+ *   Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   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.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <sound/core.h>
+#include <sound/i2c.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Generic i2c interface for ALSA");
+MODULE_LICENSE("GPL");
+
+static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
+				 unsigned char *bytes, int count);
+static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
+				 unsigned char *bytes, int count);
+static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
+				 unsigned short addr);
+
+static struct snd_i2c_ops snd_i2c_bit_ops = {
+	.sendbytes = snd_i2c_bit_sendbytes,
+	.readbytes = snd_i2c_bit_readbytes,
+	.probeaddr = snd_i2c_bit_probeaddr,
+};
+
+static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
+{
+	struct snd_i2c_bus *slave;
+	struct snd_i2c_device *device;
+
+	if (snd_BUG_ON(!bus))
+		return -EINVAL;
+	while (!list_empty(&bus->devices)) {
+		device = snd_i2c_device(bus->devices.next);
+		snd_i2c_device_free(device);
+	}
+	if (bus->master)
+		list_del(&bus->buses);
+	else {
+		while (!list_empty(&bus->buses)) {
+			slave = snd_i2c_slave_bus(bus->buses.next);
+			snd_device_free(bus->card, slave);
+		}
+	}
+	if (bus->private_free)
+		bus->private_free(bus);
+	kfree(bus);
+	return 0;
+}
+
+static int snd_i2c_bus_dev_free(struct snd_device *device)
+{
+	struct snd_i2c_bus *bus = device->device_data;
+	return snd_i2c_bus_free(bus);
+}
+
+int snd_i2c_bus_create(struct snd_card *card, const char *name,
+		       struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
+{
+	struct snd_i2c_bus *bus;
+	int err;
+	static struct snd_device_ops ops = {
+		.dev_free =	snd_i2c_bus_dev_free,
+	};
+
+	*ri2c = NULL;
+	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
+	if (bus == NULL)
+		return -ENOMEM;
+	mutex_init(&bus->lock_mutex);
+	INIT_LIST_HEAD(&bus->devices);
+	INIT_LIST_HEAD(&bus->buses);
+	bus->card = card;
+	bus->ops = &snd_i2c_bit_ops;
+	if (master) {
+		list_add_tail(&bus->buses, &master->buses);
+		bus->master = master;
+	}
+	strlcpy(bus->name, name, sizeof(bus->name));
+	err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
+	if (err < 0) {
+		snd_i2c_bus_free(bus);
+		return err;
+	}
+	*ri2c = bus;
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_i2c_bus_create);
+
+int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
+			  unsigned char addr, struct snd_i2c_device **rdevice)
+{
+	struct snd_i2c_device *device;
+
+	*rdevice = NULL;
+	if (snd_BUG_ON(!bus))
+		return -EINVAL;
+	device = kzalloc(sizeof(*device), GFP_KERNEL);
+	if (device == NULL)
+		return -ENOMEM;
+	device->addr = addr;
+	strlcpy(device->name, name, sizeof(device->name));
+	list_add_tail(&device->list, &bus->devices);
+	device->bus = bus;
+	*rdevice = device;
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_i2c_device_create);
+
+int snd_i2c_device_free(struct snd_i2c_device *device)
+{
+	if (device->bus)
+		list_del(&device->list);
+	if (device->private_free)
+		device->private_free(device);
+	kfree(device);
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_i2c_device_free);
+
+int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
+{
+	return device->bus->ops->sendbytes(device, bytes, count);
+}
+
+EXPORT_SYMBOL(snd_i2c_sendbytes);
+
+int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
+{
+	return device->bus->ops->readbytes(device, bytes, count);
+}
+
+EXPORT_SYMBOL(snd_i2c_readbytes);
+
+int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
+{
+	return bus->ops->probeaddr(bus, addr);
+}
+
+EXPORT_SYMBOL(snd_i2c_probeaddr);
+
+/*
+ *  bit-operations
+ */
+
+static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
+{
+	if (bus->hw_ops.bit->start)
+		bus->hw_ops.bit->start(bus);
+}
+
+static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
+{
+	if (bus->hw_ops.bit->stop)
+		bus->hw_ops.bit->stop(bus);
+}
+
+static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
+{
+	if (bus->hw_ops.bit->direction)
+		bus->hw_ops.bit->direction(bus, clock, data);
+}
+
+static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
+{
+	bus->hw_ops.bit->setlines(bus, clock, data);
+}
+
+#if 0
+static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
+{
+	if (bus->hw_ops.bit->getclock)
+		return bus->hw_ops.bit->getclock(bus);
+	return -ENXIO;
+}
+#endif
+
+static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
+{
+	return bus->hw_ops.bit->getdata(bus, ack);
+}
+
+static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
+{
+	snd_i2c_bit_hw_start(bus);
+	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
+	snd_i2c_bit_set(bus, 1, 1);
+	snd_i2c_bit_set(bus, 1, 0);
+	snd_i2c_bit_set(bus, 0, 0);
+}
+
+static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
+{
+	snd_i2c_bit_set(bus, 0, 0);
+	snd_i2c_bit_set(bus, 1, 0);
+	snd_i2c_bit_set(bus, 1, 1);
+	snd_i2c_bit_hw_stop(bus);
+}
+
+static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
+{
+	snd_i2c_bit_set(bus, 0, data);
+	snd_i2c_bit_set(bus, 1, data);
+	snd_i2c_bit_set(bus, 0, data);
+}
+
+static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
+{
+	int ack;
+
+	snd_i2c_bit_set(bus, 0, 1);
+	snd_i2c_bit_set(bus, 1, 1);
+	snd_i2c_bit_direction(bus, 1, 0);	/* SCL - wr, SDA - rd */
+	ack = snd_i2c_bit_data(bus, 1);
+	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
+	snd_i2c_bit_set(bus, 0, 1);
+	return ack ? -EIO : 0;
+}
+
+static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
+{
+	int i, err;
+
+	for (i = 7; i >= 0; i--)
+		snd_i2c_bit_send(bus, !!(data & (1 << i)));
+	err = snd_i2c_bit_ack(bus);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
+{
+	int i;
+	unsigned char data = 0;
+
+	snd_i2c_bit_set(bus, 0, 1);
+	snd_i2c_bit_direction(bus, 1, 0);	/* SCL - wr, SDA - rd */
+	for (i = 7; i >= 0; i--) {
+		snd_i2c_bit_set(bus, 1, 1);
+		if (snd_i2c_bit_data(bus, 0))
+			data |= (1 << i);
+		snd_i2c_bit_set(bus, 0, 1);
+	}
+	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
+	snd_i2c_bit_send(bus, !!last);
+	return data;
+}
+
+static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
+				 unsigned char *bytes, int count)
+{
+	struct snd_i2c_bus *bus = device->bus;
+	int err, res = 0;
+
+	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
+		return -EIO;		/* not yet implemented */
+	snd_i2c_bit_start(bus);
+	err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
+	if (err < 0) {
+		snd_i2c_bit_hw_stop(bus);
+		return err;
+	}
+	while (count-- > 0) {
+		err = snd_i2c_bit_sendbyte(bus, *bytes++);
+		if (err < 0) {
+			snd_i2c_bit_hw_stop(bus);
+			return err;
+		}
+		res++;
+	}
+	snd_i2c_bit_stop(bus);
+	return res;
+}
+
+static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
+				 unsigned char *bytes, int count)
+{
+	struct snd_i2c_bus *bus = device->bus;
+	int err, res = 0;
+
+	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
+		return -EIO;		/* not yet implemented */
+	snd_i2c_bit_start(bus);
+	err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
+	if (err < 0) {
+		snd_i2c_bit_hw_stop(bus);
+		return err;
+	}
+	while (count-- > 0) {
+		err = snd_i2c_bit_readbyte(bus, count == 0);
+		if (err < 0) {
+			snd_i2c_bit_hw_stop(bus);
+			return err;
+		}
+		*bytes++ = (unsigned char)err;
+		res++;
+	}
+	snd_i2c_bit_stop(bus);
+	return res;
+}
+
+static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
+{
+	int err;
+
+	if (addr & 0x8000)	/* 10-bit address */
+		return -EIO;	/* not yet implemented */
+	if (addr & 0x7f80)	/* invalid address */
+		return -EINVAL;
+	snd_i2c_bit_start(bus);
+	err = snd_i2c_bit_sendbyte(bus, addr << 1);
+	snd_i2c_bit_stop(bus);
+	return err;
+}
+
+
+static int __init alsa_i2c_init(void)
+{
+	return 0;
+}
+
+static void __exit alsa_i2c_exit(void)
+{
+}
+
+module_init(alsa_i2c_init)
+module_exit(alsa_i2c_exit)