[patch] add pca9543 driver

[patch] add pca9543 driver

[Oskar Schirmer]

support pca9543 i2c bus switch chip

Signed-off-by: Oskar Schirmer <os@emlix.com>
---
 drivers/i2c/chips/Kconfig   |    3 +
 drivers/i2c/chips/Makefile  |    1 +
 drivers/i2c/chips/pca9543.c |  188 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 192 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/chips/pca9543.c

diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index c80312c..acfc46f 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -64,6 +64,9 @@ config SENSORS_PCA9539
 	  This driver is deprecated and will be dropped soon. Use
 	  drivers/gpio/pca953x.c instead.
 
+config PCA9543
+	tristate "Philips PCA9543 i2c bus switch"
+
 config SENSORS_PCF8591
 	tristate "Philips PCF8591"
 	depends on EXPERIMENTAL
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index d142f23..c7a7fe2 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -13,6 +13,7 @@
 obj-$(CONFIG_DS1682)		+= ds1682.o
 obj-$(CONFIG_SENSORS_MAX6875)	+= max6875.o
 obj-$(CONFIG_SENSORS_PCA9539)	+= pca9539.o
+obj-$(CONFIG_PCA9543)		+= pca9543.o
 obj-$(CONFIG_SENSORS_PCF8574)	+= pcf8574.o
 obj-$(CONFIG_PCF8575)		+= pcf8575.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
diff --git a/drivers/i2c/chips/pca9543.c b/drivers/i2c/chips/pca9543.c
new file mode 100644
index 0000000..ee59497
--- /dev/null
+++ b/drivers/i2c/chips/pca9543.c
@@ -0,0 +1,188 @@
+/*
+ *  pca9543.c - i2c channel switch
+ *
+ *  Copyright (C) 2008 Emlix GmbH <info@emlix.com>
+ *  Authors:	Fabian Godehardt <fg@emlix.com>
+ *		Oskar Schirmer <os@emlix.com>
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+
+struct pca9543_data {
+	struct mutex lock;
+	struct i2c_client *client;
+};
+
+static ssize_t pca9543_read(struct pca9543_data *data, char *buf, size_t count)
+{
+	int stat;
+	struct i2c_msg msg;
+	mutex_lock(&data->lock);
+	msg.addr = data->client->addr;
+	msg.flags = I2C_M_RD;
+	msg.buf = buf;
+	msg.len = 1;
+	stat = i2c_transfer(data->client->adapter, &msg, 1);
+	mutex_unlock(&data->lock);
+	if ((stat >= 0) && (stat != 1))
+		stat = -EIO;
+	return stat;
+}
+
+static ssize_t pca9543_bin_read(struct kobject *kobj,
+		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct pca9543_data *data;
+	data = dev_get_drvdata(container_of(kobj, struct device, kobj));
+	if (unlikely(!count))
+		return count;
+	if (off)
+		return -EINVAL;
+	return pca9543_read(data, buf, count);
+}
+
+static ssize_t pca9543_write(struct pca9543_data *data, char *buf, size_t count)
+{
+	int stat;
+	struct i2c_msg msg;
+	mutex_lock(&data->lock);
+	msg.addr = data->client->addr;
+	msg.flags = 0;
+	msg.buf = buf;
+	msg.len = 1;
+	stat = i2c_transfer(data->client->adapter, &msg, 1);
+	mutex_unlock(&data->lock);
+	if ((stat >= 0) && (stat != 1))
+		stat = -EIO;
+	return stat;
+}
+
+static ssize_t pca9543_bin_write(struct kobject *kobj,
+		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct pca9543_data *data;
+	data = dev_get_drvdata(container_of(kobj, struct device, kobj));
+	if (unlikely(!count))
+		return count;
+	if (off)
+		return -EINVAL;
+	return pca9543_write(data, buf, count);
+}
+
+static struct bin_attribute pca9543_attr = {
+	.attr = {
+		.name = "switch",
+		.mode = S_IRUGO | S_IWUSR,
+	},
+	.size = 1,
+	.read = pca9543_bin_read,
+	.write = pca9543_bin_write,
+};
+
+int pca9543_set_switch(struct i2c_client *client, unsigned value)
+{
+	struct pca9543_data *data;
+	u8 buf;
+	int ret;
+	data = i2c_get_clientdata(client);
+	buf = value;
+	ret = pca9543_write(data, &buf, 1);
+	if (ret > 0)
+		ret = 0;
+	return ret;
+}
+EXPORT_SYMBOL(pca9543_set_switch);
+
+static int pca9543_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	int err;
+	struct pca9543_data *data;
+	void (*cbf)(struct i2c_client *, int(*)(struct i2c_client *, unsigned));
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		printk(KERN_ERR "pca9543 probe failure\n");
+		err = -EPFNOSUPPORT;
+		goto err;
+	}
+	data = kzalloc(sizeof(struct pca9543_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto err;
+	}
+	mutex_init(&data->lock);
+	data->client = client;
+	err = sysfs_create_bin_file(&client->dev.kobj, &pca9543_attr);
+	if (err)
+		goto errmem;
+	i2c_set_clientdata(client, data);
+	dev_info(&client->dev,
+		"pca9543 i2c switch @ x%02x\n", client->addr);
+	cbf = client->dev.platform_data;
+	if (cbf)
+		cbf(client, &pca9543_set_switch);
+	return 0;
+errmem:
+	kfree(data);
+err:
+	return err;
+}
+
+static int pca9543_remove(struct i2c_client *client)
+{
+	struct pca9543_data *data;
+	data = i2c_get_clientdata(client);
+	sysfs_remove_bin_file(&client->dev.kobj, &pca9543_attr);
+	i2c_set_clientdata(client, NULL);
+	kfree(data);
+	return 0;
+}
+
+static const struct i2c_device_id pca9543_id[] = {
+	{ "pca9543", 0 },
+	{ }
+};
+
+static struct i2c_driver pca9543_driver = {
+	.driver = {
+		.name = "pca9543",
+		.owner = THIS_MODULE,
+	},
+	.probe = pca9543_probe,
+	.remove = pca9543_remove,
+	.id_table = pca9543_id,
+};
+
+static int __init pca9543_init(void)
+{
+	return i2c_add_driver(&pca9543_driver);
+}
+
+static void __exit pca9543_exit(void)
+{
+	i2c_del_driver(&pca9543_driver);
+}
+
+MODULE_AUTHOR("emlix GmbH <info@emlix.com>");
+MODULE_DESCRIPTION("pca9543 switch driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9543_init);
+module_exit(pca9543_exit);
-- 
1.6.2.107.ge47ee

[patch] add pca9543 driver

[Oskar Schirmer]

support pca9543 i2c bus switch chip

Signed-off-by: Oskar Schirmer <os-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
---
 drivers/i2c/chips/Kconfig   |    3 +
 drivers/i2c/chips/Makefile  |    1 +
 drivers/i2c/chips/pca9543.c |  188 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 192 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/chips/pca9543.c

diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index c80312c..acfc46f 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -64,6 +64,9 @@ config SENSORS_PCA9539
 	  This driver is deprecated and will be dropped soon. Use
 	  drivers/gpio/pca953x.c instead.
 
+config PCA9543
+	tristate "Philips PCA9543 i2c bus switch"
+
 config SENSORS_PCF8591
 	tristate "Philips PCF8591"
 	depends on EXPERIMENTAL
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index d142f23..c7a7fe2 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -13,6 +13,7 @@
 obj-$(CONFIG_DS1682)		+= ds1682.o
 obj-$(CONFIG_SENSORS_MAX6875)	+= max6875.o
 obj-$(CONFIG_SENSORS_PCA9539)	+= pca9539.o
+obj-$(CONFIG_PCA9543)		+= pca9543.o
 obj-$(CONFIG_SENSORS_PCF8574)	+= pcf8574.o
 obj-$(CONFIG_PCF8575)		+= pcf8575.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
diff --git a/drivers/i2c/chips/pca9543.c b/drivers/i2c/chips/pca9543.c
new file mode 100644
index 0000000..ee59497
--- /dev/null
+++ b/drivers/i2c/chips/pca9543.c
@@ -0,0 +1,188 @@
+/*
+ *  pca9543.c - i2c channel switch
+ *
+ *  Copyright (C) 2008 Emlix GmbH <info-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
+ *  Authors:	Fabian Godehardt <fg-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
+ *		Oskar Schirmer <os-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+
+struct pca9543_data {
+	struct mutex lock;
+	struct i2c_client *client;
+};
+
+static ssize_t pca9543_read(struct pca9543_data *data, char *buf, size_t count)
+{
+	int stat;
+	struct i2c_msg msg;
+	mutex_lock(&data->lock);
+	msg.addr = data->client->addr;
+	msg.flags = I2C_M_RD;
+	msg.buf = buf;
+	msg.len = 1;
+	stat = i2c_transfer(data->client->adapter, &msg, 1);
+	mutex_unlock(&data->lock);
+	if ((stat >= 0) && (stat != 1))
+		stat = -EIO;
+	return stat;
+}
+
+static ssize_t pca9543_bin_read(struct kobject *kobj,
+		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct pca9543_data *data;
+	data = dev_get_drvdata(container_of(kobj, struct device, kobj));
+	if (unlikely(!count))
+		return count;
+	if (off)
+		return -EINVAL;
+	return pca9543_read(data, buf, count);
+}
+
+static ssize_t pca9543_write(struct pca9543_data *data, char *buf, size_t count)
+{
+	int stat;
+	struct i2c_msg msg;
+	mutex_lock(&data->lock);
+	msg.addr = data->client->addr;
+	msg.flags = 0;
+	msg.buf = buf;
+	msg.len = 1;
+	stat = i2c_transfer(data->client->adapter, &msg, 1);
+	mutex_unlock(&data->lock);
+	if ((stat >= 0) && (stat != 1))
+		stat = -EIO;
+	return stat;
+}
+
+static ssize_t pca9543_bin_write(struct kobject *kobj,
+		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct pca9543_data *data;
+	data = dev_get_drvdata(container_of(kobj, struct device, kobj));
+	if (unlikely(!count))
+		return count;
+	if (off)
+		return -EINVAL;
+	return pca9543_write(data, buf, count);
+}
+
+static struct bin_attribute pca9543_attr = {
+	.attr = {
+		.name = "switch",
+		.mode = S_IRUGO | S_IWUSR,
+	},
+	.size = 1,
+	.read = pca9543_bin_read,
+	.write = pca9543_bin_write,
+};
+
+int pca9543_set_switch(struct i2c_client *client, unsigned value)
+{
+	struct pca9543_data *data;
+	u8 buf;
+	int ret;
+	data = i2c_get_clientdata(client);
+	buf = value;
+	ret = pca9543_write(data, &buf, 1);
+	if (ret > 0)
+		ret = 0;
+	return ret;
+}
+EXPORT_SYMBOL(pca9543_set_switch);
+
+static int pca9543_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	int err;
+	struct pca9543_data *data;
+	void (*cbf)(struct i2c_client *, int(*)(struct i2c_client *, unsigned));
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		printk(KERN_ERR "pca9543 probe failure\n");
+		err = -EPFNOSUPPORT;
+		goto err;
+	}
+	data = kzalloc(sizeof(struct pca9543_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto err;
+	}
+	mutex_init(&data->lock);
+	data->client = client;
+	err = sysfs_create_bin_file(&client->dev.kobj, &pca9543_attr);
+	if (err)
+		goto errmem;
+	i2c_set_clientdata(client, data);
+	dev_info(&client->dev,
+		"pca9543 i2c switch @ x%02x\n", client->addr);
+	cbf = client->dev.platform_data;
+	if (cbf)
+		cbf(client, &pca9543_set_switch);
+	return 0;
+errmem:
+	kfree(data);
+err:
+	return err;
+}
+
+static int pca9543_remove(struct i2c_client *client)
+{
+	struct pca9543_data *data;
+	data = i2c_get_clientdata(client);
+	sysfs_remove_bin_file(&client->dev.kobj, &pca9543_attr);
+	i2c_set_clientdata(client, NULL);
+	kfree(data);
+	return 0;
+}
+
+static const struct i2c_device_id pca9543_id[] = {
+	{ "pca9543", 0 },
+	{ }
+};
+
+static struct i2c_driver pca9543_driver = {
+	.driver = {
+		.name = "pca9543",
+		.owner = THIS_MODULE,
+	},
+	.probe = pca9543_probe,
+	.remove = pca9543_remove,
+	.id_table = pca9543_id,
+};
+
+static int __init pca9543_init(void)
+{
+	return i2c_add_driver(&pca9543_driver);
+}
+
+static void __exit pca9543_exit(void)
+{
+	i2c_del_driver(&pca9543_driver);
+}
+
+MODULE_AUTHOR("emlix GmbH <info-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("pca9543 switch driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9543_init);
+module_exit(pca9543_exit);
-- 
1.6.2.107.ge47ee

Re: [patch] add pca9543 driver

[Jean Delvare]

On Thu, 26 Mar 2009 15:46:58 +0100, Oskar Schirmer wrote:
> support pca9543 i2c bus switch chip
> 
> Signed-off-by: Oskar Schirmer <os@emlix.com>
> ---
>  drivers/i2c/chips/Kconfig   |    3 +
>  drivers/i2c/chips/Makefile  |    1 +

Please read the header of these two files carefully again.

>  drivers/i2c/chips/pca9543.c |  188 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 192 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/i2c/chips/pca9543.c
> (...)

-- 
Jean Delvare

Re: [patch] add pca9543 driver

[Oskar Schirmer]

"

On Thu, Mar 26, 2009 at 15:51:05 +0100, Jean Delvare wrote:
> On Thu, 26 Mar 2009 15:46:58 +0100, Oskar Schirmer wrote:
> > support pca9543 i2c bus switch chip
> > 
> > Signed-off-by: Oskar Schirmer <os@emlix.com>
> > ---
> >  drivers/i2c/chips/Kconfig   |    3 +
> >  drivers/i2c/chips/Makefile  |    1 +
> 
> Please read the header of these two files carefully again.

Ok, I see. But how to have PCA9543 supported then?
The PCA9543 is an I2C bus switch/mux, so following
the headers it might be placed in drivers/<functionality>,
where <functionality> is "i2c bus mux", thus drivers/i2c.

As this is obviously not the solution, we might try to do the
bus muxing manually from userland, as soon as the system is up.
This wont work either, as the video drivers need the i2c bus
switch programmed before the video stuff can be initialized,
thus during bootup.

Next, the drivers proposed by Rodolfo Giometti
( http://article.gmane.org/gmane.linux.drivers.i2c/2996/ )
might add the functionality needed. As far as I can see from
Documentation/feature-removal-schedule.txt, prerequisites for
it to be accepted are given with 2.6.30, is the driver by
Rodolfo still in the queue, i.e. being merged for 2.6.30 now?

  Oskar

Re: [patch] add pca9543 driver

[Oskar Schirmer]

"

On Thu, Mar 26, 2009 at 15:51:05 +0100, Jean Delvare wrote:
> On Thu, 26 Mar 2009 15:46:58 +0100, Oskar Schirmer wrote:
> > support pca9543 i2c bus switch chip
> > 
> > Signed-off-by: Oskar Schirmer <os-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
> > ---
> >  drivers/i2c/chips/Kconfig   |    3 +
> >  drivers/i2c/chips/Makefile  |    1 +
> 
> Please read the header of these two files carefully again.

Ok, I see. But how to have PCA9543 supported then?
The PCA9543 is an I2C bus switch/mux, so following
the headers it might be placed in drivers/<functionality>,
where <functionality> is "i2c bus mux", thus drivers/i2c.

As this is obviously not the solution, we might try to do the
bus muxing manually from userland, as soon as the system is up.
This wont work either, as the video drivers need the i2c bus
switch programmed before the video stuff can be initialized,
thus during bootup.

Next, the drivers proposed by Rodolfo Giometti
( http://article.gmane.org/gmane.linux.drivers.i2c/2996/ )
might add the functionality needed. As far as I can see from
Documentation/feature-removal-schedule.txt, prerequisites for
it to be accepted are given with 2.6.30, is the driver by
Rodolfo still in the queue, i.e. being merged for 2.6.30 now?

  Oskar

Re: [patch] add pca9543 driver

[Jean Delvare]

On Thu, 26 Mar 2009 17:23:15 +0100, Oskar Schirmer wrote:
> On Thu, Mar 26, 2009 at 15:51:05 +0100, Jean Delvare wrote:
> > On Thu, 26 Mar 2009 15:46:58 +0100, Oskar Schirmer wrote:
> > > support pca9543 i2c bus switch chip
> > > 
> > > Signed-off-by: Oskar Schirmer <os@emlix.com>
> > > ---
> > >  drivers/i2c/chips/Kconfig   |    3 +
> > >  drivers/i2c/chips/Makefile  |    1 +
> > 
> > Please read the header of these two files carefully again.
> 
> Ok, I see. But how to have PCA9543 supported then?
> The PCA9543 is an I2C bus switch/mux, so following
> the headers it might be placed in drivers/<functionality>,
> where <functionality> is "i2c bus mux", thus drivers/i2c.

We could consider creating drivers/i2c/muxes or similar for I2C
multiplexer drivers, especially if we start supporting many of them.

> As this is obviously not the solution, we might try to do the
> bus muxing manually from userland, as soon as the system is up.

"From userland" is exactly what your driver is doing, and this is
clearly not acceptable. You can't do userland switching and let the
kernel instantiate devices, as you found out yourself, which means that
such multiplexed buses would only support userland-created devices
(that is, i2c-dev.) This is way too limited to spend time on it.

> This wont work either, as the video drivers need the i2c bus
> switch programmed before the video stuff can be initialized,
> thus during bootup.
> 
> Next, the drivers proposed by Rodolfo Giometti
> ( http://article.gmane.org/gmane.linux.drivers.i2c/2996/ )
> might add the functionality needed.

It's not that they "might", rather they are _exactly_ what you need.

> As far as I can see from
> Documentation/feature-removal-schedule.txt, prerequisites for
> it to be accepted are given with 2.6.30, is the driver by
> Rodolfo still in the queue, i.e. being merged for 2.6.30 now?

Unfortunately not, I'm still working on the prerequisite in question
and I _hope_ to have that done in 2.6.30, but Rodolfo's work won't make
it in time. Which does not mean you shouldn't look at it, see how it
works for you, and report to Rodolfo. The more people help him cleanup
and improve his code, the easier and faster it will be when the time
finally comes to merge it.

-- 
Jean Delvare

Re: [patch] add pca9543 driver

[Jean Delvare]

On Thu, 26 Mar 2009 17:23:15 +0100, Oskar Schirmer wrote:
> On Thu, Mar 26, 2009 at 15:51:05 +0100, Jean Delvare wrote:
> > On Thu, 26 Mar 2009 15:46:58 +0100, Oskar Schirmer wrote:
> > > support pca9543 i2c bus switch chip
> > > 
> > > Signed-off-by: Oskar Schirmer <os-QdrG9jWwCLEAvxtiuMwx3w@public.gmane.org>
> > > ---
> > >  drivers/i2c/chips/Kconfig   |    3 +
> > >  drivers/i2c/chips/Makefile  |    1 +
> > 
> > Please read the header of these two files carefully again.
> 
> Ok, I see. But how to have PCA9543 supported then?
> The PCA9543 is an I2C bus switch/mux, so following
> the headers it might be placed in drivers/<functionality>,
> where <functionality> is "i2c bus mux", thus drivers/i2c.

We could consider creating drivers/i2c/muxes or similar for I2C
multiplexer drivers, especially if we start supporting many of them.

> As this is obviously not the solution, we might try to do the
> bus muxing manually from userland, as soon as the system is up.

"From userland" is exactly what your driver is doing, and this is
clearly not acceptable. You can't do userland switching and let the
kernel instantiate devices, as you found out yourself, which means that
such multiplexed buses would only support userland-created devices
(that is, i2c-dev.) This is way too limited to spend time on it.

> This wont work either, as the video drivers need the i2c bus
> switch programmed before the video stuff can be initialized,
> thus during bootup.
> 
> Next, the drivers proposed by Rodolfo Giometti
> ( http://article.gmane.org/gmane.linux.drivers.i2c/2996/ )
> might add the functionality needed.

It's not that they "might", rather they are _exactly_ what you need.

> As far as I can see from
> Documentation/feature-removal-schedule.txt, prerequisites for
> it to be accepted are given with 2.6.30, is the driver by
> Rodolfo still in the queue, i.e. being merged for 2.6.30 now?

Unfortunately not, I'm still working on the prerequisite in question
and I _hope_ to have that done in 2.6.30, but Rodolfo's work won't make
it in time. Which does not mean you shouldn't look at it, see how it
works for you, and report to Rodolfo. The more people help him cleanup
and improve his code, the easier and faster it will be when the time
finally comes to merge it.

-- 
Jean Delvare