This patch adds a sysfs attribute "cbus" which allows to set the four CBUS
pins on the FT232H.
CBUS support could probably extended to all supporting FTDI chips.
Signed-off-by: Philipp Hachtmann <hac...@hachti.de>
---
drivers/usb/serial/ftdi_sio.c | 66 ++++++++++++++++++++++++++++++++++++++++++-
drivers/usb/serial/ftdi_sio.h | 1 +
2 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index cacba4a..c84e27c 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1354,9 +1354,39 @@ static int set_syncmode(struct usb_serial_port *port,
int enable)
urb_value, priv->interface,
NULL, 0, WDR_SHORT_TIMEOUT);
+}
+
+static int set_cbus(struct usb_serial_port *port, u8 data)
+{
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+ __u16 urb_value = 0;
+ int rv = 0;
+
+ urb_value = FTDI_BITMODE_CBUS << 8 | data;
+
+ rv = usb_control_msg(port->serial->dev,
+ usb_sndctrlpipe(port->serial->dev, 0),
+ FTDI_SIO_SET_BITBANG_REQUEST,
+ FTDI_SIO_SET_BITBANG_REQUEST_TYPE,
+ urb_value, priv->interface,
+ NULL, 0, WDR_SHORT_TIMEOUT);
+
+ if (rv)
+ return rv;
+ if (priv->syncmode) {
+ priv->syncmode = 0;
+ rv = set_syncmode(port, 1);
+ }
+
return rv;
}
+static int get_cbus(struct usb_serial_port *port)
+{
+ return -EIO;
+}
+
static int write_latency_timer(struct usb_serial_port *port)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
@@ -1684,6 +1714,34 @@ static ssize_t syncmode_store(struct device *dev,
}
static DEVICE_ATTR_RW(syncmode);
+static ssize_t cbus_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int retval;
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ retval = get_cbus(port);
+ if (retval < 0)
+ return retval;
+ return sprintf(buf, "%#-x\n", get_cbus(port));
+}
+
+static ssize_t cbus_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *valbuf, size_t count)
+{
+ unsigned long value;
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ int retval = kstrtoul(valbuf, 0, &value);
+
+ if (retval)
+ return -EINVAL;
+ retval = set_cbus(port, value);
+ if (retval < 0)
+ return -EIO;
+ return count;
+}
+static DEVICE_ATTR_RW(cbus);
+
/* Write an event character directly to the FTDI register. The ASCII
value is in the low 8 bits, with the enable bit in the 9th bit. */
static ssize_t store_event_char(struct device *dev,
@@ -1736,6 +1794,10 @@ static int create_sysfs_attrs(struct usb_serial_port
*port)
}
if ((!retval) && priv->chip_type == FT232H) {
retval = device_create_file(&port->dev,
+ &dev_attr_cbus);
+ if (retval)
+ return retval;
+ retval = device_create_file(&port->dev,
&dev_attr_syncmode);
}
return retval;
@@ -1758,8 +1820,10 @@ static void remove_sysfs_attrs(struct usb_serial_port
*port)
device_remove_file(&port->dev, &dev_attr_latency_timer);
}
}
- if (priv->chip_type == FT232H)
+ if (priv->chip_type == FT232H) {
device_remove_file(&port->dev, &dev_attr_syncmode);
+ device_remove_file(&port->dev, &dev_attr_cbus);
+ }
}
/*
diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h
index 04a29f8..f9de34c 100644
--- a/drivers/usb/serial/ftdi_sio.h
+++ b/drivers/usb/serial/ftdi_sio.h
@@ -357,6 +357,7 @@ enum ftdi_sio_baudrate {
#define FTDI_SIO_SET_BITBANG_REQUEST_TYPE 0x40
#define FTDI_BITMODE_RESET 0x00 /* Switch back to normal operation */
+#define FTDI_BITMODE_CBUS 0x20 /* Configure CBUS pins */
#define FTDI_BITMODE_SYNCFIFO 0x40 /* Switch to syncronous FIFO mode */
/*
--
2.0.0.rc2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
