[PATCH] usb: cp210x: Update to support CP2105 and multiple interface devices

From: Preston Fick
Date: Thu Feb 23 2012 - 17:03:57 EST


OS/Kernel version: GNU/Linux 3.3-rc4 (Mainline)

Description:
This patch updates the cp210x driver to support CP210x multiple
interface devices
devices from Silicon Labs. The existing driver always sends control requests to
interface 0, which is hardcoded in the usb_control_msg function calls. This only
allows for single interface devices to be used, and causes a bug when
using ports on
an interface other than 0 in the multiple interface devices.

Here are the changes included in this patch:
- Updated the device list to contain the Silicon Labs factory default
VID/PID for multiple
interface CP210x devices
- Created a cp210x_port_private struct created for each port on
startup, this struct
holds the interface number
- Added a cp210x_release function to clean up the cp210x_port_private memory
created on startup
- Modified usb_get_config and usb_set_config to get a pointer to the
cp210x_port_private
struct, and use the interface number there in the usb_control_message
wIndex param

Signed-off-by: Preston Fick <preston.fick@xxxxxxxxxx>

---

diff -uprN linux.vanilla//linux-3.3-rc4/drivers/usb/serial/cp210x.c
linux.new//linux-3.3-rc4/drivers/usb/serial/cp210x.c
--- linux.vanilla//linux-3.3-rc4/drivers/usb/serial/cp210x.c 2012-02-18
17:53:33.000000000 -0600
+++ linux.new//linux-3.3-rc4/drivers/usb/serial/cp210x.c 2012-02-23
14:43:29.703316401 -0600
@@ -49,6 +49,7 @@ static int cp210x_tiocmset_port(struct u
unsigned int, unsigned int);
static void cp210x_break_ctl(struct tty_struct *, int);
static int cp210x_startup(struct usb_serial *);
+static void cp210x_release(struct usb_serial *);
static void cp210x_dtr_rts(struct usb_serial_port *p, int on);

static bool debug;
@@ -121,6 +122,8 @@ static const struct usb_device_id id_tab
{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
+ { USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
+ { USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
@@ -147,6 +150,12 @@ static const struct usb_device_id id_tab

MODULE_DEVICE_TABLE(usb, id_table);

+struct cp210x_port_private {
+ /* loop back to the owner of this object */
+ struct usb_serial_port *port;
+ __u8 bInterfaceNumber;
+};
+
static struct usb_driver cp210x_driver = {
.name = "cp210x",
.probe = usb_serial_probe,
@@ -172,6 +181,7 @@ static struct usb_serial_driver cp210x_d
.tiocmget = cp210x_tiocmget,
.tiocmset = cp210x_tiocmset,
.attach = cp210x_startup,
+ .release = cp210x_release,
.dtr_rts = cp210x_dtr_rts
};

@@ -259,9 +269,17 @@ static int cp210x_get_config(struct usb_
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
__le32 *buf;
int result, i, length;

+ /* Return a memory error if we cannot get the port_priv */
+ if (!port_priv)
+ {
+ dev_err(&port->dev, "%s - device couldn't retrieve private
memory.\n", __func__);
+ return -ENOMEM;
+ }
+
/* Number of integers required to contain the array */
length = (((size - 1) | 3) + 1)/4;

@@ -274,7 +292,7 @@ static int cp210x_get_config(struct usb_
/* Issue the request, attempting to read 'size' bytes */
result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
request, REQTYPE_DEVICE_TO_HOST, 0x0000,
- 0, buf, size, 300);
+ port_priv->bInterfaceNumber, buf, size, 300);

/* Convert data into an array of integers */
for (i = 0; i < length; i++)
@@ -305,9 +323,17 @@ static int cp210x_set_config(struct usb_
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
__le32 *buf;
int result, i, length;

+ /* Return a memory error if we cannot get the port_priv */
+ if (!port_priv)
+ {
+ dev_err(&port->dev, "%s - device couldn't retrieve private
memory.\n", __func__);
+ return -ENOMEM;
+ }
+
/* Number of integers required to contain the array */
length = (((size - 1) | 3) + 1)/4;

@@ -326,12 +352,12 @@ static int cp210x_set_config(struct usb_
result = usb_control_msg(serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, 0x0000,
- 0, buf, size, 300);
+ port_priv->bInterfaceNumber, buf, size, 300);
} else {
result = usb_control_msg(serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, data[0],
- 0, NULL, 0, 300);
+ port_priv->bInterfaceNumber, NULL, 0, 300);
}

kfree(buf);
@@ -842,11 +868,45 @@ static void cp210x_break_ctl (struct tty

static int cp210x_startup(struct usb_serial *serial)
{
+ struct cp210x_port_private *port_priv;
+ int i;
+
/* cp210x buffers behave strangely unless device is reset */
usb_reset_device(serial->dev);
+
+ for (i = 0; i < serial->num_ports; i++)
+ {
+ port_priv = kmalloc(sizeof(*port_priv), GFP_KERNEL);
+ if (!port_priv)
+ return -ENOMEM;
+
+ memset(port_priv, 0x00, sizeof(*port_priv));
+ port_priv->port = serial->port[i];
+ port_priv->bInterfaceNumber =
+ serial->interface->cur_altsetting->desc.bInterfaceNumber;
+
+ usb_set_serial_port_data(serial->port[i], port_priv);
+ }
+
return 0;
}

+static void cp210x_release(struct usb_serial *serial)
+{
+ struct cp210x_port_private *port_priv;
+ int i;
+
+ for (i = 0; i < serial->num_ports; i++)
+ {
+ port_priv = usb_get_serial_port_data(serial->port[i]);
+ if (port_priv)
+ {
+ kfree(port_priv);
+ usb_set_serial_port_data(serial->port[i], NULL);
+ }
+ }
+}
+
static int __init cp210x_init(void)
{
int retval;
--
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