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Subject[PATCH 3/3] usb: cp210x: Add ioctl for GPIO support
Date
This patch adds support for GPIO for CP210x devices that support it through two
IOCTLs to get or set the GPIO latch on a CP210x device. The specification for
this can be found in Silicon Labs AN571 document on section 5.27.1-4.

Signed-off-by: Preston Fick <preston.fick@silabs.com>
---
drivers/usb/serial/cp210x.c | 98 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 98 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index b3646b8..9d1e542 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -35,6 +35,8 @@
*/
static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
static void cp210x_close(struct usb_serial_port *);
+static int cp210x_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg);
static void cp210x_get_termios(struct tty_struct *,
struct usb_serial_port *port);
static void cp210x_get_termios_port(struct usb_serial_port *port,
@@ -175,6 +177,7 @@ static struct usb_serial_driver cp210x_device = {
.bulk_out_size = 256,
.open = cp210x_open,
.close = cp210x_close,
+ .ioctl = cp210x_ioctl,
.break_ctl = cp210x_break_ctl,
.set_termios = cp210x_set_termios,
.tiocmget = cp210x_tiocmget,
@@ -195,6 +198,10 @@ static struct usb_serial_driver * const serial_drivers[] = {
#define CP2104_PARTNUM 0x04
#define CP2105_PARTNUM 0x05

+/* IOCTLs */
+#define IOCTL_GPIOGET 0x8000
+#define IOCTL_GPIOSET 0x8001
+
/* Config request types */
#define REQTYPE_HOST_TO_INTERFACE 0x41
#define REQTYPE_INTERFACE_TO_HOST 0xc1
@@ -235,6 +242,8 @@ static struct usb_serial_driver * const serial_drivers[] = {
#define UART_DISABLE 0x0000

/* CP210X_VENDOR_SPECIFIC */
+#define CP210X_WRITE_LATCH 0x37E1
+#define CP210X_READ_LATCH 0x00C2
#define CP210X_GET_PARTNUM 0x370B

/* CP210X_(SET|GET)_BAUDDIV */
@@ -467,6 +476,95 @@ static void cp210x_close(struct usb_serial_port *port)
mutex_unlock(&port->serial->disc_mutex);
}

+static int cp210x_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ int result = 0;
+ unsigned int latch_setting = 0;
+
+ switch (cmd) {
+
+ case IOCTL_GPIOGET:
+ if ((port_priv->bPartNumber == CP2103_PARTNUM) ||
+ (port_priv->bPartNumber == CP2104_PARTNUM)) {
+ result = usb_control_msg(port->serial->dev,
+ usb_rcvctrlpipe(port->serial->dev, 0),
+ CP210X_VENDOR_SPECIFIC,
+ REQTYPE_DEVICE_TO_HOST,
+ CP210X_READ_LATCH,
+ port_priv->bInterfaceNumber,
+ &latch_setting, 1,
+ USB_CTRL_GET_TIMEOUT);
+ if (result != 1)
+ return -EPROTO;
+ *(unsigned long *)arg = (unsigned long)latch_setting;
+ return 0;
+ } else if (port_priv->bPartNumber == CP2105_PARTNUM) {
+ result = usb_control_msg(port->serial->dev,
+ usb_rcvctrlpipe(port->serial->dev, 0),
+ CP210X_VENDOR_SPECIFIC,
+ REQTYPE_INTERFACE_TO_HOST,
+ CP210X_READ_LATCH,
+ port_priv->bInterfaceNumber,
+ &latch_setting, 1,
+ USB_CTRL_GET_TIMEOUT);
+ if (result != 1)
+ return -EPROTO;
+ *(unsigned long *)arg = (unsigned long)latch_setting;
+ return 0;
+ } else {
+ return -ENOTSUPP;
+ }
+ break;
+
+ case IOCTL_GPIOSET:
+ if ((port_priv->bPartNumber == CP2103_PARTNUM) ||
+ (port_priv->bPartNumber == CP2104_PARTNUM)) {
+ latch_setting =
+ *(unsigned int *)arg & 0x000000FF;
+ latch_setting |=
+ (*(unsigned int *)arg & 0x00FF0000) >> 8;
+ result = usb_control_msg(port->serial->dev,
+ usb_sndctrlpipe(port->serial->dev, 0),
+ CP210X_VENDOR_SPECIFIC,
+ REQTYPE_HOST_TO_DEVICE,
+ CP210X_WRITE_LATCH,
+ latch_setting,
+ NULL, 0,
+ USB_CTRL_SET_TIMEOUT);
+ if (result != 0)
+ return -EPROTO;
+ return 0;
+ } else if (port_priv->bPartNumber == CP2105_PARTNUM) {
+ latch_setting =
+ *(unsigned int *)arg & 0x000000FF;
+ latch_setting |=
+ (*(unsigned int *)arg & 0x00FF0000) >> 8;
+ result = usb_control_msg(port->serial->dev,
+ usb_sndctrlpipe(port->serial->dev, 0),
+ CP210X_VENDOR_SPECIFIC,
+ REQTYPE_HOST_TO_INTERFACE,
+ CP210X_WRITE_LATCH,
+ port_priv->bInterfaceNumber,
+ &latch_setting, 2,
+ USB_CTRL_SET_TIMEOUT);
+ if (result != 2)
+ return -EPROTO;
+ return 0;
+ } else {
+ return -ENOTSUPP;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ return -ENOIOCTLCMD;
+}
+
/*
* cp210x_get_termios
* Reads the baud rate, data bits, parity, stop bits and flow control mode
--
1.7.5.4


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