[PATCH 1/2] USB: serial: cp210x: Implement 16-bit register access functions
From: Konstantin Shkolnyy
Date: Mon Oct 19 2015 - 18:01:29 EST
Existing register access functions cp210x_get_config and cp210x_set_config
are cumbersome to use. This change introduces new functions specifically
for 16-bit registers that read and write simple u16 values.
Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@xxxxxxxxx>
---
drivers/usb/serial/cp210x.c | 119 ++++++++++++++++++++++++++++++++------------
1 file changed, 88 insertions(+), 31 deletions(-)
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index eac7cca..5a7c15e 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -301,6 +301,77 @@ static struct usb_serial_driver * const serial_drivers[] = {
#define CONTROL_WRITE_RTS 0x0200
/*
+ * Reads any 16-bit CP210X_ register (req).
+ */
+static int cp210x_read_u16_reg(struct usb_serial *serial, u8 req, u16 *pval)
+{
+ struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
+ __le16 le16_value;
+ int result;
+
+ result = usb_control_msg(serial->dev,
+ usb_rcvctrlpipe(serial->dev, 0),
+ req, REQTYPE_INTERFACE_TO_HOST, 0,
+ spriv->bInterfaceNumber, &le16_value, 2,
+ USB_CTRL_SET_TIMEOUT);
+ if (result != 2) {
+ if (result > 0)
+ result = -EPROTO;
+ dev_err(&serial->dev->dev, "%s ifc %d req 0x%x err %d\n",
+ __func__, spriv->bInterfaceNumber, req, result);
+ return result;
+ }
+ *pval = le16_to_cpu(le16_value);
+ return 0;
+}
+
+/*
+ * Writes any 16-bit CP210X_ register (req) whose value is passed
+ * entirely in the wValue field of the USB request.
+ */
+static int cp210x_write_u16_reg(struct usb_serial *serial, u8 req, u16 val)
+{
+ struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
+ int result;
+
+ result = usb_control_msg(serial->dev,
+ usb_sndctrlpipe(serial->dev, 0),
+ req, REQTYPE_HOST_TO_INTERFACE, val,
+ spriv->bInterfaceNumber, NULL, 0,
+ USB_CTRL_SET_TIMEOUT);
+ if (result < 0) {
+ dev_err(&serial->dev->dev, "%s ifc %d req 0x%x err %d\n",
+ __func__, spriv->bInterfaceNumber, req, result);
+ }
+ return result;
+}
+
+/*
+ * Command-specific wrappers around USB access functions
+ */
+static int cp210x_ifc_enable(struct usb_serial_port *port)
+{
+ return cp210x_write_u16_reg(port->serial,
+ CP210X_IFC_ENABLE, UART_ENABLE);
+}
+
+static int cp210x_ifc_disable(struct usb_serial_port *port)
+{
+ return cp210x_write_u16_reg(port->serial,
+ CP210X_IFC_ENABLE, UART_DISABLE);
+}
+
+static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *pctrl)
+{
+ return cp210x_read_u16_reg(port->serial, CP210X_GET_LINE_CTL, pctrl);
+}
+
+static int cp210x_set_line_ctl(struct usb_serial_port *port, u16 ctrl)
+{
+ return cp210x_write_u16_reg(port->serial, CP210X_SET_LINE_CTL, ctrl);
+}
+
+/*
* cp210x_get_config
* Reads from the CP210x configuration registers
* 'size' is specified in bytes.
@@ -400,17 +471,6 @@ static int cp210x_set_config(struct usb_serial_port *port, u8 request,
}
/*
- * cp210x_set_config_single
- * Convenience function for calling cp210x_set_config on single data values
- * without requiring an integer pointer
- */
-static inline int cp210x_set_config_single(struct usb_serial_port *port,
- u8 request, unsigned int data)
-{
- return cp210x_set_config(port, request, &data, 2);
-}
-
-/*
* cp210x_quantise_baudrate
* Quantises the baud rate as per AN205 Table 1
*/
@@ -456,12 +516,9 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
{
int result;
- result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
- UART_ENABLE);
- if (result) {
- dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
+ result = cp210x_ifc_enable(port);
+ if (result)
return result;
- }
/* Configure the termios structure */
cp210x_get_termios(tty, port);
@@ -476,7 +533,7 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
static void cp210x_close(struct usb_serial_port *port)
{
usb_serial_generic_close(port);
- cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
+ cp210x_ifc_disable(port);
}
/*
@@ -511,7 +568,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
struct device *dev = &port->dev;
unsigned int cflag, modem_ctl[4];
unsigned int baud;
- unsigned int bits;
+ u16 bits;
cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
@@ -520,7 +577,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
cflag = *cflagp;
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
cflag &= ~CSIZE;
switch (bits & BITS_DATA_MASK) {
case BITS_DATA_5:
@@ -544,14 +601,14 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
cflag |= CS8;
bits &= ~BITS_DATA_MASK;
bits |= BITS_DATA_8;
- cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
+ cp210x_set_line_ctl(port, bits);
break;
default:
dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
cflag |= CS8;
bits &= ~BITS_DATA_MASK;
bits |= BITS_DATA_8;
- cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
+ cp210x_set_line_ctl(port, bits);
break;
}
@@ -582,7 +639,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
cflag &= ~PARENB;
bits &= ~BITS_PARITY_MASK;
- cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
+ cp210x_set_line_ctl(port, bits);
break;
}
@@ -594,7 +651,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
case BITS_STOP_1_5:
dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
bits &= ~BITS_STOP_MASK;
- cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
+ cp210x_set_line_ctl(port, bits);
break;
case BITS_STOP_2:
dev_dbg(dev, "%s - stop bits = 2\n", __func__);
@@ -603,7 +660,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
default:
dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
bits &= ~BITS_STOP_MASK;
- cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
+ cp210x_set_line_ctl(port, bits);
break;
}
@@ -677,7 +734,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
{
struct device *dev = &port->dev;
unsigned int cflag, old_cflag;
- unsigned int bits;
+ u16 bits;
unsigned int modem_ctl[4];
cflag = tty->termios.c_cflag;
@@ -688,7 +745,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
/* If the number of data bits is to be updated */
if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_DATA_MASK;
switch (cflag & CSIZE) {
case CS5:
@@ -716,13 +773,13 @@ static void cp210x_set_termios(struct tty_struct *tty,
bits |= BITS_DATA_8;
break;
}
- if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
+ if (cp210x_set_line_ctl(port, bits))
dev_dbg(dev, "Number of data bits requested not supported by device\n");
}
if ((cflag & (PARENB|PARODD|CMSPAR)) !=
(old_cflag & (PARENB|PARODD|CMSPAR))) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_PARITY_MASK;
if (cflag & PARENB) {
if (cflag & CMSPAR) {
@@ -743,12 +800,12 @@ static void cp210x_set_termios(struct tty_struct *tty,
}
}
}
- if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
+ if (cp210x_set_line_ctl(port, bits))
dev_dbg(dev, "Parity mode not supported by device\n");
}
if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_STOP_MASK;
if (cflag & CSTOPB) {
bits |= BITS_STOP_2;
@@ -757,7 +814,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
bits |= BITS_STOP_1;
dev_dbg(dev, "%s - stop bits = 1\n", __func__);
}
- if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
+ if (cp210x_set_line_ctl(port, bits))
dev_dbg(dev, "Number of stop bits requested not supported by device\n");
}
--
1.8.4.5
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