Re: [PATCH v2 1/3 RESEND] USB: serial: cp210x: New 16-bit register access functions.
From: Martyn Welch
Date: Thu Jan 14 2016 - 11:30:58 EST
On 23/12/15 02:14, Konstantin Shkolnyy wrote:
cp210x_get_config and cp210x_set_config are cumbersome to use. This change
introduces new register access functions for 16-bit values, instead of
the above functions.
Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@xxxxxxxxx>
---
drivers/usb/serial/cp210x.c | 155 +++++++++++++++++++++++++++++++-------------
1 file changed, 111 insertions(+), 44 deletions(-)
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index fd67958..fd7c4f4 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -422,14 +422,88 @@ 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
+ * Reads a variable-sized block of CP210X_ registers, identified by req.
+ * Returns data into buf in native USB byte order.
*/
-static inline int cp210x_set_config_single(struct usb_serial_port *port,
- u8 request, unsigned int data)
+static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
+ void *buf, int bufsize)
{
- return cp210x_set_config(port, request, &data, 2);
+ struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ void *dmabuf;
+ int result;
+
+ dmabuf = kmalloc(bufsize, GFP_KERNEL);
+ if (!dmabuf) {
+ /*
+ * FIXME Some callers don't bother to check for error,
+ * at least give them consistent junk until they are fixed
+ */
+ memset(buf, 0, bufsize);
+ return -ENOMEM;
+ }
+
+ result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ req, REQTYPE_INTERFACE_TO_HOST, 0,
+ port_priv->bInterfaceNumber, dmabuf, bufsize,
+ USB_CTRL_SET_TIMEOUT);
+ if (result == bufsize) {
+ memcpy(buf, dmabuf, bufsize);
+ result = 0;
I could be wrong, but isn't dmabuf a little-endian stream (hence the
byte order swapping in the existing set and get functions). Won't this
break on big endian systems due to the lack of byte swapping?
Martyn
+ } else {
+ dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
+ req, bufsize, result);
+ if (result >= 0)
+ result = -EPROTO;
+
+ /*
+ * FIXME Some callers don't bother to check for error,
+ * at least give them consistent junk until they are fixed
+ */
+ memset(buf, 0, bufsize);
+ }
+
+ kfree(dmabuf);
+
+ return result;
+}
+
+/*
+ * Reads any 16-bit CP210X_ register identified by req.
+ */
+static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
+{
+ __le16 le16_val;
+ int err;
+
+ err = cp210x_read_reg_block(port, req, &le16_val, sizeof(le16_val));
+ if (err)
+ return err;
+
+ *val = le16_to_cpu(le16_val);
+ 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_port *port, u8 req, u16 val)
+{
+ struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ int result;
+
+ result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+ req, REQTYPE_HOST_TO_INTERFACE, val,
+ port_priv->bInterfaceNumber, NULL, 0,
+ USB_CTRL_SET_TIMEOUT);
+ if (result < 0) {
+ dev_err(&port->dev, "failed set request 0x%x status: %d\n",
+ req, result);
+ }
+
+ return result;
}
/*
@@ -441,48 +515,47 @@ static inline int cp210x_set_config_single(struct usb_serial_port *port,
static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
{
struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
- unsigned int line_ctl_save;
- unsigned int line_ctl_test;
+ u16 line_ctl_save;
+ u16 line_ctl_test;
int err;
- err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_save, 2);
+ err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_save);
if (err)
return err;
- line_ctl_test = 0x800;
- err = cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_test, 2);
+ err = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, 0x800);
if (err)
return err;
- err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_test, 2);
+ err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_test);
if (err)
return err;
/* has_swapped_line_ctl is 0 here because port_priv was kzalloced */
if (line_ctl_test == 8) {
port_priv->has_swapped_line_ctl = true;
- line_ctl_save = swab16((u16)line_ctl_save);
+ line_ctl_save = swab16(line_ctl_save);
}
- return cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_save, 2);
+ return cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, line_ctl_save);
}
/*
- * Must always be called instead of cp210x_get_config(CP210X_GET_LINE_CTL)
+ * Must always be called instead of cp210x_read_u16_reg(CP210X_GET_LINE_CTL)
* to workaround cp2108 bug and get correct value.
*/
-static int cp210x_get_line_ctl(struct usb_serial_port *port, unsigned int *ctl)
+static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl)
{
struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
int err;
- err = cp210x_get_config(port, CP210X_GET_LINE_CTL, ctl, 2);
+ err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, ctl);
if (err)
return err;
/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
if (port_priv->has_swapped_line_ctl)
- *ctl = swab16((u16)(*ctl));
+ *ctl = swab16(*ctl);
return 0;
}
@@ -531,14 +604,11 @@ static unsigned int cp210x_quantise_baudrate(unsigned int baud)
static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
{
- int result;
+ int err;
- result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
- UART_ENABLE);
- if (result) {
- dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
- return result;
- }
+ err = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
+ if (err)
+ return err;
/* Configure the termios structure */
cp210x_get_termios(tty, port);
@@ -552,15 +622,12 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
static void cp210x_close(struct usb_serial_port *port)
{
- unsigned int purge_ctl;
-
usb_serial_generic_close(port);
/* Clear both queues; cp2108 needs this to avoid an occasional hang */
- purge_ctl = PURGE_ALL;
- cp210x_set_config(port, CP210X_PURGE, &purge_ctl, 2);
+ cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
- cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
+ cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
}
/*
@@ -640,7 +707,7 @@ 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);
@@ -673,14 +740,14 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
break;
}
@@ -711,7 +778,7 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
break;
}
@@ -723,7 +790,7 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
break;
case BITS_STOP_2:
dev_dbg(dev, "%s - stop bits = 2\n", __func__);
@@ -732,7 +799,7 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
break;
}
@@ -806,7 +873,7 @@ 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;
@@ -845,7 +912,7 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
dev_dbg(dev, "Number of data bits requested not supported by device\n");
}
@@ -872,7 +939,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
}
}
}
- if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
+ if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
dev_dbg(dev, "Parity mode not supported by device\n");
}
@@ -886,7 +953,7 @@ 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_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
dev_dbg(dev, "Number of stop bits requested not supported by device\n");
}
@@ -926,7 +993,7 @@ static int cp210x_tiocmset(struct tty_struct *tty,
static int cp210x_tiocmset_port(struct usb_serial_port *port,
unsigned int set, unsigned int clear)
{
- unsigned int control = 0;
+ u16 control = 0;
if (set & TIOCM_RTS) {
control |= CONTROL_RTS;
@@ -947,7 +1014,7 @@ static int cp210x_tiocmset_port(struct usb_serial_port *port,
dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
- return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
+ return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
}
static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
@@ -981,7 +1048,7 @@ static int cp210x_tiocmget(struct tty_struct *tty)
static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
- unsigned int state;
+ u16 state;
if (break_state == 0)
state = BREAK_OFF;
@@ -989,7 +1056,7 @@ static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
state = BREAK_ON;
dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
state == BREAK_OFF ? "off" : "on");
- cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
+ cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
}
static int cp210x_port_probe(struct usb_serial_port *port)