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USB: serial: keyspan_pda: clean up comments and whitespace
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Clean up comment style, remove some stale or redundant comments and drop
superfluous white space.

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
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Johan Hovold committed Nov 4, 2020
1 parent 7604ce7 commit 491d692
Showing 1 changed file with 56 additions and 60 deletions.
116 changes: 56 additions & 60 deletions drivers/usb/serial/keyspan_pda.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,6 @@
* driver
*/


#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
Expand Down Expand Up @@ -121,8 +120,10 @@ static void keyspan_pda_request_unthrottle(struct work_struct *work)

dev_dbg(&port->dev, "%s\n", __func__);

/* ask the device to tell us when the tx buffer becomes
sufficiently empty */
/*
* Ask the device to tell us when the tx buffer becomes
* sufficiently empty.
*/
result = usb_control_msg(serial->dev,
usb_sndctrlpipe(serial->dev, 0),
7, /* request_unthrottle */
Expand Down Expand Up @@ -208,7 +209,6 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)

keyspan_pda_write_start(port);

/* queue up a wakeup at scheduler time */
usb_serial_port_softint(port);
break;
default:
Expand All @@ -227,31 +227,30 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
__func__, retval);
}


static void keyspan_pda_rx_throttle(struct tty_struct *tty)
{
/* stop receiving characters. We just turn off the URB request, and
let chars pile up in the device. If we're doing hardware
flowcontrol, the device will signal the other end when its buffer
fills up. If we're doing XON/XOFF, this would be a good time to
send an XOFF, although it might make sense to foist that off
upon the device too. */
struct usb_serial_port *port = tty->driver_data;

/*
* Stop receiving characters. We just turn off the URB request, and
* let chars pile up in the device. If we're doing hardware
* flowcontrol, the device will signal the other end when its buffer
* fills up. If we're doing XON/XOFF, this would be a good time to
* send an XOFF, although it might make sense to foist that off upon
* the device too.
*/
usb_kill_urb(port->interrupt_in_urb);
}


static void keyspan_pda_rx_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
/* just restart the receive interrupt URB */

/* just restart the receive interrupt URB */
if (usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL))
dev_dbg(&port->dev, "usb_submit_urb(read urb) failed\n");
}


static speed_t keyspan_pda_setbaud(struct usb_serial *serial, speed_t baud)
{
int rc;
Expand Down Expand Up @@ -293,8 +292,6 @@ static speed_t keyspan_pda_setbaud(struct usb_serial *serial, speed_t baud)
baud = 9600;
}

/* rather than figure out how to sleep while waiting for this
to complete, I just use the "legacy" API. */
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
0, /* set baud */
USB_TYPE_VENDOR
Expand All @@ -307,10 +304,10 @@ static speed_t keyspan_pda_setbaud(struct usb_serial *serial, speed_t baud)
2000); /* timeout */
if (rc < 0)
return 0;

return baud;
}


static void keyspan_pda_break_ctl(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
Expand All @@ -322,46 +319,43 @@ static void keyspan_pda_break_ctl(struct tty_struct *tty, int break_state)
value = 1; /* start break */
else
value = 0; /* clear break */

result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
4, /* set break */
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
value, 0, NULL, 0, 2000);
if (result < 0)
dev_dbg(&port->dev, "%s - error %d from usb_control_msg\n",
__func__, result);
/* there is something funky about this.. the TCSBRK that 'cu' performs
ought to translate into a break_ctl(-1),break_ctl(0) pair HZ/4
seconds apart, but it feels like the break sent isn't as long as it
is on /dev/ttyS0 */
}


static void keyspan_pda_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
struct usb_serial *serial = port->serial;
speed_t speed;

/* cflag specifies lots of stuff: number of stop bits, parity, number
of data bits, baud. What can the device actually handle?:
CSTOPB (1 stop bit or 2)
PARENB (parity)
CSIZE (5bit .. 8bit)
There is minimal hw support for parity (a PSW bit seems to hold the
parity of whatever is in the accumulator). The UART either deals
with 10 bits (start, 8 data, stop) or 11 bits (start, 8 data,
1 special, stop). So, with firmware changes, we could do:
8N1: 10 bit
8N2: 11 bit, extra bit always (mark?)
8[EOMS]1: 11 bit, extra bit is parity
7[EOMS]1: 10 bit, b0/b7 is parity
7[EOMS]2: 11 bit, b0/b7 is parity, extra bit always (mark?)
HW flow control is dictated by the tty->termios.c_cflags & CRTSCTS
bit.
For now, just do baud. */

/*
* cflag specifies lots of stuff: number of stop bits, parity, number
* of data bits, baud. What can the device actually handle?:
* CSTOPB (1 stop bit or 2)
* PARENB (parity)
* CSIZE (5bit .. 8bit)
* There is minimal hw support for parity (a PSW bit seems to hold the
* parity of whatever is in the accumulator). The UART either deals
* with 10 bits (start, 8 data, stop) or 11 bits (start, 8 data,
* 1 special, stop). So, with firmware changes, we could do:
* 8N1: 10 bit
* 8N2: 11 bit, extra bit always (mark?)
* 8[EOMS]1: 11 bit, extra bit is parity
* 7[EOMS]1: 10 bit, b0/b7 is parity
* 7[EOMS]2: 11 bit, b0/b7 is parity, extra bit always (mark?)
*
* HW flow control is dictated by the tty->termios.c_cflags & CRTSCTS
* bit.
*
* For now, just do baud.
*/
speed = tty_get_baud_rate(tty);
speed = keyspan_pda_setbaud(serial, speed);

Expand All @@ -370,17 +364,19 @@ static void keyspan_pda_set_termios(struct tty_struct *tty,
/* It hasn't changed so.. */
speed = tty_termios_baud_rate(old_termios);
}
/* Only speed can change so copy the old h/w parameters
then encode the new speed */
/*
* Only speed can change so copy the old h/w parameters then encode
* the new speed.
*/
tty_termios_copy_hw(&tty->termios, old_termios);
tty_encode_baud_rate(tty, speed, speed);
}


/* modem control pins: DTR and RTS are outputs and can be controlled.
DCD, RI, DSR, CTS are inputs and can be read. All outputs can also be
read. The byte passed is: DTR(b7) DCD RI DSR CTS RTS(b2) unused unused */

/*
* Modem control pins: DTR and RTS are outputs and can be controlled.
* DCD, RI, DSR, CTS are inputs and can be read. All outputs can also be
* read. The byte passed is: DTR(b7) DCD RI DSR CTS RTS(b2) unused unused.
*/
static int keyspan_pda_get_modem_info(struct usb_serial *serial,
unsigned char *value)
{
Expand All @@ -404,7 +400,6 @@ static int keyspan_pda_get_modem_info(struct usb_serial *serial,
return rc;
}


static int keyspan_pda_set_modem_info(struct usb_serial *serial,
unsigned char value)
{
Expand Down Expand Up @@ -480,10 +475,11 @@ static int keyspan_pda_write_start(struct usb_serial_port *port)
* unthrottle work is scheduled).
*/

/* we might block because of:
the TX urb is in-flight (wait until it completes)
the device is full (wait until it says there is room)
*/
/*
* We might block because of:
* the TX urb is in-flight (wait until it completes)
* the device is full (wait until it says there is room)
*/
spin_lock_irqsave(&port->lock, flags);

room = priv->tx_room;
Expand Down Expand Up @@ -542,7 +538,6 @@ static void keyspan_pda_write_bulk_callback(struct urb *urb)

keyspan_pda_write_start(port);

/* queue up a wakeup at scheduler time */
usb_serial_port_softint(port);
}

Expand Down Expand Up @@ -591,7 +586,6 @@ static int keyspan_pda_open(struct tty_struct *tty,
priv->tx_room = rc;
spin_unlock_irq(&port->lock);

/*Start reading from the device*/
rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (rc) {
dev_dbg(&port->dev, "%s - usb_submit_urb(read int) failed\n", __func__);
Expand Down Expand Up @@ -648,10 +642,12 @@ static int keyspan_pda_fake_startup(struct usb_serial *serial)
return -ENOENT;
}

/* after downloading firmware Renumeration will occur in a
moment and the new device will bind to the real driver */
/*
* After downloading firmware renumeration will occur in a moment and
* the new device will bind to the real driver.
*/

/* we want this device to fail to have a driver assigned to it. */
/* We want this device to fail to have a driver assigned to it. */
return 1;
}

Expand Down Expand Up @@ -711,7 +707,7 @@ static struct usb_serial_driver keyspan_pda_device = {
.open = keyspan_pda_open,
.close = keyspan_pda_close,
.write = keyspan_pda_write,
.write_bulk_callback = keyspan_pda_write_bulk_callback,
.write_bulk_callback = keyspan_pda_write_bulk_callback,
.read_int_callback = keyspan_pda_rx_interrupt,
.throttle = keyspan_pda_rx_throttle,
.unthrottle = keyspan_pda_rx_unthrottle,
Expand Down

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