diff options
author | Johan Hovold <johan@kernel.org> | 2020-10-25 18:45:58 +0100 |
---|---|---|
committer | Johan Hovold <johan@kernel.org> | 2020-11-04 11:01:56 +0100 |
commit | 491d6927f0de587c1d322d8b29a1187b7e06a221 (patch) | |
tree | 5330d58d911b1b2f8e25015776ae07c358b16c18 /drivers/usb/serial/keyspan_pda.c | |
parent | 7604ce70b8f675582ae68064e125be4f5174dec0 (diff) | |
download | lwn-491d6927f0de587c1d322d8b29a1187b7e06a221.tar.gz lwn-491d6927f0de587c1d322d8b29a1187b7e06a221.zip |
USB: serial: keyspan_pda: clean up comments and whitespace
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>
Diffstat (limited to 'drivers/usb/serial/keyspan_pda.c')
-rw-r--r-- | drivers/usb/serial/keyspan_pda.c | 116 |
1 files changed, 56 insertions, 60 deletions
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index f102dbf83492..8df7c54d6986 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -11,7 +11,6 @@ * driver */ - #include <linux/kernel.h> #include <linux/errno.h> #include <linux/slab.h> @@ -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 */ @@ -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: @@ -227,31 +227,30 @@ exit: __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; @@ -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 @@ -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; @@ -322,6 +319,7 @@ 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, @@ -329,39 +327,35 @@ static void keyspan_pda_break_ctl(struct tty_struct *tty, int break_state) 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); @@ -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) { @@ -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) { @@ -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; @@ -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); } @@ -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__); @@ -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; } @@ -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, |