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USB: f81232: implement set_termios()

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The original driver had do not any h/w change in driver.
This patch implements with configure H/W for
baud/parity/word length/stop bits functional in f81232_set_termios().

This patch also implement DTR/RTS control when baudrate B0.
We drop DTR/RTS when B0, otherwise enable it.

We are checking baudrate in set_termios() too, If baudrate larger then 115200,
it will be changed to 115200 and use tty_encode_baud_rate() to encode into tty

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Peter Hung 2015-03-17 17:48:25 +08:00 committed by Johan Hovold
parent 94f87309fb
commit 8bb4ca6b56
1 changed files with 108 additions and 4 deletions
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112
drivers/usb/serial/f81232.c
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@ -31,14 +31,19 @@ static const struct usb_device_id id_table[] = {
};
MODULE_DEVICE_TABLE(usb, id_table);
/* Maximum baudrate for F81232 */
#define F81232_MAX_BAUDRATE 115200
/* USB Control EP parameter */
#define F81232_REGISTER_REQUEST 0xa0
#define F81232_GET_REGISTER 0xc0
#define F81232_SET_REGISTER 0x40
#define SERIAL_BASE_ADDRESS 0x0120
#define RECEIVE_BUFFER_REGISTER (0x00 + SERIAL_BASE_ADDRESS)
#define INTERRUPT_ENABLE_REGISTER (0x01 + SERIAL_BASE_ADDRESS)
#define FIFO_CONTROL_REGISTER (0x02 + SERIAL_BASE_ADDRESS)
#define LINE_CONTROL_REGISTER (0x03 + SERIAL_BASE_ADDRESS)
#define MODEM_CONTROL_REGISTER (0x04 + SERIAL_BASE_ADDRESS)
#define MODEM_STATUS_REGISTER (0x06 + SERIAL_BASE_ADDRESS)
@ -64,6 +69,11 @@ struct f81232_private {
struct usb_serial_port *port;
};
static int calc_baud_divisor(speed_t baudrate)
{
return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
}
static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
{
int status;
@ -350,6 +360,53 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
*/
}
static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
{
u8 lcr;
int divisor, status = 0;
divisor = calc_baud_divisor(baudrate);
status = f81232_get_register(port, LINE_CONTROL_REGISTER,
&lcr); /* get LCR */
if (status) {
dev_err(&port->dev, "%s failed to get LCR: %d\n",
__func__, status);
return;
}
status = f81232_set_register(port, LINE_CONTROL_REGISTER,
lcr | UART_LCR_DLAB); /* Enable DLAB */
if (status) {
dev_err(&port->dev, "%s failed to set DLAB: %d\n",
__func__, status);
return;
}
status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
divisor & 0x00ff); /* low */
if (status) {
dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
__func__, status);
goto reapply_lcr;
}
status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
(divisor & 0xff00) >> 8); /* high */
if (status) {
dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
__func__, status);
}
reapply_lcr:
status = f81232_set_register(port, LINE_CONTROL_REGISTER,
lcr & ~UART_LCR_DLAB);
if (status) {
dev_err(&port->dev, "%s failed to set DLAB: %d\n",
__func__, status);
}
}
static int f81232_port_enable(struct usb_serial_port *port)
{
u8 val;
@ -395,15 +452,62 @@ static int f81232_port_disable(struct usb_serial_port *port)
static void f81232_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
/* FIXME - Stubbed out for now */
u8 new_lcr = 0;
int status = 0;
speed_t baudrate;
/* Don't change anything if nothing has changed */
if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
return;
/* Do the real work here... */
if (old_termios)
tty_termios_copy_hw(&tty->termios, old_termios);
if (C_BAUD(tty) == B0)
f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
baudrate = tty_get_baud_rate(tty);
if (baudrate > 0) {
if (baudrate > F81232_MAX_BAUDRATE) {
baudrate = F81232_MAX_BAUDRATE;
tty_encode_baud_rate(tty, baudrate, baudrate);
}
f81232_set_baudrate(port, baudrate);
}
if (C_PARENB(tty)) {
new_lcr |= UART_LCR_PARITY;
if (!C_PARODD(tty))
new_lcr |= UART_LCR_EPAR;
if (C_CMSPAR(tty))
new_lcr |= UART_LCR_SPAR;
}
if (C_CSTOPB(tty))
new_lcr |= UART_LCR_STOP;
switch (C_CSIZE(tty)) {
case CS5:
new_lcr |= UART_LCR_WLEN5;
break;
case CS6:
new_lcr |= UART_LCR_WLEN6;
break;
case CS7:
new_lcr |= UART_LCR_WLEN7;
break;
default:
case CS8:
new_lcr |= UART_LCR_WLEN8;
break;
}
status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
if (status) {
dev_err(&port->dev, "%s failed to set LCR: %d\n",
__func__, status);
}
}
static int f81232_tiocmget(struct tty_struct *tty)