[PATCH V7 08/11] USB: f81232: implement set_termios()

Peter Hung
2015-02-24T10:18:16Z

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.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
---
drivers/usb/serial/f81232.c | 106 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 102 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index f5c9060..0c96b9a 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -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 +69,14 @@ struct f81232_private {
struct usb_serial_port *port;
};

+static int calc_baud_divisor(u32 baudrate)
+{
+ if (!baudrate)
+ return 0;
+ else
+ return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
+}
+
static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *data)
{
int status;
@@ -369,6 +382,52 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
*/
}

+static void f81232_set_baudrate(struct usb_serial_port *port, int baudrate)
+{
+ u8 divisor, lcr;
+ int status = 0;
+
+ if (!baudrate)
+ return;
+
+ 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);
+ }
+
+ 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);
+ }
+
+ 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);
+ }
+
+ 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);
+ }
+
+ 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, int enable)
{
u8 data = 0;
@@ -399,15 +458,54 @@ static int f81232_port_enable(struct usb_serial_port *port, int enable)
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;
+

/* 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);
+
+ f81232_set_baudrate(port, tty_get_baud_rate(tty));
+
+ 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)
--
1.9.1