diff options
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 10 | ||||
| -rw-r--r-- | include/linux/atmel_serial.h | 1 |
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 5f550d9feed9..fd8aa1f4ba78 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2170,13 +2170,15 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, * accurately. This feature is enabled only when using normal mode. * baudrate = selected clock / (8 * (2 - OVER) * (CD + FP / 8)) * Currently, OVER is always set to 0 so we get - * baudrate = selected clock (16 * (CD + FP / 8)) + * baudrate = selected clock / (16 * (CD + FP / 8)) + * then + * 8 CD + FP = selected clock / (2 * baudrate) */ if (atmel_port->has_frac_baudrate && (mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_NORMAL) { - div = DIV_ROUND_CLOSEST(port->uartclk, baud); - cd = div / 16; - fp = DIV_ROUND_CLOSEST(div % 16, 2); + div = DIV_ROUND_CLOSEST(port->uartclk, baud * 2); + cd = div >> 3; + fp = div & ATMEL_US_FP_MASK; } else { cd = uart_get_divisor(port, baud); } diff --git a/include/linux/atmel_serial.h b/include/linux/atmel_serial.h index f8e452aa48d7..bd2560502f3c 100644 --- a/include/linux/atmel_serial.h +++ b/include/linux/atmel_serial.h @@ -119,6 +119,7 @@ #define ATMEL_US_BRGR 0x20 /* Baud Rate Generator Register */ #define ATMEL_US_CD GENMASK(15, 0) /* Clock Divider */ #define ATMEL_US_FP_OFFSET 16 /* Fractional Part */ +#define ATMEL_US_FP_MASK 0x7 #define ATMEL_US_RTOR 0x24 /* Receiver Time-out Register for USART */ #define ATMEL_UA_RTOR 0x28 /* Receiver Time-out Register for UART */ |