From 8e5470c9839caff94fe334e67ff7e7ace587282a Mon Sep 17 00:00:00 2001 From: Thor Thayer Date: Thu, 22 Sep 2016 14:56:16 -0500 Subject: serial: 8250: Set Altera 16550 TX FIFO Threshold The Altera 16550 soft IP UART requires 2 additional registers for TX FIFO threshold support. These 2 registers enable the TX FIFO Low Watermark and set the TX FIFO Low Watermark. Set the TX FIFO threshold to the FIFO size - tx_loadsz. Signed-off-by: Thor Thayer Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/serial_reg.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h index 1e5ac4e776da..b4c04842a8c0 100644 --- a/include/uapi/linux/serial_reg.h +++ b/include/uapi/linux/serial_reg.h @@ -376,5 +376,13 @@ #define UART_EXAR_TXTRG 0x0a /* Tx FIFO trigger level write-only */ #define UART_EXAR_RXTRG 0x0b /* Rx FIFO trigger level write-only */ +/* + * These are definitions for the Altera ALTR_16550_F32/F64/F128 + * Normalized from 0x100 to 0x40 because of shift by 2 (32 bit regs). + */ +#define UART_ALTR_AFR 0x40 /* Additional Features Register */ +#define UART_ALTR_EN_TXFIFO_LW 0x01 /* Enable the TX FIFO Low Watermark */ +#define UART_ALTR_TX_LOW 0x41 /* Tx FIFO Low Watermark */ + #endif /* _LINUX_SERIAL_REG_H */ -- cgit v1.2.3