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authorThor Thayer <tthayer@opensource.altera.com>2016-09-22 14:56:16 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-27 12:55:50 +0200
commit8e5470c9839caff94fe334e67ff7e7ace587282a (patch)
treed96d839061310f9c2e94f7fc24fc906d338f4d01 /include/uapi
parentffea043965e4634617485b4d313d6c0099d817f0 (diff)
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 <tthayer@opensource.altera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/uapi')
-rw-r--r--include/uapi/linux/serial_reg.h8
1 files changed, 8 insertions, 0 deletions
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 */