From: Thor Thayer <ttha...@opensource.altera.com> Some variants of the 16550 have a programmable TX FIFO threshold that will trigger an IRQ when the FIFO drops below the threshold. The Altera 16550 compatible soft IP supports programmable TX FIFO thresholds.
This patch series adds the tx-threshold parameter to the device tree. The tx_loadsz variable is amount of data that can be loaded into the FIFO on an IRQ and is updated based on the tx-threshold value. This patch series also adds support for the TX FIFO threshold registers in the Altera 16550-FIFOxx soft IP. Thor Thayer (4): Documentation: dt: serial: Add TX FIFO threshold parameter serial: 8250: of: Load TX FIFO Threshold from DT serial: 8250: Set Altera 16550 TX FIFO Threshold nios2: dts: 10m50: Add tx-threshold parameter Documentation/devicetree/bindings/serial/8250.txt | 2 + arch/nios2/boot/dts/10m50_devboard.dts | 1 + drivers/tty/serial/8250/8250_of.c | 7 ++++ drivers/tty/serial/8250/8250_port.c | 43 +++++++++++++++++++++ include/uapi/linux/serial_reg.h | 8 ++++ 5 files changed, 61 insertions(+) -- 1.7.9.5
