[PATCH V6 0/3] Add rs485 support to uartps driver

[Manikanta Guntupalli <manikanta.guntupalli@amd.com>]

Add reference to rs485.yaml.
Add rs485 support to uartps driver.
---
Changes for V2:
Modify optional gpio name to xlnx,phy-ctrl-gpios.
Update commit description.
Add support for RTS, delay_rts_before_send and delay_rts_after_send in RS485 mode.

Changes for V3:
Modify optional gpio name to rts-gpios.
Update commit description.
Move cdns_uart_tx_empty function to avoid prototype statement.
Remove assignment of struct serial_rs485 to port->rs485 as
serial core performs that.
Switch to native RTS in non GPIO case.
Handle rs485 during stop tx.
Remove explicit calls to configure gpio direction and value,
as devm_gpiod_get_optional performs that by using GPIOD_OUT_LOW argument.
Update implementation to support configuration of GPIO/RTS value
based on user configuration of SER_RS485_RTS_ON_SEND and
SER_RS485_RTS_AFTER_SEND. Move implementation to start_tx from handle_tx.

Changes for V4:
Update rts-gpios description.
Create separate patch for cdns_uart_tx_empty relocation.
Call cdns_rs485_rx_setup() before uart_add_one_port() in probe.
Update gpio descriptor name to gpiod_rts.
Instead of cdns_rs485_config_gpio_rts_high() and
cdns_rs485_config_gpio_rts_low() functions for RTS/GPIO value
configuration implement cdns_rts_gpio_enable().
Disable auto rts and call cdns_uart_stop_tx() from cdns_rs485_config.
Use timer instead of mdelay for delay_rts_before_send and delay_rts_after_send.
Update cdns_uart_set_mctrl to support GPIO/RTS.

Changes for V5:
Remove rts-gpios description.
Update commit message and description.

Changes for V6:
Update commit description.
Disable the TX and RX in cdns_rs485_config() when rs485 disabled.
Hold lock for cdns_uart_handle_tx() in cdns_rs485_tx_callback().

Manikanta Guntupalli (3):
  dt-bindings: Add reference to rs485.yaml
  tty: serial: uartps: Relocate cdns_uart_tx_empty to facilitate rs485
  tty: serial: uartps: Add rs485 support to uartps driver

 .../devicetree/bindings/serial/cdns,uart.yaml |   1 +
 drivers/tty/serial/xilinx_uartps.c            | 252 ++++++++++++++++--
 2 files changed, 229 insertions(+), 24 deletions(-)

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2.25.1