This patchset adds RS-485 9th bit addressing mode support to the DW UART driver and the necessary serial core bits to handle it. The addressing mode is configured through ->rs485_config() as was requested during the review of the earlier versions. The line configuration related ADDRB is still kept in ktermios->c_cflag to be able to take account the extra addressing bit while calculating timing, etc. but it is set/cleared by ->rs485_config(). Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: linux-api@xxxxxxxxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx v8 -> v9: - Tweak comments (struct fields info & one callback style correction) - Add struct layout checks as static_asserts v7 -> v8: - Use anonymous union/struct in serial_rs485 to create "v2" of it - Remove a stray newline change - Reorder local var declarations - Put ktermios param before serial_rs485 for rs485_config v6 -> v7: - Fixed typos in documentation & comment - Changes lsr typing from unsigned int to u16 v5 -> v6: - Reorder remaining patches - LSR changes are simpler due to helper added by LSR fix series - Depend on rs485_struct sanitization on catching much of invalid config - In order to be able to alter ADDRB in termios .c_cflag within .rs485_config(), take termios_rwsem and pass ktermios to it. - Moved addressing mode setup entirely into .rs485_config() - Use ndelay() instead of udelay() (uart_port->frame_time is in nsecs) Ilpo Järvinen (6): serial: 8250: make saved LSR larger serial: 8250: create lsr_save_mask serial: 8250_lpss: Use 32-bit reads serial: take termios_rwsem for ->rs485_config() & pass termios as param serial: Support for RS-485 multipoint addresses serial: 8250_dwlib: Support for 9th bit multipoint addressing Documentation/driver-api/serial/driver.rst | 2 + .../driver-api/serial/serial-rs485.rst | 26 ++++- drivers/tty/serial/8250/8250.h | 9 +- drivers/tty/serial/8250/8250_core.c | 4 + drivers/tty/serial/8250/8250_dw.c | 2 +- drivers/tty/serial/8250/8250_dwlib.c | 105 +++++++++++++++++- drivers/tty/serial/8250/8250_exar.c | 11 +- drivers/tty/serial/8250/8250_fintek.c | 2 +- drivers/tty/serial/8250/8250_fsl.c | 2 +- drivers/tty/serial/8250/8250_ingenic.c | 2 +- drivers/tty/serial/8250/8250_lpc18xx.c | 2 +- drivers/tty/serial/8250/8250_lpss.c | 2 +- drivers/tty/serial/8250/8250_omap.c | 7 +- drivers/tty/serial/8250/8250_pci.c | 2 +- drivers/tty/serial/8250/8250_port.c | 20 ++-- drivers/tty/serial/amba-pl011.c | 2 +- drivers/tty/serial/ar933x_uart.c | 2 +- drivers/tty/serial/atmel_serial.c | 2 +- drivers/tty/serial/fsl_lpuart.c | 4 +- drivers/tty/serial/imx.c | 2 +- drivers/tty/serial/max310x.c | 2 +- drivers/tty/serial/mcf.c | 3 +- drivers/tty/serial/omap-serial.c | 3 +- drivers/tty/serial/sc16is7xx.c | 2 +- drivers/tty/serial/serial_core.c | 36 +++++- drivers/tty/serial/stm32-usart.c | 2 +- drivers/tty/tty_ioctl.c | 4 + include/linux/serial_8250.h | 7 +- include/linux/serial_core.h | 1 + include/uapi/asm-generic/termbits-common.h | 1 + include/uapi/linux/serial.h | 20 +++- 31 files changed, 238 insertions(+), 53 deletions(-) -- 2.30.2