[v2,0/9] Fixes and cleanup for RS485

Message

Lino Sanfilippo July 3, 2022, 5 p.m. UTC

From: Lino Sanfilippo <[e-mail]>

The following series includes cleanup and fixes around RS485 in the serial
core and uart drivers:

Patch 1: Only request the rs485 termination gpio if it is supported.
	 NOTE: 
	 This patch follows the design decision that "rs485_supported" is
	 set by the driver at initialization and cannot be modified
	 afterwards. However the better approach would be to let the serial
	 core modify the termination GPIO support setting based on the
	 existence of a termination GPIO. If "rs485_supported" is not a 
	 read-only value any more in future the logic implemented in this
	 patch should be adjusted accordingly.
Patch 2: Set the rs485 termination GPIO in the serial core. This is needed
	 since if the gpio is only accessible in sleepable context. It also
	 is a further step to make the RS485 handling more generic.
Patch 3: Move sanitizing of RS485 delays into an own function. This is in 
	 preparation of patch 4.
Patch 4: Sanitize RS485 delays read from device tree.
Patch 5: Correct RS485 delays in binding documentation.
Patch 6: Remove redundant code in 8250_dwlib.
Patch 7: Fix check for RS485 support.
Patch 8: Remove redundant code in ar933x.
Patch 9: Remove redundant code in 8250-lpc18xx.

Changes in v2:
- print a warning if termination GPIO is specified in DT/ACPI but is not
  supported by driver 
- fixed commit message for devtree documentation (as suggested by Andy)
- fixed code comment
- added patch 7


Lino Sanfilippo (9):
  serial: core: only get RS485 termination GPIO if supported
  serial: core, 8250: set RS485 termination gpio in serial core
  serial: core: move sanitizing of RS485 delays into own function
  serial: core: sanitize RS485 delays read from device tree
  dt_bindings: rs485: Correct delay values
  serial: 8250_dwlib: remove redundant sanity check for RS485 flags
  serial: ar933x: Fix check for RS485 support
  serial: ar933x: Remove redundant assignment in rs485_config
  serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags

 .../devicetree/bindings/serial/rs485.yaml     |  4 +-
 drivers/tty/serial/8250/8250_dwlib.c          | 10 +--
 drivers/tty/serial/8250/8250_lpc18xx.c        |  6 +-
 drivers/tty/serial/8250/8250_port.c           |  3 -
 drivers/tty/serial/ar933x_uart.c              | 18 ++---
 drivers/tty/serial/serial_core.c              | 70 +++++++++++++------
 6 files changed, 60 insertions(+), 51 deletions(-)


base-commit: 7349660438603ed19282e75949561406531785a5