git.openwrt.org Git - openwrt/staging/stintel.git/blob

   1 From 694247173f2e136196d7cb3a392c84cda65674d2 Mon Sep 17 00:00:00 2001
   2 From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
   3 Date: Mon, 7 Oct 2024 12:27:15 -0400
   4 Subject: [PATCH] serial: sc16is7xx: announce support for SER_RS485_RTS_ON_SEND
   5
   6 commit 068d35a7be65fa3bca4bba21c269bfe0b39158a6 upstream.
   7
   8 When specifying flag SER_RS485_RTS_ON_SEND in RS485 configuration,
   9 we get the following warning after commit 4afeced55baa ("serial: core:
  10 fix sanitizing check for RTS settings"):
  11
  12     invalid RTS setting, using RTS_AFTER_SEND instead
  13
  14 This results in SER_RS485_RTS_AFTER_SEND being set and the
  15 driver always write to the register field SC16IS7XX_EFCR_RTS_INVERT_BIT,
  16 which breaks some hardware using these chips.
  17
  18 The hardware supports both RTS_ON_SEND and RTS_AFTER_SEND modes, so fix
  19 this by announcing support for RTS_ON_SEND.
  20
  21 Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
  22 Suggested-by: Konstantin Pugin <ria.freelander@gmail.com>
  23 Link: https://lore.kernel.org/lkml/20240422133219.2710061-2-ria.freelander@gmail.com
  24 Reviewed-by: Andy Shevchenko <andy@kernel.org>
  25 Tested-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
  26 Link: https://lore.kernel.org/r/20241007162716.3122912-1-hugo@hugovil.com
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28 ---
  29  drivers/tty/serial/sc16is7xx.c | 2 +-
  30  1 file changed, 1 insertion(+), 1 deletion(-)
  31
  32 --- a/drivers/tty/serial/sc16is7xx.c
  33 +++ b/drivers/tty/serial/sc16is7xx.c
  34 @@ -1457,7 +1457,7 @@ static int sc16is7xx_setup_mctrl_ports(s
  35  }
  36
  37  static const struct serial_rs485 sc16is7xx_rs485_supported = {
  38 -       .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
  39 +       .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
  40         .delay_rts_before_send = 1,
  41         .delay_rts_after_send = 1,      /* Not supported but keep returning -EINVAL */
  42  };