target/linux/generic/pending-4.19/950-tty-serial-exar-generalize-rs485-setup.patch

   1 From 24d5ba8ad40c3ac7903f688580c345aafa764dc7 Mon Sep 17 00:00:00 2001
   2 From: Daniel Golle <daniel@makrotopia.org>
   3 Date: Mon, 4 Jun 2018 14:51:29 +0200
   4 Subject: [PATCH] tty: serial: exar: generalize rs485 setup
   5 To: linux-serial@vger.kernel.org,
   6     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   7 Cc: Linus Walleij <linus.walleij@linaro.org>,
   8     Jan Kiszka <jan.kiszka@siemens.com>
   9
  10 Move the non-board-specific part of the RS485 initialization
  11 from iot2040_rs485_config function to a new generic function
  12 used also for other boards.
  13 This allows using PCIe boards which are hard-wired to RS485
  14 or have jumpers for their configurations.
  15
  16 Signed-off-by: Daniel Golle <daniel@makrotopia.org>
  17 ---
  18  drivers/tty/serial/8250/8250_exar.c | 38 +++++++++++++++++++----------
  19  1 file changed, 25 insertions(+), 13 deletions(-)
  20
  21 --- a/drivers/tty/serial/8250/8250_exar.c
  22 +++ b/drivers/tty/serial/8250/8250_exar.c
  23 @@ -275,8 +275,32 @@ static int xr17v35x_register_gpio(struct
  24         return 0;
  25  }
  26
  27 +static int generic_rs485_config(struct uart_port *port,
  28 +                               struct serial_rs485 *rs485)
  29 +{
  30 +       bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
  31 +       u8 __iomem *p = port->membase;
  32 +       u8 value;
  33 +
  34 +       value = readb(p + UART_EXAR_FCTR);
  35 +       if (is_rs485)
  36 +               value |= UART_FCTR_EXAR_485;
  37 +       else
  38 +               value &= ~UART_FCTR_EXAR_485;
  39 +
  40 +       writeb(value, p + UART_EXAR_FCTR);
  41 +
  42 +       if (is_rs485)
  43 +               writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
  44 +
  45 +       port->rs485 = *rs485;
  46 +
  47 +       return 0;
  48 +}
  49 +
  50  static const struct exar8250_platform exar8250_default_platform = {
  51         .register_gpio = xr17v35x_register_gpio,
  52 +       .rs485_config = generic_rs485_config,
  53  };
  54
  55  static int iot2040_rs485_config(struct uart_port *port,
  56 @@ -309,19 +333,7 @@ static int iot2040_rs485_config(struct u
  57         value |= mode;
  58         writeb(value, p + UART_EXAR_MPIOLVL_7_0);
  59
  60 -       value = readb(p + UART_EXAR_FCTR);
  61 -       if (is_rs485)
  62 -               value |= UART_FCTR_EXAR_485;
  63 -       else
  64 -               value &= ~UART_FCTR_EXAR_485;
  65 -       writeb(value, p + UART_EXAR_FCTR);
  66 -
  67 -       if (is_rs485)
  68 -               writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
  69 -
  70 -       port->rs485 = *rs485;
  71 -
  72 -       return 0;
  73 +       return generic_rs485_config(port, rs485);
  74  }
  75
  76  static const struct property_entry iot2040_gpio_properties[] = {