queue-4.19/tty-serial-atmel-add-is_half_duplex-helper.patch

   1 From f3040983132bf3477acd45d2452a906e67c2fec9 Mon Sep 17 00:00:00 2001
   2 From: Razvan Stefanescu <razvan.stefanescu@microchip.com>
   3 Date: Tue, 19 Mar 2019 15:20:34 +0200
   4 Subject: tty/serial: atmel: Add is_half_duplex helper
   5
   6 From: Razvan Stefanescu <razvan.stefanescu@microchip.com>
   7
   8 commit f3040983132bf3477acd45d2452a906e67c2fec9 upstream.
   9
  10 Use a helper function to check that a port needs to use half duplex
  11 communication, replacing several occurrences of multi-line bit checking.
  12
  13 Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done")
  14 Cc: stable <stable@vger.kernel.org>
  15 Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
  16 Acked-by: Richard Genoud <richard.genoud@gmail.com>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19
  20 ---
  21  drivers/tty/serial/atmel_serial.c |   19 +++++++++++--------
  22  1 file changed, 11 insertions(+), 8 deletions(-)
  23
  24 --- a/drivers/tty/serial/atmel_serial.c
  25 +++ b/drivers/tty/serial/atmel_serial.c
  26 @@ -225,6 +225,12 @@ static inline void atmel_uart_write_char
  27         __raw_writeb(value, port->membase + ATMEL_US_THR);
  28  }
  29
  30 +static inline int atmel_uart_is_half_duplex(struct uart_port *port)
  31 +{
  32 +       return (port->rs485.flags & SER_RS485_ENABLED) &&
  33 +               !(port->rs485.flags & SER_RS485_RX_DURING_TX);
  34 +}
  35 +
  36  #ifdef CONFIG_SERIAL_ATMEL_PDC
  37  static bool atmel_use_pdc_rx(struct uart_port *port)
  38  {
  39 @@ -481,9 +487,9 @@ static void atmel_stop_tx(struct uart_po
  40         /* Disable interrupts */
  41         atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
  42
  43 -       if ((port->rs485.flags & SER_RS485_ENABLED) &&
  44 -           !(port->rs485.flags & SER_RS485_RX_DURING_TX))
  45 +       if (atmel_uart_is_half_duplex(port))
  46                 atmel_start_rx(port);
  47 +
  48  }
  49
  50  /*
  51 @@ -500,8 +506,7 @@ static void atmel_start_tx(struct uart_p
  52                 return;
  53
  54         if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
  55 -               if ((port->rs485.flags & SER_RS485_ENABLED) &&
  56 -                   !(port->rs485.flags & SER_RS485_RX_DURING_TX))
  57 +               if (atmel_uart_is_half_duplex(port))
  58                         atmel_stop_rx(port);
  59
  60         if (atmel_use_pdc_tx(port))
  61 @@ -799,8 +804,7 @@ static void atmel_complete_tx_dma(void *
  62          */
  63         if (!uart_circ_empty(xmit))
  64                 atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
  65 -       else if ((port->rs485.flags & SER_RS485_ENABLED) &&
  66 -                !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
  67 +       else if (atmel_uart_is_half_duplex(port)) {
  68                 /* DMA done, stop TX, start RX for RS485 */
  69                 atmel_start_rx(port);
  70         }
  71 @@ -1377,8 +1381,7 @@ static void atmel_tx_pdc(struct uart_por
  72                 atmel_uart_writel(port, ATMEL_US_IER,
  73                                   atmel_port->tx_done_mask);
  74         } else {
  75 -               if ((port->rs485.flags & SER_RS485_ENABLED) &&
  76 -                   !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
  77 +               if (atmel_uart_is_half_duplex(port)) {
  78                         /* DMA done, stop TX, start RX for RS485 */
  79                         atmel_start_rx(port);
  80                 }