1. 20 Aug, 2013 1 commit
    • Tim Kryger's avatar
      serial: 8250_dw: Report CTS asserted for auto flow · 33acbb82
      Tim Kryger authored
      When a serial port is configured for RTS/CTS flow control, serial core
      will disable the transmitter if it observes CTS is de-asserted. This is
      perfectly reasonable and appropriate when the UART lacks the ability to
      automatically perform CTS flow control.
      
      However, if the UART hardware can manage flow control automatically, it
      is important that software not get involved.  When the DesignWare UART
      enables 16C750 style auto-RTS/CTS it stops generating interrupts for
      changes in CTS state so software mostly stays out of the way.  However,
      it does report the true state of CTS in the MSR so software may notice
      it is de-asserted and respond by improperly disabling the transmitter.
      Once this happens the transmitter will be blocked forever.
      
      To avoid this situation, we simply lie to the 8250 and serial core by
      reporting that CTS is asserted whenever auto-RTS/CTS mode is enabled.
      Signed-off-by: default avatarTim Kryger <tim.kryger@linaro.org>
      Reviewed-by: default avatarMatt Porter <matt.porter@linaro.org>
      Reviewed-by: default avatarMarkus Mayer <markus.mayer@linaro.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      33acbb82
  2. 16 Aug, 2013 1 commit
  3. 15 Aug, 2013 4 commits
  4. 14 Aug, 2013 2 commits
    • Mark Jackson's avatar
      OMAP: add RS485 support · 4a0ac0f5
      Mark Jackson authored
      This patch adds RS485 support to the OMAP serial driver, as
      defined in:-
      
      Documentation/devicetree/bindings/serial/rs485.txt
      
      When a UART transmitter is connected to (eg) a RS485 driver, it is
      necessary to turn the driver on/off as quickly as possible.  This is
      best achieved in the serial driver itself (rather than in userspace
      where the latency can be quite large).
      
      This patch allows a GPIO pin to be defined (via DT) that controls
      the enabling of the driver at the start of a message, and disables
      the driver when the message has been completed.
      
      When RS485 is disabled, the RTS pin is set to on.
      Signed-off-by: default avatarMark Jackson <mpfj@newflow.co.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4a0ac0f5
    • Julia Lawall's avatar
      tty: ar933x_uart: simplify use of devm_ioremap_resource · 071eb0ff
      Julia Lawall authored
      Remove unneeded error handling on the result of a call to
      platform_get_resource when the value is passed to devm_ioremap_resource.
      
      Move the call to platform_get_resource adjacent to the call to
      devm_ioremap_resource to make the connection between them more clear.
      
      A simplified version of the semantic patch that makes this change is as
      follows: (http://coccinelle.lip6.fr/)
      
      // <smpl>
      @@
      expression pdev,res,n,e,e1;
      expression ret != 0;
      identifier l;
      @@
      
      - res = platform_get_resource(pdev, IORESOURCE_MEM, n);
        ... when != res
      - if (res == NULL) { ... \(goto l;\|return ret;\) }
        ... when != res
      + res = platform_get_resource(pdev, IORESOURCE_MEM, n);
        e = devm_ioremap_resource(e1, res);
      // </smpl>
      Signed-off-by: default avatarJulia Lawall <Julia.Lawall@lip6.fr>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      071eb0ff
  5. 12 Aug, 2013 22 commits
  6. 05 Aug, 2013 5 commits
  7. 04 Aug, 2013 5 commits