linux/drivers/tty/serial/sh-sci.c, branch v4.8

serial: sh-sci: Stop transfers in sci_shutdown()

2016-06-26T17:57:13Z

Make sure the transmitter and receiver are stopped when shutting down the port, and related interrupts are disabled. Without this: - New input data may be received into the RX FIFO, possibly triggering a new RX DMA completion, - Transfers will still be enabled on a subsequent startup of the UART, before the UART's FIFOs have been reset, causing reading of stale data. Inspired by a patch in the BSP by Koji Matsuoka . Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Clear (H)SCIF timeout and overrun during reset

2016-06-25T16:09:53Z

Add the missing timeout bit definition for (H)SCIF. Clear the timeout and overrun flag bits during UART reset, cfr. the initialization flowchart in the datasheet. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Clear RX, error, and break flags during reset

2016-06-25T16:09:53Z

Setting the FIFO reset bits is not sufficient to reset the RX FIFO. After this the status register's RDF flag bit may still be set, causing the reception of one stale byte of data. To fix this, clear all status flag bits related to reception, error, and break handling, cfr. the initialization flowchart in the datasheet. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Do not start transfers from sci_startup()

2016-06-25T16:09:53Z

FIFO reset is done in sci_reset(), called from sci_set_termios(), while sci_start_tx() and sci_start_rx() are called before, from sci_startup(). However, starting transfers before the UART's FIFOs have been reset may cause reading of stale data. Remove the calls to sci_start_tx() and sci_start_rx() from sci_startup() to fix this. Transfers are still started when needed: - sci_start_rx() is called from sci_set_termios() after FIFO reset, if the CREAD flag is set, - sci_start_tx() is called from uart_change_speed() immediately thereafter, if transmission is enabled. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Add DT support for dedicated RTS/CTS

2016-06-25T16:07:51Z

Add support for indicating the availability of dedicated lines for RTS/CTS hardware flow control, using the standard "uart-has-rtscts" DT property. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix support for hardware-assisted RTS/CTS

2016-06-25T16:07:51Z

The existing support for hardware-assisted RTS/CTS is rudimentary and doesn't work. Add support for hardware-assisted RTS/CTS hardware flow control for the (H)SCIF, SCIFA, and SCIFB variants. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Add pin initialization for SCIFA/SCIFB

2016-06-25T16:07:51Z

Before, the driver relied on initialization by the boot loader, or by implicit reset state. Note that unlike on (H)SCIF, the RTS/CTS bits exist only if dedicated RTS/CTS pins are available, which depends on the SoC and UART instance. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Correct pin initialization on (H)SCIF

2016-06-25T16:07:51Z

Correct pin initialization on (H)SCIF: - RTS must be deasserted (it's active low), - SCK must be an input, as it may be used as the optional external clock input. Initial pin configuration must always be done: - Regardless of the presence of dedicated RTS and CTS pins: if the register exists, the RTS/CTS bits exist, too, - Regardless of hardware flow control being enabled or not: RTS must be deasserted. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Do not open-code sci_getreg()

2016-06-25T16:07:51Z

Replace open-coded variants of sci_getreg() by function calls, and drop intermediate variables where appropriate. Signed-off-by: Geert Uytterhoeven Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Add support for GPIO-controlled modem lines

2016-06-25T16:07:51Z

Enhance the Renesas SCI UART driver to add support for GPIO-controlled modem lines (CTS, DSR, DCD, RNG, RTS, DTR), using the serial_mctrl_gpio helpers. GPIO-controlled modem lines can be used when dedicated modem lines are not available. Invalid configurations specifying both GPIO RTS/CTS and dedicated RTS/CTS are rejected. Signed-off-by: Geert Uytterhoeven Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman