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| author | Soren Brinkmann <soren.brinkmann@xilinx.com> | 2015-12-26 02:43:53 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-06 22:52:09 -0800 |
| commit | 6e14f7c1f2c2e8d783b4bc50e7ac31b468910698 (patch) | |
| tree | a14a5f9c328e2635bc878f3b1eac3b5e72baa4f2 /drivers/tty/serial/xilinx_uartps.c | |
| parent | aea8f3ddcf5de21188b737345fc2f62526350874 (diff) | |
| download | linux-6e14f7c1f2c2e8d783b4bc50e7ac31b468910698.tar.gz linux-6e14f7c1f2c2e8d783b4bc50e7ac31b468910698.tar.bz2 linux-6e14f7c1f2c2e8d783b4bc50e7ac31b468910698.zip | |
tty: xuartps: Improve startup function
The startup function is supposed to initialize the UART for receiving.
Hence, don't enable the TX part. Also, protect HW accesses with the port
lock.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/xilinx_uartps.c')
| -rw-r--r-- | drivers/tty/serial/xilinx_uartps.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index ef114d7a0623..6ffd3bbe3e18 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -758,6 +758,7 @@ static void cdns_uart_set_termios(struct uart_port *port, */ static int cdns_uart_startup(struct uart_port *port) { + unsigned long flags; unsigned int retval = 0, status = 0; retval = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, @@ -765,6 +766,8 @@ static int cdns_uart_startup(struct uart_port *port) if (retval) return retval; + spin_lock_irqsave(&port->lock, flags); + /* Disable the TX and RX */ writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS, port->membase + CDNS_UART_CR_OFFSET); @@ -775,15 +778,14 @@ static int cdns_uart_startup(struct uart_port *port) writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST, port->membase + CDNS_UART_CR_OFFSET); - status = readl(port->membase + CDNS_UART_CR_OFFSET); - - /* Clear the RX disable and TX disable bits and then set the TX enable - * bit and RX enable bit to enable the transmitter and receiver. + /* + * Clear the RX disable bit and then set the RX enable bit to enable + * the receiver. */ - writel((status & ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS)) - | (CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN | - CDNS_UART_CR_STOPBRK), - port->membase + CDNS_UART_CR_OFFSET); + status = readl(port->membase + CDNS_UART_CR_OFFSET); + status &= CDNS_UART_CR_RX_DIS; + status |= CDNS_UART_CR_RX_EN; + writel(status, port->membase + CDNS_UART_CR_OFFSET); /* Set the Mode Register with normal mode,8 data bits,1 stop bit, * no parity. @@ -814,6 +816,8 @@ static int cdns_uart_startup(struct uart_port *port) CDNS_UART_IXR_RXTRIG | CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER_OFFSET); + spin_unlock_irqrestore(&port->lock, flags); + return retval; } |