diff options
| author | Nava kishore Manne <nava.manne@xilinx.com> | 2017-03-31 17:50:20 +0530 |
|---|---|---|
| committer | Michal Simek <michal.simek@xilinx.com> | 2017-03-31 14:26:35 +0200 |
| commit | 9fb8e58728e8e4ded9504f0c833c56054c0306f1 (patch) | |
| tree | 2f868f68c6ba16fb027d17b68905218b490e4e83 | |
| parent | c5958f8629809f24ca884dac98fcca851bfd4c54 (diff) | |
| download | linux-9fb8e58728e8e4ded9504f0c833c56054c0306f1.tar.gz | |
serial: xuartps: Enable uart loopback mode
This patch adds xilinx uart loopback support by modifying the
cdns_uart_set_mctrl function to handle the switch to loopback mode.
After this patch, the loopback mode can be enabled/disabled by
setting/clearing the TIOCM_LOOP modem bit via TIOCMBIS/TIOCMBIC
ioctls respectively.
Signed-off-by: Nava kishore Manne <navam@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
| -rw-r--r-- | drivers/tty/serial/xilinx_uartps.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 51e6dddd10591c..cbedcb59c7e85a 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -94,6 +94,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); #define CDNS_UART_MR_CLKSEL 0x00000001 /* Pre-scalar selection */ #define CDNS_UART_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */ #define CDNS_UART_MR_CHMODE_NORM 0x00000000 /* Normal mode */ +#define CDNS_UART_MR_CHMODE_MASK 0x00000300 /* Mask for mode bits */ #define CDNS_UART_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */ #define CDNS_UART_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */ @@ -1000,17 +1001,25 @@ static unsigned int cdns_uart_get_mctrl(struct uart_port *port) static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { u32 val; + u32 mode_reg; val = readl(port->membase + CDNS_UART_MODEMCR); + mode_reg = readl(port->membase + CDNS_UART_MR); val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR); + mode_reg &= ~CDNS_UART_MR_CHMODE_MASK; if (mctrl & TIOCM_RTS) val |= CDNS_UART_MODEMCR_RTS; if (mctrl & TIOCM_DTR) val |= CDNS_UART_MODEMCR_DTR; + if (mctrl & TIOCM_LOOP) + mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP; + else + mode_reg |= CDNS_UART_MR_CHMODE_NORM; writel(val, port->membase + CDNS_UART_MODEMCR); + writel(mode_reg, port->membase + CDNS_UART_MR); } #ifdef CONFIG_CONSOLE_POLL |