serial: xilinx_uartps: Let get_mctrl return status
Some of the applications like microcom do not work if
modem is disabled. To fix them we always return
TIOCM_CTS | TIOCM_DSR | TIOCM_CAR instead of 0 when
using cts_override. Make get_mctrl return actual status
when not using cts_override.
Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1574687731-21563-1-git-send-email-shubhrajyoti.datta@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 2b56064..f33b895 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -154,6 +154,16 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
#define CDNS_UART_MODEMCR_DTR 0x00000001 /* Data Terminal Ready */
/*
+ * Modem Status register:
+ * The read/write Modem Status register reports the interface with the modem
+ * or data set, or a peripheral device emulating a modem.
+ */
+#define CDNS_UART_MODEMSR_DCD BIT(7) /* Data Carrier Detect */
+#define CDNS_UART_MODEMSR_RI BIT(6) /* Ting Indicator */
+#define CDNS_UART_MODEMSR_DSR BIT(5) /* Data Set Ready */
+#define CDNS_UART_MODEMSR_CTS BIT(4) /* Clear To Send */
+
+/*
* Channel Status Register:
* The channel status register (CSR) is provided to enable the control logic
* to monitor the status of bits in the channel interrupt status register,
@@ -1003,12 +1013,24 @@ static void cdns_uart_config_port(struct uart_port *port, int flags)
*/
static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
{
+ u32 val;
+ unsigned int mctrl = 0;
struct cdns_uart *cdns_uart_data = port->private_data;
if (cdns_uart_data->cts_override)
- return 0;
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
- return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+ val = readl(port->membase + CDNS_UART_MODEMSR);
+ if (val & CDNS_UART_MODEMSR_CTS)
+ mctrl |= TIOCM_CTS;
+ if (val & CDNS_UART_MODEMSR_DSR)
+ mctrl |= TIOCM_DSR;
+ if (val & CDNS_UART_MODEMSR_RI)
+ mctrl |= TIOCM_RNG;
+ if (val & CDNS_UART_MODEMSR_DCD)
+ mctrl |= TIOCM_CAR;
+
+ return mctrl;
}
static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
