From 422c6d3b09afb187b5aeedc3a99d759703023be0 Mon Sep 17 00:00:00 2001 From: Maarten Brock Date: Mon, 25 Nov 2019 18:45:29 +0530 Subject: [PATCH] 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 Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/1574687731-21563-1-git-send-email-shubhrajyoti.datta@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/xilinx_uartps.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 2b5606469bed..f33b89587786 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) -- 2.11.0