serial: 8250_dw: Fix get_mctrl behaviour

[deliverable/linux.git] / drivers / tty / serial / 8250 / 8250_dw.c

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index e60116235836498e5b20ce56219b7d8c949acd25..2ab229ddee389ee20fa7923f93e43ddda944bbf0 100644 (file)
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -59,6 +59,8 @@ struct dw8250_data {
        u8                      usr_reg;
        int                     last_mcr;
        int                     line;
+       int                     msr_mask_on;
+       int                     msr_mask_off;
        struct clk              *clk;
        struct clk              *pclk;
        struct reset_control    *rst;
@@ -81,6 +83,12 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
                value &= ~UART_MSR_DCTS;
        }
 
+       /* Override any modem control signals if needed */
+       if (offset == UART_MSR) {
+               value |= d->msr_mask_on;
+               value &= ~d->msr_mask_off;
+       }
+
        return value;
 }
 
@@ -334,6 +342,30 @@ static int dw8250_probe_of(struct uart_port *p,
        if (id >= 0)
                p->line = id;
 
+       if (of_property_read_bool(np, "dcd-override")) {
+               /* Always report DCD as active */
+               data->msr_mask_on |= UART_MSR_DCD;
+               data->msr_mask_off |= UART_MSR_DDCD;
+       }
+
+       if (of_property_read_bool(np, "dsr-override")) {
+               /* Always report DSR as active */
+               data->msr_mask_on |= UART_MSR_DSR;
+               data->msr_mask_off |= UART_MSR_DDSR;
+       }
+
+       if (of_property_read_bool(np, "cts-override")) {
+               /* Always report DSR as active */
+               data->msr_mask_on |= UART_MSR_DSR;
+               data->msr_mask_off |= UART_MSR_DDSR;
+       }
+
+       if (of_property_read_bool(np, "ri-override")) {
+               /* Always report Ring indicator as inactive */
+               data->msr_mask_off |= UART_MSR_RI;
+               data->msr_mask_off |= UART_MSR_TERI;
+       }
+
        /* clock got configured through clk api, all done */
        if (p->uartclk)
                return 0;