diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 76a8daadff47..daf710f5c3fc 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -57,11 +57,25 @@ struct dw8250_data { int last_lcr; + int last_mcr; int line; struct clk *clk; u8 usr_reg; }; +static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) +{ + struct dw8250_data *d = p->private_data; + + /* If reading MSR, report CTS asserted when auto-CTS/RTS enabled */ + if (offset == UART_MSR && d->last_mcr & UART_MCR_AFE) { + value |= UART_MSR_CTS; + value &= ~UART_MSR_DCTS; + } + + return value; +} + static void dw8250_serial_out(struct uart_port *p, int offset, int value) { struct dw8250_data *d = p->private_data; @@ -69,15 +83,17 @@ static void dw8250_serial_out(struct uart_port *p, int offset, int value) if (offset == UART_LCR) d->last_lcr = value; - offset <<= p->regshift; - writeb(value, p->membase + offset); + if (offset == UART_MCR) + d->last_mcr = value; + + writeb(value, p->membase + (offset << p->regshift)); } static unsigned int dw8250_serial_in(struct uart_port *p, int offset) { - offset <<= p->regshift; + unsigned int value = readb(p->membase + (offset << p->regshift)); - return readb(p->membase + offset); + return dw8250_modify_msr(p, offset, value); } /* Read Back (rb) version to ensure register access ording. */ @@ -94,15 +110,17 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value) if (offset == UART_LCR) d->last_lcr = value; - offset <<= p->regshift; - writel(value, p->membase + offset); + if (offset == UART_MCR) + d->last_mcr = value; + + writel(value, p->membase + (offset << p->regshift)); } static unsigned int dw8250_serial_in32(struct uart_port *p, int offset) { - offset <<= p->regshift; + unsigned int value = readl(p->membase + (offset << p->regshift)); - return readl(p->membase + offset); + return dw8250_modify_msr(p, offset, value); } static int dw8250_handle_irq(struct uart_port *p)