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path: root/drivers/tty/serial/8250/8250_dw.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
-rw-r--r--drivers/tty/serial/8250/8250_dw.c34
1 files changed, 26 insertions, 8 deletions
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)
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