@@ -30,6 +30,7 @@
#include <linux/of_platform.h>
#include <linux/serial_core.h>
#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
#define DRIVER_NAME "st-asc"
#define ASC_SERIAL_NAME "ttyAS"
@@ -38,6 +39,7 @@
struct asc_port {
struct uart_port port;
+ struct gpio_desc *rts;
struct clk *clk;
unsigned int hw_flow_control:1;
unsigned int force_m1:1;
@@ -391,12 +393,27 @@ static unsigned int asc_tx_empty(struct uart_port *port)
static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
+ struct asc_port *ascport = to_asc_port(port);
+
/*
- * This routine is used for seting signals of: DTR, DCD, CTS/RTS
- * We use ASC's hardware for CTS/RTS, so don't need any for that.
- * Some boards have DTR and DCD implemented using PIO pins,
- * code to do this should be hooked in here.
+ * This routine is used for seting signals of: DTR, DCD, CTS and RTS.
+ * We use ASC's hardware for CTS/RTS when hardware flow-control is
+ * enabled, however if the RTS line is required for another purpose,
+ * commonly controlled using HUP from userspace, then we need to toggle
+ * it manually, using GPIO.
+ *
+ * Some boards also have DTR and DCD implemented using PIO pins, code to
+ * do this should be hooked in here.
*/
+
+ if (!ascport->rts)
+ return;
+
+ /* If HW flow-control is enabled, we can't fiddle with the RTS line */
+ if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE)
+ return;
+
+ gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
}
static unsigned int asc_get_mctrl(struct uart_port *port)
@@ -726,6 +743,8 @@ static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
"st,hw-flow-control");
asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1");
asc_ports[id].port.line = id;
+ asc_ports[id].rts = NULL;
+
return &asc_ports[id];
}