Hi Lee
On 12/02/2016 03:11 PM, Lee Jones wrote:
> Until this point, it has not been possible for serial applications
> to toggle the UART RTS line. This can be useful with certain
> configurations. For example, when using a Mezzanine on a Linaro
> 96board, RTS line is used to take the the on-board microcontroller
typo "the the on"
> in and out of reset.
>
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> drivers/tty/serial/st-asc.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> index 379e5bd..ce46898 100644
> --- a/drivers/tty/serial/st-asc.c
> +++ b/drivers/tty/serial/st-asc.c
> @@ -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;
> @@ -381,12 +383,16 @@ 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.
> */
> +
> + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
> }
>
> static unsigned int asc_get_mctrl(struct uart_port *port)
> @@ -731,12 +737,20 @@ MODULE_DEVICE_TABLE(of, asc_match);
> static int asc_serial_probe(struct platform_device *pdev)
> {
> int ret;
> + struct device_node *np = pdev->dev.of_node;
> struct asc_port *ascport;
> + struct gpio_desc *gpiod;
>
> ascport = asc_of_get_asc_port(pdev);
> if (!ascport)
> return -ENODEV;
>
> + gpiod = devm_get_gpiod_from_child(&pdev->dev, "rts", &np->fwnode);
> + if (!IS_ERR(gpiod)) {
> + gpiod_direction_output(gpiod, 0);
> + ascport->rts = gpiod;
> + }
> +
> ret = asc_init_port(ascport, pdev);
> if (ret)
> return ret;
>
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