[PATCHv2 1/3] serial: mctrl_gpio: implement mctrl_gpio_use_rtscts

[Uwe Kleine-König]

On Mon, Sep 12, 2016 at 11:47:31AM +0200, Richard Genoud wrote:
> This function returns true if CTS and RTS are used as GPIOs.
> Some drivers (like atmel_serial) needs to know if the flow control is
> handled by the controller or by GPIOs.
> 
> Signed-off-by: Richard Genoud <richard.genoud at gmail.com>
> ---
>  drivers/tty/serial/serial_mctrl_gpio.c |  8 ++++++++
>  drivers/tty/serial/serial_mctrl_gpio.h | 10 ++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
> index d2da6aa7f27d..93bed8c99796 100644
> --- a/drivers/tty/serial/serial_mctrl_gpio.c
> +++ b/drivers/tty/serial/serial_mctrl_gpio.c
> @@ -17,6 +17,7 @@
>  #include <linux/err.h>
>  #include <linux/device.h>
>  #include <linux/irq.h>
> +#include <linux/err.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/termios.h>
>  #include <linux/serial_core.h>
> @@ -72,6 +73,13 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
>  }
>  EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
>  
> +bool mctrl_gpio_use_rtscts(struct mctrl_gpios *gpios)
> +{
> +	return !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) &&
> +		!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_RTS));

mctrl_gpio_to_gpiod cannot return an error pointer. So this is
(surprise!) a wrong usage of IS_ERR_OR_NULL.

Best regards
Uwe


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Pengutronix e.K.                           | Uwe Kleine-König            |
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