[PATCH] serial: a3720: Implement pending method for output direction

[Stefan Roese]

On 14.01.21 15:46, Pali Rohár wrote:
> To check if some output characters are waiting either in Transmitter
> Holding Register or Transmitter Shift Register we need to look at
> TX_EMPTY bit of UART Status Register.
> 
> Signed-off-by: Pali Rohár <pali at kernel.org>

Reviewed-by: Stefan Roese <sr at denx.de>

BTW: How did you detect this issue?

Thanks,
Stefan

> ---
>   drivers/serial/serial_mvebu_a3700.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/serial/serial_mvebu_a3700.c b/drivers/serial/serial_mvebu_a3700.c
> index fb43f88eaf..909901c9f0 100644
> --- a/drivers/serial/serial_mvebu_a3700.c
> +++ b/drivers/serial/serial_mvebu_a3700.c
> @@ -23,6 +23,7 @@ struct mvebu_platdata {
>   #define UART_POSSR_REG		0x14
>   
>   #define UART_STATUS_RX_RDY	0x10
> +#define UART_STATUS_TX_EMPTY	0x40
>   #define UART_STATUS_TXFIFO_FULL	0x800
>   
>   #define UART_CTRL_RXFIFO_RESET	0x4000
> @@ -59,8 +60,13 @@ static int mvebu_serial_pending(struct udevice *dev, bool input)
>   	struct mvebu_platdata *plat = dev_get_platdata(dev);
>   	void __iomem *base = plat->base;
>   
> -	if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
> -		return 1;
> +	if (input) {
> +		if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
> +			return 1;
> +	} else {
> +		if (!(readl(base + UART_STATUS_REG) & UART_STATUS_TX_EMPTY))
> +			return 1;
> +	}
>   
>   	return 0;
>   }
> 


Viele Grüße,
Stefan

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