[PATCH] tty: serial: cpm_uart: Add udbg support for enabling xmon

[Christophe Leroy]

Le 23/12/2020 à 10:38, Christophe Leroy a écrit :
> In order to use xmon with powerpc 8xx, the serial driver
> must provide udbg_putc() and udpb_getc().
> 
> Provide them via cpm_put_poll_char() and cpm_get_poll_char().
> 
> This requires CONFIG_CONSOLE_POLL.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>

This patch has been merged in tty-next, it is visible in linux-next

Christophe

> ---
>   drivers/tty/serial/cpm_uart/cpm_uart_core.c | 40 ++++++++++++++++++++-
>   1 file changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> index ba14ec5b9bc4..2920b9b602b3 100644
> --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
> @@ -1145,6 +1145,32 @@ static void cpm_put_poll_char(struct uart_port *port,
>   	ch[0] = (char)c;
>   	cpm_uart_early_write(pinfo, ch, 1, false);
>   }
> +
> +static struct uart_port *udbg_port;
> +
> +static void udbg_cpm_putc(char c)
> +{
> +	if (c == '\n')
> +		cpm_put_poll_char(udbg_port, '\r');
> +	cpm_put_poll_char(udbg_port, c);
> +}
> +
> +static int udbg_cpm_getc_poll(void)
> +{
> +	int c = cpm_get_poll_char(udbg_port);
> +
> +	return c == NO_POLL_CHAR ? -1 : c;
> +}
> +
> +static int udbg_cpm_getc(void)
> +{
> +	int c;
> +
> +	while ((c = udbg_cpm_getc_poll()) == -1)
> +		cpu_relax();
> +	return c;
> +}
> +
>   #endif /* CONFIG_CONSOLE_POLL */
>   
>   static const struct uart_ops cpm_uart_pops = {
> @@ -1251,7 +1277,10 @@ static int cpm_uart_init_port(struct device_node *np,
>   		pinfo->gpios[i] = NULL;
>   
>   #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
> -	udbg_putc = NULL;
> +#ifdef CONFIG_CONSOLE_POLL
> +	if (!udbg_port)
> +#endif
> +		udbg_putc = NULL;
>   #endif
>   
>   	return cpm_uart_request_port(&pinfo->port);
> @@ -1370,6 +1399,15 @@ static int __init cpm_uart_console_setup(struct console *co, char *options)
>   	uart_set_options(port, co, baud, parity, bits, flow);
>   	cpm_line_cr_cmd(pinfo, CPM_CR_RESTART_TX);
>   
> +#ifdef CONFIG_CONSOLE_POLL
> +	if (!udbg_port) {
> +		udbg_port = &pinfo->port;
> +		udbg_putc = udbg_cpm_putc;
> +		udbg_getc = udbg_cpm_getc;
> +		udbg_getc_poll = udbg_cpm_getc_poll;
> +	}
> +#endif
> +
>   	return 0;
>   }
>   
>