linux-kernel - Re: [PATCH 2/3 v6] serial: 8250: Add MSR/MCR TIOCM conversion wrapper functions

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Message-ID: <20190613170741.GD9224@smile.fi.intel.com>
Date:   Thu, 13 Jun 2019 20:07:41 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Stefan Roese <sr@...x.de>
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Yegor Yefremov <yegorslists@...glemail.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Giulio Benetti <giulio.benetti@...ronovasrl.com>
Subject: Re: [PATCH 2/3 v6] serial: 8250: Add MSR/MCR TIOCM conversion
 wrapper functions

On Thu, Jun 13, 2019 at 05:45:41PM +0200, Stefan Roese wrote:
> This patch adds wrapper functions to convert MSR <-> TIOCM and also
> MCR <-> TIOCM. These functions are used now in serial8250_do_set_mctrl()
> and serial8250_do_get_mctrl().
> 

Yes, and we may use them in the other drivers later on.
Thanks!

Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

> Signed-off-by: Stefan Roese <sr@...x.de>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@...ux.intel.com>
> Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> Cc: Yegor Yefremov <yegorslists@...glemail.com>
> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> Cc: Giulio Benetti <giulio.benetti@...ronovasrl.com>
> ---
> v6:
> - New patch
> 
>  drivers/tty/serial/8250/8250.h      | 54 +++++++++++++++++++++++++++++
>  drivers/tty/serial/8250/8250_port.c | 25 ++-----------
>  2 files changed, 57 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
> index ebfb0bd5bef5..793da2e510e0 100644
> --- a/drivers/tty/serial/8250/8250.h
> +++ b/drivers/tty/serial/8250/8250.h
> @@ -139,6 +139,60 @@ void serial8250_rpm_put_tx(struct uart_8250_port *p);
>  int serial8250_em485_init(struct uart_8250_port *p);
>  void serial8250_em485_destroy(struct uart_8250_port *p);
>  
> +/* MCR <-> TIOCM conversion */
> +static inline int serial8250_TIOCM_to_MCR(int tiocm)
> +{
> +	int mcr = 0;
> +
> +	if (tiocm & TIOCM_RTS)
> +		mcr |= UART_MCR_RTS;
> +	if (tiocm & TIOCM_DTR)
> +		mcr |= UART_MCR_DTR;
> +	if (tiocm & TIOCM_OUT1)
> +		mcr |= UART_MCR_OUT1;
> +	if (tiocm & TIOCM_OUT2)
> +		mcr |= UART_MCR_OUT2;
> +	if (tiocm & TIOCM_LOOP)
> +		mcr |= UART_MCR_LOOP;
> +
> +	return mcr;
> +}
> +
> +static inline int serial8250_MCR_to_TIOCM(int mcr)
> +{
> +	int tiocm = 0;
> +
> +	if (mcr & UART_MCR_RTS)
> +		tiocm |= TIOCM_RTS;
> +	if (mcr & UART_MCR_DTR)
> +		tiocm |= TIOCM_DTR;
> +	if (mcr & UART_MCR_OUT1)
> +		tiocm |= TIOCM_OUT1;
> +	if (mcr & UART_MCR_OUT2)
> +		tiocm |= TIOCM_OUT2;
> +	if (mcr & UART_MCR_LOOP)
> +		tiocm |= TIOCM_LOOP;
> +
> +	return tiocm;
> +}
> +
> +/* MSR <-> TIOCM conversion */
> +static inline int serial8250_MSR_to_TIOCM(int msr)
> +{
> +	int tiocm = 0;
> +
> +	if (msr & UART_MSR_DCD)
> +		tiocm |= TIOCM_CAR;
> +	if (msr & UART_MSR_RI)
> +		tiocm |= TIOCM_RNG;
> +	if (msr & UART_MSR_DSR)
> +		tiocm |= TIOCM_DSR;
> +	if (msr & UART_MSR_CTS)
> +		tiocm |= TIOCM_CTS;
> +
> +	return tiocm;
> +}
> +
>  static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
>  {
>  	serial_out(up, UART_MCR, value);
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index 2304a84eee3b..47f0a8d01a57 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -1944,22 +1944,12 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
>  {
>  	struct uart_8250_port *up = up_to_u8250p(port);
>  	unsigned int status;
> -	unsigned int ret;
>  
>  	serial8250_rpm_get(up);
>  	status = serial8250_modem_status(up);
>  	serial8250_rpm_put(up);
>  
> -	ret = 0;
> -	if (status & UART_MSR_DCD)
> -		ret |= TIOCM_CAR;
> -	if (status & UART_MSR_RI)
> -		ret |= TIOCM_RNG;
> -	if (status & UART_MSR_DSR)
> -		ret |= TIOCM_DSR;
> -	if (status & UART_MSR_CTS)
> -		ret |= TIOCM_CTS;
> -	return ret;
> +	return serial8250_MSR_to_TIOCM(status);
>  }
>  EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
>  
> @@ -1973,18 +1963,9 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
>  void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
>  {
>  	struct uart_8250_port *up = up_to_u8250p(port);
> -	unsigned char mcr = 0;
> +	unsigned char mcr;
>  
> -	if (mctrl & TIOCM_RTS)
> -		mcr |= UART_MCR_RTS;
> -	if (mctrl & TIOCM_DTR)
> -		mcr |= UART_MCR_DTR;
> -	if (mctrl & TIOCM_OUT1)
> -		mcr |= UART_MCR_OUT1;
> -	if (mctrl & TIOCM_OUT2)
> -		mcr |= UART_MCR_OUT2;
> -	if (mctrl & TIOCM_LOOP)
> -		mcr |= UART_MCR_LOOP;
> +	mcr = serial8250_TIOCM_to_MCR(mctrl);
>  
>  	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
>  
> -- 
> 2.22.0
> 

-- 
With Best Regards,
Andy Shevchenko