From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.ferre@atmel.com (Nicolas Ferre) Date: Mon, 10 Feb 2014 11:37:56 +0100 Subject: [PATCH 5/8] tty/serial: at91: add dtr control via gpio In-Reply-To: References: <1391785155-18525-1-git-send-email-richard.genoud@gmail.com> <1391785155-18525-6-git-send-email-richard.genoud@gmail.com> <1391786494.259974704@f81.i.mail.ru> Message-ID: <52F8AC04.50103@atmel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/02/2014 11:24, Richard Genoud : > 2014-02-07 16:21 GMT+01:00 Alexander Shiyan : >> Hello. >> >> ???????, 7 ??????? 2014, 15:59 +01:00 ?? Richard Genoud : >>> On sam9x5, the USART controller doesn't handle DTR/DSR/DCD/RI signals, >>> so we have to control them via GPIO. >>> >>> This patch permits to use a GPIO to control the DTR signal. >>> >>> Signed-off-by: Richard Genoud >>> --- >> ... >>> + if (gpio_is_valid(atmel_port->gpio.dtr)) { >>> + if (mctrl & TIOCM_DTR) >>> + gpio_set_value(atmel_port->gpio.dtr, 0); >>> + else >>> + gpio_set_value(atmel_port->gpio.dtr, 1); >>> + } >> >> So, if you use GPIO for such purpose (here and in the other patches), >> you should take and use GPIO active level from bindings. >> It will make use of GPIO more flexible and deliver us from further special >> possible bindings to declare the active level. > Yes, I could do that. I'll have to change the alreday merged RTS > binding so that it gets it's active level from DTS, but I don't think > it's a problem, since it's not already in mainline. > Linus, Nicolas, what do you think ? Yes I agree. It is not used yet, so the sooner we move to this specification, the better. >> Actually, it would be good to have a separate unit for mctrl GPIOs, >> which could be used for other drivers. > good idea, I can add them in serial_core.c That would be great. Thanks Richard! Bye, -- Nicolas Ferre