From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Ferre Subject: Re: [PATCH v3 3/9] serial: Add common rs485 device tree parsing function Date: Tue, 27 Jun 2017 09:40:22 +0200 Message-ID: <6e8bbe02-ce38-4025-73cf-a9ae562ead20@microchip.com> References: <20170626090803.10981-1-u.kleine-koenig@pengutronix.de> <20170626090803.10981-4-u.kleine-koenig@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20170626090803.10981-4-u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Sascha Hauer , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org List-Id: linux-serial@vger.kernel.org On 26/06/2017 at 11:07, Uwe Kleine-König wrote: > From: Sascha Hauer > > Several drivers have the same device tree parsing code. Create > a common helper function for it. > > Signed-off-by: Sascha Hauer > [ukl: implement default <0 0> for rts-delay, unset unspecified flags] > Signed-off-by: Uwe Kleine-König Acked-by: Nicolas Ferre > --- > drivers/tty/serial/Kconfig | 4 ++++ > drivers/tty/serial/Makefile | 2 ++ > drivers/tty/serial/of.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ > include/linux/serial_core.h | 13 +++++++++++++ > 4 files changed, 66 insertions(+) > create mode 100644 drivers/tty/serial/of.c > > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig > index 5c8850f7a2a0..8baef5b95bed 100644 > --- a/drivers/tty/serial/Kconfig > +++ b/drivers/tty/serial/Kconfig > @@ -14,6 +14,10 @@ config SERIAL_EARLYCON > the console before standard serial driver is probed. The console is > enabled when early_param is processed. > > +config OF_SERIAL > + depends on SERIAL_CORE > + def_bool y > + > source "drivers/tty/serial/8250/Kconfig" > > comment "Non-8250 serial port support" > diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile > index 53c03e005132..0fee8f4e36cb 100644 > --- a/drivers/tty/serial/Makefile > +++ b/drivers/tty/serial/Makefile > @@ -7,6 +7,8 @@ obj-$(CONFIG_SERIAL_CORE) += serial_core.o > obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o > obj-$(CONFIG_SERIAL_EARLYCON_ARM_SEMIHOST) += earlycon-arm-semihost.o > > +obj-$(CONFIG_OF_SERIAL) += of.o > + > # These Sparc drivers have to appear before others such as 8250 > # which share ttySx minor node space. Otherwise console device > # names change and other unplesantries. > diff --git a/drivers/tty/serial/of.c b/drivers/tty/serial/of.c > new file mode 100644 > index 000000000000..b24e4357661b > --- /dev/null > +++ b/drivers/tty/serial/of.c > @@ -0,0 +1,47 @@ > +#include > +#include > +#include > +#include > + > +/** > + * of_get_rs485_mode() - Implement parsing rs485 properties > + * @np: uart node > + * @rs485conf: output parameter > + * > + * This function implements the device tree binding described in > + * Documentation/devicetree/bindings/serial/rs485.txt. > + * > + * Return: 0 on success, 1 if the node doesn't contain rs485 stuff. > + */ > +int of_get_rs485_mode(struct device_node *np, struct serial_rs485 *rs485conf) > +{ > + u32 rs485_delay[2]; > + int ret; > + > + if (!IS_ENABLED(CONFIG_OF) || !np) > + return 1; > + > + ret = of_property_read_u32_array(np, "rs485-rts-delay" rs485_delay, 2); > + if (!ret) { > + rs485conf->delay_rts_before_send = rs485_delay[0]; > + rs485conf->delay_rts_after_send = rs485_delay[1]; > + } else { > + rs485conf->delay_rts_before_send = 0; > + rs485conf->delay_rts_after_send = 0; > + } > + > + /* > + * clear full-duplex and enabled flags to get to a defined state with > + * the two following properties. > + */ > + rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED); > + > + if (of_property_read_bool(np, "rs485-rx-during-tx")) > + rs485conf->flags |= SER_RS485_RX_DURING_TX; > + > + if (of_property_read_bool(np, "linux,rs485-enabled-at-boot-time")) > + rs485conf->flags |= SER_RS485_ENABLED; > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_get_rs485_mode); > diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h > index 64d892f1e5cd..5ba00b1be093 100644 > --- a/include/linux/serial_core.h > +++ b/include/linux/serial_core.h > @@ -500,4 +500,17 @@ static inline int uart_handle_break(struct uart_port *port) > (cflag) & CRTSCTS || \ > !((cflag) & CLOCAL)) > > +/* > + * Common device tree parsing helpers > + */ > +#ifdef CONFIG_OF_SERIAL > +int of_get_rs485_mode(struct device_node *np, struct serial_rs485 *rs485conf); > +#else > +static inline int of_get_rs485_mode(struct device_node *np, > + struct serial_rs485 *rs485conf) > +{ > + return 1; > +} > +#endif > + > #endif /* LINUX_SERIAL_CORE_H */ > -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html