On Fri, Sep 22, 2017 at 03:23:05PM +0200, Linus Walleij wrote: > On Thu, Sep 21, 2017 at 8:28 AM, Uwe Kleine-König > <u.kleine-koenig@xxxxxxxxxxxxxx> wrote: > > > on an i.MX25 machine on my desk a UART RX line is guarded by a transistor > > like this: > > > > ,------------------------. > > | ,---------. | > > | | imx25 o--RX----◁---o--- > > | | o--GPIO--' | > > | `---------' | > > `------------------------' > > This is inside the SoC, right, not outside it? > > In the rest of my answer I assume this. No, that's on the board. So your reply unfortunately doesn't match the problem :-| > If this is on the board, using enable-gpios is proper. enable-gpios as I suggested below that is? If so I assume you will be open for a generic approach to implement this? > > My first idea was to make this a property of the UART and added a > > enable-gpios property for it[1]. But now I wonder if this is better > > abstracted as an enable-gpios property in the pinctrl node. Something > > like: > > > > pinctrl_uart5: uart5 { > > fsl,pins = < > > MX25_PAD_ECB__UART5_TXD 0x00002080 /* TXD */ > > MX25_PAD_LBA__UART5_RXD 0x00000000 /* RXD */ > > MX25_PAD_CS4__UART5_CTS 0x00002001 /* RTS */ > > MX25_PAD_CS5__GPIO_3_21 0x00002001 /* #RXD_EN */ > > >; > > enable-gpios = <&gpio3 21 GPIO_ACTIVE_LOW>; > > }; > > > > Would this make sense? Maybe with a more intuitive name? (kept for reference) Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html