From: Andrew Lunn <andrew@lunn.ch>
To: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 0/7] gpiolib: add bias support
Date: Thu, 14 Dec 2017 17:06:25 +0100 [thread overview]
Message-ID: <20171214160625.GG19186@lunn.ch> (raw)
In-Reply-To: <20171214142138.23008-1-ludovic.desroches@microchip.com>
> I have not introduced a gpiod_set_bias() because I think the only place to
> setup this is in the device tree. It's useless to setup a bias pull up if there
> is an external pull up on the board.
Hi Ludovic
I have a use case where having gpiod_set_bias() would be good. The
DLN2 is a USB device, which offers GPIO, I2C, and SPI services on its
pins. It is a hot pluggable device, and i'm using it on Intel
machines, making it double hard to use with Device Tree.
It would be good to be able to set the pull up/down on the GPIO pins,
probably from a small kernel module which calls gpiod_set_bias(), or
via /sysfs.
Andrew
next prev parent reply other threads:[~2017-12-14 16:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-14 14:21 [RFC PATCH 0/7] gpiolib: add bias support Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 1/7] gpio: of: use the BIT macro for of_gpio_flags Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 2/7] gpio: gpiolib: split the gpiod_configure_flags function Ludovic Desroches
2017-12-15 9:26 ` Julien Thierry
2017-12-18 7:02 ` Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 3/7] gpio: gpiolib: save GPIO flags in of_get_named_gpiod_flags Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 4/7] gpio: gpiolib: add bias support Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 5/7] pinctrl: at91-pio4: allow the gpiolib to set pin configuration Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 6/7] pinctrl: at91-pio4: use strict mode if explicitly requested Ludovic Desroches
2017-12-14 14:21 ` [RFC PATCH 7/7] ARM: dts: at91-sama5d2_xplained: remove gpios from pinmux Ludovic Desroches
2017-12-14 16:06 ` Andrew Lunn [this message]
2017-12-15 6:54 ` [RFC PATCH 0/7] gpiolib: add bias support Ludovic Desroches
2017-12-19 9:40 ` [RFC PATCH v2] draft for gpio pinconf Ludovic Desroches
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