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* docs: w1: convert to ReST and add to the kAPI group of docsMauro Carvalho Chehab2019-07-311-44/+0
| | | | | | | | | The 1wire documentation was written with w1 developers in mind, so, it makes sense to add it together with the driver-api set. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* w1: w1-gpio: Convert to use GPIO descriptorsLinus Walleij2017-12-081-3/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The w1 master driver includes a complete open drain emulation reimplementation among other things. This converts the driver and all board files using it to use GPIO descriptors associated with the device to look up the GPIO wire, as well ass the optional pull-up GPIO line. When probed from the device tree, the driver will just pick descriptors and use them right off. For the two board files in the kernel, we add descriptor lookups so we do not need to keep any old platform data handling around for the GPIO lines. As the platform data is also a state container for this driver, we augment it to contain the GPIO descriptors. w1_gpio_write_bit_dir() and w1_gpio_write_bit_val() are gone since this pair was a reimplementation of open drain emulation which is now handled by gpiolib. The special "linux,open-drain" flag is a bit of mishap here: it has the same semantic as the same flags in I2C: it means that something in the platform is setting up the line as open drain behind our back. We handle this the same way as in I2C. To drive the pull-up, we need to bypass open drain emulation in gpiolib for the line, and this is done by driving it high using gpiod_set_raw_value() which has been augmented to have the semantic of overriding the open drain emulation. We also augment the documentation to reflect the way to pass GPIO descriptors from the machine. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
* w1-gpio: add GPIO w1 bus master driverVille Syrjala2008-02-061-0/+33
Add a GPIO 1-wire bus master driver. The driver used the GPIO API to control the wire and the GPIO pin can be specified using platform data similar to i2c-gpio. The driver was tested with AT91SAM9260 + DS2401. Signed-off-by: Ville Syrjala <syrjala@sci.fi> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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