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path: root/drivers/gpio/gpio-mmio.c
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2018-01-16gpio: mmio: Also read bits that are zeroLinus Walleij
The code for .get_multiple() has bugs: 1. The simple .get_multiple() just reads a register, masks it and sets the return value. This is not correct: we only want to assign values (whether 0 or 1) to the bits that are set in the mask. Fix this by using &= ~mask to clear all bits in the mask and then |= val & mask to set the corresponding bits from the read. 2. The bgpio_get_multiple_be() call has a similar problem: it uses the |= operator to set the bits, so only the bits in the mask are affected, but it misses to clear all returned bits from the mask initially, so some bits will be returned erroneously set to 1. 3. The bgpio_get_set_multiple() again fails to clear the bits from the mask. 4. find_next_bit() wasn't handled correctly, use a totally different approach for one function and change the other function to follow the design pattern of assigning the first bit to -1, then use bit + 1 in the for loop and < num_iterations as break condition. Fixes: 80057cb417b2 ("gpio-mmio: Use the new .get_multiple() callback") Cc: Bartosz Golaszewski <brgl@bgdev.pl> Reported-by: Clemens Gruber <clemens.gruber@pqgruber.com> Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com> Reported-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-10-30gpio-mmio: Use the new .get_multiple() callbackLinus Walleij
It is possible to read all lines of a generic MMIO GPIO chip with a single register read so support this if we are in native endianness. Add an especially quirky callback to read multiple lines for the variants that require you to read values from the output registers if and only if the line is set as output. We managed to do that with a maximum of two register reads, and just one read if the requested lines are all input or all output. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-10-25gpio: mmio: Make pin2mask() a private businessLinus Walleij
The vtable call pin2mask() was introducing a vtable function call in every gpiochip callback for a generic MMIO GPIO chip. This was not exactly efficient. (Maybe link-time optimization could get rid of it, I don't know.) After removing all external calls into this API we can make it a boolean flag in the struct gpio_chip call and sink the function into the gpio-mmio driver yielding encapsulation and potential speedups. Cc: Anton Vorontsov <anton@enomsg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-23gpio: mmio: add support for NI 169445 NAND GPIONathan Sullivan
The GPIO-based NAND controller on National Instruments 169445 hardware exposes a set of simple lines for the control signals. Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-08-11gpio: mmio: add brcm,bcm6345 supportChristian Lamparter
This patch adds support for the GPIO found in Broadcom's bcm63xx-gpio chips. This GPIO controller is used in the following Broadcom SoCs: BCM6338, BCM6345. It can be used in newer SoCs, without the capability of pin multiplexing. Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08gpio: mmio: add MyBook Live GPIO supportChristian Lamparter
This patch adds support for the Western Digital's MyBook Live memory-mapped GPIO controllers. The GPIOs will be supported by the generic driver for memory-mapped GPIO controllers. Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08gpio: mmio: add DT support for memory-mapped GPIOsÁlvaro Fernández Rojas
This patch adds support for defining memory-mapped GPIOs which are compatible with the existing gpio-mmio interface. The generic library provides support for many memory-mapped GPIO controllers that are found in various on-board FPGA and ASIC solutions that are used to control board's switches, LEDs, chip-selects, Ethernet/USB PHY power, etc. For setting GPIOs there are three configurations: 1. single input/output register resource (named "dat"), 2. set/clear pair (named "set" and "clr"), 3. single output register resource and single input resource ("set" and dat"). The configuration is detected by which resources are present. For the single output register, this drives a 1 by setting a bit and a zero by clearing a bit. For the set clr pair, this drives a 1 by setting a bit in the set register and clears it by setting a bit in the clear register. For setting the GPIO direction, there are three configurations: a. simple bidirectional GPIOs that requires no configuration. b. an output direction register (named "dirout") where a 1 bit indicates the GPIO is an output. c. an input direction register (named "dirin") where a 1 bit indicates the GPIO is an input. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-29gpio: rename gpio-generic.c into gpio-mmio.cChristian Lamparter
This patch renames the gpio-generic.c into gpio-mmio.c. This is because currently the file only contains code for a memory-mapped GPIO driver. There isn't any support for ioports or other resource type. Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>