The bgpio_init() takes one of two arguments to specify a register
to set the direction of the GPIO line: either dirout that
indicates that a 1 in the bit in that register sets the
corresponding line to output, or dirin which indicates that
a 1 in the bit in that register sets the corresponding line to
input. Conversely setting the bit to 0 on these will turn the
line into input and output respectively. One of these can
be defined but not both.
This means that a platform that sets a bit to 1 for output
only defines dirout and a platform that sets a bit to 0 for
output only defines dirin. In short this defines the polarity
of the direction register.
Both can also be left as NULL meaning the GPIO chip is either
input only or output only.
Tomer Maimon discovered that for get/set chips (those where the
get and set registers are defined but no separate clear register,
and specifying BGPIOF_READ_OUTPUT_REG_SET so that we say we
want to read the output value from the SET register)
we are unconditionally reading the value from the SET register
when the direction bit is 1 and from the DAT register when the
direction bit is 0, not taking the direction bit polarity into
account.
It would be expected that when the direction bit is inverted
(dirin is defined but not dirout) we read the current value from
the DAT register when the bit is 1 and from the SET register
when the bit is 0.
Currently only some versions of ATH79, brcmstb, some versions of
CLP711x, GE, IOP and Loongson use the dirin mode (a 1 in the
register means input). They are unaffected because
BGPIOF_READ_OUTPUT_REG_SET is not set on any of them. (They
do not read back the SET register to figure out the output
value.) So this is no regression with current drivers.
However the behaviour is wrong and does not work with Tomer's
new driver where he needs to use the BGIOF_READ_OUTPUT_REG_SET.
This fixes the above issue by:
- Instead of defining separate functions for the inverted case,
set up a flag in the gpio_chip that indicates that the
direction is inverted.
- Remove the special inverted functions for setting
input/output and getting the direction, rely on the flag
instead.
- Respect this flag in bgpio_get_set() and
bgpio_get_set_multiple()
Reported-by: Tomer Maimon <tmaimon77@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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: 80057cb417 ("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>
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>
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>
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>
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>
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>
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>
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>
