Gcc cannot always see that BUG_ON(1) is guaranteed to not
return, so we get a warning message in some configurations:
drivers/gpio/gpio-aspeed.c: In function 'bank_reg':
drivers/gpio/gpio-aspeed.c:244:1: error: control reaches end of non-void function [-Werror=return-type]
Using a plain BUG() is easier here and avoids the problem.
Fixes: 44ddf559d5 ("gpio: aspeed: Rework register type accessors")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
On the Aspeed chip, the GPIOs can be under control of the ARM
chip or of the ColdFire coprocessor. (There's a third command
source, the LPC bus, which we don't use or support yet).
The control of which master is allowed to modify a given
GPIO is per-bank (8 GPIOs).
Unfortunately, systems already exist for which we want to
use GPIOs of both sources in the same bank.
This provides an API exported by the gpio-aspeed driver
that an aspeed coprocessor driver can use to "grab" some
GPIOs for use by the coprocessor, and allow the coprocessor
driver to provide callbacks for arbitrating access.
Once at least one GPIO of a given bank has been "grabbed"
by the coprocessor, the entire bank is marked as being
under coprocessor control. It's command source is switched
to the coprocessor.
If the ARM then tries to write to a GPIO in such a marked bank,
the provided callbacks are used to request access from the
coprocessor driver, which is responsible to doing whatever
is necessary to "pause" the coprocessor or prevent it from
trying to use the GPIOs while the ARM is doing its accesses.
During that time, the command source for the bank is temporarily
switched back to the ARM.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds the definitions for the command source registers
and a helper to set them.
Those registers allow to control which bus master on the
SoC is allowed to modify a given bank of GPIOs and will
be used by subsequent patches.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The Aspeed GPIO hardware has a quirk: the value register, for an
output GPIO, doesn't contain the last value written (the write
latch content) but the sampled input value.
This means that when reading back shortly after writing, you can
get an incorrect value as the input value is delayed by a few
synchronizers.
The HW supports a separate read-only register "Data Read Register"
which allows you to read the write latch instead.
This adds the definition for it, and uses it for the initial
population of the GPIO value cache. It will be used more in
subsequent patches.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Use a single accessor function for all register types instead
of several spread around. This will make it easier/cleaner
to introduce new registers and keep the mechanism in one
place.
The big switch/case is optimized at compile time since the
switch value is a constant.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
cycle.
Core changes:
- We have killed off VLA from the core library and all drivers.
The background should be clear for everyone at this point:
https://lwn.net/Articles/749064/
Also I just don't like VLA's, kernel developers hate it when
compilers do things behind their back. It's as simple as that.
I'm sorry that they even slipped in to begin with.
Kudos to Laura Abbott for exorcising them.
- Support GPIO hogs in machines/board files.
New drivers and chip support:
- R-Car r8a77470 (RZ/G1C)
- R-Car r8a77965 (M3-N)
- R-Car r8a77990 (E3)
- PCA953x driver improvements to accomodate more variants.
Improvements and new features:
- Support one interrupt per line on port A in the DesignWare
dwapb driver.
Misc:
- Random cleanups, right header files in the drivers, some
size optimizations etc.
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Merge tag 'gpio-v4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.18 development cycle.
Core changes:
- We have killed off VLA from the core library and all drivers.
The background should be clear for everyone at this point:
https://lwn.net/Articles/749064/
Also I just don't like VLA's, kernel developers hate it when
compilers do things behind their back. It's as simple as that.
I'm sorry that they even slipped in to begin with. Kudos to Laura
Abbott for exorcising them.
- Support GPIO hogs in machines/board files.
New drivers and chip support:
- R-Car r8a77470 (RZ/G1C)
- R-Car r8a77965 (M3-N)
- R-Car r8a77990 (E3)
- PCA953x driver improvements to accomodate more variants.
Improvements and new features:
- Support one interrupt per line on port A in the DesignWare dwapb
driver.
Misc:
- Random cleanups, right header files in the drivers, some size
optimizations etc"
* tag 'gpio-v4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
gpio: davinci: fix build warning when !CONFIG_OF
gpio: dwapb: Fix rework support for 1 interrupt per port A GPIO
gpio: pxa: Include the right header
gpio: pl061: Include the right header
gpio: pch: Include the right header
gpio: pcf857x: Include the right header
gpio: pca953x: Include the right header
gpio: palmas: Include the right header
gpio: omap: Include the right header
gpio: octeon: Include the right header
gpio: mxs: Switch to SPDX identifier
gpio: Remove VLA from stmpe driver
gpio: mxc: Switch to SPDX identifier
gpio: mxc: add clock operation
gpio: Remove VLA from gpiolib
gpio: aspeed: Use a cache of output data registers
gpio: aspeed: Set output latch before changing direction
gpio: pca953x: fix address calculation for pcal6524
gpio: pca953x: define masks for addressing common and extended registers
gpio: pca953x: set the PCA_PCAL flag also when matching by DT
...
The current driver does a read/modify/write of the output
registers when changing a bit in __aspeed_gpio_set().
This is sub-optimal for a couple of reasons:
- If any of the neighbouring GPIOs (sharing the shared
register) isn't (yet) configured as an output, it will
read the current input value, and then apply it to the
output latch, which may not be what the user expects. There
should be no bug in practice as aspeed_gpio_dir_out() will
establish a new value but it's not great either.
- The GPIO block in the aspeed chip is clocked rather
slowly (typically 25Mhz). That extra MMIO read halves the maximum
speed at which we can toggle the GPIO.
This provides a significant performance improvement to the GPIO
based FSI master.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In aspeed_gpio_dir_out(), we need to establish the new output
value in the output latch *before* we change the direction
to output in order to avoid a glitch on the output line if
the previous value of the latch was different.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The unmask function disables all interrupts in a bank when unmasking an
interrupt. Only disable the given interrupt.
Cc: stable@vger.kernel.org
Signed-off-by: Govert Overgaauw <govert.overgaauw@prodrive-technologies.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The test should be >= ARRAY_SIZE() instead of > ARRAY_SIZE().
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Use the new pinconf parameter for state persistence to expose the
associated capability of the Aspeed GPIO controller.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The pinctrl_request_gpio() and pinctrl_free_gpio() break the nice
namespacing in the other cross-calls like pinctrl_gpio_foo().
Just rename them and all references so we have one namespace
with all cross-calls under pinctrl_gpio_*().
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
HPLL is in fact not the clock we need. Remove the description of which clock we
failed to find a phandle to in order to avoid any further error.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We warn the user at driver probe time that debouncing is disabled.
However, if they request debouncing later on we print a confusing error
message:
gpio_aspeed 1e780000.gpio: Failed to convert 5000us to cycles at 0Hz: -524
Instead bail out when the clock is not present.
Fixes: 5ae4cb94b3 (gpio: aspeed: Add debounce support)
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As per the datasheet, manage the IO and value states to implement
open-source/open-drain, but do this by falling back to gpiolib's
emulation.
This commit simply makes the behaviour explicit for clarity, rather than
relying on the implicit return of -ENOTSUPP to trigger the emulation.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Each GPIO in the Aspeed GPIO controller can choose one of four input
debounce states: to disable debouncing for an input, or select from one
of three programmable debounce timer values. Each GPIO in a
four-bank-set is assigned one bit in each of two debounce configuration
registers dedicated to the set, and selects a debounce state by
configuring the two bits to select one of the four options.
The limitation on debounce timer values is managed by mapping offsets
onto a configured timer value and keeping count of the number of users
a timer has. Timer values are configured on a first-come-first-served
basis.
A small twist in the hardware design is that the debounce configuration
register numbering is reversed with respect to the binary representation
of the debounce timer of interest (i.e. debounce register 1 represents
bit 1, and debounce register 2 represents bit 0 of the timer numbering).
Tested on an AST2500EVB with additional inspection under QEMU's
romulus-bmc machine.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1736f75d35 is a (v2) patch which had
unresolved review comments[1]. Address the comments by removing the use
of macros from the consumer header (this patch represents the diff
between v2 and v3[2]).
[1] https://lkml.org/lkml/2017/1/26/337
[2] https://lkml.org/lkml/2017/1/26/786
Fixes: 1736f75d35 ("gpio: aspeed: Add banks Y, Z, AA, AB and AC")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This is less straight-forward than one would hope, as some banks only
have 4 pins rather than 8, others are output only, yet more (W and
X, already supported) are input-only, and in the case of the g4 SoC bank
AC doesn't exist.
Add some structs to describe the varying properties of different banks
and integrate mechanisms to deny requests for unsupported
configurations.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The Aspeed SoCs have more GPIOs than can be represented with A-Z. The
documentation uses two letter names such as AA and AB, so make the names
a three-character array in the bank struct to accommodate this.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Remove unneeded error handling on the result of a call
to platform_get_resource() when the value is passed to
devm_ioremap_resource().
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should
be replaced with IS_ERR().
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The build complains about missing MODULE_LICENSE() in
the Aspeed GPIO driver. The license is evident from the
file header, put in "GPL".
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The Aspeed SoCs contain GPIOs banked by letter, where each bank contains
8 pins. The GPIO banks are then grouped in sets of four in the register
layout.
The implementation exposes multiple banks through the one driver and
requests and releases pins via the pinctrl subsystem. The hardware
supports generation of interrupts from all GPIO-capable pins.
A number of hardware features are not yet supported: Configuration of
interrupt direction (ARM or LPC), debouncing, and WDT reset tolerance
for output ports.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Arnd Bergmann