The CH422G offers eight bi-directional pins, IO0-IO7, and four open-drain
outputs, OC0-OC3. It appears on boards that have run out of usable GPIOs
once a parallel RGB panel has taken its share, the Waveshare
ESP32-S3-Touch-LCD-7 among them, where it holds the panel and touch
controller in and out of reset and switches the backlight.
Two things about the device do not fit the shape a register-per-address
I2C driver usually takes, and both are handled here rather than pushed on
to board logic:
- A register is selected by the I2C address the transfer is addressed
to, not by a register address written ahead of the data. Each access
carries a single byte to one of four addresses.
- None of the write-only registers can be read back, so the driver
keeps a shadow copy of each and updates it in step with the device.
IO0-IO7 have no individual direction control; one bit of the system
parameter register drives the whole group. The driver records the
direction asked of each pin and puts the group in output mode once at
least one of them is an output, which is what a board that drives some of
the pins would expect. Reading a pin of a group held in output mode
reports the value last written, because the hardware cannot report the
level, and that is documented rather than hidden.
The four open-drain outputs are presented as pins 8-11 of the same
ioexpander_dev_s so that one instance covers the chip, which means
CONFIG_IOEXPANDER_NPINS must be at least 12.
Builds clean with no new warnings on esp32s3-touch-lcd7:usbnsh and passes
nxstyle.
Signed-off-by: Alan Carvalho de Assis <acassis@gmail.com>
Assisted-by: Claude Code
The pins a board publishes are visible in /dev and each can be read
through its own node, but surveying a whole board that way means an open
and two ioctls per pin, and the signal and interrupt counters the upper
half keeps are not reachable through any of them.
Adds a list of registered pins and publishes it as /proc/gpio, behind
GPIO_PROCFS: a quality of life view of the same kind as /proc/pinctrl
and /proc/reset. Every common field comes from state the upper half
already holds: the pin type, the value through go_read(), how many times
the pin has been registered for signals, and how many interrupts it has
taken. Lines carry the same key:value tokens in the same order, so the
file is machine parseable.
Lower halves may supply an optional go_describe() adding what only they
can say, such as which pad carries the line or how its trigger is
configured. It writes text into a caller supplied buffer and the upper
half owns the line, so a lower half needs no procfs knowledge. A lower
half without it is listed with the common tokens alone.
The pin type index is bounded before use: it comes from the lower half
and the name table cannot cover a type the enumeration does not define.
A pin that cannot be read reports val:- rather than a zero that would
read as a real level.
procfs_register() appends without checking for duplicates, so the entry
is claimed once for the lifetime of the system rather than whenever the
list is empty; pins come and go at run time.
The name is held in a buffer as long as the one gpio_pin_register()
accepts, so a listing always names the same string as /dev.
The pin type name table is declared without an explicit size so that the
assertion beside it compares against the enumeration and can fail; sized
as [GPIO_NPINTYPES] it would have been tautological.
Documents the entry, its tokens, and how a lower half describes a pin.
Off by default: with GPIO_PROCFS unset the list, the lock and the procfs
entry are compiled out, and go_describe() is one more member at the end
of a structure existing lower halves do not reach.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Justin Hammond <justin@dynam.ac>
Adds support for the PIO4IOE IO Expander, more specifically the PIO4IOE5V6408 version.
Assisted-by: Cursor IDE agents
Signed-off-by: Filipe Cavalcanti <filipe.cavalcanti@espressif.com>
DEV_GPIO_NSIGNALS relies on signal support. Add an explicit Kconfig
dependency on SIGNALS to prevent invalid no-signal configurations.
Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>
This is an I2C driver for the Awinic AW9523B I/O expander. As well
as the supporting usual digital I/Os, this device features the
ability to drive LEDs directly, and can control the drive current
to each LED individually. The driver was derived from the PCA9555
driver, provides all the standard interfaces of an i/o expander
driver. It also features support for the special features of the
AW9523B through pin direction IOEXPANDER_DIRECTION_OUT_LED and
IOEXPANDER_OPTION_NONGENERIC with AW9523B_OPTION_* options.
The driver has a number of configurable features including interrupt
handling and a shadow register mode based on the PCA9555 driver,
plus new LED/dimming support.
Testing was done using an ESP32S3 host and I2C connection to the
Adafruit AW9523 breakout board.
Signed-off-by: Zik Saleeba <zik@zikzak.net>
There might be multiple expanders, one with interrupt used and other
without. This commit fixes initial incorrect interrupt design by
introducing ICJX_INT_ENABLE config option.
Also fixes naming of ICJX_MULTIPLE option.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
This commit adds basic support for iC-JX expander in SPI mode. The
expander is functional and supports both input and output pins. Further
expander functionalities (filtering, adc, interrupt support) are not
yet implemented.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
This commit adds basic support for electrically isolated 8 bit expander.
The expander communicates with the MCU via SPI interface. Both single
and multiple pin read are supported.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
This commit adds support for galvanic isolated ISO1H812G SPI expander.
Both single pin and multiple pin writes are supported.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
This adds support for 16 bit io expander pcf8575. The driver is basically
the same as for pcf8574 however it is for 16 bits instead of 8 bits. Since
pcf8575 and pcf8574 can be both used on the same i2c bus the driver for
pcf8575 is implemented in a different file to reduce the code size
and complexity and to have less if statements in the driver.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
drivers/ioexpander/Kconfig:28:
warning:
config symbol 'IOEXPANDER_RPMSG_INT_NCALLBACKS' uses select, but is not boolean or tristate
Signed-off-by: chao.an <anchao@xiaomi.com>
driver/ioexpander: Add gpio_pin_unregister function to GPIO driver
driver/ioexpander: Add pinset struct to GPIO driver for interrupt pins larger than 64
driver/ioexpander: Initialize pintype/inttype when registering ioexpander device
driver/ioexpander: Add SETPINTYPE ioctl command to the GPIO driver
The same interrupt handler is entered with the device structure parameter in all situations,
multiple or single PCA. One should still be careful if multiple PCA devices share the same IRQ.
PCA9555 Driver: Replace the signalling logic with a simple callback using the new definitons of ioexpander.h. This repartitioning of functionality is necessary because (1) the I/O expander driver is the lower-lower part of any driver that uses GPIOs (include the GPIO driver itself) and should not be interacting directly with the much higher level application layer. And (2) in order to be compatible with the GPIO driver (and any arbitrary upper half driver), the PCA9555 should not directly signal, but should call back into the upper half. The upper half driver that interacts directly with the application is the appropriate place to be generating signal.
are held in the microcontrollers memory and only written to the IO-Expander.
This reduces bus traffic and is more error-proof than the normal read-
modify-write operation.
Retry Mode: If enabled and an error occurs while writing to the IO-Expander the
current transmission is automatically repeated once.
-headers in nuttx/ioexpander to define the "generic" ioexpander framework
-files in drivers/ioexpander for the implementation of the NXP PCA9555 framework
-bindings in drivers/Kconfig and drivers/Makefile
From Sebastien Lorquet
