Messages in this thread | | | From | Bartosz Golaszewski <> | Subject | [PATCH 0/3] i2c: mux: don't access GPIOLIB internal structures | Date | Wed, 11 Oct 2023 15:02:01 +0200 |
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From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The backstory for this short series is that we are identyfing and removing all unauthorized uses of GPIOLIB structures across the kernel.
For example: there are many users that access struct gpio_chip when the only user allowed to safely do this is the provider of that chip.
We are very close to removing gpiochip_find(). Another function that poses a similar problem is gpiod_to_chip() which also returns the address of the underlying gpio_chip without assuring that it will not go away e.g. due to a hot-unplug event or a device unbind.
We'll need to replace it with gpiod_to_gpio_device() across the entire tree. Let's start by actually providing it and adding the first user: the i2c-mux-gpio driver which dereferences the otherwise opaque struct gpio_desc.
Let's also add a helper that allows to retrieve the address of the struct device backing the GPIO device as this is another valid use-case.
Finally, let's un-include the GPIO private header and fix the code to access the device in a safe way.
As the change is pretty minor, it would be best if patch 3/3 could be acked by the I2C mux maintainers and went through the GPIO tree. Otherwise, I can apply patches 1 and 2 and provide an immutable branch.
Bartosz Golaszewski (3): gpiolib: provide gpio_device_to_device() gpiolib: provide gpiod_to_gpio_device() i2c: mux: gpio: don't fiddle with GPIOLIB internals
drivers/gpio/gpiolib.c | 38 ++++++++++++++++++++++++++++++++ drivers/i2c/muxes/i2c-mux-gpio.c | 12 +++++----- include/linux/gpio/driver.h | 3 +++ 3 files changed, 47 insertions(+), 6 deletions(-)
-- 2.39.2
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