On 3/19/21 1:19 PM, Greg Kroah-Hartman wrote:
From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ Upstream commit b41ba2ec54a70908067034f139aa23d0dd2985ce ]
On STM32MP1, the GPIO banks are subnodes of pin-controller@50002000, see arch/arm/boot/dts/stm32mp151.dtsi. The driver for pin-controller@50002000 is in drivers/pinctrl/stm32/pinctrl-stm32.c and iterates over all of its DT subnodes when registering each GPIO bank gpiochip. Each gpiochip has:
- gpio_chip.parent = dev, where dev is the device node of the pin controller
- gpio_chip.of_node = np, which is the OF node of the GPIO bank
Therefore, dev_fwnode(chip->parent) != of_fwnode_handle(chip.of_node), i.e. pin-controller@50002000 != pin-controller@50002000/gpio@5000*000.
The original code behaved correctly, as it extracted the "gpio-line-names" from of_fwnode_handle(chip.of_node) = pin-controller@50002000/gpio@5000*000.
To achieve the same behaviour, read property from the firmware node.
I think we agreed to drop this one for now before, see [PATCH 5.10 081/290] gpiolib: Read "gpio-line-names" from a firmware node Message-ID: YFIo3A14Fb4Hty4O@kroah.com