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[v3,0/4] gpio: Hide and obey valid_mask

Message ID cover.1741180097.git.mazziesaccount@gmail.com
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Series gpio: Hide and obey valid_mask | expand

Message

Matti Vaittinen March 5, 2025, 1:11 p.m. UTC 
GPIO controllers may have some pins which can be excluded from the GPIO
usage on certain hardware configurations. The valid_mask member of the
struct gpio_chip has been used to denote usable pins if some pins should
be excluded.

The GPIO request should fail for GPIOs which are masked. Under certain
conditions this was only done when GPIO chip provided the 'request'
callback. We fix this to be always done.

The valid_mask member of the gpio_chip should no longer be directly
populated by the drivers but GPIO core does this (unconditionally,
overwriting any mask set directly by the drivers). Drivers are intended
to populate the valid_mask using the init_valid_mask -callback.

This series enforces using the init_valid_mask by hiding the valid_mask
in structure which is internal to the GPIO core. A single in-tree driver
was found to access the valid_mask directly. This series also removes
those direct accesses as has been discussed [1]. Additionally, we
introduce a getter-function which can be used to obtain the valid_mask.

[1]: https://lore.kernel.org/all/TY3PR01MB11346EC54C8672C4D28F931F686CC2@TY3PR01MB11346.jpnprd01.prod.outlook.com/

Revision history:
v2 => v3:
 - Rebased on top of the gpio/for-next
v1 => v2:
 - Hide the 'valid_mask' instead of documenting it to be internal
 - Make the gpio_request() to obey the valid_mask whether the gpio_chip
   has the 'request' -callback populated or not.

---


Matti Vaittinen (4):
  gpio: Respect valid_mask when requesting GPIOs
  gpio: Add a valid_mask getter
  gpio: gpio-rcar: Drop direct use of valid_mask
  gpio: Hide valid_mask from direct assignments

 drivers/gpio/gpio-rcar.c    | 13 +++++-------
 drivers/gpio/gpiolib.c      | 40 ++++++++++++++++++++++++++-----------
 drivers/gpio/gpiolib.h      |  3 +++
 include/linux/gpio/driver.h |  9 +--------
 4 files changed, 37 insertions(+), 28 deletions(-)


base-commit: 44fe79020b91a1a8620e44d4f361b389e8fc552f