mbox series

[0/3] Support qcom pinctrl protected pins

Message ID 20180110015848.11480-1-sboyd@codeaurora.org
Headers show
Series Support qcom pinctrl protected pins | expand

Message

Stephen Boyd Jan. 10, 2018, 1:58 a.m. UTC 
This patchset proposes a solution to describing the valid
pins for a pin controller in a semi-generic way so that qcom
platforms can expose the pins that are really available.

Typically, this has been done by having drivers and firmware 
descriptions only use pins they know they have access to, and that
still works now because we no longer read the pin direction at
boot. But there are still some userspace drivers and debugfs facilities
that don't know what pins are available and attempt to read everything
they can. On qcom platforms, this may lead to a system hang, which isn't 
very nice behavior, even if root is the only user that can trigger it.

The proposal is to describe the valid pins and then not allow things to
cause problems by using the invalid pins. Obviously, the firmware may
mess this up, so this is mostly a nice to have feature or a safety net
so that things don't blow up easily.

Stephen Boyd (3):
  gpiolib: Export gpiochip_irqchip_irq_valid() to drivers
  dt-bindings: pinctrl: Add a ngpios-ranges property
  pinctrl: qcom: Don't allow protected pins to be requested

 .../bindings/pinctrl/qcom,msm8996-pinctrl.txt      |  6 ++
 drivers/gpio/gpiolib.c                             |  5 +-
 drivers/pinctrl/qcom/pinctrl-msm.c                 | 98 +++++++++++++++++++++-
 include/linux/gpio/driver.h                        |  3 +
 4 files changed, 106 insertions(+), 6 deletions(-)