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[v2,0/2] am335x: set pinmux registers from pins debug file

Message ID 20210517200002.6316-1-dariobin@libero.it
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Series am335x: set pinmux registers from pins debug file | expand

Message

Dario Binacchi May 17, 2021, 8 p.m. UTC 
The patch was born from the need to change the slew rate of the LCD pins
of a custom AM335x board during EMC tests. The AM335x, as described in a
note in section 9.1 of its reference manual [1], is unable to write
pinmux registers from user space. The series now makes it possible to
write these registers from the pins debug file.

[1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf


Changes in v2:
- Remove CONFIG_SOC_AM33XX dependency.

Dario Binacchi (2):
  pinctrl: core: configure pinmux from pins debug file
  pinctrl: single: set pinmux from pins debug file

 drivers/pinctrl/core.c           | 56 ++++++++++++++++++++++++++++++--
 drivers/pinctrl/pinctrl-single.c | 20 ++++++++++++
 include/linux/pinctrl/pinctrl.h  |  2 ++
 3 files changed, 76 insertions(+), 2 deletions(-)

Comments

Andy Shevchenko May 19, 2021, 11:31 a.m. UTC | #1 
On Wed, May 19, 2021 at 3:58 AM Dario Binacchi <dariobin@libero.it> wrote:
>

>

> The patch was born from the need to change the slew rate of the LCD pins

> of a custom AM335x board during EMC tests. The AM335x, as described in a

> note in section 9.1 of its reference manual [1], is unable to write

> pinmux registers from user space. The series now makes it possible to

> write these registers from the pins debug file.


Even for debugfs it would be nice to have a piece of documentation.
Because pin control is a quite sensitive area and if something goes
wrong, it may damage the hardware.

> [1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf



-- 
With Best Regards,
Andy Shevchenko