[PATCH v3 3/3] pinctrl: single: set pinmux from pins debug file

Vladimir Zapolskiy vz at mleia.com
Thu May 20 23:44:09 PDT 2021


Hello Dario,

On 5/20/21 11:27 PM, Dario Binacchi wrote:
> As described in section 9.1 of the TI reference manual for AM335x [1],
> "For writing to the control module registers, the MPU will need to be in
> privileged mode of operation and writes will not work from user mode".
> By adding the pin_dbg_set helper to pcs_pinctrl_ops it will be possible
> to write these registers from the pins debug:

this makes little sense, because it should be possible to write to the
registers without introduction of this interface, pin group/function
is the right level of abstraction for your particular task.

> cd /sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/
> echo <pin-number> <reg-value> >pins
> 
> [1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf
> 
> Signed-off-by: Dario Binacchi <dariobin at libero.it>

I strongly object against this new interface to be added.

--
Best wishes,
Vladimir



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