linux-kernel - Re: [RFC PATCH] i2c: core: dont change pinmux state to GPIO during recovery setup

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Message-ID: <CA+HBbNEM6AfwX87DLRNAuJSWPKboGuuJJDRK_E+G3sJDF73oZA@mail.gmail.com>
Date:   Wed, 6 Sep 2023 16:41:33 +0200
From:   Robert Marko <robert.marko@...tura.hr>
To:     wsa@...nel.org, codrin.ciubotariu@...rochip.com,
        linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     luka.perkov@...tura.hr, rmk+kernel@...linux.org.uk
Subject: Re: [RFC PATCH] i2c: core: dont change pinmux state to GPIO during
 recovery setup

On Fri, Sep 1, 2023 at 1:49 PM Robert Marko <robert.marko@...tura.hr> wrote:
>
> Ever since PXA I2C driver was moved to the generic I2C recovery, I2C has
> stopped working completely on Armada 3720 if the pins are specified in DTS.
>
> After a while it was traced down to the only difference being that PXA
> driver did not change the pinmux state to GPIO before trying to acquire the
> GPIO pins.
> And indeed as soon as this call is removed I2C starts working.
>
> To me it seems that this call is not required at all as devm_gpiod_get()
> will result in the pinmux state being changed to GPIO via the pinmux
> set_mux() op.
>
> Fixes: 0b01392c18b9 ("i2c: pxa: move to generic GPIO recovery")
> Signed-off-by: Robert Marko <robert.marko@...tura.hr>
> ---
> I am aware this probably isnt the correct fix, so I am sending it as RFC
> cause I have ran out of ideas.

CC-ing Russel as well since I forgot him.

Regards,
Robert
>
>  drivers/i2c/i2c-core-base.c | 7 -------
>  1 file changed, 7 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 60746652fd52..b34d939078a1 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -359,13 +359,6 @@ static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)
>         if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)
>                 return 0;
>
> -       /*
> -        * pins might be taken as GPIO, so we should inform pinctrl about
> -        * this and move the state to GPIO
> -        */
> -       if (bri->pinctrl)
> -               pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
> -
>         /*
>          * if there is incomplete or no recovery information, see if generic
>          * GPIO recovery is available
> --
> 2.41.0
>


-- 
Robert Marko
Staff Embedded Linux Engineer
Sartura Ltd.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko@...tura.hr
Web: www.sartura.hr