linux-kernel - Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN

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Date:   Thu, 5 Oct 2017 09:27:50 -0700
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     fenglinw@...eaurora.org
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Linus Walleij <linus.walleij@...aro.org>,
        linux-gpio@...r.kernel.org, collinsd@...eaurora.org,
        aghayal@...eaurora.org, wruan@...eaurora.org,
        subbaram@...eaurora.org, kgunda@...eaurora.org
Subject: Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when
 setting pin config

On Mon 11 Sep 17:32 PDT 2017, fenglinw@...eaurora.org wrote:

> From: Fenglin Wu <fenglinw@...eaurora.org>
> 
> GPIO is expected to be disabled iff PIN_CONFIG_BIAS_HIGH_IMPEDANCE is
> configured. Update is_enabled flag in config_set() so that it can
> reflect GPIO status correctly. Also modify EN_CTL register based on
> is_enabled flag in config_set() to configure the GPIO properly.
> 
> Signed-off-by: Fenglin Wu <fenglinw@...eaurora.org>
> ---
>  drivers/pinctrl/qcom/pinctrl-spmi-gpio.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
> index c2c0bab..a0edaa8 100644
> --- a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
> +++ b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
> @@ -453,6 +453,7 @@ static int pmic_gpio_config_set(struct pinctrl_dev *pctldev, unsigned int pin,
>  
>  	pad = pctldev->desc->pins[pin].drv_data;
>  
> +	pad->is_enabled = true;
>  	for (i = 0; i < nconfs; i++) {
>  		param = pinconf_to_config_param(configs[i]);
>  		arg = pinconf_to_config_argument(configs[i]);
> @@ -600,6 +601,10 @@ static int pmic_gpio_config_set(struct pinctrl_dev *pctldev, unsigned int pin,
>  			return ret;
>  	}
>  
> +	val = pad->is_enabled << PMIC_GPIO_REG_MASTER_EN_SHIFT;
> +
> +	ret = pmic_gpio_write(state, pad, PMIC_GPIO_REG_EN_CTL, val);
> +

This looks good.

Acked-by: Bjorn Andersson <bjorn.andersson@...aro.org>


But I spotted another issue while reviewing this; currently the initial
state of is_enabled is unconditionally set to enabled in
pmic_gpio_populate(), so reading the initial pinconf or configuring a
pinmux before setting a pinconf will operate on the potentially wrong
information.

So I think the initial value should be read out from REG_EN_CTL rather
than being just "true".

Can you please either submit another patch for this?

Regards,
Bjorn