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    SubjectRe: [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when setting pin config
    On Sun 08 Oct 22:34 PDT 2017, Fenglin Wu wrote:

    > On 10/6/2017 12:27 AM, Bjorn Andersson wrote:
    > > On Mon 11 Sep 17:32 PDT 2017, fenglinw@codeaurora.org wrote:
    > >
    > > > From: Fenglin Wu <fenglinw@codeaurora.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@codeaurora.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@linaro.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?
    >
    > Hmm, considering a GPIO which is disabled by default in hardware
    > setting, what's its expected state if we only define "function" for it?
    > I was thinking we need to enable it once it has any setting in pinmux or
    > pinconf. If you think that we need to keep its original state until we
    > set pinconf for it, yes, I can submit a change to address this.
    >

    Are there valid cases where only function should be selected and no
    other configuration is used? If so it makes sense to make
    pmic_gpio_set_mux() enable the block.


    Regardless of this, if there are disabled pins that are not mentioned in
    DT they will still appear as enabled in the debugfs interface; and this
    I consider an error worth fixing.

    Regards,
    Bjorn

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