From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when setting pin config Date: Sun, 8 Oct 2017 22:56:43 -0700 Message-ID: <20171009055643.GB1165@minitux> References: <20170912003331.3092-1-fenglinw@codeaurora.org> <20171005162750.GY1165@minitux> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Fenglin Wu Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Walleij , linux-gpio@vger.kernel.org, collinsd@codeaurora.org, aghayal@codeaurora.org, wruan@codeaurora.org, subbaram@codeaurora.org, kgunda@codeaurora.org List-Id: linux-gpio@vger.kernel.org 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 > > > > > > 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 > > > --- > > > 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 > > > > > > 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