Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762494Ab3IDNMO (ORCPT ); Wed, 4 Sep 2013 09:12:14 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21]:50085 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751993Ab3IDNMM (ORCPT ); Wed, 4 Sep 2013 09:12:12 -0400 Date: Wed, 4 Sep 2013 14:11:11 +0100 From: Mark Rutland To: Lee Jones Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "jic23@cam.ac.uk" , "linux-iio@vger.kernel.org" , "linus.walleij@linaro.org" , "denis.ciocca@st.com" , "arnd@arndb.de" , broonie@kernel.org Subject: Re: [PATCH 11/11] iio: pressure-core: st: Provide correct regulator support Message-ID: <20130904131111.GJ18206@e106331-lin.cambridge.arm.com> References: <1378287103-21765-1-git-send-email-lee.jones@linaro.org> <1378287103-21765-12-git-send-email-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1378287103-21765-12-git-send-email-lee.jones@linaro.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4100 Lines: 111 Hi Lee, On Wed, Sep 04, 2013 at 10:31:43AM +0100, Lee Jones wrote: > The power to some of the sensors are controlled by regulators. In most > cases these are 'always on', but if not they will fail to work until > the regulator is enabled using the relevant APIs. > > Signed-off-by: Lee Jones > --- > drivers/iio/pressure/st_pressure_core.c | 13 +++++++++++++ > include/linux/iio/common/st_sensors.h | 3 +++ > 2 files changed, 16 insertions(+) > > diff --git a/drivers/iio/pressure/st_pressure_core.c b/drivers/iio/pressure/st_pressure_core.c > index f452417..7beed89 100644 > --- a/drivers/iio/pressure/st_pressure_core.c > +++ b/drivers/iio/pressure/st_pressure_core.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > #include > > #include > @@ -315,6 +316,15 @@ int st_press_common_probe(struct iio_dev *indio_dev) > indio_dev->modes = INDIO_DIRECT_MODE; > indio_dev->info = &press_info; > > + /* Regulator not mandatory, but if requested we should enable it. */ > + pdata->regulator = regulator_get(&indio_dev->dev, "vdd"); > + if (!IS_ERR_OR_NULL(pdata->regulator)) { Can regulator_get return NULL? As far as I can see, it either returns a valid reulator pointer or an ERR_PTR value. When you say "if requested", do you mean "if described in the dt"? If so, the above doesn't distunguish between a regulator not being listed and one failing to be got (e.g. if we got EPROBE_DEFER from regulator_get). I think this would be better handled with something like Mark Brown's suggested regulator_get_optional [1,2]. Thanks, Mark. [1] https://lkml.org/lkml/2013/7/30/328 (cover) [2] https://lkml.org/lkml/2013/7/30/334 (patches) > + err = regulator_enable(pdata->regulator); > + if (err != 0) > + dev_warn(&indio_dev->dev, > + "Failed to enable specified vdd regulator\n"); > + } > + > err = st_sensors_check_device_support(indio_dev, > ARRAY_SIZE(st_press_sensors), > st_press_sensors); > @@ -363,6 +373,9 @@ void st_press_common_remove(struct iio_dev *indio_dev) > { > struct st_sensor_data *pdata = iio_priv(indio_dev); > > + if (!IS_ERR_OR_NULL(pdata->regulator)) > + regulator_disable(pdata->regulator); > + > iio_device_unregister(indio_dev); > if (pdata->get_irq_data_ready(indio_dev) > 0) { > st_sensors_deallocate_trigger(indio_dev); > diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h > index 4aef925..eb6ef3f 100644 > --- a/include/linux/iio/common/st_sensors.h > +++ b/include/linux/iio/common/st_sensors.h > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > > #define ST_SENSORS_TX_MAX_LENGTH 2 > #define ST_SENSORS_RX_MAX_LENGTH 6 > @@ -197,6 +198,7 @@ struct st_sensors { > * @trig: The trigger in use by the core driver. > * @sensor: Pointer to the current sensor struct in use. > * @current_fullscale: Maximum range of measure by the sensor. > + * @regulator: Pointer to sensor's power supply > * @enabled: Status of the sensor (false->off, true->on). > * @multiread_bit: Use or not particular bit for [I2C/SPI] multiread. > * @buffer_data: Data used by buffer part. > @@ -211,6 +213,7 @@ struct st_sensor_data { > struct iio_trigger *trig; > struct st_sensors *sensor; > struct st_sensor_fullscale_avl *current_fullscale; > + struct regulator *regulator; > > bool enabled; > bool multiread_bit; > -- > 1.8.1.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/