From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Wed, 4 Sep 2013 14:26:38 +0100 Subject: [PATCH 11/11] iio: pressure-core: st: Provide correct regulator support In-Reply-To: <5227331A.5050507@metafoo.de> References: <1378287103-21765-1-git-send-email-lee.jones@linaro.org> <1378287103-21765-12-git-send-email-lee.jones@linaro.org> <20130904131111.GJ18206@e106331-lin.cambridge.arm.com> <5227331A.5050507@metafoo.de> Message-ID: <20130904132638.GG20150@lee--X1> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 04 Sep 2013, Lars-Peter Clausen wrote: > On 09/04/2013 03:11 PM, Mark Rutland wrote: > > 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, I didn't know that existed. > It can return NULL, but NULL is actually a valid regulator in that case, so > the check should only be IS_ERR. And yes regulator_get_optional is what > should be used here. Okay, I'll use that instead. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog