From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751594AbdAVM6K (ORCPT ); Sun, 22 Jan 2017 07:58:10 -0500 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:40124 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751267AbdAVM6F (ORCPT ); Sun, 22 Jan 2017 07:58:05 -0500 Subject: Re: [PATCH 3/7] iio: adc: stm32: add trigger polarity extended attribute To: Fabrice Gasnier , linux@armlinux.org.uk, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <1484832854-6314-1-git-send-email-fabrice.gasnier@st.com> <1484832854-6314-4-git-send-email-fabrice.gasnier@st.com> Cc: linux-iio@vger.kernel.org, mark.rutland@arm.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, lars@metafoo.de, knaack.h@gmx.de, pmeerw@pmeerw.net, benjamin.gaignard@linaro.org, benjamin.gaignard@st.com From: Jonathan Cameron Message-ID: <17e5b8ba-0ef3-34eb-aa30-a899f87616f7@kernel.org> Date: Sun, 22 Jan 2017 12:58:01 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <1484832854-6314-4-git-send-email-fabrice.gasnier@st.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/01/17 13:34, Fabrice Gasnier wrote: > Define extended attribute so that user may choose rising, falling or both > edges for external trigger sources. > Default to rising edge in case it isn't set. > > Signed-off-by: Fabrice Gasnier Creates a custom attibute. Documentation please! /Documentation/ABI/testing/sysfs-bus-iio-stm32 or similar. The approach seems reasonable, but easier to discuss when it's formally described. I'd also not care about characters saved and go with trigger_polarity rather than the short form (unless this you have a good reason for it!) Jonathan > --- > drivers/iio/adc/stm32-adc.c | 51 ++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index 30708bc..9753c39 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -164,6 +164,7 @@ struct stm32_adc_trig_info { > * @lock: spinlock > * @bufi: data buffer index > * @num_conv: expected number of scan conversions > + * @exten: external trigger config (enable/polarity) > */ > struct stm32_adc { > struct stm32_adc_common *common; > @@ -175,6 +176,7 @@ struct stm32_adc { > spinlock_t lock; /* interrupt lock */ > int bufi; > int num_conv; > + enum stm32_adc_exten exten; > }; > > /** > @@ -449,7 +451,9 @@ static int stm32_adc_set_trig(struct iio_dev *indio_dev, > > /* set trigger source, default to rising edge */ > extsel = ret; > - exten = STM32_EXTEN_HWTRIG_RISING_EDGE; > + if (adc->exten == STM32_EXTEN_SWTRIG) > + adc->exten = STM32_EXTEN_HWTRIG_RISING_EDGE; > + exten = adc->exten; > } > > spin_lock_irqsave(&adc->lock, flags); > @@ -463,6 +467,39 @@ static int stm32_adc_set_trig(struct iio_dev *indio_dev, > return 0; > } > > +static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev, > + const struct iio_chan_spec *chan, > + unsigned int type) > +{ > + struct stm32_adc *adc = iio_priv(indio_dev); > + > + adc->exten = type; > + > + return 0; > +} > + > +static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev, > + const struct iio_chan_spec *chan) > +{ > + struct stm32_adc *adc = iio_priv(indio_dev); > + > + return adc->exten; > +} > + > +static const char * const stm32_trig_pol_items[] = { > + [STM32_EXTEN_SWTRIG] = "swtrig", > + [STM32_EXTEN_HWTRIG_RISING_EDGE] = "rising-edge", > + [STM32_EXTEN_HWTRIG_FALLING_EDGE] = "falling-edge", > + [STM32_EXTEN_HWTRIG_BOTH_EDGES] = "both-edges", > +}; > + > +const struct iio_enum stm32_adc_trig_pol = { > + .items = stm32_trig_pol_items, > + .num_items = ARRAY_SIZE(stm32_trig_pol_items), > + .get = stm32_adc_get_trig_pol, > + .set = stm32_adc_set_trig_pol, > +}; > + > /** > * stm32_adc_single_conv() - Performs a single conversion > * @indio_dev: IIO device > @@ -745,6 +782,17 @@ static irqreturn_t stm32_adc_trigger_handler(int irq, void *p) > return IRQ_HANDLED; > } > > +static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = { > + IIO_ENUM("trigger_pol", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol), > + { > + .name = "trigger_pol_available", > + .shared = IIO_SHARED_BY_ALL, > + .read = iio_enum_available_read, > + .private = (uintptr_t)&stm32_adc_trig_pol, > + }, > + {}, > +}; > + > static void stm32_adc_chan_init_one(struct iio_dev *indio_dev, > struct iio_chan_spec *chan, > const struct stm32_adc_chan_spec *channel, > @@ -760,6 +808,7 @@ static void stm32_adc_chan_init_one(struct iio_dev *indio_dev, > chan->scan_type.sign = 'u'; > chan->scan_type.realbits = 12; > chan->scan_type.storagebits = 16; > + chan->ext_info = stm32_adc_ext_info; > } > > static int stm32_adc_chan_of_init(struct iio_dev *indio_dev) >