Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756370AbcJ3NVI (ORCPT ); Sun, 30 Oct 2016 09:21:08 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:41900 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754273AbcJ3NVH (ORCPT ); Sun, 30 Oct 2016 09:21:07 -0400 Subject: Re: [PATCH v3 2/8] iio: inkern: add helpers to query available values from channels To: Peter Rosin , linux-kernel@vger.kernel.org References: <1477262381-7800-1-git-send-email-peda@axentia.se> <1477262381-7800-3-git-send-email-peda@axentia.se> Cc: Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Rob Herring , Mark Rutland , linux-iio@vger.kernel.org, devicetree@vger.kernel.org From: Jonathan Cameron Message-ID: Date: Sun, 30 Oct 2016 13:21:04 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1477262381-7800-3-git-send-email-peda@axentia.se> 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 Content-Length: 6197 Lines: 195 On 23/10/16 23:39, Peter Rosin wrote: > Specifically a helper for reading the available maximum raw value of a > channel and a helper for forwarding read_avail requests for raw values > from one iio driver to an iio channel that is consumed. > > These rather specific helpers are in turn built with generic helpers > making it easy to build more helpers for available values as needed. > > Signed-off-by: Peter Rosin Looks good to me. Just what I was after. Jonathan > --- > drivers/iio/inkern.c | 97 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/iio/consumer.h | 29 +++++++++++++ > include/linux/iio/iio.h | 17 ++++++++ > 3 files changed, 143 insertions(+) > > diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c > index c4757e6367e7..74808f8a187a 100644 > --- a/drivers/iio/inkern.c > +++ b/drivers/iio/inkern.c > @@ -703,6 +703,103 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2) > } > EXPORT_SYMBOL_GPL(iio_read_channel_scale); > > +static int iio_channel_read_avail(struct iio_channel *chan, > + const int **vals, int *type, int *length, > + enum iio_chan_info_enum info) > +{ > + if (!iio_channel_has_available(chan->channel, info)) > + return -EINVAL; > + > + return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel, > + vals, type, length, info); > +} > + > +int iio_read_avail_channel_raw(struct iio_channel *chan, > + const int **vals, int *type, int *length) > +{ > + int ret; > + > + mutex_lock(&chan->indio_dev->info_exist_lock); > + if (!chan->indio_dev->info) { > + ret = -ENODEV; > + goto err_unlock; > + } > + > + ret = iio_channel_read_avail(chan, > + vals, type, length, IIO_CHAN_INFO_RAW); > +err_unlock: > + mutex_unlock(&chan->indio_dev->info_exist_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw); > + > +static int iio_channel_read_max(struct iio_channel *chan, > + int *val, int *val2, int *type, > + enum iio_chan_info_enum info) > +{ > + int unused; > + const int *vals; > + int length; > + int ret; > + > + if (!val2) > + val2 = &unused; > + > + ret = iio_channel_read_avail(chan, &vals, type, &length, info); > + switch (ret) { > + case IIO_AVAIL_RANGE: > + switch (*type) { > + case IIO_VAL_INT: > + *val = vals[2]; > + break; > + default: > + *val = vals[4]; > + *val2 = vals[5]; > + } > + return 0; > + > + case IIO_AVAIL_LIST: > + if (length <= 0) > + return -EINVAL; > + switch (*type) { > + case IIO_VAL_INT: > + *val = vals[--length]; > + while (length) { > + if (vals[--length] > *val) > + *val = vals[length]; > + } > + break; > + default: > + /* FIXME: learn about max for other iio values */ > + return -EINVAL; > + } > + return 0; > + > + default: > + return ret; > + } > +} > + > +int iio_read_max_channel_raw(struct iio_channel *chan, int *val) > +{ > + int ret; > + int type; > + > + mutex_lock(&chan->indio_dev->info_exist_lock); > + if (!chan->indio_dev->info) { > + ret = -ENODEV; > + goto err_unlock; > + } > + > + ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW); > +err_unlock: > + mutex_unlock(&chan->indio_dev->info_exist_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(iio_read_max_channel_raw); > + > int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type) > { > int ret = 0; > diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h > index 9edccfba1ffb..baab5e45734f 100644 > --- a/include/linux/iio/consumer.h > +++ b/include/linux/iio/consumer.h > @@ -226,6 +226,35 @@ int iio_read_channel_processed(struct iio_channel *chan, int *val); > int iio_write_channel_raw(struct iio_channel *chan, int val); > > /** > + * iio_read_max_channel_raw() - read maximum available raw value from a given > + * channel > + * @chan: The channel being queried. > + * @val: Value read back. > + * > + * Note raw reads from iio channels are in adc counts and hence > + * scale will need to be applied if standard units are required. > + */ > +int iio_read_max_channel_raw(struct iio_channel *chan, int *val); > + > +/** > + * iio_read_avail_channel_raw() - read available raw values from a given channel > + * @chan: The channel being queried. > + * @vals: Available values read back. > + * @type: Type of available values in vals. > + * @length: Number of entries in vals. > + * > + * Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST. > + * > + * For ranges, three vals are always returned; min, step and max. > + * For lists, all the possible values are enumerated. > + * > + * Note raw available values from iio channels are in adc counts and > + * hence scale will need to be applied if standard units are required. > + */ > +int iio_read_avail_channel_raw(struct iio_channel *chan, > + const int **vals, int *type, int *length); > + > +/** > * iio_get_channel_type() - get the type of a channel > * @channel: The channel being queried. > * @type: The type of the channel. > diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h > index 45b781084a4b..e565701d13ce 100644 > --- a/include/linux/iio/iio.h > +++ b/include/linux/iio/iio.h > @@ -315,6 +315,23 @@ static inline bool iio_channel_has_info(const struct iio_chan_spec *chan, > (chan->info_mask_shared_by_all & BIT(type)); > } > > +/** > + * iio_channel_has_available() - Checks if a channel has an available attribute > + * @chan: The channel to be queried > + * @type: Type of the available attribute to be checked > + * > + * Returns true if the channels supports reporting available values for the > + * given attribute type, false otherwise. > + */ > +static inline bool iio_channel_has_available(const struct iio_chan_spec *chan, > + enum iio_chan_info_enum type) > +{ > + return (chan->info_mask_separate_available & BIT(type)) | > + (chan->info_mask_shared_by_type_available & BIT(type)) | > + (chan->info_mask_shared_by_dir_available & BIT(type)) | > + (chan->info_mask_shared_by_all_available & BIT(type)); > +} > + > #define IIO_CHAN_SOFT_TIMESTAMP(_si) { \ > .type = IIO_TIMESTAMP, \ > .channel = -1, \ >