Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756751AbcJ3PXG (ORCPT ); Sun, 30 Oct 2016 11:23:06 -0400 Received: from ns.pmeerw.net ([84.19.176.92]:38502 "EHLO pmeerw.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753224AbcJ3PXE (ORCPT ); Sun, 30 Oct 2016 11:23:04 -0400 Date: Sun, 30 Oct 2016 16:23:00 +0100 (CET) From: Peter Meerwald-Stadler To: Jonathan Cameron , Peter Rosin cc: linux-kernel@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Rob Herring , Mark Rutland , linux-iio@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v3 2/8] iio: inkern: add helpers to query available values from channels In-Reply-To: Message-ID: References: <1477262381-7800-1-git-send-email-peda@axentia.se> <1477262381-7800-3-git-send-email-peda@axentia.se> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7021 Lines: 223 > 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. some comments below > 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 "Note: raw reads..." would be easier... here and below why is there no val2 here? just reading the documentation ("maximum available raw value") I am not sure what the function does: does it return the maximum value possible? or the maximum value in some internal buffer? maximum value ever seen? > > + * 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. no vals2? > > + * @type: Type of available values in vals. it is not clear what type is > > + * @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 channel > > + * 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, \ > > > -- Peter Meerwald-Stadler +43-664-2444418 (mobile)