From 8a848e754956dcbc35cd2fcf417f66dafa020c9e Mon Sep 17 00:00:00 2001 From: Peter Rosin Date: Sun, 14 May 2017 21:51:08 +0200 Subject: [PATCH] iio: inkern: api for manipulating ext_info of iio channels Extend the inkern api with functions for reading and writing ext_info of iio channels. Acked-by: Jonathan Cameron Signed-off-by: Peter Rosin Signed-off-by: Greg Kroah-Hartman --- drivers/iio/inkern.c | 60 ++++++++++++++++++++++++++++++++++++ include/linux/iio/consumer.h | 37 ++++++++++++++++++++++ 2 files changed, 97 insertions(+) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index 7a13535dc3e9..8292ad4435ea 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -869,3 +869,63 @@ err_unlock: return ret; } EXPORT_SYMBOL_GPL(iio_write_channel_raw); + +unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan) +{ + const struct iio_chan_spec_ext_info *ext_info; + unsigned int i = 0; + + if (!chan->channel->ext_info) + return i; + + for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++) + ++i; + + return i; +} +EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count); + +static const struct iio_chan_spec_ext_info *iio_lookup_ext_info( + const struct iio_channel *chan, + const char *attr) +{ + const struct iio_chan_spec_ext_info *ext_info; + + if (!chan->channel->ext_info) + return NULL; + + for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) { + if (!strcmp(attr, ext_info->name)) + return ext_info; + } + + return NULL; +} + +ssize_t iio_read_channel_ext_info(struct iio_channel *chan, + const char *attr, char *buf) +{ + const struct iio_chan_spec_ext_info *ext_info; + + ext_info = iio_lookup_ext_info(chan, attr); + if (!ext_info) + return -EINVAL; + + return ext_info->read(chan->indio_dev, ext_info->private, + chan->channel, buf); +} +EXPORT_SYMBOL_GPL(iio_read_channel_ext_info); + +ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr, + const char *buf, size_t len) +{ + const struct iio_chan_spec_ext_info *ext_info; + + ext_info = iio_lookup_ext_info(chan, attr); + if (!ext_info) + return -EINVAL; + + return ext_info->write(chan->indio_dev, ext_info->private, + chan->channel, buf, len); +} +EXPORT_SYMBOL_GPL(iio_write_channel_ext_info); diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 47eeec3218b5..5e347a9805fd 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -312,4 +312,41 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, int *processed, unsigned int scale); +/** + * iio_get_channel_ext_info_count() - get number of ext_info attributes + * connected to the channel. + * @chan: The channel being queried + * + * Returns the number of ext_info attributes + */ +unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan); + +/** + * iio_read_channel_ext_info() - read ext_info attribute from a given channel + * @chan: The channel being queried. + * @attr: The ext_info attribute to read. + * @buf: Where to store the attribute value. Assumed to hold + * at least PAGE_SIZE bytes. + * + * Returns the number of bytes written to buf (perhaps w/o zero termination; + * it need not even be a string), or an error code. + */ +ssize_t iio_read_channel_ext_info(struct iio_channel *chan, + const char *attr, char *buf); + +/** + * iio_write_channel_ext_info() - write ext_info attribute from a given channel + * @chan: The channel being queried. + * @attr: The ext_info attribute to read. + * @buf: The new attribute value. Strings needs to be zero- + * terminated, but the terminator should not be included + * in the below len. + * @len: The size of the new attribute value. + * + * Returns the number of accepted bytes, which should be the same as len. + * An error code can also be returned. + */ +ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr, + const char *buf, size_t len); + #endif -- 2.20.1