On Thu, 7 Jan 2021 13:20:49 +0200 Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > From: Lars-Peter Clausen <lars@xxxxxxxxxx> > > Some enums might have gaps or reserved values in the middle of their value > range. E.g. consider a 2-bit enum where the values 0, 1 and 3 have a > meaning, but 2 is a reserved value and can not be used. > > Add support for such enums to the IIO enum helper functions. A reserved > values is marked by setting its entry in the items array to NULL rather > than the normal descriptive string value. > > Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> Applied to the togreg branch of iio.git and pushed out as testing for all the normal autobuilder related reasons. Note I can still rebase so if anyone wants to add tags or comment it's not yet too late! Jonathan > --- > > Changelog v7 -> v8: > * https://lore.kernel.org/linux-iio/20210107084434.35283-1-alexandru.ardelean@xxxxxxxxxx/ > * dropped patch 'lib/string.c: add __sysfs_match_string_with_gaps() helper' > * merged __sysfs_match_string_with_gaps into drivers/iio/industrial-core.c > as iio_sysfs_match_string_with_gaps() > > drivers/iio/industrialio-core.c | 39 ++++++++++++++++++++++++++++++--- > 1 file changed, 36 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index e9ee9363fed0..db20e2ab437d 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -169,6 +169,36 @@ static const char * const iio_chan_info_postfix[] = { > [IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient", > }; > > +/** > + * iio_sysfs_match_string_with_gaps - matches given string in an array with gaps > + * @array: array of strings > + * @n: number of strings in the array > + * @str: string to match with > + * > + * Returns index of @str in the @array or -EINVAL, similar to match_string(). > + * Uses sysfs_streq instead of strcmp for matching. > + * > + * This routine will look for a string in an array of strings. > + * The search will continue until the element is found or the n-th element > + * is reached, regardless of any NULL elements in the array. > + */ > +static int iio_sysfs_match_string_with_gaps(const char * const *array, size_t n, > + const char *str) > +{ > + const char *item; > + int index; > + > + for (index = 0; index < n; index++) { > + item = array[index]; > + if (!item) > + continue; > + if (sysfs_streq(item, str)) > + return index; > + } > + > + return -EINVAL; > +} > + > #if defined(CONFIG_DEBUG_FS) > /* > * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for > @@ -470,8 +500,11 @@ ssize_t iio_enum_available_read(struct iio_dev *indio_dev, > if (!e->num_items) > return 0; > > - for (i = 0; i < e->num_items; ++i) > + for (i = 0; i < e->num_items; ++i) { > + if (!e->items[i]) > + continue; > len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]); > + } > > /* replace last space with a newline */ > buf[len - 1] = '\n'; > @@ -492,7 +525,7 @@ ssize_t iio_enum_read(struct iio_dev *indio_dev, > i = e->get(indio_dev, chan); > if (i < 0) > return i; > - else if (i >= e->num_items) > + else if (i >= e->num_items || !e->items[i]) > return -EINVAL; > > return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]); > @@ -509,7 +542,7 @@ ssize_t iio_enum_write(struct iio_dev *indio_dev, > if (!e->set) > return -EINVAL; > > - ret = __sysfs_match_string(e->items, e->num_items, buf); > + ret = iio_sysfs_match_string_with_gaps(e->items, e->num_items, buf); > if (ret < 0) > return ret; >
