| Message ID | 20201221151551.52511-1-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4] iio: Handle enumerated properties with gaps | expand |
On Mon, Dec 21, 2020 at 5:11 PM Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > > From: Lars-Peter Clausen <lars@metafoo.de> > > 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. ... > I tried a few shots at working with 'lib/string.c', and that went > slow. The __sysfs_match_string_with_gaps() approach has stalled. > https://lore.kernel.org/linux-iio/20190422140251.8960-1-alexandru.ardelean@analog.com/ Hmm... If you are not going to push that forward, perhaps better is to provide iio_sysfs_match_string() and if we need it in the future for other users, it would be easier to find and export. Also it will be a matter of one line change in the caller.
On Mon, Dec 21, 2020 at 8:02 PM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Mon, Dec 21, 2020 at 5:11 PM Alexandru Ardelean > <alexandru.ardelean@analog.com> wrote: > > > > From: Lars-Peter Clausen <lars@metafoo.de> > > > > 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. > > ... > > > I tried a few shots at working with 'lib/string.c', and that went > > slow. The __sysfs_match_string_with_gaps() approach has stalled. > > https://lore.kernel.org/linux-iio/20190422140251.8960-1-alexandru.ardelean@analog.com/ > > Hmm... If you are not going to push that forward, perhaps better is to provide > iio_sysfs_match_string() and if we need it in the future for other > users, it would be easier to find and export. Also it will be a matter > of one line change in the caller. That can work as well. Maybe add the __sysfs_match_string_with_gaps() here directly? > > -- > With Best Regards, > Andy Shevchenko
On Tue, Dec 22, 2020 at 9:21 AM Alexandru Ardelean <ardeleanalex@gmail.com> wrote: > > On Mon, Dec 21, 2020 at 8:02 PM Andy Shevchenko > <andy.shevchenko@gmail.com> wrote: > > > > On Mon, Dec 21, 2020 at 5:11 PM Alexandru Ardelean > > <alexandru.ardelean@analog.com> wrote: > > > > > > From: Lars-Peter Clausen <lars@metafoo.de> > > > > > > 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. > > > > ... > > > > > I tried a few shots at working with 'lib/string.c', and that went > > > slow. The __sysfs_match_string_with_gaps() approach has stalled. > > > https://lore.kernel.org/linux-iio/20190422140251.8960-1-alexandru.ardelean@analog.com/ > > > > Hmm... If you are not going to push that forward, perhaps better is to provide > > iio_sysfs_match_string() and if we need it in the future for other > > users, it would be easier to find and export. Also it will be a matter > > of one line change in the caller. > > That can work as well. > Maybe add the __sysfs_match_string_with_gaps() here directly? Maybe I can try again to address __sysfs_match_string() in lib/string.c But I don't want to touch 'match_string()' ; that is way too spread out. > > > > > -- > > With Best Regards, > > Andy Shevchenko
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index e9ee9363fed0..a88494066811 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -470,8 +470,11 @@ 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 +495,7 @@ 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]); @@ -504,16 +507,21 @@ ssize_t iio_enum_write(struct iio_dev *indio_dev, size_t len) { const struct iio_enum *e = (const struct iio_enum *)priv; + unsigned int i; int ret; if (!e->set) return -EINVAL; - ret = __sysfs_match_string(e->items, e->num_items, buf); - if (ret < 0) - return ret; + for (i = 0; i < e->num_items; i++) { + if (e->items[i] && sysfs_streq(buf, e->items[i])) + break; + } + + if (i == e->num_items) + return -EINVAL; - ret = e->set(indio_dev, chan, ret); + ret = e->set(indio_dev, chan, i); return ret ? ret : len; } EXPORT_SYMBOL_GPL(iio_enum_write);