From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from www381.your-server.de ([78.46.137.84]:51529 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbdLGJmR (ORCPT ); Thu, 7 Dec 2017 04:42:17 -0500 From: Lars-Peter Clausen To: Jonathan Cameron Cc: Hartmut Knaack , Peter Meerwald-Stadler , Andy Shevchenko , linux-iio@vger.kernel.org, Lars-Peter Clausen Subject: [PATCH] iio: Handle enumerated properties with gaps Date: Thu, 7 Dec 2017 10:42:09 +0100 Message-Id: <20171207094209.14748-1-lars@metafoo.de> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org 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 must not be used. Add support for such enums to the IIO enum helper functions. A reserved value is marked by setting its entry in the items array to NULL rather than the normal descriptive string value. Unfortunately that means we can no longer use __sysfs_match_string() since it treats a NULL entry as the array terminator. But the amount of boilerplate is manageable. Signed-off-by: Lars-Peter Clausen --- Open for suggestions on how to massage __sysfs_match_string() into handling this use-case. --- drivers/iio/industrialio-core.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 2e8e36f9da61..e69bef13d005 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -446,8 +446,12 @@ 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'; @@ -468,7 +472,7 @@ 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]); @@ -480,16 +484,21 @@ 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); -- 2.11.0