Add attribute and show the components string. This is useful to see
what is provided to userspace and e.g. used by UCM to understand the
card configuration:
root@plb:~# more /sys/class/sound/card0/components
HDA:8086280b,80860101,00100000 cfg-spk:2 hs:rt711 spk:rt1308 mic:rt715
Note that the style uses what's recommended by checkpatch.pl and is
slightly different from other sysfs attributes.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
sound/core/init.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/sound/core/init.c b/sound/core/init.c
index b02a99766351..decaf944a8ad 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -695,9 +695,21 @@ card_number_show_attr(struct device *dev,
static DEVICE_ATTR(number, 0444, card_number_show_attr, NULL);
+static ssize_t
+components_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%s\n", card->components);
+}
+
+static DEVICE_ATTR_RO(components);
+
static struct attribute *card_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_number.attr,
+ &dev_attr_components.attr,
NULL
};
--
2.20.1
