1 files changed, 83 insertions, 31 deletions

diff --git a/drivers/soundwire/sysfs_slave.c b/drivers/soundwire/sysfs_slave.c
index f510071b0add..c5c22d1708ec 100644
--- a/drivers/soundwire/sysfs_slave.c
+++ b/drivers/soundwire/sysfs_slave.c
@@ -16,9 +16,13 @@
 
 /*
  * The sysfs for Slave reflects the MIPI description as given
- * in the MIPI DisCo spec
+ * in the MIPI DisCo spec.
+ * status and device_number come directly from the MIPI SoundWire
+ * 1.x specification.
  *
  * Base file is device
+ *	|---- status
+ *	|---- device_number
  *	|---- modalias
  *	|---- dev-properties
  *		|---- mipi_revision
@@ -101,7 +105,10 @@ static struct attribute *slave_attrs[] = {
 	&dev_attr_modalias.attr,
 	NULL,
 };
-ATTRIBUTE_GROUPS(slave);
+
+static const struct attribute_group slave_attr_group = {
+	.attrs = slave_attrs,
+};
 
 static struct attribute *slave_dev_attrs[] = {
 	&dev_attr_mipi_revision.attr,
@@ -122,11 +129,7 @@ static struct attribute *slave_dev_attrs[] = {
 	NULL,
 };
 
-/*
- * we don't use ATTRIBUTES_GROUP here since we want to add a subdirectory
- * for device-level properties
- */
-static struct attribute_group sdw_slave_dev_attr_group = {
+static const struct attribute_group sdw_slave_dev_attr_group = {
 	.attrs	= slave_dev_attrs,
 	.name = "dev-properties",
 };
@@ -177,38 +180,87 @@ static struct attribute *dp0_attrs[] = {
 	NULL,
 };
 
-/*
- * we don't use ATTRIBUTES_GROUP here since we want to add a subdirectory
- * for dp0-level properties
- */
+static umode_t dp0_attr_visible(struct kobject *kobj, struct attribute *attr,
+			      int n)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(kobj_to_dev(kobj));
+
+	if (slave->prop.dp0_prop)
+		return attr->mode;
+	return 0;
+}
+
+static bool dp0_group_visible(struct kobject *kobj)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(kobj_to_dev(kobj));
+
+	if (slave->prop.dp0_prop)
+		return true;
+	return false;
+}
+DEFINE_SYSFS_GROUP_VISIBLE(dp0);
+
 static const struct attribute_group dp0_group = {
 	.attrs = dp0_attrs,
+	.is_visible = SYSFS_GROUP_VISIBLE(dp0),
 	.name = "dp0",
 };
 
-int sdw_slave_sysfs_init(struct sdw_slave *slave)
-{
-	int ret;
+const struct attribute_group *sdw_attr_groups[] = {
+	&slave_attr_group,
+	&sdw_slave_dev_attr_group,
+	&dp0_group,
+	NULL,
+};
 
-	ret = devm_device_add_groups(&slave->dev, slave_groups);
-	if (ret < 0)
-		return ret;
+/*
+ * the status is shown in capital letters for UNATTACHED and RESERVED
+ * on purpose, to highlight users to the fact that these status values
+ * are not expected.
+ */
+static const char *const slave_status[] = {
+	[SDW_SLAVE_UNATTACHED] =  "UNATTACHED",
+	[SDW_SLAVE_ATTACHED] = "Attached",
+	[SDW_SLAVE_ALERT] = "Alert",
+	[SDW_SLAVE_RESERVED] = "RESERVED",
+};
 
-	ret = devm_device_add_group(&slave->dev, &sdw_slave_dev_attr_group);
-	if (ret < 0)
-		return ret;
+static ssize_t status_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 
-	if (slave->prop.dp0_prop) {
-		ret = devm_device_add_group(&slave->dev, &dp0_group);
-		if (ret < 0)
-			return ret;
-	}
+	return sprintf(buf, "%s\n", slave_status[slave->status]);
+}
+static DEVICE_ATTR_RO(status);
 
-	if (slave->prop.source_ports || slave->prop.sink_ports) {
-		ret = sdw_slave_sysfs_dpn_init(slave);
-		if (ret < 0)
-			return ret;
-	}
+static ssize_t device_number_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 
-	return 0;
+	if (slave->status == SDW_SLAVE_UNATTACHED)
+		return sprintf(buf, "%s", "N/A");
+	else
+		return sprintf(buf, "%d", slave->dev_num);
 }
+static DEVICE_ATTR_RO(device_number);
+
+static struct attribute *slave_status_attrs[] = {
+	&dev_attr_status.attr,
+	&dev_attr_device_number.attr,
+	NULL,
+};
+
+/*
+ * we don't use ATTRIBUTES_GROUP here since the group is used in a
+ * separate file and can't be handled as a static.
+ */
+static const struct attribute_group sdw_slave_status_attr_group = {
+	.attrs	= slave_status_attrs,
+};
+
+const struct attribute_group *sdw_slave_status_attr_groups[] = {
+	&sdw_slave_status_attr_group,
+	NULL
+};