[PATCH v6 12/15] net: qrtr: mhi: Report endpoint id in sysfs

[Juha-Matti Tilli]

From: Denis Kenzior <denkenz@xxxxxxxxx>

Add a read-only 'endpoint' sysfs entry that contains the qrtr endpoint
identifier assigned to this mhi device.  Can be used to direct / receive
qrtr traffic only from a particular MHI device.

Signed-off-by: Denis Kenzior <denkenz@xxxxxxxxx>
Reviewed-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Reviewed-by: Andy Gross <agross@xxxxxxxxxx>
Signed-off-by: Mihai Moldovan <ionic@xxxxxxxx>
Signed-off-by: Juha-Matti Tilli <juha-matti.tilli@xxxxxx>
---
 net/qrtr/mhi.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
index 3990da1a65dc4..630ce0da060e5 100644
--- a/net/qrtr/mhi.c
+++ b/net/qrtr/mhi.c
@@ -106,6 +106,16 @@ static int qcom_mhi_qrtr_queue_dl_buffers(struct mhi_device *mhi_dev)
 	return 0;
 }
 
+static ssize_t endpoint_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", qdev->ep.id);
+}
+
+static DEVICE_ATTR_RO(endpoint);
+
 static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 			       const struct mhi_device_id *id)
 {
@@ -135,6 +145,9 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 	if (rc)
 		goto err_unregister;
 
+	if (device_create_file(&mhi_dev->dev, &dev_attr_endpoint) < 0)
+		dev_err(qdev->dev, "Failed to create endpoint attribute\n");
+
 	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
 
 	return 0;
@@ -151,6 +164,7 @@ static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
 {
 	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
 
+	device_remove_file(&mhi_dev->dev, &dev_attr_endpoint);
 	qrtr_endpoint_unregister(&qdev->ep);
 	mhi_unprepare_from_transfer(mhi_dev);
 	dev_set_drvdata(&mhi_dev->dev, NULL);
-- 
2.34.1