From 5063ec589dca71b87029f6a38385b89639663103 Mon Sep 17 00:00:00 2001
From: Guru Das Srinagesh <gurus@codeaurora.org>
Date: Mon, 24 Feb 2020 17:53:47 -0800
Subject: [PATCH] soc: altmode: Add debugfs nodes to send PAN EN and PAN ACK

Add debugfs nodes to send Pin Assignment Notifications Enable (PAN EN)
and Acknowledgment (ACK) commands manually if needed, to aid in
debugging situations where it is unclear whether clients are sending
these commands synchronously as per design.

Change-Id: I7a68d676df86cbf6952158202c8e4958db032d5b
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/soc/qcom/altmode-glink.c | 93 ++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/drivers/soc/qcom/altmode-glink.c b/drivers/soc/qcom/altmode-glink.c
index e721cc197f76..fefd672fe881 100644
--- a/drivers/soc/qcom/altmode-glink.c
+++ b/drivers/soc/qcom/altmode-glink.c
@@ -5,6 +5,7 @@
 
 #define pr_fmt(fmt)	"altmode-glink: %s: " fmt, __func__
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/ktime.h>
@@ -54,6 +55,7 @@ struct usbc_write_buffer_req_msg {
  * @client_list:	Linked list head keeping track of this device's clients
  * @pan_en_sent:	Flag to ensure PAN Enable msg is sent only once
  * @send_pan_en_work:	To schedule the sending of the PAN Enable message
+ * @debugfs_dir:	Dentry for debugfs directory "altmode"
  */
 struct altmode_dev {
 	struct device			*dev;
@@ -64,6 +66,7 @@ struct altmode_dev {
 	struct list_head		client_list;
 	atomic_t			pan_en_sent;
 	struct delayed_work		send_pan_en_work;
+	struct dentry			*debugfs_dir;
 };
 
 /**
@@ -528,6 +531,86 @@ static void altmode_notify_clients(struct altmode_dev *amdev)
 	mutex_unlock(&notify_lock);
 }
 
+#ifdef CONFIG_QTI_PMIC_GLINK_CLIENT_DEBUG
+static int pan_en_write(void *data, u64 val)
+{
+	struct altmode_dev *amdev = data;
+
+	schedule_delayed_work(&amdev->send_pan_en_work,
+				msecs_to_jiffies(20));
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(pan_en_fops, NULL, pan_en_write, "%llu\n");
+
+static int send_ack_write(void *data, u64 val)
+{
+	int rc;
+	struct altmode_dev *amdev = data;
+	struct altmode_pan_ack_msg ack;
+
+	if (val >= MAX_NUM_PORTS)
+		return -EINVAL;
+
+	ack.cmd_type = ALTMODE_PAN_ACK;
+	ack.port_index = val;
+
+	rc = __altmode_send_data(amdev, &ack, sizeof(ack));
+	if (rc < 0) {
+		dev_err(amdev->dev, "port %d: Failed sending PAN ACK: %llu\n",
+				val, rc);
+		return rc;
+	}
+
+	dev_dbg(amdev->dev, "port %llu: Sent PAN ACK via debugfs\n", val);
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(send_ack_fops, NULL, send_ack_write, "%llu\n");
+
+static int altmode_setup_debugfs(struct altmode_dev *amdev)
+{
+	int rc;
+	struct dentry *am_dir, *file;
+
+	am_dir = debugfs_create_dir("altmode", NULL);
+	if (IS_ERR(am_dir)) {
+		rc = PTR_ERR(am_dir);
+		dev_err(amdev->dev, "Failed to create altmode directory: %d\n",
+				rc);
+		return rc;
+	}
+
+	file = debugfs_create_file_unsafe("send_pan_en", 0200, am_dir, amdev,
+					  &pan_en_fops);
+	if (IS_ERR(file)) {
+		rc = PTR_ERR(file);
+		dev_err(amdev->dev, "Failed to create send_pan_en: %d\n", rc);
+		goto error;
+	}
+
+	file = debugfs_create_file_unsafe("send_pan_ack", 0200, am_dir,
+					  amdev, &send_ack_fops);
+	if (IS_ERR(file)) {
+		rc = PTR_ERR(file);
+		dev_err(amdev->dev, "Failed to create send_pan_ack: %d\n", rc);
+		goto error;
+	}
+
+	amdev->debugfs_dir = am_dir;
+
+	return 0;
+
+error:
+	debugfs_remove_recursive(am_dir);
+	return rc;
+}
+#else
+static int altmode_setup_debugfs(struct altmode_dev *amdev)
+{
+	return 0;
+}
+#endif
+
 static int altmode_probe(struct platform_device *pdev)
 {
 	int rc;
@@ -565,10 +648,18 @@ static int altmode_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, amdev);
 
+	rc = altmode_setup_debugfs(amdev);
+	if (rc < 0) {
+		dev_err(amdev->dev, "Failed to create debugfs: %d\n", rc);
+		goto unreg_pmic_glink;
+	}
+
 	altmode_notify_clients(amdev);
 
 	return 0;
 
+unreg_pmic_glink:
+	pmic_glink_unregister_client(amdev->pgclient);
 error_register:
 	idr_destroy(&amdev->client_idr);
 	return rc;
@@ -581,6 +672,8 @@ static int altmode_remove(struct platform_device *pdev)
 	struct altmode_client *client, *tmp;
 	struct probe_notify_node *npos, *ntmp;
 
+	debugfs_remove_recursive(amdev->debugfs_dir);
+
 	cancel_delayed_work_sync(&amdev->send_pan_en_work);
 	idr_destroy(&amdev->client_idr);
 	atomic_set(&amdev->pan_en_sent, 0);