[PATCH 2/3] platform/chrome: cros_ec_debugfs: Add PD port info to debugfs

[Enric Balletbo i Serra <enric.balletbo@collabora.com>]

From: Shawn Nematbakhsh <shawnn@chromium.org>

Add info useful for debugging USB-PD port state.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---
 drivers/platform/chrome/cros_ec_debugfs.c | 86 +++++++++++++++++++++++++++++--
 1 file changed, 82 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
index 0328856ec3a2..1d7e28c633f2 100644
--- a/drivers/platform/chrome/cros_ec_debugfs.c
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -35,7 +35,8 @@
 
 #define CIRC_ADD(idx, size, value)	(((idx) + (value)) & ((size) - 1))
 
-/* struct cros_ec_debugfs - ChromeOS EC debugging information
+/*
+ * struct cros_ec_debugfs - ChromeOS EC debugging information
  *
  * @ec: EC device this debugfs information belongs to
  * @dir: dentry for debugfs files
@@ -170,7 +171,8 @@ static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
 		mutex_lock(&debug_info->log_mutex);
 	}
 
-	/* Only copy until the end of the circular buffer, and let userspace
+	/*
+	 * Only copy until the end of the circular buffer, and let userspace
 	 * retry to get the rest of the data.
 	 */
 	ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
@@ -211,6 +213,61 @@ static int cros_ec_console_log_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static ssize_t cros_ec_pdinfo_read(struct file *file,
+				   char __user *user_buf,
+				   size_t count,
+				   loff_t *ppos)
+{
+	char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf;
+	struct cros_ec_debugfs *debug_info = file->private_data;
+	struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
+
+	struct {
+		struct cros_ec_command msg;
+		union {
+			struct ec_response_usb_pd_control_v1 resp;
+			struct ec_params_usb_pd_control params;
+		};
+	} __packed ec_buf;
+
+	struct cros_ec_command *msg;
+	struct ec_response_usb_pd_control_v1 *resp;
+	struct ec_params_usb_pd_control *params;
+
+	int i;
+
+	msg = &ec_buf.msg;
+	params = (struct ec_params_usb_pd_control *)msg->data;
+	resp = (struct ec_response_usb_pd_control_v1 *)msg->data;
+
+	msg->command = EC_CMD_USB_PD_CONTROL;
+	msg->version = 1;
+	msg->insize = sizeof(*resp);
+	msg->outsize = sizeof(*params);
+
+	/*
+	 * Read status from all PD ports until failure, typically caused
+	 * by attempting to read status on a port that doesn't exist.
+	 */
+	for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {
+		params->port = i;
+		params->role = 0;
+		params->mux = 0;
+		params->swap = 0;
+
+		if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)
+			break;
+
+		p += scnprintf(p, sizeof(read_buf) + read_buf - p,
+			"p%d: %s en:%.2x role:%.2x pol:%.2x\n",
+			i, resp->state, resp->enabled, resp->role,
+			resp->polarity);
+	}
+
+	return simple_read_from_buffer(user_buf, count, ppos,
+				       read_buf, p - read_buf);
+}
+
 const struct file_operations cros_ec_console_log_fops = {
 	.owner = THIS_MODULE,
 	.open = cros_ec_console_log_open,
@@ -220,6 +277,13 @@ const struct file_operations cros_ec_console_log_fops = {
 	.release = cros_ec_console_log_release,
 };
 
+const struct file_operations cros_ec_pdinfo_fops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = cros_ec_pdinfo_read,
+	.llseek = default_llseek,
+};
+
 static int ec_read_version_supported(struct cros_ec_dev *ec)
 {
 	struct ec_params_get_cmd_versions_v1 *params;
@@ -288,7 +352,7 @@ static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
 	init_waitqueue_head(&debug_info->log_wq);
 
 	if (!debugfs_create_file("console_log",
-				 S_IFREG | S_IRUGO,
+				 S_IFREG | 0444,
 				 debug_info->dir,
 				 debug_info,
 				 &cros_ec_console_log_fops))
@@ -341,7 +405,7 @@ static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
 	debug_info->panicinfo_blob.size = ret;
 
 	if (!debugfs_create_blob("panicinfo",
-				 S_IFREG | S_IRUGO,
+				 S_IFREG | 0444,
 				 debug_info->dir,
 				 &debug_info->panicinfo_blob)) {
 		ret = -ENOMEM;
@@ -355,6 +419,16 @@ static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
 	return ret;
 }
 
+static int cros_ec_create_pdinfo(struct cros_ec_debugfs *debug_info)
+{
+	if (!debugfs_create_file("pdinfo", S_IFREG | 0444,
+				 debug_info->dir, debug_info,
+				 &cros_ec_pdinfo_fops))
+		return -ENOMEM;
+
+	return 0;
+}
+
 int cros_ec_debugfs_init(struct cros_ec_dev *ec)
 {
 	struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
@@ -379,6 +453,10 @@ int cros_ec_debugfs_init(struct cros_ec_dev *ec)
 	if (ret)
 		goto remove_debugfs;
 
+	ret = cros_ec_create_pdinfo(debug_info);
+	if (ret)
+		goto remove_debugfs;
+
 	ec->debug_info = debug_info;
 
 	return 0;
-- 
2.16.1