[RFC 9/9] platform/x86: huawei-wmi: Add debugfs support

From: Ayman Bagabas
Date: Sun Jun 30 2019 - 01:42:00 EST


Add a debugfs interface that can be used to call the WMI management
interface function.

The WMI interface takes a 64 bit integer and returns 256-260 bytes
buffer. This debugfs interface creates two files, one stores a 64 bit
int and the other calls the WMI interface and dumps out the returned
buffer.

Signed-off-by: Ayman Bagabas <ayman.bagabas@xxxxxxxxx>
---
drivers/platform/x86/huawei-wmi.c | 98 +++++++++++++++++++++++++++++++
1 file changed, 98 insertions(+)

diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
index f7041fb71026..bdca8bd76c8c 100644
--- a/drivers/platform/x86/huawei-wmi.c
+++ b/drivers/platform/x86/huawei-wmi.c
@@ -6,6 +6,7 @@
*/

#include <linux/acpi.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/input.h>
@@ -45,7 +46,13 @@ struct quirk_entry {

static struct quirk_entry *quirks;

+struct huawei_wmi_debug {
+ struct dentry *root;
+ u64 arg;
+};
+
struct huawei_wmi_priv {
+ struct huawei_wmi_debug debug;
struct input_dev *idev[2];
struct led_classdev cdev;
struct mutex battery_lock;
@@ -456,6 +463,94 @@ static struct attribute *huawei_wmi_attrs[] = {

ATTRIBUTE_GROUPS(huawei_wmi);

+/* debugfs */
+
+static void huawei_wmi_debugfs_call_dump(struct seq_file *m, void *data,
+ union acpi_object *obj)
+{
+ struct huawei_wmi_priv *priv = m->private;
+ int i;
+
+ switch (obj->type) {
+ case ACPI_TYPE_INTEGER:
+ seq_printf(m, "0x%llx", obj->integer.value);
+ break;
+ case ACPI_TYPE_STRING:
+ seq_printf(m, "\"%*s\"", obj->string.length, obj->string.pointer);
+ break;
+ case ACPI_TYPE_BUFFER:
+ seq_puts(m, "{");
+ for (i = 0; i < obj->buffer.length; i++) {
+ seq_printf(m, "0x%02x", obj->buffer.pointer[i]);
+ if (i < obj->buffer.length - 1)
+ seq_puts(m, ",");
+ }
+ seq_puts(m, "}");
+ break;
+ case ACPI_TYPE_PACKAGE:
+ seq_puts(m, "[");
+ for (i = 0; i < obj->package.count; i++) {
+ huawei_wmi_debugfs_call_dump(m, priv, &obj->package.elements[i]);
+ if (i < obj->package.count - 1)
+ seq_puts(m, ",");
+ }
+ seq_puts(m, "]");
+ break;
+ default:
+ dev_err(&priv->pdev->dev, "Unexpected obj type, got %d\n", obj->type);
+ return;
+ }
+}
+
+static int huawei_wmi_debugfs_call_show(struct seq_file *m, void *data)
+{
+ struct huawei_wmi_priv *priv = m->private;
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer in;
+ union acpi_object *obj;
+ int err;
+
+ in.length = sizeof(u64);
+ in.pointer = &priv->debug.arg;
+
+ err = huawei_wmi_call(&priv->pdev->dev, &in, &out);
+ if (err)
+ return err;
+
+ obj = out.pointer;
+ if (!obj) {
+ err = -EIO;
+ goto fail_debugfs_call;
+ }
+
+ huawei_wmi_debugfs_call_dump(m, priv, obj);
+
+fail_debugfs_call:
+ kfree(out.pointer);
+ return err;
+}
+
+DEFINE_SHOW_ATTRIBUTE(huawei_wmi_debugfs_call);
+
+static void huawei_wmi_debugfs_exit(struct device *dev)
+{
+ struct huawei_wmi_priv *priv = dev_get_drvdata(dev);
+
+ debugfs_remove_recursive(priv->debug.root);
+}
+
+static void huawei_wmi_debugfs_setup(struct device *dev)
+{
+ struct huawei_wmi_priv *priv = dev_get_drvdata(dev);
+
+ priv->debug.root = debugfs_create_dir("huawei-wmi", NULL);
+
+ debugfs_create_x64("arg", 0644, priv->debug.root,
+ &priv->debug.arg);
+ debugfs_create_file("call", 0400,
+ priv->debug.root, priv, &huawei_wmi_debugfs_call_fops);
+}
+
/* Input */

static void huawei_wmi_process_key(struct input_dev *idev, int code)
@@ -589,6 +684,8 @@ static int huawei_wmi_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "Failed to create sysfs interface\n");
return err;
}
+
+ huawei_wmi_debugfs_setup(&pdev->dev);
}

return 0;
@@ -603,6 +700,7 @@ static int huawei_wmi_remove(struct platform_device *pdev)
wmi_remove_notify_handler(HWMI_EVENT_GUID);

if (wmi_has_guid(HWMI_METHOD_GUID)) {
+ huawei_wmi_debugfs_exit(&pdev->dev);
sysfs_remove_groups(&pdev->dev.kobj, huawei_wmi_groups);
}

--
2.20.1