[PATCH v2 8/8] platform/x86: huawei-wmi: add debugfs files support

From: Ayman Bagabas
Date: Thu Jun 13 2019 - 12:57:34 EST


A debugfs interface that creates two attributes `arg` and `call` to set
an argument to be called by the WMI device and show the results
returned. This argument is a 64 bit long which complies the properties
of the HWMI interface.

Signed-off-by: Ayman Bagabas <ayman.bagabas@xxxxxxxxx>
---
drivers/platform/x86/huawei-wmi.c | 117 ++++++++++++++++++++++++++++++
1 file changed, 117 insertions(+)

diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
index cc6745ff1bad..a74ddd9adb47 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>
@@ -46,8 +47,14 @@ struct quirk_entry {

static struct quirk_entry *quirks;

+struct huawei_wmi_debug {
+ struct dentry *root;
+ u64 arg;
+};
+
struct huawei_wmi {
struct led_classdev cdev;
+ struct huawei_wmi_debug debug;
struct input_dev *idev[2];
struct mutex wmi_lock;
struct mutex battery_lock;
@@ -463,6 +470,110 @@ 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 *huawei = 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_printf(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_printf(m, ",");
+ }
+ seq_printf(m, "}");
+ break;
+ case ACPI_TYPE_PACKAGE:
+ seq_printf(m, "[");
+ for (i = 0; i < obj->package.count; i++) {
+ huawei_wmi_debugfs_call_dump(m, huawei, &obj->package.elements[i]);
+ if (i < obj->package.count - 1)
+ seq_printf(m, ",");
+ }
+ seq_printf(m, "]");
+ break;
+ default:
+ dev_err(&huawei->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 *huawei = 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 = &huawei->debug.arg;
+
+ err = huawei_wmi_call(&huawei->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, huawei, 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 *huawei = dev_get_drvdata(dev);
+
+ debugfs_remove_recursive(huawei->debug.root);
+}
+
+static int huawei_wmi_debugfs_init(struct device *dev)
+{
+ struct huawei_wmi *huawei = dev_get_drvdata(dev);
+ struct dentry *dent;
+
+ huawei->debug.root = debugfs_create_dir("huawei-wmi", NULL);
+ if (!huawei->debug.root) {
+ dev_err(dev, "Failed to create debugfs directory\n");
+ goto fail_debugfs;
+ }
+
+ dent = debugfs_create_x64("arg", S_IRUGO | S_IWUSR, huawei->debug.root,
+ &huawei->debug.arg);
+ if (!dent)
+ goto fail_debugfs;
+
+ dent = debugfs_create_file("call", S_IFREG | S_IRUSR,
+ huawei->debug.root, huawei, &huawei_wmi_debugfs_call_fops);
+ if (!dent)
+ goto fail_debugfs;
+
+ return 0;
+
+fail_debugfs:
+ huawei_wmi_debugfs_exit(dev);
+ return -ENOMEM;
+}
+
/* Input */

static void huawei_wmi_process_key(struct input_dev *idev, int code)
@@ -597,7 +708,12 @@ static int huawei_wmi_probe(struct platform_device *pdev)
err = huawei_wmi_leds_setup(&pdev->dev);
if (err)
dev_err(&pdev->dev, "Failed to setup leds\n");
+
+ err = huawei_wmi_debugfs_init(&pdev->dev);
+ if (err)
+ dev_err(&pdev->dev, "Failed to setup debugfs\n");
}
+
return 0;
}

@@ -610,6 +726,7 @@ 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_group(&pdev->dev.kobj, &huawei_wmi_group);
}

--
2.20.1