[PATCH v6 12/22] ACPI: platform_profile: Add choices attribute for class interface

[Mario Limonciello <mario.limonciello@amd.com>]

The `choices` file will show all possible choices that a given platform
profile handler can support.

Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * Fix kdoc
 * Add tag
 * Fix whitespace
 * Adjust mutex use
---
 drivers/acpi/platform_profile.c | 44 +++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index 4e2eda18f7f5f..86d0eb7cc6fc3 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -25,6 +25,27 @@ static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
 
 static DEFINE_IDA(platform_profile_ida);
 
+/**
+ * _commmon_choices_show - Show the available profile choices
+ * @choices: The available profile choices
+ * @buf: The buffer to write to
+ * Return: The number of bytes written
+ */
+static ssize_t _commmon_choices_show(unsigned long *choices, char *buf)
+{
+	int i, len = 0;
+
+	for_each_set_bit(i, choices, PLATFORM_PROFILE_LAST) {
+		if (len == 0)
+			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
+		else
+			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
+	}
+	len += sysfs_emit_at(buf, len, "\n");
+
+	return len;
+}
+
 /**
  * name_show - Show the name of the profile handler
  * @dev: The device
@@ -44,9 +65,32 @@ static ssize_t name_show(struct device *dev,
 	return -ERESTARTSYS;
 }
 
+/**
+ * choices_show - Show the available profile choices
+ * @dev: The device
+ * @attr: The attribute
+ * @buf: The buffer to write to
+ */
+static ssize_t choices_show(struct device *dev,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	struct platform_profile_handler *handler;
+
+	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
+		handler = dev_get_drvdata(dev);
+		return _commmon_choices_show(handler->choices, buf);
+	}
+
+	return -ERESTARTSYS;
+}
+
 static DEVICE_ATTR_RO(name);
+static DEVICE_ATTR_RO(choices);
+
 static struct attribute *profile_attrs[] = {
 	&dev_attr_name.attr,
+	&dev_attr_choices.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(profile);
-- 
2.43.0