ACPI: thinkpad-acpi: add sysfs support to hotkey subdriver

Add the hotkey sysfs support.

Signed-off-by: Henrique de Moraes Holschuh <[e-mail]>
Signed-off-by: Len Brown <[e-mail]>

Documentation/thinkpad-acpi.txt

···
 subsystems are not documented here, nor are they tracked by this
 attribute.
 
-Hot keys -- /proc/acpi/ibm/hotkey
----------------------------------
+Hot keys
+--------
+
+procfs: /proc/acpi/ibm/hotkey
+sysfs device attribute: hotkey/*
 
 Without this driver, only the Fn-F4 key (sleep button) generates an
 ACPI event. With the driver loaded, the hotkey feature enabled and the
···
 All labeled Fn-Fx key combinations generate distinct events. In
 addition, the lid microswitch and some docking station buttons may
 also generate such events.
-
-The following commands can be written to this file:
-
-	echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
-	echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
-	echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys
-	echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
-	... any other 4-hex-digit mask ...
-	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
 
 The bit mask allows some control over which hot keys generate ACPI
 events. Not all bits in the mask can be modified. Not all bits that
···
 buttons do not generate ACPI events even with this driver. They *can*
 be used through the "ThinkPad Buttons" utility, see
 http://www.nongnu.org/tpb/
+
+procfs notes:
+
+The following commands can be written to the /proc/acpi/ibm/hotkey file:
+
+	echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
+	echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
+	echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys
+	echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
+	... any other 4-hex-digit mask ...
+	echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
+
+sysfs notes:
+
+	The hot keys attributes are in a hotkey/ subdirectory off the
+	thinkpad device.
+
+	bios_enabled:
+		Returns the status of the hot keys feature when
+		thinkpad-acpi was loaded.  Upon module unload, the hot
+		key feature status will be restored to this value.
+
+		0: hot keys were disabled
+		1: hot keys were enabled
+
+	bios_mask:
+		Returns the hot keys mask when thinkpad-acpi was loaded.
+		Upon module unload, the hot keys mask will be restored
+		to this value.
+
+	enable:
+		Enables/disables the hot keys feature, and reports
+		current status of the hot keys feature.
+
+		0: disables the hot keys feature / feature disabled
+		1: enables the hot keys feature / feature enabled
+
+	mask:
+		bit mask to enable ACPI event generation for each hot
+		key (see above).  Returns the current status of the hot
+		keys mask, and allows one to modify it.
+
 
 Bluetooth -- /proc/acpi/ibm/bluetooth
 -------------------------------------

drivers/misc/thinkpad_acpi.c

···
 static int hotkey_orig_status;
 static int hotkey_orig_mask;
 
+static struct attribute_set *hotkey_dev_attributes = NULL;
+
+/* sysfs hotkey enable ------------------------------------------------- */
+static ssize_t hotkey_enable_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	int res, status, mask;
+
+	res = hotkey_get(&status, &mask);
+	if (res)
+		return res;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t hotkey_enable_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	unsigned long t;
+	int res, status, mask;
+
+	if (parse_strtoul(buf, 1, &t))
+		return -EINVAL;
+
+	res = hotkey_get(&status, &mask);
+	if (!res)
+		res = hotkey_set(t, mask);
+
+	return (res) ? res : count;
+}
+
+static struct device_attribute dev_attr_hotkey_enable =
+	__ATTR(enable, S_IWUSR | S_IRUGO,
+		hotkey_enable_show, hotkey_enable_store);
+
+/* sysfs hotkey mask --------------------------------------------------- */
+static ssize_t hotkey_mask_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	int res, status, mask;
+
+	res = hotkey_get(&status, &mask);
+	if (res)
+		return res;
+
+	return snprintf(buf, PAGE_SIZE, "0x%04x\n", mask);
+}
+
+static ssize_t hotkey_mask_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	unsigned long t;
+	int res, status, mask;
+
+	if (parse_strtoul(buf, 0xffff, &t))
+		return -EINVAL;
+
+	res = hotkey_get(&status, &mask);
+	if (!res)
+		hotkey_set(status, t);
+
+	return (res) ? res : count;
+}
+
+static struct device_attribute dev_attr_hotkey_mask =
+	__ATTR(mask, S_IWUSR | S_IRUGO,
+		hotkey_mask_show, hotkey_mask_store);
+
+/* sysfs hotkey bios_enabled ------------------------------------------- */
+static ssize_t hotkey_bios_enabled_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n", hotkey_orig_status);
+}
+
+static struct device_attribute dev_attr_hotkey_bios_enabled =
+	__ATTR(bios_enabled, S_IRUGO, hotkey_bios_enabled_show, NULL);
+
+/* sysfs hotkey bios_mask ---------------------------------------------- */
+static ssize_t hotkey_bios_mask_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "0x%04x\n", hotkey_orig_mask);
+}
+
+static struct device_attribute dev_attr_hotkey_bios_mask =
+	__ATTR(bios_mask, S_IRUGO, hotkey_bios_mask_show, NULL);
+
+/* --------------------------------------------------------------------- */
+
+static struct attribute *hotkey_mask_attributes[] = {
+	&dev_attr_hotkey_mask.attr,
+	&dev_attr_hotkey_bios_enabled.attr,
+	&dev_attr_hotkey_bios_mask.attr,
+};
+
 static int __init hotkey_init(struct ibm_init_struct *iibm)
 {
 	int res;
···
 		str_supported(tp_features.hotkey));
 
 	if (tp_features.hotkey) {
+		hotkey_dev_attributes = create_attr_set(4,
+						TPACPI_HOTKEY_SYSFS_GROUP);
+		if (!hotkey_dev_attributes)
+			return -ENOMEM;
+		res = add_to_attr_set(hotkey_dev_attributes,
+				&dev_attr_hotkey_enable.attr);
+		if (res)
+			return res;
+
 		/* mask not supported on 570, 600e/x, 770e, 770x, A21e, A2xm/p,
 		   A30, R30, R31, T20-22, X20-21, X22-24 */
 		tp_features.hotkey_mask =
···
 			str_supported(tp_features.hotkey_mask));
 
 		res = hotkey_get(&hotkey_orig_status, &hotkey_orig_mask);
+		if (!res && tp_features.hotkey_mask) {
+			res = add_many_to_attr_set(hotkey_dev_attributes,
+				hotkey_mask_attributes,
+				ARRAY_SIZE(hotkey_mask_attributes));
+		}
+		if (!res)
+			res = register_attr_set_with_sysfs(
+					hotkey_dev_attributes,
+					&tpacpi_pdev->dev.kobj);
+
 		if (res)
 			return res;
 	}
···
 		res = hotkey_set(hotkey_orig_status, hotkey_orig_mask);
 		if (res)
 			printk(IBM_ERR "failed to restore hotkey to BIOS defaults\n");
+	}
+
+	if (hotkey_dev_attributes) {
+		delete_attr_set(hotkey_dev_attributes, &tpacpi_pdev->dev.kobj);
+		hotkey_dev_attributes = NULL;
 	}
 }
 
···
 	return 0;
 }
 
+/* procfs -------------------------------------------------------------- */
 static int hotkey_read(char *p)
 {
 	int res, status, mask;

drivers/misc/thinkpad_acpi.h

···
  * Hotkey subdriver
  */
 
+#define TPACPI_HOTKEY_SYSFS_GROUP "hotkey"
+
 static int hotkey_orig_status;
 static int hotkey_orig_mask;