ACPI: introduce ACPI int340x thermal scan handler

Newer laptops and tablets that use ACPI may have thermal sensors and
other devices with thermal control capabilities outside the core CPU/SOC,
for thermal safety reasons.
They are exposed for the OS to use via
1) INT3400 ACPI device object as the master.
2) INT3401 ~ INT340B ACPI device objects as the slaves.

This patch introduces a scan handler to enumerate the INT3400
ACPI device object to platform bus, and prevent its slaves
from being enumerated before the controller driver being probed.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/drivers/acpi/int340x_thermal.c b/drivers/acpi/int340x_thermal.c
new file mode 100644
index 000000000000..2103bb6d9016
--- /dev/null
+++ b/drivers/acpi/int340x_thermal.c
@@ -0,0 +1,51 @@
+/*
+ * ACPI support for int340x thermal drivers
+ *
+ * Copyright (C) 2014, Intel Corporation
+ * Authors: Zhang Rui <rui.zhang@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+#define DO_ENUMERATION 0x01
+static const struct acpi_device_id int340x_thermal_device_ids[] = {
+	{"INT3400", DO_ENUMERATION },
+	{"INT3401"},
+	{"INT3402"},
+	{"INT3403"},
+	{"INT3404"},
+	{"INT3406"},
+	{"INT3407"},
+	{"INT3408"},
+	{"INT3409"},
+	{"INT340A"},
+	{"INT340B"},
+	{""},
+};
+
+static int int340x_thermal_handler_attach(struct acpi_device *adev,
+					const struct acpi_device_id *id)
+{
+#ifdef CONFIG_INT340X_THERMAL
+	if (id->driver_data == DO_ENUMERATION)
+		acpi_create_platform_device(adev);
+#endif
+	return 1;
+}
+
+static struct acpi_scan_handler int340x_thermal_handler = {
+	.ids = int340x_thermal_device_ids,
+	.attach = int340x_thermal_handler_attach,
+};
+
+void __init acpi_int340x_thermal_init(void)
+{
+	acpi_scan_add_handler(&int340x_thermal_handler);
+}