ACPI: thinkpad-acpi: preserve radio state across shutdown

Store in firmware NVRAM the radio state on machine shutdown for WWAN and
bluetooth.  Also, try to set the initial boot state of these radios as the
rfkill default state for their respective classes.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/thinkpad_acpi.c

@@ -222,6 +222,7 @@ struct ibm_struct {
 	void (*exit) (void);
 	void (*resume) (void);
 	void (*suspend) (pm_message_t state);
+	void (*shutdown) (void);
 
 	struct list_head all_drivers;
 
@@ -759,6 +760,18 @@ static int tpacpi_resume_handler(struct platform_device *pdev)
 	return 0;
 }
 
+static void tpacpi_shutdown_handler(struct platform_device *pdev)
+{
+	struct ibm_struct *ibm, *itmp;
+
+	list_for_each_entry_safe(ibm, itmp,
+				 &tpacpi_all_drivers,
+				 all_drivers) {
+		if (ibm->shutdown)
+			(ibm->shutdown)();
+	}
+}
+
 static struct platform_driver tpacpi_pdriver = {
 	.driver = {
 		.name = TPACPI_DRVR_NAME,
@@ -766,6 +779,7 @@ static struct platform_driver tpacpi_pdriver = {
 	},
 	.suspend = tpacpi_suspend_handler,
 	.resume = tpacpi_resume_handler,
+	.shutdown = tpacpi_shutdown_handler,
 };
 
 static struct platform_driver tpacpi_hwmon_pdriver = {
@@ -957,7 +971,22 @@ static int __init tpacpi_new_rfkill(const unsigned int id,
 			int (*get_state)(void *, enum rfkill_state *))
 {
 	int res;
-	enum rfkill_state initial_state;
+	enum rfkill_state initial_state = RFKILL_STATE_SOFT_BLOCKED;
+
+	res = get_state(NULL, &initial_state);
+	if (res < 0) {
+		printk(TPACPI_ERR
+			"failed to read initial state for %s, error %d; "
+			"will turn radio off\n", name, res);
+	} else {
+		/* try to set the initial state as the default for the rfkill
+		 * type, since we ask the firmware to preserve it across S5 in
+		 * NVRAM */
+		rfkill_set_default(rfktype,
+				(initial_state == RFKILL_STATE_UNBLOCKED) ?
+					RFKILL_STATE_UNBLOCKED :
+					RFKILL_STATE_SOFT_BLOCKED);
+	}
 
 	*rfk = rfkill_allocate(&tpacpi_pdev->dev, rfktype);
 	if (!*rfk) {
@@ -969,9 +998,7 @@ static int __init tpacpi_new_rfkill(const unsigned int id,
 	(*rfk)->name = name;
 	(*rfk)->get_state = get_state;
 	(*rfk)->toggle_radio = toggle_radio;
-
-	if (!get_state(NULL, &initial_state))
-		(*rfk)->state = initial_state;
+	(*rfk)->state = initial_state;
 
 	res = rfkill_register(*rfk);
 	if (res < 0) {
@@ -2943,8 +2970,19 @@ static int tpacpi_bluetooth_rfk_set(void *data, enum rfkill_state state)
 	return bluetooth_set_radiosw((state == RFKILL_STATE_UNBLOCKED), 0);
 }
 
+static void bluetooth_shutdown(void)
+{
+	/* Order firmware to save current state to NVRAM */
+	if (!acpi_evalf(NULL, NULL, "\\BLTH", "vd",
+			TP_ACPI_BLTH_SAVE_STATE))
+		printk(TPACPI_NOTICE
+			"failed to save bluetooth state to NVRAM\n");
+}
+
 static void bluetooth_exit(void)
 {
+	bluetooth_shutdown();
+
 	if (tpacpi_bluetooth_rfkill)
 		rfkill_unregister(tpacpi_bluetooth_rfkill);
 
@@ -3050,6 +3088,7 @@ static struct ibm_struct bluetooth_driver_data = {
 	.write = bluetooth_write,
 	.exit = bluetooth_exit,
 	.suspend = bluetooth_suspend,
+	.shutdown = bluetooth_shutdown,
 };
 
 /*************************************************************************
@@ -3207,8 +3246,19 @@ static int tpacpi_wan_rfk_set(void *data, enum rfkill_state state)
 	return wan_set_radiosw((state == RFKILL_STATE_UNBLOCKED), 0);
 }
 
+static void wan_shutdown(void)
+{
+	/* Order firmware to save current state to NVRAM */
+	if (!acpi_evalf(NULL, NULL, "\\WGSV", "vd",
+			TP_ACPI_WGSV_SAVE_STATE))
+		printk(TPACPI_NOTICE
+			"failed to save WWAN state to NVRAM\n");
+}
+
 static void wan_exit(void)
 {
+	wan_shutdown();
+
 	if (tpacpi_wan_rfkill)
 		rfkill_unregister(tpacpi_wan_rfkill);
 
@@ -3312,6 +3362,7 @@ static struct ibm_struct wan_driver_data = {
 	.write = wan_write,
 	.exit = wan_exit,
 	.suspend = wan_suspend,
+	.shutdown = wan_shutdown,
 };
 
 /*************************************************************************