[PATCH] wifi: mt76: mt7921: fix suspend issue on MediaTek COB platform

[Mingyen Hsieh]

From: Michael Lo <michael.lo at mediatek.com>

MediaTek's controller driver on COB platform (e.g. MT8188) is
capable of controlling power supplies and reset pin of a component
(e.g. a WIFI chip) in power-on and power-off process.

Due to this optional feature, mt76 need to inform controller
that mt76 need to keep power during suspend. Otherwise WIFI will be
powered off when system enters suspend process.

The "wakeup-source" property was used for the device that need
this to go into suspend mode so that mt76 suspend handler doesn't
fail and the system is able to enter into a suspend state.

An example:
wifi: mt7921 at 0 {
	wifi0{
		reg = <0x0000 0 0 0 0>;
		wakeup-source;
	};
};

Signed-off-by: Michael Lo <michael.lo at mediatek.com>
Signed-off-by: Ming Yen Hsieh <MingYen.Hsieh at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7921/pci.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index fabd24726f3e..e673a153d3cb 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -6,6 +6,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/of.h>
 
 #include "mt7921.h"
 #include "../mt76_connac2_mac.h"
@@ -369,6 +370,9 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		goto err_free_irq;
 
+	if (of_property_read_bool(dev->mt76.dev->of_node, "wakeup-source"))
+		device_init_wakeup(dev->mt76.dev, true);
+
 	return 0;
 
 err_free_irq:
@@ -386,6 +390,9 @@ static void mt7921_pci_remove(struct pci_dev *pdev)
 	struct mt76_dev *mdev = pci_get_drvdata(pdev);
 	struct mt792x_dev *dev = container_of(mdev, struct mt792x_dev, mt76);
 
+	if (of_property_read_bool(dev->mt76.dev->of_node, "wakeup-source"))
+		device_init_wakeup(dev->mt76.dev, false);
+
 	mt7921e_unregister_device(dev);
 	set_bit(MT76_REMOVED, &mdev->phy.state);
 	devm_free_irq(&pdev->dev, pdev->irq, dev);
-- 
2.18.0