[PATCH v6 01/11] Bluetooth: hci_qca: Add M.2 Bluetooth device support using pwrseq

[Loic Poulain <loic.poulain@oss.qualcomm.com>]

From: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Power supply to the M.2 Bluetooth device attached to the host using M.2
connector is controlled using the 'uart' pwrseq device. So add support for
getting the pwrseq device if the OF graph link is present. Once obtained,
the existing pwrseq APIs can be used to control the power supplies of the
M.2 card.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Tested-by: Wei Deng <wei.deng@oss.qualcomm.com>
---
 drivers/bluetooth/hci_qca.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index faa964735adb17a05f2a8fac16f553b37b96020b..c8ea5507bdc2c83f214e3154b5ad6d05f418a1d4 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -25,6 +25,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/acpi.h>
 #include <linux/platform_device.h>
 #include <linux/pwrseq/consumer.h>
@@ -2448,6 +2449,18 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 	case QCA_WCN6750:
 	case QCA_WCN6855:
 	case QCA_WCN7850:
+		/*
+		 * OF graph link is only present for BT devices attached through
+		 * the M.2 Key E connector.
+		 */
+		if (of_graph_is_present(dev_of_node(&serdev->ctrl->dev))) {
+			qcadev->bt_power->pwrseq = devm_pwrseq_get(&serdev->ctrl->dev,
+								   "uart");
+			if (IS_ERR(qcadev->bt_power->pwrseq))
+				return PTR_ERR(qcadev->bt_power->pwrseq);
+			break;
+		}
+
 		if (!device_property_present(&serdev->dev, "enable-gpios")) {
 			/*
 			 * Backward compatibility with old DT sources. If the

-- 
2.34.1