[PATCH v7 3/8] Bluetooth: hci_qca: Set 'bt_en_available' based on pwrseq power controllability

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

A Bluetooth device only needs the non-persistent setup if the host can
gate its power, so that it is actually reset on the next power-on. When the
power is controlled by a power sequencer, whether the host can gate it
depends on the hardware wiring, e.g. the presence of the BT_EN or
W_DISABLE2# line.

Query the generic pwrseq_is_controllable() helper whenever the BT power
comes from a sequencer, regardless of which provider it is (M2, WCN, ...).
If the power is not controllable, clear 'bt_en_available' so that
HCI_QUIRK_NON_PERSISTENT_SETUP is not set.

This is based on Manivannan's original patch that keyed the decision off
the W_DISABLE2# device tree property, it now uses the generic pwrseq helper
and handles the always-on case.

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/bluetooth/hci_qca.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index f53f95601693dcd8356b4b825776317061050f1b..20d8c5e890a8903a07c3e7e37d037c44d383e8df 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -2557,7 +2557,20 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 			return PTR_ERR(qcadev->susclk);
 		}
 	}
-	
+
+	if (qcadev->bt_power->pwrseq) {
+		bt_en_available = pwrseq_is_controllable(qcadev->bt_power->pwrseq);
+		if (!bt_en_available) {
+			/* The host cannot gate the BT power individually.
+			 * Treat it as always-on and drop the pwrseq handle.
+			 * The descriptor itself is still released by devres,
+			 * so dropping the handle here is not a leak.
+			 */
+			pwrseq_power_on(qcadev->bt_power->pwrseq);
+			qcadev->bt_power->pwrseq = NULL;
+		}
+	}
+
 	err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
 	if (err) {
 		BT_ERR("serdev registration failed");

-- 
2.34.1