Re: [PATCH v7 5/8] Bluetooth: hci_qca: Support QCA2066 on M.2 connector via pwrseq

[Val Packett <val@packett.cool>]

On 10/5/26 9:21 AM, Loic Poulain wrote:
> For QCA2066 (and other QCA chips) on M.2 connectors, the UART enable is
> controlled by the W_DISABLE2# signal managed by the pcie-m2 power sequencer
> rather than a dedicated BT enable GPIO.
>
> When the serdev controller has an OF graph (indicating it is connected to
> an M.2 connector), acquire the 'uart' pwrseq target from the connector's
> power sequencer and use it to control BT power instead of the bt-enable
> GPIO. This is factored out into qca_serdev_get_m2_pwrseq().
>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
> ---
>   drivers/bluetooth/hci_qca.c | 47 +++++++++++++++++++++++++++++++++++----------
>   1 file changed, 37 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index 1d27ff98034ba99d0783e48db5c605f3b31117ea..b6ec1a57248e2cf4bd138898ffc5cad45b1b4a8b 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1875,6 +1875,9 @@ static int qca_power_on(struct hci_dev *hdev)
>   			/* Controller needs time to bootup. */
>   			msleep(150);
>   		}
> +
> +		if (qcadev->bt_power.pwrseq)
> +			pwrseq_power_on(qcadev->bt_power.pwrseq);
>   	}
>   
>   	clear_bit(QCA_BT_OFF, &qca->flags);
> @@ -2396,6 +2399,34 @@ static int qca_init_regulators(struct qca_power *qca,
>   	return 0;
>   }
>   
> +static void qca_serdev_put_pwrseq(void *data)
> +{
> +	pwrseq_put(data);
> +}
> +
> +static int qca_serdev_get_m2_pwrseq(struct qca_serdev *qcadev)
> +{
> +	struct serdev_device *serdev = qcadev->serdev_hu.serdev;
> +	struct pwrseq_desc *pwrseq;
> +
> +	if (!of_graph_is_present(dev_of_node(&serdev->ctrl->dev)))
> +		return 0;
Seems like of_graph_is_present does *not* return false for the existing 
(non-connector) setup which is currently used in all the laptop device 
trees..
> +
> +	/* The pwrseq is looked up on the serdev controller (which holds the
> +	 * OF graph to the M.2 connector), but its lifetime must follow this
> +	 * serdev consumer device, not the controller. So acquire it with the
> +	 * non-devres pwrseq_get() and release it via a devres action bound to
> +	 * &serdev->dev instead of using devm_pwrseq_get(&serdev->ctrl->dev).
> +	 */
> +	pwrseq = pwrseq_get(&serdev->ctrl->dev, "uart");
> +	if (IS_ERR(pwrseq))
> +		return PTR_ERR(pwrseq);
> [..]

So this returns EPROBE_DEFER and bluetooth gets deferred forever :(

~val