Re: [PATCH 3/8] Bluetooth: btnxpuart: Add M.2 Bluetooth device support using pwrseq

[Frank Li]

On Thu, Jun 18, 2026 at 06:10:42PM +0800, Sherry Sun (OSS) wrote:
> From: Sherry Sun <sherry.sun@xxxxxxx>
>
> 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.
>
> Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
> ---
>  drivers/bluetooth/btnxpuart.c | 33 ++++++++++++++++++++++++++++++---
>  1 file changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index e7036a48ce48..1aa8972f0dab 100644
> --- a/drivers/bluetooth/btnxpuart.c
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -9,6 +9,8 @@
>
>  #include <linux/serdev.h>
>  #include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/pwrseq/consumer.h>
>  #include <linux/skbuff.h>
>  #include <linux/unaligned.h>
>  #include <linux/firmware.h>
> @@ -211,6 +213,7 @@ struct btnxpuart_dev {
>
>  	struct ps_data psdata;
>  	struct btnxpuart_data *nxp_data;
> +	struct pwrseq_desc *pwrseq;
>  	struct reset_control *pdn;
>  	struct hci_uart hu;
>  };
> @@ -1866,11 +1869,27 @@ static int nxp_serdev_probe(struct serdev_device *serdev)
>  		return err;
>  	}
>
> +	if (of_graph_is_present(dev_of_node(&serdev->ctrl->dev))) {
> +		struct pwrseq_desc *pwrseq;
> +
> +		pwrseq = devm_pwrseq_get(&serdev->ctrl->dev, "uart");
> +		if (IS_ERR(pwrseq))
> +			return PTR_ERR(pwrseq);
> +
> +		nxpdev->pwrseq = pwrseq;
> +		err = pwrseq_power_on(pwrseq);
> +		if (err) {
> +			dev_err(&serdev->dev, "Failed to power on pwrseq\n");
> +			return err;
> +		}

Can you provide helper function like devm clk get and enabled?
like devm_pwrsq_get_on()

So simple below error handle.

Frank

> +	}
> +
>  	/* Initialize and register HCI device */
>  	hdev = hci_alloc_dev();
>  	if (!hdev) {
>  		dev_err(&serdev->dev, "Can't allocate HCI device\n");
> -		return -ENOMEM;
> +		err = -ENOMEM;
> +		goto err_pwrseq_power_off;
>  	}
>
>  	reset_control_deassert(nxpdev->pdn);
> @@ -1903,11 +1922,14 @@ static int nxp_serdev_probe(struct serdev_device *serdev)
>
>  	if (hci_register_dev(hdev) < 0) {
>  		dev_err(&serdev->dev, "Can't register HCI device\n");
> +		err = -ENODEV;
>  		goto probe_fail;
>  	}
>
> -	if (ps_setup(hdev))
> +	if (ps_setup(hdev)) {
> +		err = -ENODEV;
>  		goto probe_fail;
> +	}
>
>  	hci_devcd_register(hdev, nxp_coredump, nxp_coredump_hdr,
>  			   nxp_coredump_notify);
> @@ -1917,7 +1939,10 @@ static int nxp_serdev_probe(struct serdev_device *serdev)
>  probe_fail:
>  	reset_control_assert(nxpdev->pdn);
>  	hci_free_dev(hdev);
> -	return -ENODEV;
> +err_pwrseq_power_off:
> +	if (nxpdev->pwrseq)
> +		pwrseq_power_off(nxpdev->pwrseq);
> +	return err;
>  }
>
>  static void nxp_serdev_remove(struct serdev_device *serdev)
> @@ -1944,6 +1969,8 @@ static void nxp_serdev_remove(struct serdev_device *serdev)
>  	ps_cleanup(nxpdev);
>  	hci_unregister_dev(hdev);
>  	reset_control_assert(nxpdev->pdn);
> +	if (nxpdev->pwrseq)
> +		pwrseq_power_off(nxpdev->pwrseq);
>  	hci_free_dev(hdev);
>  }
>
> --
> 2.50.1
>
>