[PATCH V6 3/4] Bluetooth: btnxpuart: Add M.2 Bluetooth device support using pwrseq

[Manivannan Sadhasivam]

On Mon, Jul 13, 2026 at 10:34:34AM +0800, Sherry Sun (OSS) wrote:
> From: Sherry Sun <sherry.sun at nxp.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, pwrseq_power_on() is called to power up the M.2 Bluetooth
> card. The power sequencer descriptor is obtained via pwrseq_get() with
> the UART controller device (serdev->ctrl->dev), since the OF graph
> link is defined on the UART controller node.
> 
> Also add the explicit pwrseq_put() call in all exit paths, pwrseq_put()
> already calls pwrseq_power_off() internally, so no separate
> pwrseq_power_off() call is needed.
> 
> Signed-off-by: Sherry Sun <sherry.sun at nxp.com>

Reviewed-by: Manivannan Sadhasivam <mani at kernel.org>

- Mani

> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski at oss.qualcomm.com>
> Reviewed-by: Frank Li <Frank.Li at nxp.com>
> ---
> Hi Frank and Bartosz, this V6 patch using pwrseq_put() in all exit paths to
> fix the power sequencer reference leak issue during BT driver unload and
> reload as reported by sashiko. I'm keeping your Reviewed-by tag. I can
> remove it if you think it's inappropriate.
> ---
>  drivers/bluetooth/btnxpuart.c | 34 ++++++++++++++++++++++++++++++----
>  1 file changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index 0bb300eef157..81a11ac05114 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;
>  };
> @@ -1872,11 +1875,26 @@ 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 = pwrseq_get(&serdev->ctrl->dev, "uart");
> +		if (IS_ERR(pwrseq))
> +			return dev_err_probe(&serdev->dev, PTR_ERR(pwrseq),
> +					     "failed to get pwrseq\n");
> +
> +		nxpdev->pwrseq = pwrseq;
> +		err = pwrseq_power_on(pwrseq);
> +		if (err)
> +			goto err_pwrseq_put;
> +	}
> +
>  	/* 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_put;
>  	}
>  
>  	reset_control_deassert(nxpdev->pdn);
> @@ -1907,13 +1925,16 @@ static int nxp_serdev_probe(struct serdev_device *serdev)
>  	if (bacmp(&ba, BDADDR_ANY))
>  		hci_set_quirk(hdev, HCI_QUIRK_USE_BDADDR_PROPERTY);
>  
> -	if (hci_register_dev(hdev) < 0) {
> +	err = hci_register_dev(hdev);
> +	if (err < 0) {
>  		dev_err(&serdev->dev, "Can't register HCI device\n");
>  		goto probe_fail;
>  	}
>  
> -	if (ps_setup(hdev))
> +	if (ps_setup(hdev)) {
> +		err = -ENODEV;
>  		goto probe_fail_unregister;
> +	}
>  
>  	hci_devcd_register(hdev, nxp_coredump, nxp_coredump_hdr,
>  			   nxp_coredump_notify);
> @@ -1925,7 +1946,10 @@ static int nxp_serdev_probe(struct serdev_device *serdev)
>  probe_fail:
>  	reset_control_assert(nxpdev->pdn);
>  	hci_free_dev(hdev);
> -	return -ENODEV;
> +err_pwrseq_put:
> +	if (nxpdev->pwrseq)
> +		pwrseq_put(nxpdev->pwrseq);
> +	return err;
>  }
>  
>  static void nxp_serdev_remove(struct serdev_device *serdev)
> @@ -1952,6 +1976,8 @@ 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_put(nxpdev->pwrseq);
>  	hci_free_dev(hdev);
>  }
>  
> -- 
> 2.50.1
> 

-- 
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