[PATCH v4 11/13] phy: qcom: qmp-usbc: Add USB/DP mutex handling

[Dmitry Baryshkov]

On Thu, Sep 11, 2025 at 10:55:08PM +0800, Xiangxu Yin wrote:
> Introduce mutual exclusion between USB and DP PHY modes to prevent
> simultaneous activation.

Describe the problem that you are trying to solve first.

> 
> Signed-off-by: Xiangxu Yin <xiangxu.yin at oss.qualcomm.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-usbc.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> index 613239d15a6a3bba47a647db4e663713f127c93e..866277036089c588cf0c63204efb91bbec5430ae 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> @@ -1061,6 +1061,19 @@ static int qmp_usbc_usb_power_off(struct phy *phy)
>  	return 0;
>  }
>  
> +static int qmp_check_mutex_phy(struct qmp_usbc *qmp, bool is_dp)

mutex has a very well defined use case - a sleeping lock. Please find
some ofther name.

> +{
> +	if ((is_dp && qmp->usb_init_count) ||
> +	    (!is_dp && qmp->dp_init_count)) {
> +		dev_err(qmp->dev,
> +			"PHY is configured for %s, can not enable %s\n",
> +			is_dp ? "USB" : "DP", is_dp ? "DP" : "USB");
> +		return -EBUSY;
> +	}
> +
> +	return 0;
> +}
> +
>  static int qmp_usbc_usb_enable(struct phy *phy)
>  {
>  	struct qmp_usbc *qmp = phy_get_drvdata(phy);

-- 
With best wishes
Dmitry