Re: [PATCH 2/5] phy: qcom: qmp-pcie: Add multiple power-domains support

[Dmitry Baryshkov]

On Wed, Mar 04, 2026 at 12:21:56AM -0800, Qiang Yu wrote:
> The Glymur SoC's 3rd PCIe instance supports 8-lane mode using two PHYs in
> a bifurcated configuration. Each PHY has its own power domain (phy_gdsc)
> that must be powered on before initialization per hardware requirements.
> 
> Current PHY power management assumes a single power domain per PHY,
> preventing proper setup for this dual-PHY scenario. Add support for
> multiple power domains by using devm_pm_domain_attach_list() to attach
> power domains manually, while maintaining compatibility with single
> power domain PHYs.
> 
> Enable runtime PM to allow power domain control when the PCIe driver
> calls phy_power_on/phy_power_off:
> 
> - Single power domain: QMP PHY platform device directly attaches to
>   power domain and controls it during runtime resume/suspend
> - Multiple power domains: devm_pm_domain_attach_list() creates virtual
>   devices as power domain suppliers, linked to the QMP PHY platform
>   device as consumer
> 
> This ensures power domains are properly attached and turned on/off
> for both single and multiple power domain configurations.
> 
> Signed-off-by: Qiang Yu <qiang.yu@xxxxxxxxxxxxxxxx>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index fed2fc9bb31108d51f88d34f3379c7744681f485..7369c291be51aa1ad7a330459dcb857f5a1988f6 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -17,6 +17,7 @@
>  #include <linux/phy/pcie.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/reset.h>
> @@ -3334,6 +3335,8 @@ struct qmp_pcie {
>  
>  	struct clk_fixed_rate pipe_clk_fixed;
>  	struct clk_fixed_rate aux_clk_fixed;
> +
> +	struct dev_pm_domain_list *pd_list;
>  };
>  
>  static bool qphy_checkbits(const void __iomem *base, u32 offset, u32 val)
> @@ -5348,6 +5351,16 @@ static int qmp_pcie_probe(struct platform_device *pdev)
>  	WARN_ON_ONCE(!qmp->cfg->pwrdn_ctrl);
>  	WARN_ON_ONCE(!qmp->cfg->phy_status);
>  
> +	ret = devm_pm_domain_attach_list(dev, NULL, &qmp->pd_list);
> +	if (ret < 0 && ret != -EEXIST) {
> +		dev_err(dev, "Failed to attach power domain\n");
> +		return ret;
> +	}
> +
> +	ret = devm_pm_runtime_enable(dev);
> +	if (ret)
> +		return ret;

These two should be separate commits.

> +
>  	ret = qmp_pcie_clk_init(qmp);
>  	if (ret)
>  		return ret;
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry