Re: [PATCH 2/3] usb: dwc3: qcom: Add multi-pd support

From: Felipe Balbi <balbi@kernel.org>
To: Sandeep Maheswaram <sanm@codeaurora.org>
Cc: Rob Herring <robh+dt@kernel.org>, Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Stephen Boyd <swboyd@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	Matthias Kaehlcke <mka@chromium.org>,
	devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	Pratham Pratap <prathampratap@codeaurora.org>
Subject: Re: [PATCH 2/3] usb: dwc3: qcom: Add multi-pd support
Date: Tue, 31 Aug 2021 08:34:56 +0300	[thread overview]
Message-ID: <87r1each0s.fsf@kernel.org> (raw)
In-Reply-To: <1630346073-7099-3-git-send-email-sanm@codeaurora.org>

Hi,

Sandeep Maheswaram <sanm@codeaurora.org> writes:
> Add multi pd support to set performance state for cx domain
> to maintain minimum corner voltage for USB clocks.
>
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 49 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 49 insertions(+)
>
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 9abbd01..777a647 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -17,6 +17,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/phy/phy.h>
> +#include <linux/pm_domain.h>
>  #include <linux/usb/of.h>
>  #include <linux/reset.h>
>  #include <linux/iopoll.h>
> @@ -89,6 +90,10 @@ struct dwc3_qcom {
>  	bool			pm_suspended;
>  	struct icc_path		*icc_path_ddr;
>  	struct icc_path		*icc_path_apps;
> +	/* power domain for cx */
> +	struct device		*pd_cx;
> +	/* power domain for usb gdsc */
> +	struct device		*pd_usb_gdsc;
>  };
>  
>  static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
> @@ -521,6 +526,46 @@ static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int dwc3_qcom_attach_pd(struct device *dev)
> +{
> +	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
> +	struct device_link *link;
> +
> +	/* Do nothing when in a single power domain */
> +	if (dev->pm_domain)
> +		return 0;
> +
> +	qcom->pd_cx = dev_pm_domain_attach_by_name(dev, "cx");
> +	if (IS_ERR(qcom->pd_cx))
> +		return PTR_ERR(qcom->pd_cx);
> +	/* Do nothing when power domain missing */
> +	if (!qcom->pd_cx)
> +		return 0;
> +	link = device_link_add(dev, qcom->pd_cx,
> +			DL_FLAG_STATELESS |
> +			DL_FLAG_PM_RUNTIME |
> +			DL_FLAG_RPM_ACTIVE);
> +	if (!link) {
> +		dev_err(dev, "Failed to add device_link to cx pd.\n");

do you need to call dev_pm_domain_dettach() here?

> +		return -EINVAL;
> +	}
> +
> +	qcom->pd_usb_gdsc = dev_pm_domain_attach_by_name(dev, "usb_gdsc");
> +	if (IS_ERR(qcom->pd_usb_gdsc))

do you need to call dev_pm_domain_dettach() here?

> +		return PTR_ERR(qcom->pd_usb_gdsc);
> +
> +	link = device_link_add(dev, qcom->pd_usb_gdsc,
> +			DL_FLAG_STATELESS |
> +			DL_FLAG_PM_RUNTIME |
> +			DL_FLAG_RPM_ACTIVE);
> +	if (!link) {
> +		dev_err(dev, "Failed to add device_link to usb gdsc pd.\n");

do you need to call dev_pm_domain_dettach() here?

-- 
balbi