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From:   Sandeep Maheswaram <sanm@codeaurora.org>
To:     Rob Herring <robh+dt@kernel.org>, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Felipe Balbi <balbi@kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Doug Anderson <dianders@chromium.org>,
        Matthias Kaehlcke <mka@chromium.org>
Cc:     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>,
        Sandeep Maheswaram <sanm@codeaurora.org>
Subject: [PATCH 2/3] usb: dwc3: qcom: Add multi-pd support
Date:   Mon, 30 Aug 2021 23:24:32 +0530
Message-Id: <1630346073-7099-3-git-send-email-sanm@codeaurora.org>
In-Reply-To: <1630346073-7099-1-git-send-email-sanm@codeaurora.org>
References: <1630346073-7099-1-git-send-email-sanm@codeaurora.org>
Precedence: bulk

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");
+		return -EINVAL;
+	}
+
+	qcom->pd_usb_gdsc = dev_pm_domain_attach_by_name(dev, "usb_gdsc");
+	if (IS_ERR(qcom->pd_usb_gdsc))
+		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");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
 {
 	struct device		*dev = qcom->dev;
@@ -837,6 +882,10 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 	if (ret)
 		goto interconnect_exit;
 
+	ret = dwc3_qcom_attach_pd(dev);
+	if (ret)
+		goto interconnect_exit;
+
 	device_init_wakeup(&pdev->dev, 1);
 	qcom->is_suspended = false;
 	pm_runtime_set_active(dev);
-- 
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