linux-kernel - [PATCH v7 1/2] usb: host: xhci-plat: Get PHYs for xhci's hcds

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Date:	Fri, 31 Oct 2014 18:56:28 +0530
From:	Vivek Gautam <gautam.vivek@...sung.com>
To:	linux-usb@...r.kernel.org
Cc:	linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, gregkh@...uxfoundation.org,
	kishon@...com, balbi@...com, stern@...land.harvard.edu,
	kgene.kim@...sung.com, heikki.krogerus@...ux.intel.com,
	mathias.nyman@...el.com, sergei.shtylyov@...entembedded.com,
	jwerner@...gle.com, jg1.han@...sung.com,
	Vivek Gautam <gautam.vivek@...sung.com>
Subject: [PATCH v7 1/2] usb: host: xhci-plat: Get PHYs for xhci's hcds

The host controller by itself may sometimes need to handle PHY
and re-initialize it to re-configure some of the PHY parameters
to get full support out of the PHY controller.
Therefore, facilitate getting the two possible PHYs, viz.
USB 2.0 type (UTMI+) and USB 3.0 type (PIPE3), and initialize them.

Signed-off-by: Vivek Gautam <gautam.vivek@...sung.com>
---
 drivers/usb/host/xhci-plat.c |   74 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 3d78b0c..5207d5b 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/phy/phy.h>
 #include <linux/slab.h>
 #include <linux/usb/xhci_pdriver.h>
 
@@ -129,10 +130,41 @@ static int xhci_plat_probe(struct platform_device *pdev)
 			goto put_hcd;
 	}
 
+	/* Get possile USB 2.0 type PHY (UTMI+) available with xhci */
+	hcd->phy = devm_phy_get(&pdev->dev, "usb2-phy");
+	if (IS_ERR(hcd->phy)) {
+		ret = PTR_ERR(hcd->phy);
+		if (ret == -EPROBE_DEFER) {
+			goto disable_clk;
+		} else if (ret != -ENOSYS && ret != -ENODEV) {
+			hcd->phy = NULL;
+			dev_warn(&pdev->dev,
+				 "Error retrieving usb2 phy: %d\n", ret);
+		}
+	}
+
 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (ret)
 		goto disable_clk;
 
+	/*
+	 * Initialize and power-on USB 2.0 PHY
+	 * FIXME: Isn't this a hacky way of initializing the PHY again ?
+	 * xhci's parent would have already initialized the PHY, but we
+	 * wanna do it again.
+	 */
+	hcd->phy->init_count = 0;
+	ret = phy_init(hcd->phy);
+	if (ret)
+		goto dealloc_usb2_hcd;
+
+	hcd->phy->power_count = 0;
+	ret = phy_power_on(hcd->phy);
+	if (ret) {
+		phy_exit(hcd->phy);
+		goto dealloc_usb2_hcd;
+	}
+
 	device_wakeup_enable(hcd->self.controller);
 
 	/* USB 2.0 roothub is stored in the platform_device now. */
@@ -158,12 +190,41 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
 		xhci->shared_hcd->can_do_streams = 1;
 
+	/* Get possile USB 3.0 type PHY (PIPE3) available with xhci */
+	xhci->shared_hcd->phy = devm_phy_get(&pdev->dev, "usb3-phy");
+	if (IS_ERR(xhci->shared_hcd->phy)) {
+		ret = PTR_ERR(xhci->shared_hcd->phy);
+		if (ret == -EPROBE_DEFER) {
+			goto put_usb3_hcd;
+		} else if (ret != -ENOSYS && ret != -ENODEV) {
+			xhci->shared_hcd->phy = NULL;
+			dev_warn(&pdev->dev,
+				 "Error retrieving usb3 phy: %d\n", ret);
+		}
+	}
+
 	ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
 	if (ret)
 		goto put_usb3_hcd;
 
+	/* Initialize and power-on USB 3.0 PHY */
+	xhci->shared_hcd->phy->init_count = 0;
+	ret = phy_init(xhci->shared_hcd->phy);
+	if (ret)
+		goto dealloc_usb3_hcd;
+
+	xhci->shared_hcd->phy->power_count = 0;
+	ret = phy_power_on(xhci->shared_hcd->phy);
+	if (ret) {
+		phy_exit(xhci->shared_hcd->phy);
+		goto dealloc_usb3_hcd;
+	}
+
 	return 0;
 
+dealloc_usb3_hcd:
+	usb_remove_hcd(xhci->shared_hcd);
+
 put_usb3_hcd:
 	usb_put_hcd(xhci->shared_hcd);
 
@@ -186,9 +247,15 @@ static int xhci_plat_remove(struct platform_device *dev)
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 	struct clk *clk = xhci->clk;
 
+	phy_power_off(xhci->shared_hcd->phy);
+	phy_exit(xhci->shared_hcd->phy);
+
 	usb_remove_hcd(xhci->shared_hcd);
 	usb_put_hcd(xhci->shared_hcd);
 
+	phy_power_off(hcd->phy);
+	phy_exit(hcd->phy);
+
 	usb_remove_hcd(hcd);
 	if (!IS_ERR(clk))
 		clk_disable_unprepare(clk);
@@ -204,6 +271,8 @@ static int xhci_plat_suspend(struct device *dev)
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 
+	phy_exit(hcd->phy);
+
 	return xhci_suspend(xhci);
 }
 
@@ -211,6 +280,11 @@ static int xhci_plat_resume(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+	int ret;
+
+	ret = phy_init(hcd->phy);
+	if (ret)
+		return ret;
 
 	return xhci_resume(xhci, 0);
 }
-- 
1.7.10.4

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