From cd84f009e98b3aa6109503f80f66ccf3e19e8fa9 Mon Sep 17 00:00:00 2001
From: Peter Chen <peter.chen@freescale.com>
Date: Thu, 24 Apr 2014 08:15:27 +0800
Subject: [PATCH] usb: chipidea: coordinate usb phy initialization for
 different phy type

For internal PHY (like UTMI), the phy clock may from internal pll,
it is on/off on the fly, the access PORTSC.PTS will hang without
phy clock. So, the usb_phy_init which will open phy clock needs to
be called before hw_phymode_configure.
See: http://marc.info/?l=linux-arm-kernel&m=139350618732108&w=2

For external PHY (like ulpi), it needs to configure portsc.pts before
visit viewport, or the viewport can't be visited. so phy_phymode_configure
needs to be called before usb_phy_init.
See: cd0b42c2a6d2a74244f0053f8960f5dad5842278

It may not the best solution, but it can work for all situations.

Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Cc: shc_work@mail.ru
Cc: denis@eukrea.com
Cc: festevam@gmail.com
Cc: stable <stable@vger.kernel.org> # 3.14
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/chipidea/core.c | 37 ++++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index ca6831c5b7630..1cd5d0ba587c8 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -276,6 +276,39 @@ static void hw_phymode_configure(struct ci_hdrc *ci)
 	}
 }
 
+/**
+ * ci_usb_phy_init: initialize phy according to different phy type
+ * @ci: the controller
+  *
+ * This function returns an error code if usb_phy_init has failed
+ */
+static int ci_usb_phy_init(struct ci_hdrc *ci)
+{
+	int ret;
+
+	switch (ci->platdata->phy_mode) {
+	case USBPHY_INTERFACE_MODE_UTMI:
+	case USBPHY_INTERFACE_MODE_UTMIW:
+	case USBPHY_INTERFACE_MODE_HSIC:
+		ret = usb_phy_init(ci->transceiver);
+		if (ret)
+			return ret;
+		hw_phymode_configure(ci);
+		break;
+	case USBPHY_INTERFACE_MODE_ULPI:
+	case USBPHY_INTERFACE_MODE_SERIAL:
+		hw_phymode_configure(ci);
+		ret = usb_phy_init(ci->transceiver);
+		if (ret)
+			return ret;
+		break;
+	default:
+		ret = usb_phy_init(ci->transceiver);
+	}
+
+	return ret;
+}
+
 /**
  * hw_device_reset: resets chip (execute without interruption)
  * @ci: the controller
@@ -543,8 +576,6 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	hw_phymode_configure(ci);
-
 	if (ci->platdata->phy)
 		ci->transceiver = ci->platdata->phy;
 	else
@@ -564,7 +595,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		return -EPROBE_DEFER;
 	}
 
-	ret = usb_phy_init(ci->transceiver);
+	ret = ci_usb_phy_init(ci);
 	if (ret) {
 		dev_err(dev, "unable to init phy: %d\n", ret);
 		return ret;
-- 
GitLab