Exynos5250 has external PLL (XusbXTI) for USB 3.0 PHY's
ref_pad_clk. So use this clock based on availability of
gpio to power control this PLL, otherwise use internal
clock only from XXTI.

Signed-off-by: Vivek Gautam <gautam.vi...@samsung.com>
---
 drivers/usb/phy/samsung-usb3phy.c |   14 ++++++++++----
 drivers/usb/phy/samsung-usbphy.c  |   26 ++++++++++++++++++++++++++
 drivers/usb/phy/samsung-usbphy.h  |    1 +
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/phy/samsung-usb3phy.c 
b/drivers/usb/phy/samsung-usb3phy.c
index 46dd97c..16b024e 100644
--- a/drivers/usb/phy/samsung-usb3phy.c
+++ b/drivers/usb/phy/samsung-usb3phy.c
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/gpio.h>
 #include <linux/pm_runtime.h>
 #include <linux/usb/samsung_usb_phy.h>
 #include <linux/platform_data/samsung-usbphy.h>
@@ -224,12 +225,17 @@ static int samsung_exynos5_usb3phy_init(struct usb_phy 
*phy, bool use_ext_clk)
  */
 static int samsung_usb3phy_init(struct usb_phy *phy)
 {
+       struct samsung_usbphy *sphy = phy_to_sphy(phy);
+
        /*
-        * We start with using PHY refclk from external PLL,
-        * once runtime suspend for the device is called this
-        * will change to internal core clock
+        * We check if we have a PHY ref_clk gpio available, then only
+        * use XusbXTI (external PLL); otherwise use internal core clock
+        * from XXTI.
         */
-       return samsung_exynos5_usb3phy_init(phy, true);
+       if (gpio_is_valid(sphy->phyclk_gpio))
+               return samsung_exynos5_usb3phy_init(phy, true);
+       else
+               return samsung_exynos5_usb3phy_init(phy, false);
 }
 
 /*
diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
index ab4fa11..6968d12 100644
--- a/drivers/usb/phy/samsung-usbphy.c
+++ b/drivers/usb/phy/samsung-usbphy.c
@@ -27,6 +27,7 @@
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_gpio.h>
 #include <linux/usb/samsung_usb_phy.h>
 
 #include "samsung-usbphy.h"
@@ -34,6 +35,7 @@
 int samsung_usbphy_parse_dt(struct samsung_usbphy *sphy)
 {
        struct device_node *usbphy_sys;
+       int ret;
 
        /* Getting node for system controller interface for usb-phy */
        usbphy_sys = of_get_child_by_name(sphy->dev->of_node, "usbphy-sys");
@@ -58,6 +60,30 @@ int samsung_usbphy_parse_dt(struct samsung_usbphy *sphy)
        if (sphy->sysreg == NULL)
                dev_warn(sphy->dev, "Can't get usb-phy sysreg cfg register\n");
 
+       /* Getting PHY clk gpio here to enable/disable PHY clock PLL, if any */
+       sphy->phyclk_gpio = of_get_named_gpio(sphy->dev->of_node,
+                                               "samsung,phyclk-gpio", 0);
+       /*
+        * We don't want to return error code here in case we don't get the
+        * PHY clock gpio, some PHYs may not have it.
+        */
+       if (gpio_is_valid(sphy->phyclk_gpio)) {
+               ret = gpio_request_one(sphy->phyclk_gpio, GPIOF_INIT_HIGH,
+                                               "samsung_usb_phy_clock_en");
+               if (ret) {
+                       /*
+                        * We don't want to return error code here,
+                        * sometimes either of usb2 phy or usb3 phy may not
+                        * have the PHY clock gpio.
+                        */
+                       dev_err(sphy->dev, "can't request phyclk gpio %d\n",
+                                               sphy->phyclk_gpio);
+                       sphy->phyclk_gpio = -EINVAL;
+               }
+       } else {
+               dev_warn(sphy->dev, "Can't get usb-phy clock gpio\n");
+       }
+
        of_node_put(usbphy_sys);
 
        return 0;
diff --git a/drivers/usb/phy/samsung-usbphy.h b/drivers/usb/phy/samsung-usbphy.h
index f7e657d..1921ab0 100644
--- a/drivers/usb/phy/samsung-usbphy.h
+++ b/drivers/usb/phy/samsung-usbphy.h
@@ -300,6 +300,7 @@ struct samsung_usbphy {
        enum samsung_usb_phy_type phy_type;
        atomic_t        phy_usage;
        spinlock_t      lock;
+       int             phyclk_gpio;
 };
 
 #define phy_to_sphy(x)         container_of((x), struct samsung_usbphy, phy)
-- 
1.7.6.5

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