phy: exynos-usb2: add vbus regulator support

Exynos USB2 PHY has separate power supply, which is usually provided by
VBUS regulator. This patch adds support for it. VBUS regulator is
optional, to keep compatibility with boards, which have VBUS provided
from some always-on power source.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/phy/phy-samsung-usb2.c b/drivers/phy/phy-samsung-usb2.c
index f278a9c547e1..1d22d93b552d 100644
--- a/drivers/phy/phy-samsung-usb2.c
+++ b/drivers/phy/phy-samsung-usb2.c
@@ -27,6 +27,13 @@ static int samsung_usb2_phy_power_on(struct phy *phy)
 
         dev_dbg(drv->dev, "Request to power_on \"%s\" usb phy\n",
                 inst->cfg->label);
+
+        if (drv->vbus) {
+                ret = regulator_enable(drv->vbus);
+                if (ret)
+                        goto err_regulator;
+        }
+
         ret = clk_prepare_enable(drv->clk);
         if (ret)
                 goto err_main_clk;
@@ -48,6 +55,9 @@ err_power_on:
 err_instance_clk:
         clk_disable_unprepare(drv->clk);
 err_main_clk:
+        if (drv->vbus)
+                regulator_disable(drv->vbus);
+err_regulator:
         return ret;
 }
 
@@ -55,7 +65,7 @@ static int samsung_usb2_phy_power_off(struct phy *phy)
 {
         struct samsung_usb2_phy_instance *inst = phy_get_drvdata(phy);
         struct samsung_usb2_phy_driver *drv = inst->drv;
-        int ret;
+        int ret = 0;
 
         dev_dbg(drv->dev, "Request to power_off \"%s\" usb phy\n",
                 inst->cfg->label);
@@ -68,7 +78,10 @@ static int samsung_usb2_phy_power_off(struct phy *phy)
         }
         clk_disable_unprepare(drv->ref_clk);
         clk_disable_unprepare(drv->clk);
-        return 0;
+        if (drv->vbus)
+                ret = regulator_disable(drv->vbus);
+
+        return ret;
 }
 
 static const struct phy_ops samsung_usb2_phy_ops = {
@@ -203,6 +216,14 @@ static int samsung_usb2_phy_probe(struct platform_device *pdev)
                         return ret;
         }
 
+        drv->vbus = devm_regulator_get(dev, "vbus");
+        if (IS_ERR(drv->vbus)) {
+                ret = PTR_ERR(drv->vbus);
+                if (ret == -EPROBE_DEFER)
+                        return ret;
+                drv->vbus = NULL;
+        }
+
         for (i = 0; i < drv->cfg->num_phys; i++) {
                 char *label = drv->cfg->phys[i].label;
                 struct samsung_usb2_phy_instance *p = &drv->instances[i];