[RESEND PATCH v6 2/5] usb: host: dwc2: add phy support

[Patrick Delaunay <patrick.delaunay@st.com>]

Use generic phy to initialize the PHY associated to the
DWC2 device and available in the device tree.

This patch don't added dependency because when CONFIG_PHY
is not activated, the generic PHY function are stubbed.

Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
---

Changes in v6: None
Changes in v5:
- inverse logic for -ENOENT test on generic_phy_get_by_index result
- Add some comments

Changes in v4: None
Changes in v3: None
Changes in v2:
- update dev_err
- update commit message
- change dev_err to dev_dbg for PHY function call
- treat dwc2_shutdown_phy error

 drivers/usb/host/dwc2.c | 66 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index e4efaf1e59..a8e64825b5 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -8,6 +8,7 @@
 #include <cpu_func.h>
 #include <dm.h>
 #include <errno.h>
+#include <generic-phy.h>
 #include <usb.h>
 #include <malloc.h>
 #include <memalign.h>
@@ -37,6 +38,7 @@ struct dwc2_priv {
 #ifdef CONFIG_DM_REGULATOR
 	struct udevice *vbus_supply;
 #endif
+	struct phy phy;
 #else
 	uint8_t *aligned_buffer;
 	uint8_t *status_buffer;
@@ -1322,13 +1324,71 @@ static int dwc2_usb_ofdata_to_platdata(struct udevice *dev)
 	return 0;
 }
 
+static int dwc2_setup_phy(struct udevice *dev)
+{
+	struct dwc2_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = generic_phy_get_by_index(dev, 0, &priv->phy);
+	if (ret) {
+		if (ret == -ENOENT)
+			return 0; /* no PHY, nothing to do */
+		dev_err(dev, "Failed to get USB PHY: %d.\n", ret);
+		return ret;
+	}
+
+	ret = generic_phy_init(&priv->phy);
+	if (ret) {
+		dev_dbg(dev, "Failed to init USB PHY: %d.\n", ret);
+		return ret;
+	}
+
+	ret = generic_phy_power_on(&priv->phy);
+	if (ret) {
+		dev_dbg(dev, "Failed to power on USB PHY: %d.\n", ret);
+		generic_phy_exit(&priv->phy);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dwc2_shutdown_phy(struct udevice *dev)
+{
+	struct dwc2_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	/* PHY is not valid when generic_phy_get_by_index() = -ENOENT */
+	if (!generic_phy_valid(&priv->phy))
+		return 0; /* no PHY, nothing to do */
+
+	ret = generic_phy_power_off(&priv->phy);
+	if (ret) {
+		dev_dbg(dev, "Failed to power off USB PHY: %d.\n", ret);
+		return ret;
+	}
+
+	ret = generic_phy_exit(&priv->phy);
+	if (ret) {
+		dev_dbg(dev, "Failed to power off USB PHY: %d.\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int dwc2_usb_probe(struct udevice *dev)
 {
 	struct dwc2_priv *priv = dev_get_priv(dev);
 	struct usb_bus_priv *bus_priv = dev_get_uclass_priv(dev);
+	int ret;
 
 	bus_priv->desc_before_addr = true;
 
+	ret = dwc2_setup_phy(dev);
+	if (ret)
+		return ret;
+
 	return dwc2_init_common(dev, priv);
 }
 
@@ -1341,6 +1401,12 @@ static int dwc2_usb_remove(struct udevice *dev)
 	if (ret)
 		return ret;
 
+	ret = dwc2_shutdown_phy(dev);
+	if (ret) {
+		dev_dbg(dev, "Failed to shutdown USB PHY: %d.\n", ret);
+		return ret;
+	}
+
 	dwc2_uninit_common(priv->regs);
 
 	reset_release_bulk(&priv->resets);
-- 
2.17.1