usb: fotg210-udc: Implement VBUS session

Implement VBUS session handling for FOTG210. This is
mainly used by the UDC driver which needs to call down to
the FOTG210 core and enable/disable VBUS, as this needs to be
handled outside of the HCD and UDC drivers, by platform
specific glue code.

The Gemini has a special bit in a system register to turn
VBUS on and off so we implement this in the FOTG210 core.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230103-gemini-fotg210-usb-v2-7-100388af9810@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/fotg210/fotg210-core.c b/drivers/usb/fotg210/fotg210-core.c
index b69167b..c06f8eb 100644 (file)
--- a/drivers/usb/fotg210/fotg210-core.c
+++ b/drivers/usb/fotg210/fotg210-core.c
@@ -95,6 +95,35 @@ static int fotg210_gemini_init(struct fotg210 *fotg, struct resource *res,
        return 0;
 }
 
+/**
+ * fotg210_vbus() - Called by gadget driver to enable/disable VBUS
+ * @enable: true to enable VBUS, false to disable VBUS
+ */
+void fotg210_vbus(struct fotg210 *fotg, bool enable)
+{
+       u32 mask;
+       u32 val;
+       int ret;
+
+       switch (fotg->port) {
+       case GEMINI_PORT_0:
+               mask = GEMINI_MISC_USB0_VBUS_ON;
+               val = enable ? GEMINI_MISC_USB0_VBUS_ON : 0;
+               break;
+       case GEMINI_PORT_1:
+               mask = GEMINI_MISC_USB1_VBUS_ON;
+               val = enable ? GEMINI_MISC_USB1_VBUS_ON : 0;
+               break;
+       default:
+               return;
+       }
+       ret = regmap_update_bits(fotg->map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
+       if (ret)
+               dev_err(fotg->dev, "failed to %s VBUS\n",
+                       enable ? "enable" : "disable");
+       dev_info(fotg->dev, "%s: %s VBUS\n", __func__, enable ? "enable" : "disable");
+}
+
 static int fotg210_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;

diff --git a/drivers/usb/fotg210/fotg210-udc.c b/drivers/usb/fotg210/fotg210-udc.c
index 7740df6..4334504 100644 (file)
--- a/drivers/usb/fotg210/fotg210-udc.c
+++ b/drivers/usb/fotg210/fotg210-udc.c
@@ -1082,9 +1082,26 @@ static int fotg210_udc_stop(struct usb_gadget *g)
        return 0;
 }
 
+/**
+ * fotg210_vbus_session - Called by external transceiver to enable/disable udc
+ * @_gadget: usb gadget
+ * @is_active: 0 if should disable UDC VBUS, 1 if should enable
+ *
+ * Returns 0
+ */
+static int fotg210_vbus_session(struct usb_gadget *g, int is_active)
+{
+       struct fotg210_udc *fotg210 = gadget_to_fotg210(g);
+
+       /* Call down to core integration layer to drive or disable VBUS */
+       fotg210_vbus(fotg210->fotg, is_active);
+       return 0;
+}
+
 static const struct usb_gadget_ops fotg210_gadget_ops = {
        .udc_start              = fotg210_udc_start,
        .udc_stop               = fotg210_udc_stop,
+       .vbus_session           = fotg210_vbus_session,
 };
 
 /**

diff --git a/drivers/usb/fotg210/fotg210.h b/drivers/usb/fotg210/fotg210.h
index 4d0d4ae..c44c0af 100644 (file)
--- a/drivers/usb/fotg210/fotg210.h
+++ b/drivers/usb/fotg210/fotg210.h
@@ -17,6 +17,8 @@ struct fotg210 {
        enum gemini_port port;
 };
 
+void fotg210_vbus(struct fotg210 *fotg, bool enable);
+
 #ifdef CONFIG_USB_FOTG210_HCD
 int fotg210_hcd_probe(struct platform_device *pdev, struct fotg210 *fotg);
 int fotg210_hcd_remove(struct platform_device *pdev);