fotg210-udc: Support optional external PHY

This adds support for an optional external PHY to the FOTG210
UDC driver.

Tested with the GPIO VBUS PHY driver on the Gemini SoC.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221114115201.302887-2-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/fotg210/fotg210-udc.c b/drivers/usb/fotg210/fotg210-udc.c
index b3106e4..4026103 100644 (file)
--- a/drivers/usb/fotg210/fotg210-udc.c
+++ b/drivers/usb/fotg210/fotg210-udc.c
@@ -15,6 +15,8 @@
 #include <linux/platform_device.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/phy.h>
 
 #include "fotg210.h"
 #include "fotg210-udc.h"
@@ -1008,11 +1010,19 @@ static int fotg210_udc_start(struct usb_gadget *g,
 {
        struct fotg210_udc *fotg210 = gadget_to_fotg210(g);
        u32 value;
+       int ret;
 
        /* hook up the driver */
        driver->driver.bus = NULL;
        fotg210->driver = driver;
 
+       if (!IS_ERR_OR_NULL(fotg210->phy)) {
+               ret = otg_set_peripheral(fotg210->phy->otg,
+                                        &fotg210->gadget);
+               if (ret)
+                       dev_err(fotg210->dev, "can't bind to phy\n");
+       }
+
        /* enable device global interrupt */
        value = ioread32(fotg210->reg + FOTG210_DMCR);
        value |= DMCR_GLINT_EN;
@@ -1054,6 +1064,9 @@ static int fotg210_udc_stop(struct usb_gadget *g)
        struct fotg210_udc *fotg210 = gadget_to_fotg210(g);
        unsigned long   flags;
 
+       if (!IS_ERR_OR_NULL(fotg210->phy))
+               return otg_set_peripheral(fotg210->phy->otg, NULL);
+
        spin_lock_irqsave(&fotg210->lock, flags);
 
        fotg210_init(fotg210);
@@ -1069,12 +1082,50 @@ static const struct usb_gadget_ops fotg210_gadget_ops = {
        .udc_stop               = fotg210_udc_stop,
 };
 
+/**
+ * fotg210_phy_event - Called by phy upon VBus event
+ * @nb: notifier block
+ * @action: phy action, is vbus connect or disconnect
+ * @data: the usb_gadget structure in fotg210
+ *
+ * Called by the USB Phy when a cable connect or disconnect is sensed.
+ *
+ * Returns NOTIFY_OK or NOTIFY_DONE
+ */
+static int fotg210_phy_event(struct notifier_block *nb, unsigned long action,
+                            void *data)
+{
+       struct usb_gadget *gadget = data;
+
+       if (!gadget)
+               return NOTIFY_DONE;
+
+       switch (action) {
+       case USB_EVENT_VBUS:
+               usb_gadget_vbus_connect(gadget);
+               return NOTIFY_OK;
+       case USB_EVENT_NONE:
+               usb_gadget_vbus_disconnect(gadget);
+               return NOTIFY_OK;
+       default:
+               return NOTIFY_DONE;
+       }
+}
+
+static struct notifier_block fotg210_phy_notifier = {
+       .notifier_call = fotg210_phy_event,
+};
+
 int fotg210_udc_remove(struct platform_device *pdev)
 {
        struct fotg210_udc *fotg210 = platform_get_drvdata(pdev);
        int i;
 
        usb_del_gadget_udc(&fotg210->gadget);
+       if (!IS_ERR_OR_NULL(fotg210->phy)) {
+               usb_unregister_notifier(fotg210->phy, &fotg210_phy_notifier);
+               usb_put_phy(fotg210->phy);
+       }
        iounmap(fotg210->reg);
        free_irq(platform_get_irq(pdev, 0), fotg210);
 
@@ -1114,6 +1165,22 @@ int fotg210_udc_probe(struct platform_device *pdev)
        if (fotg210 == NULL)
                goto err;
 
+       fotg210->dev = dev;
+
+       fotg210->phy = devm_usb_get_phy_by_phandle(dev->parent, "usb-phy", 0);
+       if (IS_ERR(fotg210->phy)) {
+               ret = PTR_ERR(fotg210->phy);
+               if (ret == -EPROBE_DEFER)
+                       goto err;
+               dev_info(dev, "no PHY found\n");
+               fotg210->phy = NULL;
+       } else {
+               ret = usb_phy_init(fotg210->phy);
+               if (ret)
+                       goto err;
+               dev_info(dev, "found and initialized PHY\n");
+       }
+
        for (i = 0; i < FOTG210_MAX_NUM_EP; i++) {
                _ep[i] = kzalloc(sizeof(struct fotg210_ep), GFP_KERNEL);
                if (_ep[i] == NULL)
@@ -1185,6 +1252,9 @@ int fotg210_udc_probe(struct platform_device *pdev)
                goto err_req;
        }
 
+       if (!IS_ERR_OR_NULL(fotg210->phy))
+               usb_register_notifier(fotg210->phy, &fotg210_phy_notifier);
+
        ret = usb_add_gadget_udc(dev, &fotg210->gadget);
        if (ret)
                goto err_add_udc;
@@ -1194,6 +1264,8 @@ int fotg210_udc_probe(struct platform_device *pdev)
        return 0;
 
 err_add_udc:
+       if (!IS_ERR_OR_NULL(fotg210->phy))
+               usb_unregister_notifier(fotg210->phy, &fotg210_phy_notifier);
        free_irq(ires->start, fotg210);
 
 err_req:

diff --git a/drivers/usb/fotg210/fotg210-udc.h b/drivers/usb/fotg210/fotg210-udc.h
index 08c3295..e3067d2 100644 (file)
--- a/drivers/usb/fotg210/fotg210-udc.h
+++ b/drivers/usb/fotg210/fotg210-udc.h
@@ -234,6 +234,8 @@ struct fotg210_udc {
 
        unsigned long           irq_trigger;
 
+       struct device                   *dev;
+       struct usb_phy                  *phy;
        struct usb_gadget               gadget;
        struct usb_gadget_driver        *driver;