Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes:
> Hi,
>
> Robert Jarzmik <robert.jarzmik@xxxxxxx> writes:
>> I don't know if there are other users than pxa, I'll make the assumption there
>> aren't.
>
> yeah, we can keep patches in linux-next for as long as possible. If
> nobody complains, we're good.
Hi Felipe,
Just a small update. I made the change, but I'm not submitting it yet because my
testings show me that even if the VBus is correctly detected, the enumeration
fails, which means I have an error in my flow somewhere.
The current patch is in [1], I'm still working on it.
Cheers.
--
Robert
[1] Current patch
---8>---
>From c801e9eba7cfe177a93b2c1675c8a19b408c8ac5 Mon Sep 17 00:00:00 2001
From: Robert Jarzmik <robert.jarzmik@xxxxxxx>
Date: Thu, 7 Jul 2016 19:53:43 +0200
Subject: [PATCH] usb: gadget: pxa27x: add phy notifier event handler
In the legacy behavior, and USB phy, upon detection a VBus signal, was
calling usb_gadget_vbus_(dis)connect().
This model doesn't work if the phy is generic and doesn't have an
adherence to the gadget API.
Instead of relying on the phy to call the gadget API, hook up the phy
notifier to report the VBus event, and upon it call the usb gadget API
ourselves.
This brings a new ordering problem, as before even if the usb_get_phy()
was failing because the UDC was probed before the phy, the phy would
call the gadget anyway, making the VBus connection event forwarded to
the gadget. Now we rely on the notifier, we have to ensure the
xxx_get_phy() does indeed work.
In order to cope with this, it is assumed that :
- for legacy platform_data machine, as the ordering cannot be ensured,
the phy must call usb_gadget_vbus_(dis)connect, such as
phy-gpio-vbus-usb.c
- for new devicetree platforms, we'll rely on the probe deferral, and
the phy can be gadget API agnostic.
Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
drivers/usb/gadget/udc/pxa27x_udc.c | 45 ++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/udc/pxa27x_udc.c b/drivers/usb/gadget/udc/pxa27x_udc.c
index 001a3b74a993..f79a74304d4d 100644
--- a/drivers/usb/gadget/udc/pxa27x_udc.c
+++ b/drivers/usb/gadget/udc/pxa27x_udc.c
@@ -33,6 +33,7 @@
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
+#include <linux/usb/phy.h>
#include "pxa27x_udc.h"
@@ -1655,6 +1656,37 @@ static int pxa_udc_vbus_draw(struct usb_gadget *_gadget, unsigned mA)
return -EOPNOTSUPP;
}
+/**
+ * pxa_udc_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 pxa_udc
+ *
+ * Called by the USB Phy when a cable connect or disconnect is sensed.
+ *
+ * Returns 0
+ */
+static int pxa_udc_phy_event(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct usb_gadget *gadget = data;
+
+ 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 pxa27x_udc_phy = {
+ .notifier_call = pxa_udc_phy_event,
+};
+
static int pxa27x_udc_start(struct usb_gadget *g,
struct usb_gadget_driver *driver);
static int pxa27x_udc_stop(struct usb_gadget *g);
@@ -2435,7 +2467,14 @@ static int pxa_udc_probe(struct platform_device *pdev)
return udc->irq;
udc->dev = &pdev->dev;
- udc->transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
+ if (of_have_populated_dt()) {
+ udc->transceiver =
+ devm_usb_get_phy_by_phandle(udc->dev, "phys", 0);
+ if (IS_ERR(udc->transceiver))
+ return PTR_ERR(udc->transceiver);
+ } else {
+ udc->transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
+ }
if (IS_ERR(udc->gpiod)) {
dev_err(&pdev->dev, "Couldn't find or request D+ gpio : %ld\n",
@@ -2472,6 +2511,8 @@ static int pxa_udc_probe(struct platform_device *pdev)
if (retval)
goto err;
+ if (!IS_ERR_OR_NULL(udc->transceiver))
+ usb_register_notifier(udc->transceiver, &pxa27x_udc_phy);
pxa_init_debugfs(udc);
if (should_enable_udc(udc))
udc_enable(udc);
@@ -2492,6 +2533,8 @@ static int pxa_udc_remove(struct platform_device *_dev)
usb_del_gadget_udc(&udc->gadget);
pxa_cleanup_debugfs(udc);
+ if (!IS_ERR_OR_NULL(udc->transceiver))
+ usb_unregister_notifier(udc->transceiver, &pxa27x_udc_phy);
usb_put_phy(udc->transceiver);
udc->transceiver = NULL;
--
2.1.4
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