RE: [PATCH v2] usb: renesas_usbhs: Allow an OTG PHY driver to provide VBUS

[Phil Edworthy]

Hi Laurent,

On 02 July 2015 09:15, Laurent wrote:
> Hi Phil,
> 
> (CC'ing Morimoto-san)
> 
> Thank you for the patch.
> 
> On Thursday 02 July 2015 08:36:42 Phil Edworthy wrote:
> > These changes allow a PHY driver to trigger a VBUS interrupt and
> > to provide the value of VBUS.
> >
> > Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> >
> > ---
> > v2:
> >   - vbus variables changed from int to bool.
> >   - dev_info() changed to dev_err()
> > ---
> >  drivers/usb/renesas_usbhs/common.h     |  2 ++
> >  drivers/usb/renesas_usbhs/mod.c        |  3 +++
> >  drivers/usb/renesas_usbhs/mod_gadget.c | 38
> +++++++++++++++++++++++++++++++
> >  3 files changed, 43 insertions(+)
> >
> > diff --git a/drivers/usb/renesas_usbhs/common.h
> > b/drivers/usb/renesas_usbhs/common.h index 8c5fc12..478700c 100644
> > --- a/drivers/usb/renesas_usbhs/common.h
> > +++ b/drivers/usb/renesas_usbhs/common.h
> > @@ -255,6 +255,8 @@ struct usbhs_priv {
> >  	struct renesas_usbhs_driver_param	dparam;
> >
> >  	struct delayed_work notify_hotplug_work;
> > +	bool vbus_is_indirect;
> > +	bool vbus_indirect_value;
> >  	struct platform_device *pdev;
> >
> >  	struct extcon_dev *edev;
> > diff --git a/drivers/usb/renesas_usbhs/mod.c
> > b/drivers/usb/renesas_usbhs/mod.c index 9a705b1..8a2d3dd 100644
> > --- a/drivers/usb/renesas_usbhs/mod.c
> > +++ b/drivers/usb/renesas_usbhs/mod.c
> > @@ -42,6 +42,9 @@ static int usbhsm_autonomy_get_vbus(struct
> platform_device
> > *pdev) {
> >  	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
> >
> > +	if (priv->vbus_is_indirect)
> > +		return priv->vbus_indirect_value;
> > +
> 
> Something is bothering me. The comment block right before this function states
> that "these functions are used if platform doesn't have external phy".
> However, the mechanism you implement here is aimed at letting a PHY control
> vbus. I have a feeling this isn't the right mechanism.

I took the comment as though it was talking about an physically external PHY, but
I suppose it makes no difference from the point of view of this driver. I'll have a
look to see if there is a better way to hook this in.


> >  	return  VBSTS & usbhs_read(priv, INTSTS0);
> >  }
> >
> > diff --git a/drivers/usb/renesas_usbhs/mod_gadget.c
> > b/drivers/usb/renesas_usbhs/mod_gadget.c index dc2aa32..51b63f9 100644
> > --- a/drivers/usb/renesas_usbhs/mod_gadget.c
> > +++ b/drivers/usb/renesas_usbhs/mod_gadget.c
> > @@ -21,6 +21,7 @@
> >  #include <linux/platform_device.h>
> >  #include <linux/usb/ch9.h>
> >  #include <linux/usb/gadget.h>
> > +#include <linux/usb/otg.h>
> >  #include "common.h"
> >
> >  /*
> > @@ -50,6 +51,7 @@ struct usbhsg_gpriv {
> >  	int			 uep_size;
> >
> >  	struct usb_gadget_driver	*driver;
> > +	struct usb_phy		*transceiver;
> >
> >  	u32	status;
> >  #define USBHSG_STATUS_STARTED		(1 << 0)
> > @@ -882,6 +884,8 @@ static int usbhsg_gadget_start(struct usb_gadget
> > *gadget, {
> >  	struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
> >  	struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
> > +	struct device *dev = usbhs_priv_to_dev(priv);
> > +	int ret;
> >
> >  	if (!driver		||
> >  	    !driver->setup	||
> > @@ -891,6 +895,17 @@ static int usbhsg_gadget_start(struct usb_gadget
> > *gadget, /* first hook up the driver ... */
> >  	gpriv->driver = driver;
> >
> > +	/* connect to bus through transceiver */
> > +	if (!IS_ERR_OR_NULL(gpriv->transceiver)) {
> > +		ret = otg_set_peripheral(gpriv->transceiver->otg,
> > +					&gpriv->gadget);
> > +		if (ret) {
> > +			dev_err(dev, "%s: can't bind to transceiver\n",
> > +				gpriv->gadget.name);
> 
> Shouldn't gpriv->driver be set to NULL here ? Or possibly better, this code
> block moved before setting gpriv->driver ?
Makes sense.

> > +			return ret;
> > +		}
> > +	}
> > +
> >  	return usbhsg_try_start(priv, USBHSG_STATUS_REGISTERD);
> >  }
> >
> > @@ -900,6 +915,10 @@ static int usbhsg_gadget_stop(struct usb_gadget
> > *gadget) struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
> >
> >  	usbhsg_try_stop(priv, USBHSG_STATUS_REGISTERD);
> > +
> > +	if (!IS_ERR_OR_NULL(gpriv->transceiver))
> > +		(void) otg_set_peripheral(gpriv->transceiver->otg, NULL);
> 
> Is there really a need for (void) ?
Oops, none at all.

> > +
> >  	gpriv->driver = NULL;
> >
> >  	return 0;
> > @@ -947,12 +966,27 @@ static int usbhsg_set_selfpowered(struct usb_gadget
> > *gadget, int is_self) return 0;
> >  }
> >
> > +static int usbhsg_vbus_session(struct usb_gadget *gadget, int is_active)
> > +{
> > +	struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
> > +	struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
> > +	struct platform_device *pdev = usbhs_priv_to_pdev(priv);
> > +
> > +	priv->vbus_is_indirect = 1;
> > +	priv->vbus_indirect_value = !!is_active;
> > +
> > +	renesas_usbhs_call_notify_hotplug(pdev);
> > +
> > +	return 0;
> > +}
> > +
> >  static const struct usb_gadget_ops usbhsg_gadget_ops = {
> >  	.get_frame		= usbhsg_get_frame,
> >  	.set_selfpowered	= usbhsg_set_selfpowered,
> >  	.udc_start		= usbhsg_gadget_start,
> >  	.udc_stop		= usbhsg_gadget_stop,
> >  	.pullup			= usbhsg_pullup,
> > +	.vbus_session		= usbhsg_vbus_session,
> >  };
> >
> >  static int usbhsg_start(struct usbhs_priv *priv)
> > @@ -994,6 +1028,10 @@ int usbhs_mod_gadget_probe(struct usbhs_priv
> *priv)
> >  		goto usbhs_mod_gadget_probe_err_gpriv;
> >  	}
> >
> > +	gpriv->transceiver = usb_get_phy(USB_PHY_TYPE_UNDEFINED);
> > +	dev_info(dev, "%s transceiver found\n",
> > +		 gpriv->transceiver ? "" : "No");
> > +
> >  	/*
> >  	 * CAUTION
> >  	 *
> 
> --
> Regards,
> 
> Laurent Pinchart

Thanks
Phil

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