[PATCH 2/4] usb: phy: twl4030: allow charger to see usb current draw limits.

NeilBrown
2015-02-24T03:42:22Z

The charger needs to know when a USB gadget has been enumerated
and what the agreed maximum current was so that it can adjust
charging accordingly.

So define a "set_power()" function to record the permitted
draw, and pass a pointer to that when sending USB_EVENT_ENUMERATED
notification.

Signed-off-by: NeilBrown <neilb@suse.de>
---
drivers/phy/phy-twl4030-usb.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
index 97c59074233f..023fe150c7a1 100644
--- a/drivers/phy/phy-twl4030-usb.c
+++ b/drivers/phy/phy-twl4030-usb.c
@@ -163,6 +163,11 @@ struct twl4030_usb {
enum omap_musb_vbus_id_status linkstat;
bool vbus_supplied;

+ /* Permitted vbus draw - only meaningful after
+ * USB_EVENT_ENUMERATED
+ */
+ unsigned vbus_draw;
+
struct delayed_work id_workaround_work;
};

@@ -547,12 +552,7 @@ static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
mutex_unlock(&twl->lock);

if (status_changed) {
- /* FIXME add a set_power() method so that B-devices can
- * configure the charger appropriately. It's not always
- * correct to consume VBUS power, and how much current to
- * consume is a function of the USB configuration chosen
- * by the host.
- *
+ /*
* REVISIT usb_gadget_vbus_connect(...) as needed, ditto
* its disconnect() sibling, when changing to/from the
* USB_LINK_VBUS state. musb_hdrc won't care until it
@@ -625,6 +625,20 @@ static int twl4030_set_host(struct usb_otg *otg, struct usb_bus *host)
return 0;
}

+static int twl4030_set_power(struct usb_phy *phy, unsigned mA)
+{
+ struct twl4030_usb *twl = phy_to_twl(phy);
+
+ if (twl->vbus_draw != mA) {
+ phy->last_event = USB_EVENT_ENUMERATED;
+ twl->vbus_draw = mA;
+ atomic_notifier_call_chain(&phy->notifier,
+ USB_EVENT_ENUMERATED,
+ &twl->vbus_draw);
+ }
+ return 0;
+}
+
static const struct phy_ops ops = {
.init = twl4030_phy_init,
.power_on = twl4030_phy_power_on,
@@ -675,6 +689,7 @@ static int twl4030_usb_probe(struct platform_device *pdev)
twl->phy.label = "twl4030";
twl->phy.otg = otg;
twl->phy.type = USB_PHY_TYPE_USB2;
+ twl->phy.set_power = twl4030_set_power;

otg->usb_phy = &twl->phy;
otg->set_host = twl4030_set_host;