[PATCH] USB: msm72k_udc: Add charging notification support

[Pavankumar Kondeti <pkondeti@codeaurora.org>]

Provide Host PC (after configured), Wall charger notifications.
Typically Battery/Charger driver is subscribed to these notifications
and responsible for notifying user space and drawing the current.

This patch was originally developed by Google and is available at
http://android.git.kernel.org/?p=kernel/experimental.git.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
 drivers/usb/gadget/msm72k_udc.c |   17 +++++++++++++++++
 include/linux/usb/msm_hsusb.h   |   16 ++++++++++++++++
 2 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/gadget/msm72k_udc.c b/drivers/usb/gadget/msm72k_udc.c
index 2b476a6..80f6003 100644
--- a/drivers/usb/gadget/msm72k_udc.c
+++ b/drivers/usb/gadget/msm72k_udc.c
@@ -173,6 +173,8 @@ static void usb_do_work(struct work_struct *w);
  *             comes from platform data.
  * @hw_reset: function pointer to assert/de-assert of link.
  *            comes from platform data.
+ * @usb_connected: callback function registered to receive charger type
+ *                 notifications. comes from platform data.
  * @work: work_struct for state transitions.
  * @gadget: gadget struct of this driver.
  * @driver: gadget driver bound to this driver.
@@ -211,6 +213,8 @@ struct usb_info {
 	void (*phy_reset)(void);
 	void (*hw_reset)(bool en);
 
+	void (*usb_connected)(int);
+
 	struct work_struct work;
 
 	struct usb_gadget		gadget;
@@ -733,6 +737,8 @@ static void handle_setup(struct usb_info *ui)
 	if (ctl.bRequestType == (USB_DIR_OUT | USB_TYPE_STANDARD)) {
 		if (ctl.bRequest == USB_REQ_SET_CONFIGURATION) {
 			ui->online = !!ctl.wValue;
+			if (ui->online && ui->usb_connected)
+				ui->usb_connected(USB_CHG_HOST);
 		} else if (ctl.bRequest == USB_REQ_SET_ADDRESS) {
 			/* write address delayed (will take effect
 			** after the next IN txn)
@@ -1263,6 +1269,9 @@ static void usb_do_work(struct work_struct *w)
 				msm72k_pullup(&ui->gadget, 0);
 				spin_unlock_irqrestore(&ui->lock, iflags);
 
+				if (ui->usb_connected)
+					ui->usb_connected(USB_CHG_NONE);
+
 				/* terminate any transactions, etc */
 				flush_all_endpoints(ui);
 
@@ -1302,6 +1311,13 @@ static void usb_do_work(struct work_struct *w)
 				clk_enable(ui->pclk);
 				usb_reset(ui);
 
+				/* detect shorted D+/D-, indicating AC power */
+				usleep_range(10000, 12000);
+				if ((readl(USB_PORTSC) & PORTSC_LS) ==
+						PORTSC_LS)
+					if (ui->usb_connected)
+						ui->usb_connected(USB_CHG_WALL);
+
 				ui->state = USB_STATE_ONLINE;
 				usb_do_work_check_vbus(ui);
 			}
@@ -1790,6 +1806,7 @@ static int msm72k_probe(struct platform_device *pdev)
 		struct msm_hsusb_platform_data *pdata = pdev->dev.platform_data;
 		ui->phy_reset = pdata->phy_reset;
 		ui->phy_init_seq = pdata->phy_init_seq;
+		ui->usb_connected = pdata->usb_connected;
 	}
 
 	irq = platform_get_irq(pdev, 0);
diff --git a/include/linux/usb/msm_hsusb.h b/include/linux/usb/msm_hsusb.h
index 758d140..f95b62c 100644
--- a/include/linux/usb/msm_hsusb.h
+++ b/include/linux/usb/msm_hsusb.h
@@ -20,11 +20,26 @@
 #include <linux/types.h>
 
 /**
+ * USB charger types.
+ *
+ * USB_CHG_NONE         Charger is not connected.
+ * USB_CHG_HOST         Connected to Host PC.
+ * USB_CHG_WALL         Connected to Wall charger.
+ *
+ */
+enum usb_chg_type {
+	USB_CHG_NONE = 0,
+	USB_CHG_HOST,
+	USB_CHG_WALL,
+};
+
+/**
  * struct msm_hsusb_platform_data - platform device data
  *              for msm72k_udc driver.
  * @phy_reset:	assert followed by de-assert of PHY.
  * @hw_reset:	if enable is true, assert link otherwise
  *              de-assert link.
+ * @usb_connected: callback function to receive usb charger type notifications.
  * @phy_init_seq: PHY configuration sequence. val, reg pairs
  *              terminated by -1.
  *
@@ -32,6 +47,7 @@
 struct msm_hsusb_platform_data {
 	void (*phy_reset)(void);
 	void (*hw_reset)(bool enable);
+	void (*usb_connected)(int);
 	int *phy_init_seq;
 };
 
-- 
1.7.1