usb: gadget: udc: USB charger detection support

Adding the USB charger detection support for
device controller.

Bug 819334

Change-Id: I9350c6abaa2be38ecb40db6bc9bc5e84c5303998
Reviewed-on: http://git-master/r/42299
Reviewed-by: Rakesh Bodla <rbodla@nvidia.com>
Tested-by: Rakesh Bodla <rbodla@nvidia.com>
Reviewed-by: Hanumanth Venkateswa Moganty <vmoganty@nvidia.com>

3 files changed, 39 insertions, 0 deletions

diff --git a/drivers/usb/gadget/fsl_tegra_udc.c b/drivers/usb/gadget/fsl_tegra_udc.c
index 712636d8ee8e..3e44aea98eeb 100644
--- a/drivers/usb/gadget/fsl_tegra_udc.c
+++ b/drivers/usb/gadget/fsl_tegra_udc.c
@@ -132,3 +132,8 @@ void fsl_udc_clk_resume(bool is_dpd)
 	clk_enable(udc_clk);
 	tegra_usb_phy_power_on(phy,  is_dpd);
 }
+
+bool fsl_udc_charger_detect(void)
+{
+	return tegra_usb_phy_charger_detect(phy);
+}
diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c
index 82118cd1cbf7..1dba4dfcacfd 100644
--- a/drivers/usb/gadget/fsl_udc_core.c
+++ b/drivers/usb/gadget/fsl_udc_core.c
@@ -39,6 +39,7 @@
 #include <linux/fsl_devices.h>
 #include <linux/dmapool.h>
 #include <linux/delay.h>
+#include <linux/workqueue.h>
 
 #include <asm/byteorder.h>
 #include <asm/io.h>
@@ -71,6 +72,9 @@ static struct usb_dr_device *dr_regs;
 static struct usb_sys_interface *usb_sys_regs;
 #endif
 
+/* 1 sec wait time for charger detection after vbus is detected */
+#define USB_CHARGER_DETECTION_WAIT_TIME_MS 1000
+
 /* it is initialized in probe()  */
 static struct fsl_udc *udc_controller = NULL;
 
@@ -1207,6 +1211,8 @@ static int fsl_vbus_session(struct usb_gadget *gadget, int is_active)
 
 	if (udc->transceiver) {
 		if (udc->vbus_active && !is_active) {
+			/* If cable disconnected, cancel any delayed work */
+			cancel_delayed_work(&udc->work);
 			spin_lock_irqsave(&udc->lock, flags);
 			/* reset all internal Queues and inform client driver */
 			reset_queues(udc);
@@ -1230,6 +1236,9 @@ static int fsl_vbus_session(struct usb_gadget *gadget, int is_active)
 			udc->vbus_active = 1;
 			/* start the controller */
 			dr_controller_run(udc);
+			/* Schedule work to wait for 1000 msec and check for
+			 * charger if setup packet is not received */
+			schedule_delayed_work(&udc->work, USB_CHARGER_DETECTION_WAIT_TIME_MS);
 		}
 		return 0;
 	}
@@ -1999,6 +2008,18 @@ static void reset_irq(struct fsl_udc *udc)
 #endif
 }
 
+/*
+ * If VBUS is detected and setup packet is not received in 100ms then
+ * work thread starts and checks for the USB charger detection.
+ */
+static void fsl_udc_charger_detect_work(struct work_struct* work)
+{
+	/* check for the platform charger detection */
+	if (fsl_udc_charger_detect()) {
+		printk(KERN_INFO "USB compliant charger detected\n");
+	}
+}
+
 #if defined(CONFIG_ARCH_TEGRA)
 /*
  * Restart device controller in the OTG mode on VBUS detection
@@ -2053,6 +2074,9 @@ static irqreturn_t fsl_udc_irq(int irq, void *_udc)
 		VDBG("Packet int");
 		/* Setup package, we only support ep0 as control ep */
 		if (fsl_readl(&dr_regs->endptsetupstat) & EP_SETUP_STATUS_EP0) {
+			/* Setup packet received, we are connected to host and
+			 * not charger. Cancel any delayed work */
+			cancel_delayed_work(&udc->work);
 			tripwire_handler(udc, 0,
 					(u8 *) (&udc->local_setup_buff));
 			setup_received_irq(udc, &udc->local_setup_buff);
@@ -2751,6 +2775,9 @@ static int __init fsl_udc_probe(struct platform_device *pdev)
 	}
 	create_proc_file();
 
+	/* create a delayed work for detecting the USB charger */
+	INIT_DELAYED_WORK(&udc_controller->work, fsl_udc_charger_detect_work);
+
 #ifdef CONFIG_USB_OTG_UTILS
 	udc_controller->transceiver = otg_get_transceiver();
 	if (udc_controller->transceiver) {
@@ -2800,6 +2827,7 @@ static int __exit fsl_udc_remove(struct platform_device *pdev)
 		return -ENODEV;
 	udc_controller->done = &done;
 
+	cancel_delayed_work(&udc_controller->work);
 	if (udc_controller->transceiver)
 		otg_set_peripheral(udc_controller->transceiver, NULL);
 
diff --git a/drivers/usb/gadget/fsl_usb2_udc.h b/drivers/usb/gadget/fsl_usb2_udc.h
index 415b7c088962..599327d16634 100644
--- a/drivers/usb/gadget/fsl_usb2_udc.h
+++ b/drivers/usb/gadget/fsl_usb2_udc.h
@@ -512,6 +512,7 @@ struct fsl_udc {
 	u32 ep0_dir;		/* Endpoint zero direction: can be
 				   USB_DIR_IN or USB_DIR_OUT */
 	u8 device_address;	/* Device USB address */
+	struct delayed_work work;	/* delayed work for charger detection */
 };
 
 /*-------------------------------------------------------------------------*/
@@ -593,6 +594,7 @@ void fsl_udc_clk_finalize(struct platform_device *pdev);
 void fsl_udc_clk_release(void);
 void fsl_udc_clk_suspend(bool is_dpd);
 void fsl_udc_clk_resume(bool is_dpd);
+bool fsl_udc_charger_detect(void);
 #else
 static inline int fsl_udc_clk_init(struct platform_device *pdev)
 {
@@ -610,6 +612,10 @@ static inline void fsl_udc_clk_suspend(bool is_dpd)
 static inline void fsl_udc_clk_resume(bool is_dpd)
 {
 }
+static inline bool fsl_udc_charger_detect(void)
+{
+	return false;
+}
 #endif
 
 #endif