[PATCH v3 3/7] usb: chipidea: add otg id switch and vbus connect/disconnect detect

Peter Chen peter.chen at freescale.com
Mon Nov 26 04:11:04 EST 2012


The main design flow is the same with msm otg driver, that is the id and
vbus interrupt are handled at core driver, others are handled by
individual drivers.

- At former design, when switch usb role from device->host, it will call
udc_stop, it will remove the gadget driver, so when switch role
from host->device, it can't add gadget driver any more.
At new design, when role switch occurs, the gadget just calls
usb_gadget_vbus_disconnect/usb_gadget_vbus_connect as well as
reset controller, it will not free any device/gadget structure

- Add vbus connect and disconnect to core interrupt handler, it can
notify udc driver by calling usb_gadget_vbus_disconnect
/usb_gadget_vbus_connect.

Signed-off-by: Peter Chen <peter.chen at freescale.com>
---
Changes for v3:
- Add prefix CI_ for ID and B_SESS_VALID
- Use new API hw_wait_reg which is alexander sugguested to wait vbus
voltage stable

 drivers/usb/chipidea/bits.h |   10 +++
 drivers/usb/chipidea/ci.h   |    5 +
 drivers/usb/chipidea/core.c |  182 ++++++++++++++++++++++++++++++++++++++----
 drivers/usb/chipidea/otg.c  |    1 +
 drivers/usb/chipidea/udc.c  |    2 +
 5 files changed, 182 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/chipidea/bits.h b/drivers/usb/chipidea/bits.h
index 050de85..ba9c6ef 100644
--- a/drivers/usb/chipidea/bits.h
+++ b/drivers/usb/chipidea/bits.h
@@ -65,11 +65,21 @@
 #define OTGSC_ASVIS	      BIT(18)
 #define OTGSC_BSVIS	      BIT(19)
 #define OTGSC_BSEIS	      BIT(20)
+#define OTGSC_1MSIS	      BIT(21)
+#define OTGSC_DPIS	      BIT(22)
 #define OTGSC_IDIE	      BIT(24)
 #define OTGSC_AVVIE	      BIT(25)
 #define OTGSC_ASVIE	      BIT(26)
 #define OTGSC_BSVIE	      BIT(27)
 #define OTGSC_BSEIE	      BIT(28)
+#define OTGSC_1MSIE	      BIT(29)
+#define OTGSC_DPIE	      BIT(30)
+#define OTGSC_INT_EN_BITS	(OTGSC_IDIE | OTGSC_AVVIE | OTGSC_ASVIE \
+				| OTGSC_BSVIE | OTGSC_BSEIE | OTGSC_1MSIE \
+				| OTGSC_DPIE)
+#define OTGSC_INT_STATUS_BITS	(OTGSC_IDIS | OTGSC_AVVIS | OTGSC_ASVIS	\
+				| OTGSC_BSVIS | OTGSC_BSEIS | OTGSC_1MSIS \
+				| OTGSC_DPIS)
 
 /* USBMODE */
 #define USBMODE_CM            (0x03UL <<  0)
diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index 8702871..12665fa 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -130,6 +130,7 @@ struct hw_bank {
  * @transceiver: pointer to USB PHY, if any
  * @hcd: pointer to usb_hcd for ehci host driver
  * @otg: for otg support
+ * @events: events for otg, and handled at ci_role_work
  */
 struct ci13xxx {
 	struct device			*dev;
@@ -140,6 +141,7 @@ struct ci13xxx {
 	enum ci_role			role;
 	bool				is_otg;
 	struct work_struct		work;
+	struct delayed_work		dwork;
 	struct workqueue_struct		*wq;
 
 	struct dma_pool			*qh_pool;
@@ -166,6 +168,9 @@ struct ci13xxx {
 	struct usb_phy			*transceiver;
 	struct usb_hcd			*hcd;
 	struct usb_otg      otg;
+#define CI_ID		0
+#define CI_B_SESS_VALID	1
+	unsigned long events;
 };
 
 static inline struct ci_role_driver *ci_role(struct ci13xxx *ci)
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index f69d029..e0392fa 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -73,6 +73,7 @@
 #include "bits.h"
 #include "host.h"
 #include "debug.h"
+#include "otg.h"
 
 /* Controller register map */
 static uintptr_t ci_regs_nolpm[] = {
@@ -265,24 +266,124 @@ static enum ci_role ci_otg_role(struct ci13xxx *ci)
 }
 
 /**
- * ci_role_work - perform role changing based on ID pin
- * @work: work struct
+ * hw_wait_reg: wait the register value
+ *
+ * Sometimes, it needs to wait register value before going on.
+ * Eg, when switch to device mode, the vbus value should be lower
+ * than OTGSC_BSV before connects to host.
+ *
+ * @ci: the controller
+ * @reg: register index
+ * @mask: mast bit
+ * @value: the bit value to wait
+ * @timeout: timeout to indicate an error
+ *
+ * This function returns an error code if timeout
  */
-static void ci_role_work(struct work_struct *work)
+static int hw_wait_reg(struct ci13xxx *ci, enum ci13xxx_regs reg, u32 mask,
+				u32 value, unsigned long timeout)
+{
+	unsigned long elapse = jiffies + timeout;
+
+	while (hw_read(ci, reg, mask) != value) {
+		if (time_after(jiffies, elapse)) {
+			dev_err(ci->dev, "timeout waiting for %08x in %d\n",
+					mask, reg);
+			return -ETIMEDOUT;
+		}
+		msleep(20);
+	}
+
+	return 0;
+}
+
+#define CI_VBUS_STABLE_TIMEOUT 500
+static void ci_handle_id_switch(struct ci13xxx *ci)
 {
-	struct ci13xxx *ci = container_of(work, struct ci13xxx, work);
 	enum ci_role role = ci_otg_role(ci);
 
 	if (role != ci->role) {
 		dev_dbg(ci->dev, "switching from %s to %s\n",
 			ci_role(ci)->name, ci->roles[role]->name);
 
-		ci_role_stop(ci);
-		ci_role_start(ci, role);
-		enable_irq(ci->irq);
+		/* 1. Finish the current role */
+		if (ci->role == CI_ROLE_GADGET) {
+			usb_gadget_vbus_disconnect(&ci->gadget);
+			/* host doesn't care B_SESSION_VALID event */
+			hw_write(ci, OP_OTGSC, OTGSC_BSVIE, ~OTGSC_BSVIE);
+			hw_write(ci, OP_OTGSC, OTGSC_BSVIS, OTGSC_BSVIS);
+			ci->role = CI_ROLE_END;
+			/* reset controller */
+			hw_device_reset(ci, USBMODE_CM_IDLE);
+		} else if (ci->role == CI_ROLE_HOST) {
+			ci_role_stop(ci);
+			/* reset controller */
+			hw_device_reset(ci, USBMODE_CM_IDLE);
+		}
+
+		/* 2. Turn on/off vbus according to coming role */
+		if (ci_otg_role(ci) == CI_ROLE_GADGET) {
+			otg_set_vbus(&ci->otg, false);
+			/* wait vbus lower than OTGSC_BSV */
+			hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0,
+					CI_VBUS_STABLE_TIMEOUT);
+		} else if (ci_otg_role(ci) == CI_ROLE_HOST) {
+			otg_set_vbus(&ci->otg, true);
+			/* wait vbus higher than OTGSC_AVV */
+			hw_wait_reg(ci, OP_OTGSC, OTGSC_AVV, OTGSC_AVV,
+					CI_VBUS_STABLE_TIMEOUT);
+		}
+
+		/* 3. Begin the new role */
+		if (ci_otg_role(ci) == CI_ROLE_GADGET) {
+			ci->role = role;
+			hw_write(ci, OP_OTGSC, OTGSC_BSVIS, OTGSC_BSVIS);
+			hw_write(ci, OP_OTGSC, OTGSC_BSVIE, OTGSC_BSVIE);
+		} else if (ci_otg_role(ci) == CI_ROLE_HOST) {
+			ci_role_start(ci, role);
+		}
 	}
 }
 
+static void ci_handle_vbus_change(struct ci13xxx *ci)
+{
+	u32 otgsc = hw_read(ci, OP_OTGSC, ~0);
+
+	if (otgsc & OTGSC_BSV)
+		usb_gadget_vbus_connect(&ci->gadget);
+	else
+		usb_gadget_vbus_disconnect(&ci->gadget);
+}
+
+/**
+ * ci_otg_work - perform otg (vbus/id) event handle
+ * @work: work struct
+ */
+static void ci_otg_work(struct work_struct *work)
+{
+	struct ci13xxx *ci = container_of(work, struct ci13xxx, work);
+
+	if (test_bit(CI_ID, &ci->events)) {
+		clear_bit(CI_ID, &ci->events);
+		ci_handle_id_switch(ci);
+	} else if (test_bit(CI_B_SESS_VALID, &ci->events)) {
+		clear_bit(CI_B_SESS_VALID, &ci->events);
+		ci_handle_vbus_change(ci);
+	} else
+		dev_err(ci->dev, "unexpected event occurs at %s\n", __func__);
+
+	enable_irq(ci->irq);
+}
+
+static void ci_delayed_work(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct ci13xxx *ci = container_of(dwork, struct ci13xxx, dwork);
+
+	otg_set_vbus(&ci->otg, true);
+
+}
+
 static ssize_t show_role(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
@@ -321,19 +422,36 @@ static irqreturn_t ci_irq(int irq, void *data)
 	irqreturn_t ret = IRQ_NONE;
 	u32 otgsc = 0;
 
-	if (ci->is_otg)
-		otgsc = hw_read(ci, OP_OTGSC, ~0);
-
-	if (ci->role != CI_ROLE_END)
-		ret = ci_role(ci)->irq(ci);
+	otgsc = hw_read(ci, OP_OTGSC, ~0);
 
-	if (ci->is_otg && (otgsc & OTGSC_IDIS)) {
+	/*
+	 * Handle id change interrupt, it indicates device/host function
+	 * switch.
+	 */
+	if (ci->is_otg && (otgsc & OTGSC_IDIE) && (otgsc & OTGSC_IDIS)) {
+		set_bit(CI_ID, &ci->events);
 		hw_write(ci, OP_OTGSC, OTGSC_IDIS, OTGSC_IDIS);
 		disable_irq_nosync(ci->irq);
 		queue_work(ci->wq, &ci->work);
-		ret = IRQ_HANDLED;
+		return IRQ_HANDLED;
+	}
+
+	/*
+	 * Handle vbus change interrupt, it indicates device connection
+	 * and disconnection events.
+	 */
+	if ((otgsc & OTGSC_BSVIE) && (otgsc & OTGSC_BSVIS)) {
+		set_bit(CI_B_SESS_VALID, &ci->events);
+		hw_write(ci, OP_OTGSC, OTGSC_BSVIS, OTGSC_BSVIS);
+		disable_irq_nosync(ci->irq);
+		queue_work(ci->wq, &ci->work);
+		return IRQ_HANDLED;
 	}
 
+	/* Handle device/host interrupt */
+	if (ci->role != CI_ROLE_END)
+		ret = ci_role(ci)->irq(ci);
+
 	return ret;
 }
 
@@ -397,6 +515,7 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 	struct resource	*res;
 	void __iomem	*base;
 	int		ret;
+	u32		otgsc;
 
 	if (!dev->platform_data) {
 		dev_err(dev, "platform data missing\n");
@@ -421,6 +540,7 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	ci->events = 0;
 	ci->dev = dev;
 	ci->platdata = dev->platform_data;
 	if (ci->platdata->phy)
@@ -442,12 +562,20 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	INIT_WORK(&ci->work, ci_role_work);
+	INIT_WORK(&ci->work, ci_otg_work);
+	INIT_DELAYED_WORK(&ci->dwork, ci_delayed_work);
 	ci->wq = create_singlethread_workqueue("ci_otg");
 	if (!ci->wq) {
 		dev_err(dev, "can't create workqueue\n");
 		return -ENODEV;
 	}
+	/* Disable all interrupts bits */
+	hw_write(ci, OP_USBINTR, 0xffffffff, 0);
+	hw_write(ci, OP_OTGSC, OTGSC_INT_EN_BITS, 0);
+
+	/* Clear all interrupts status bits*/
+	hw_write(ci, OP_USBSTS, 0xffffffff, 0xffffffff);
+	hw_write(ci, OP_OTGSC, OTGSC_INT_STATUS_BITS, OTGSC_INT_STATUS_BITS);
 
 	/* initialize role(s) before the interrupt is requested */
 	ret = ci_hdrc_host_init(ci);
@@ -465,6 +593,7 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 	}
 
 	if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
+		dev_dbg(dev, "support otg\n");
 		ci->is_otg = true;
 		/* ID pin needs 1ms debouce time, we delay 2ms for safe */
 		mdelay(2);
@@ -475,13 +604,29 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 			: CI_ROLE_GADGET;
 	}
 
+	if (ci->is_otg)
+		/* if otg is supported, create struct usb_otg */
+		ci_hdrc_otg_init(ci);
+
 	ret = ci_role_start(ci, ci->role);
 	if (ret) {
-		dev_err(dev, "can't start %s role\n", ci_role(ci)->name);
+		dev_err(dev, "can't start %s role, ret=%d\n",
+				ci_role(ci)->name, ret);
 		ret = -ENODEV;
 		goto rm_wq;
 	}
 
+	otgsc = hw_read(ci, OP_OTGSC, ~0);
+	/*
+	 * if it is device mode:
+	 * - Enable vbus detect
+	 * - If it has already connected to host, notify udc
+	 */
+	if (ci->role == CI_ROLE_GADGET) {
+		hw_write(ci, OP_OTGSC, OTGSC_BSVIE, OTGSC_BSVIE);
+		ci_handle_vbus_change(ci);
+	}
+
 	platform_set_drvdata(pdev, ci);
 	ret = request_irq(ci->irq, ci_irq, IRQF_SHARED, ci->platdata->name,
 			  ci);
@@ -492,8 +637,9 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 	if (ret)
 		goto rm_attr;
 
-	if (ci->is_otg)
-		hw_write(ci, OP_OTGSC, OTGSC_IDIE, OTGSC_IDIE);
+	/* Handle the situation that usb device at the MicroB to A cable */
+	if (ci->is_otg && !(otgsc & OTGSC_ID))
+		queue_delayed_work(ci->wq, &ci->dwork, msecs_to_jiffies(500));
 
 	return ret;
 
diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index 7dea3b3..01ae162 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -55,6 +55,7 @@ int ci_hdrc_otg_init(struct ci13xxx *ci)
 	ci->otg.set_host = ci_otg_set_host;
 	if (!IS_ERR_OR_NULL(ci->transceiver))
 		ci->transceiver->otg = &ci->otg;
+	hw_write(ci, OP_OTGSC, OTGSC_IDIE, OTGSC_IDIE);
 
 	return 0;
 }
diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index d214448..b52cb10 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -1371,6 +1371,7 @@ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
 			pm_runtime_get_sync(&_gadget->dev);
 			hw_device_reset(ci, USBMODE_CM_DC);
 			hw_device_state(ci, ci->ep0out->qh.dma);
+			dev_dbg(ci->dev, "Connected to host\n");
 		} else {
 			hw_device_state(ci, 0);
 			if (ci->platdata->notify_event)
@@ -1378,6 +1379,7 @@ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
 				CI13XXX_CONTROLLER_STOPPED_EVENT);
 			_gadget_stop_activity(&ci->gadget);
 			pm_runtime_put_sync(&_gadget->dev);
+			dev_dbg(ci->dev, "disconnected from host\n");
 		}
 	}
 
-- 
1.7.0.4





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