[PATCH v3 1/3] usb: renesas_usbhs: enable DVSE interrupt

[PATCH v3 1/3] usb: renesas_usbhs: enable DVSE interrupt

[Veeraiyan Chidambaram]

From: Eugeniu Rosca <erosca@de.adit-jv.com>

Commit [1] enabled the possibility of checking the DVST (Device State
Transition) bit of INTSTS0 (Interrupt Status Register 0) and calling
the irq_dev_state() handler if the DVST bit is set. But neither
commit [1] nor commit [2] actually enabled the DVSE (Device State
Transition Interrupt Enable) bit in the INTENB0 (Interrupt Enable
Register 0). As a consequence, irq_dev_state() handler is getting
called as a side effect of other (non-DVSE) interrupts being fired,
which definitely can't be relied upon, if DVST notifications are of
any value.

Why this doesn't hurt is because usbhsg_irq_dev_state() currently
doesn't do much except of a dev_dbg(). Once more work is added to
the handler (e.g. detecting device "Suspended" state and notifying
other USB gadget components about it), enabling DVSE becomes a hard
requirement. Do it in a standalone commit for better visibility and
clear explanation.

[1] f1407d5 ("usb: renesas_usbhs: Add Renesas USBHS common code")
[2] 2f98382 ("usb: renesas_usbhs: Add Renesas USBHS Gadget")

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>
---
 drivers/usb/renesas_usbhs/mod.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/renesas_usbhs/mod.c b/drivers/usb/renesas_usbhs/mod.c
index 7475c4f64724..87e08b1512ad 100644
--- a/drivers/usb/renesas_usbhs/mod.c
+++ b/drivers/usb/renesas_usbhs/mod.c
@@ -349,10 +349,6 @@ void usbhs_irq_callback_update(struct usbhs_priv *priv, struct usbhs_mod *mod)
 	 *	usbhs_interrupt
 	 */
 
-	/*
-	 * it don't enable DVSE (intenb0) here
-	 * but "mod->irq_dev_state" will be called.
-	 */
 	if (info->irq_vbus)
 		intenb0 |= VBSE;
 
@@ -363,6 +359,9 @@ void usbhs_irq_callback_update(struct usbhs_priv *priv, struct usbhs_mod *mod)
 		if (mod->irq_ctrl_stage)
 			intenb0 |= CTRE;
 
+		if (mod->irq_dev_state)
+			intenb0 |= DVSE;
+
 		if (mod->irq_empty && mod->irq_bempsts) {
 			usbhs_write(priv, BEMPENB, mod->irq_bempsts);
 			intenb0 |= BEMPE;
-- 
2.7.4

[PATCH v3 2/3] usb: renesas_usbhs: simplify usbhs_status_get_device_state()

[Veeraiyan Chidambaram]

From: Eugeniu Rosca <erosca@de.adit-jv.com>

Similar to usbhs_status_get_ctrl_stage(), *_get_device_state() is not
supposed to return any error code since its return value is the DVSQ
bitfield of the INTSTS0 register. According to SoC HW manual rev1.00,
every single value of DVSQ[2:0] is valid and none is an error:

----8<----
Device State
000: Powered state
001: Default state
010: Address state
011: Configuration state
1xx: Suspended state
----8<----

Hence, simplify the function body. The motivation behind dropping the
switch/case construct is being able to implement reading the suspended
state. The latter (based on the above DVSQ[2:0] description) doesn't
have a unique value, but is rather a list of states (which makes
switch/case less suitable for reading/validating it):

100: (Suspended) Powered state
101: (Suspended) Default state
110: (Suspended) Address state
111: (Suspended) Configuration state

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>
---
 drivers/usb/renesas_usbhs/mod.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/usb/renesas_usbhs/mod.c b/drivers/usb/renesas_usbhs/mod.c
index 87e08b1512ad..3384308169f5 100644
--- a/drivers/usb/renesas_usbhs/mod.c
+++ b/drivers/usb/renesas_usbhs/mod.c
@@ -170,17 +170,7 @@ void usbhs_mod_remove(struct usbhs_priv *priv)
  */
 int usbhs_status_get_device_state(struct usbhs_irq_state *irq_state)
 {
-	int state = irq_state->intsts0 & DVSQ_MASK;
-
-	switch (state) {
-	case POWER_STATE:
-	case DEFAULT_STATE:
-	case ADDRESS_STATE:
-	case CONFIGURATION_STATE:
-		return state;
-	}
-
-	return -EIO;
+	return (int)irq_state->intsts0 & DVSQ_MASK;
 }
 
 int usbhs_status_get_ctrl_stage(struct usbhs_irq_state *irq_state)
-- 
2.7.4

[PATCH v3 3/3] usb: renesas_usbhs: add suspend event support in gadget mode

[Veeraiyan Chidambaram]

From: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>

When R-Car Gen3 USB 2.0 is in Gadget mode, if host is detached an interrupt
will be generated and Suspended state bit is set in interrupt status
register. Interrupt handler will call driver->suspend(composite_suspend)
if suspended state bit is set. composite_suspend will call
ffs_func_suspend which will post FUNCTIONFS_SUSPEND and will be consumed
by user space application via /dev/ep0.

To be able to detect host detach, extend the DVSQ_MASK to cover the
Suspended bit of the DVSQ[2:0] bitfield from the Interrupt Status
Register 0 (INTSTS0) register and perform appropriate action in the
DVST interrupt handler (usbhsg_irq_dev_state).

Without this commit, disconnection of the phone from R-Car H3 ES2.0
Salvator-X CN9 port is not recognized and reverse role switch does
not not happen. If phone is connected again it does not enumerate.

With this commit, disconnection will be recognized and reverse role
switch will happen by a user space application. If phone is connected
again it will enumerate properly and will become visible in the output
of 'lsusb'.

Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
 drivers/usb/renesas_usbhs/common.h     |  3 ++-
 drivers/usb/renesas_usbhs/mod_gadget.c | 12 +++++++++---
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/renesas_usbhs/common.h b/drivers/usb/renesas_usbhs/common.h
index 3777af848a35..142319c7585d 100644
--- a/drivers/usb/renesas_usbhs/common.h
+++ b/drivers/usb/renesas_usbhs/common.h
@@ -159,11 +159,12 @@ struct usbhs_priv;
 #define VBSTS	(1 << 7)	/* VBUS_0 and VBUSIN_0 Input Status */
 #define VALID	(1 << 3)	/* USB Request Receive */
 
-#define DVSQ_MASK		(0x3 << 4)	/* Device State */
+#define DVSQ_MASK		(0x7 << 4)	/* Device State */
 #define  POWER_STATE		(0 << 4)
 #define  DEFAULT_STATE		(1 << 4)
 #define  ADDRESS_STATE		(2 << 4)
 #define  CONFIGURATION_STATE	(3 << 4)
+#define  SUSPENDED_STATE	(4 << 4)
 
 #define CTSQ_MASK		(0x7)	/* Control Transfer Stage */
 #define  IDLE_SETUP_STAGE	0	/* Idle stage or setup stage */
diff --git a/drivers/usb/renesas_usbhs/mod_gadget.c b/drivers/usb/renesas_usbhs/mod_gadget.c
index 34ee9ebe12a3..d8972ab3c2f9 100644
--- a/drivers/usb/renesas_usbhs/mod_gadget.c
+++ b/drivers/usb/renesas_usbhs/mod_gadget.c
@@ -456,12 +456,18 @@ static int usbhsg_irq_dev_state(struct usbhs_priv *priv,
 {
 	struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
 	struct device *dev = usbhsg_gpriv_to_dev(gpriv);
+	int state = usbhs_status_get_device_state(irq_state);
 
 	gpriv->gadget.speed = usbhs_bus_get_speed(priv);
 
-	dev_dbg(dev, "state = %x : speed : %d\n",
-		usbhs_status_get_device_state(irq_state),
-		gpriv->gadget.speed);
+	dev_dbg(dev, "state = %x : speed : %d\n", state, gpriv->gadget.speed);
+
+	if (gpriv->gadget.speed != USB_SPEED_UNKNOWN &&
+	    (state & SUSPENDED_STATE)) {
+		if (gpriv->driver && gpriv->driver->suspend)
+			gpriv->driver->suspend(&gpriv->gadget);
+		usb_gadget_set_state(&gpriv->gadget, USB_STATE_SUSPENDED);
+	}
 
 	return 0;
 }
-- 
2.7.4