Re: [PATCH v8 08/14] usb: otg: add OTG/dual-role core

[Roger Quadros]

On 13/05/16 13:03, Roger Quadros wrote:
> It provides APIs for the following tasks
> 
> - Registering an OTG/dual-role capable controller
> - Registering Host and Gadget controllers to OTG core
> - Providing inputs to and kicking the OTG state machine
> 
> Provide a dual-role device (DRD) state machine.
> DRD mode is a reduced functionality OTG mode. In this mode
> we don't support SRP, HNP and dynamic role-swap.
> 
> In DRD operation, the controller mode (Host or Peripheral)
> is decided based on the ID pin status. Once a cable plug (Type-A
> or Type-B) is attached the controller selects the state
> and doesn't change till the cable in unplugged and a different
> cable type is inserted.
> 
> As we don't need most of the complex OTG states and OTG timers
> we implement a lean DRD state machine in usb-otg.c.
> The DRD state machine is only interested in 2 hardware inputs
> 'id' and 'b_sess_vld'.
> 
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
>  drivers/usb/common/Makefile  |    2 +-
>  drivers/usb/common/usb-otg.c | 1042 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/core/Kconfig     |    4 +-
>  include/linux/usb/gadget.h   |    2 +
>  include/linux/usb/hcd.h      |    1 +
>  include/linux/usb/otg-fsm.h  |    7 +
>  include/linux/usb/otg.h      |  154 ++++++-
>  7 files changed, 1206 insertions(+), 6 deletions(-)
>  create mode 100644 drivers/usb/common/usb-otg.c


This patch causes the following build issues when CONFIG_USB_GADGET=m, CONFIG_USB=m,
CONFIG_USB_COMMON=m and CONFIG_USB_OTG=y

ERROR: "usb_otg_register_gadget" [drivers/usb/gadget/udc/udc-core.ko] undefined!
ERROR: "usb_otg_unregister_gadget" [drivers/usb/gadget/udc/udc-core.ko] undefined!
ERROR: "usb_otg_register_hcd" [drivers/usb/core/usbcore.ko] undefined!
ERROR: "usb_otg_unregister_hcd" [drivers/usb/core/usbcore.ko] undefined!
ERROR: "otg_statemachine" [drivers/usb/chipidea/ci_hdrc.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1141: recipe for target 'modules' failed
make: *** [modules] Error 2
make: *** Waiting for unfinished jobs....

drivers/built-in.o: In function `drd_set_state':
usb-otg.c:(.text+0x2b4242): undefined reference to `usb_otg_state_string'
drivers/built-in.o: In function `drd_statemachine':
(.text+0x2b4b4c): undefined reference to `usb_otg_state_string'
Makefile:937: recipe for target 'vmlinux' failed

I'll fix it up with the following diff.

diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index dca7856..16a5b55 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile
@@ -59,5 +59,6 @@ obj-$(CONFIG_USB_RENESAS_USBHS)	+= renesas_usbhs/
 obj-$(CONFIG_USB_GADGET)	+= gadget/
 
 obj-$(CONFIG_USB_COMMON)	+= common/
+obj-$(CONFIG_USB_OTG)		+= common/
 
 obj-$(CONFIG_USBIP_CORE)	+= usbip/
diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
index 77048aa..17e449e 100644
--- a/drivers/usb/common/usb-otg.c
+++ b/drivers/usb/common/usb-otg.c
@@ -56,6 +56,30 @@ static int usb_otg_hcd_is_primary_hcd(struct usb_hcd *hcd)
 	return hcd == hcd->primary_hcd;
 }
 
+static const char *otg_state_string(enum usb_otg_state state)
+{
+	static const char *const names[] = {
+		[OTG_STATE_A_IDLE] = "a_idle",
+		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
+		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
+		[OTG_STATE_A_HOST] = "a_host",
+		[OTG_STATE_A_SUSPEND] = "a_suspend",
+		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
+		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
+		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
+		[OTG_STATE_B_IDLE] = "b_idle",
+		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
+		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
+		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
+		[OTG_STATE_B_HOST] = "b_host",
+	};
+
+	if (state < 0 || state >= ARRAY_SIZE(names))
+		return "UNDEFINED";
+
+	return names[state];
+}
+
 /**
  * Check if the OTG device is in our wait list and return
  * otg_wait_data, else NULL.
@@ -433,7 +457,7 @@ static void drd_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 
 	fsm->state_changed = 1;
 	dev_dbg(otg->dev, "otg: set state: %s\n",
-		usb_otg_state_string(new_state));
+		otg_state_string(new_state));
 	switch (new_state) {
 	case OTG_STATE_B_IDLE:
 		drd_set_protocol(fsm, PROTO_UNDEF);
@@ -449,7 +473,7 @@ static void drd_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 		break;
 	default:
 		dev_warn(otg->dev, "%s: otg: invalid state: %s\n",
-			 __func__, usb_otg_state_string(new_state));
+			 __func__, otg_state_string(new_state));
 		break;
 	}
 
@@ -507,7 +531,7 @@ int drd_statemachine(struct usb_otg *otg)
 
 	default:
 		dev_err(otg->dev, "%s: otg: invalid usb-drd state: %s\n",
-			__func__, usb_otg_state_string(state));
+			__func__, otg_state_string(state));
 		break;
 	}
 
--
cheers,
-roger