On 6/9/2016 10:53 AM, 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>
[...]
diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
new file mode 100644
index 0000000..baebe5c
--- /dev/null
+++ b/drivers/usb/common/usb-otg.c
@@ -0,0 +1,833 @@
[...]
+/**
+ * Change USB protocol when there is a protocol change.
+ * fsm->lock must be held.
+ */
If you're using the kernel-doc comment, please follow the rules.
+static int drd_set_protocol(struct otg_fsm *fsm, int protocol)
[...]
+/**
+ * Called when entering a DRD state.
+ * fsm->lock must be held.
+ */
Same here.
+static void drd_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
[...]
+/**
+ * DRD state change judgement
+ *
+ * For DRD we're only interested in some of the OTG states
+ * i.e. OTG_STATE_B_IDLE: both peripheral and host are stopped
+ * OTG_STATE_B_PERIPHERAL: peripheral active
+ * OTG_STATE_A_HOST: host active
+ * we're only interested in the following inputs
+ * fsm->id, fsm->b_sess_vld
+ */
And here.
+/**
+ * Dual-role device (DRD) work function
+ */
And here.
+static void usb_drd_work(struct work_struct *work)
+{
+ struct usb_otg *otg = container_of(work, struct usb_otg, work);
+
+ pm_runtime_get_sync(otg->dev);
+ while (drd_statemachine(otg))
+ ;
Indent it more please.
[...]
+/**
+ * start/kick the OTG FSM if we can
+ * fsm->lock must be held
+ */
Please follow the kernel-doc rules.
[...]
+/**
+ * stop the OTG FSM. Stops Host & Gadget controllers as well.
+ * fsm->lock must be held
+ */
Likewise.
[...]
+/**
+ * usb_otg_sync_inputs - Sync OTG inputs with the OTG state machine
+ * @fsm: OTG FSM instance
Doesn't match the prototype.
+ *
+ * Used by the OTG driver to update the inputs to the OTG
+ * state machine.
+ *
+ * Can be called in IRQ context.
+ */
+void usb_otg_sync_inputs(struct usb_otg *otg)
[...]
+/**
+ * usb_otg_register_gadget - Register the gadget controller to OTG core
+ * @gadget: gadget controller
We call that USB device controller (UDC). I'm not sure what you meant here...
And what about the 2nd arg, 'ops'?
[...]
diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
index 85b8fb5..5d4850a 100644
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -10,10 +10,68 @@
#define __LINUX_USB_OTG_H
#include <linux/phy/phy.h>
-#include <linux/usb/phy.h>
-#include <linux/usb/otg-fsm.h>
+#include <linux/device.h>
+#include <linux/usb.h>
#include <linux/usb/hcd.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/otg-fsm.h>
+#include <linux/usb/phy.h>
+
+/**
+ * struct otg_hcd - host controller state and interface
+ *
+ * @hcd: host controller
+ * @irqnum: irq number
+ * @irqflags: irq flags
IRQ?
+ * @ops: otg to host controller interface
+ * @ops: otg to host controller interface
Once is enough. :-)
+ * @otg_dev: otg controller device
OTG?
+/**
+ * struct usb_otg - usb otg controller state
+ *
+ * @default_a: Indicates we are an A device. i.e. Host.
+ * @phy: USB phy interface
PHY?
+ * @usb_phy: old usb_phy interface
+ * @host: host controller bus
+ * @gadget: gadget device
+ * @state: current otg state
+ * @dev: otg controller device
+ * @caps: otg capabilities revision, hnp, srp, etc
+ * @fsm: otg finite state machine
OTG?
+ * @hcd_ops: host controller interface
+ * ------- internal use only -------
+ * @primary_hcd: primary host state and interface
+ * @shared_hcd: shared host state and interface
+ * @gadget_ops: gadget controller interface
+ * @list: list of otg controllers
+ * @work: otg state machine work
+ * @wq: otg state machine work queue
+ * @flags: to track if host/gadget is running
+ */
struct usb_otg {
u8 default_a;
[...]
@@ -42,26 +116,101 @@ struct usb_otg {
/* start or continue HNP role switch */
int (*start_hnp)(struct usb_otg *otg);
-
+/*---------------------------------------------------------------*/
};
/**
- * struct usb_otg_caps - describes the otg capabilities of the device
- * @otg_rev: The OTG revision number the device is compliant with, it's
- * in binary-coded decimal (i.e. 2.0 is 0200H).
- * @hnp_support: Indicates if the device supports HNP.
- * @srp_support: Indicates if the device supports SRP.
- * @adp_support: Indicates if the device supports ADP.
+ * struct usb_otg_config - otg controller configuration
+ * @caps: otg capabilities of the controller
+ * @ops: otg fsm operations
OTG FSM?
+ * @otg_work: optional custom otg state machine work function
OTG?
*/
[...]
Phew, that was a long patch... normally I don't review the patches that
are such big. :-)
MBR, Sergei
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