Keeps implementation details out of host and peripheral
side USB controller drivers ... needed for some upcoming
merges (which may come first through the OMAP tree).
Please merge.
- Dave
Hardware implementing USB-OTG needs to use an OTG controller and/or
transceiver driver to switch the Mini-AB connector between the host
and peripheral side controller drivers (and the USB device role
supported by that driver).
This patch adds a simple "otg_transceiver" interface that can abstract
implementation details for that port, as needed for some upcoming patches:
- Neither host nor peripheral controller drivers need to know about
how the OTG controller is implemented. Example: is the transceiver
internal? If not, which external chip?
- The OTG controller doesn't need to know if the Host Controller
is OHCI, EHCI, or something custom ... all it knows is that the
HCD looks like a "usb_bus".
- In the same way, the peripheral controller is just a "usb_gadget".
One implementation of this will be posted soon; the interface is by
no means cast in stone, other implementations may need to morph this
interface a bit.
Signed-off-by: David Brownell <[EMAIL PROTECTED]>
--- omap-2.6ref/include/linux/usb_otg.h 1969-12-31 16:00:00.000000000 -0800
+++ omap-2.6/include/linux/usb_otg.h 2004-07-13 17:08:45.000000000 -0700
@@ -0,0 +1,116 @@
+// include/linux/usb_otg.h
+
+/*
+ * These APIs may be used between USB controllers. USB device drivers
+ * (for either host or peripheral roles) don't use these calls; they
+ * continue to use just usb_device and usb_gadget.
+ */
+
+
+/* OTG defines lots of enumeration states before device reset */
+enum usb_otg_state {
+ OTG_STATE_UNDEFINED = 0,
+
+ /* single-role peripheral, and dual-role default-b */
+ OTG_STATE_B_IDLE,
+ OTG_STATE_B_SRP_INIT,
+ OTG_STATE_B_PERIPHERAL,
+
+ /* extra dual-role default-b states */
+ OTG_STATE_B_WAIT_ACON,
+ OTG_STATE_B_HOST,
+
+ /* dual-role default-a */
+ OTG_STATE_A_IDLE,
+ OTG_STATE_A_WAIT_VRISE,
+ OTG_STATE_A_WAIT_BCON,
+ OTG_STATE_A_HOST,
+ OTG_STATE_A_SUSPEND,
+ OTG_STATE_A_PERIPHERAL,
+ OTG_STATE_A_WAIT_VFALL,
+ OTG_STATE_A_VBUS_ERR,
+};
+
+/*
+ * the otg driver needs to interact with both device side and host side
+ * usb controllers. it decides which controller is active at a given
+ * moment, using the transceiver, ID signal, HNP and sometimes static
+ * configuration information (including "board isn't wired for otg").
+ */
+struct otg_transceiver {
+ struct device *dev;
+ const char *label;
+
+ u8 default_a;
+ enum usb_otg_state state;
+
+ struct usb_bus *host;
+ struct usb_gadget *gadget;
+
+ /* to pass extra port status to the root hub */
+ u16 port_status;
+ u16 port_change;
+
+ /* bind/unbind the host controller */
+ int (*set_host)(struct otg_transceiver *otg,
+ struct usb_bus *host);
+
+ /* bind/unbind the peripheral controller */
+ int (*set_peripheral)(struct otg_transceiver *otg,
+ struct usb_gadget *gadget);
+
+ /* effective for B devices, ignored for A-peripheral */
+ int (*set_power)(struct otg_transceiver *otg,
+ unsigned mA);
+
+ /* for B devices only: start session with A-Host */
+ int (*start_srp)(struct otg_transceiver *otg);
+
+ /* start or continue HNP role switch */
+ int (*start_hnp)(struct otg_transceiver *otg);
+
+};
+
+
+/* for board-specific init logic */
+extern int otg_set_transceiver(struct otg_transceiver *);
+
+
+/* for usb host and peripheral controller drivers */
+extern struct otg_transceiver *otg_get_transceiver(void);
+
+static inline int
+otg_start_hnp(struct otg_transceiver *otg)
+{
+ return otg->start_hnp(otg);
+}
+
+
+/* for HCDs */
+static inline int
+otg_set_host(struct otg_transceiver *otg, struct usb_bus *host)
+{
+ return otg->set_host(otg, host);
+}
+
+
+/* for usb peripheral controller drivers */
+static inline int
+otg_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *periph)
+{
+ return otg->set_peripheral(otg, periph);
+}
+
+static inline int
+otg_set_power(struct otg_transceiver *otg, unsigned mA)
+{
+ return otg->set_power(otg, mA);
+}
+
+static inline int
+otg_start_srp(struct otg_transceiver *otg)
+{
+ return otg->start_srp(otg);
+}
+
+
