Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call it

This provides a new API allows different OLPC architectures to override the
EC driver.  x86 and ARM OLPC machines use completely different EC backends.

The olpc_ec_cmd is synchronous, and waits for the workqueue to send the
command to the EC.  Multiple callers can run olpc_ec_cmd() at once, and
they will by serialized and sleep while only one executes on the EC at a time.

We don't provide an unregister function, as that doesn't make sense within
the context of OLPC machines - there's only ever 1 EC, it's critical to
functionality, and it certainly not hotpluggable.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Acked-by: Paul Fox <pgf@laptop.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/olpc-ec.h b/include/linux/olpc-ec.h
index 6d4e426d9fdc..231e96f5dfe2 100644
--- a/include/linux/olpc-ec.h
+++ b/include/linux/olpc-ec.h
@@ -14,8 +14,14 @@
 #define EC_SCI_QUERY                    0x84
 #define EC_EXT_SCI_QUERY                0x85
 
+struct olpc_ec_driver {
+        int (*ec_cmd)(u8, u8 *, size_t, u8 *, size_t, void *);
+};
+
 #ifdef CONFIG_OLPC
 
+extern void olpc_ec_driver_register(struct olpc_ec_driver *drv, void *arg);
+
 extern int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf,
                 size_t outlen);