bc12: create bc12 driver structure

To support linking multiple bc12 drivers into ec binary, we have to
remove the common symbols in drivers.

This CL creates a bc12_drv structure to hold the original driver-specific
usb_charger_* functions, and implements common usb_charger_* functions
which whill dispatch the function call based on the information in
bc12_drv table.

Also add a CONFIG_BC12_SINGLE_DRIVER and enabled by default for
backward compatibility. If CONFIG_BC12_SINGLE_DRIVER is defined,
a default bc12_drv array with proper size and content will be created
for the board.

BUG=b:155611686
TEST=1) make buildall.
     2) verify single driver mode on krane (rt946x) and juniper
        (pi3usb9201).
     3) verify multiple driver works on asurada, see CL:2189624 for
        example usage.
     4) verify single driver multi chip on blooglet.
BRANCH=none

Signed-off-by: Ting Shen <phoenixshen@google.com>
Change-Id: I8a96eda47c94aeb6cc150b498cfa1a6eefcc4a5b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2187080
Reviewed-by: Jett Rink <jettrink@chromium.org>
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: Ting Shen <phoenixshen@chromium.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/driver/bc12/pi3usb9201.h b/driver/bc12/pi3usb9201.h
index d9ee80a0d0..e3029999ca 100644
--- a/driver/bc12/pi3usb9201.h
+++ b/driver/bc12/pi3usb9201.h
@@ -50,3 +50,4 @@ enum pi3usb9201_mode {
 /* Configuration struct defined at board level */
 extern const struct pi3usb9201_config_t pi3usb9201_bc12_chips[];
 
+extern const struct bc12_drv pi3usb9201_drv;