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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-28 03:39:39 +0400 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-29 23:47:42 +0400 |
| commit | b0209b39951868069710c1e39ca14add9fa77ada (patch) | |
| tree | 56f69726580d40ee2ea8004ee8387907dc291aa7 /include/linux/i2c-algo-bit.h | |
| parent | 1298330bd6ab5ea7c9616a242a6f40ef4968521d (diff) | |
| download | linux-b0209b39951868069710c1e39ca14add9fa77ada.tar.xz | |
i2c: export bit-banging algo functions
i915 has a hw i2c controller (gmbus) but for a bunch of stupid reasons
we need to be able to fall back to the bit-banging algo on gpio pins.
The current code sets up a 2nd i2c controller for the same i2c bus using
the bit-banging algo. This has a bunch of issues, the major one being
that userspace can directly access this fallback i2c adaptor behind
the drivers back.
But we need to frob a few registers before and after using fallback
gpio bit-banging, so this horribly fails.
The new plan is to only set up one i2c adaptor and transparently fall
back to bit-banging by directly calling the xfer function of the bit-
banging algo in the i2c core.
To make that possible, export the 2 i2c algo functions.
v2: As suggested by Jean Delvare, simply export the i2c_bit_algo
vtable instead of the individual functions.
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/linux/i2c-algo-bit.h')
| -rw-r--r-- | include/linux/i2c-algo-bit.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h index 4f98148c11c3..584ffa0f3282 100644 --- a/include/linux/i2c-algo-bit.h +++ b/include/linux/i2c-algo-bit.h @@ -49,5 +49,6 @@ struct i2c_algo_bit_data { int i2c_bit_add_bus(struct i2c_adapter *); int i2c_bit_add_numbered_bus(struct i2c_adapter *); +extern const struct i2c_algorithm i2c_bit_algo; #endif /* _LINUX_I2C_ALGO_BIT_H */ |