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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-28 00:39:39 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-29 20:47:42 +0100 |
| commit | b0209b39951868069710c1e39ca14add9fa77ada (patch) | |
| tree | 56f69726580d40ee2ea8004ee8387907dc291aa7 | |
| parent | 1298330bd6ab5ea7c9616a242a6f40ef4968521d (diff) | |
| download | op-kernel-dev-b0209b39951868069710c1e39ca14add9fa77ada.zip op-kernel-dev-b0209b39951868069710c1e39ca14add9fa77ada.tar.gz | |
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>
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 3 | ||||
| -rw-r--r-- | include/linux/i2c-algo-bit.h | 1 |
2 files changed, 3 insertions, 1 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 525c734..ad0459c 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -610,10 +610,11 @@ static u32 bit_func(struct i2c_adapter *adap) /* -----exported algorithm data: ------------------------------------- */ -static const struct i2c_algorithm i2c_bit_algo = { +const struct i2c_algorithm i2c_bit_algo = { .master_xfer = bit_xfer, .functionality = bit_func, }; +EXPORT_SYMBOL(i2c_bit_algo); /* * registering functions to load algorithms at runtime diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h index 4f98148..584ffa0 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 */ |
