From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH] i2c: export bit-banging algo functions Date: Tue, 28 Feb 2012 00:39:39 +0100 Message-ID: <1330385979-19406-1-git-send-email-daniel.vetter@ffwll.ch> References: <20120227225223.GB1050@phenom.ffwll.local> Mime-Version: 1.0 Return-path: In-Reply-To: <20120227225223.GB1050-dv86pmgwkMBes7Z6vYuT8azUEOm+Xw19@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: Intel Graphics Development , DRI Development , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Daniel Vetter List-Id: linux-i2c@vger.kernel.org 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. Signed-off-by: Daniel Vetter --- drivers/i2c/algos/i2c-algo-bit.c | 3 ++- 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 */ -- 1.7.7.5