On 09/14/2011 09:19 AM, Daniel Glöckner wrote:
On Wed, Sep 14, 2011 at 04:03:58AM +0300, Antti Palosaari wrote:
On 09/09/2011 02:46 PM, Daniel Glöckner wrote:
On Thu, Sep 08, 2011 at 07:34:32PM +0300, Antti Palosaari wrote:
I am working with AF9015 I2C-adapter lock. I need lock I2C-bus since
there is two tuners having same I2C address on same bus, demod I2C
gate is used to select correct tuner.
Would it be possible to use the i2c-mux framework to handle this?
Each tuner will then have its own i2c bus.
Interesting idea, but it didn't worked. It deadlocks. I think it
locks since I2C-mux is controlled by I2C "switch" in same I2C bus,
not GPIO or some other HW.
Take a look at drivers/i2c/muxes/pca954x.c. You need to use
parent->algo->master_xfer/smbus_xfer directly as the lock that
protects you from having both gates open is the lock of the
root i2c bus.
Ah yes, rather similar case. I see it as commented in pca954x.c:
/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
for this as they will try to lock adapter a second time */
This looks even more hackish solution than calling existing demod
.i2c_gate_ctrl() callback from USB-interface driver. But yes, it must
work - not beautiful but workable workaround.
regards
Antti
--
http://palosaari.fi/
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