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path: root/drivers/i2c/muxes
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2011-06-29i2c/pca954x: Initialize the mux to disconnected statePetri Gynther
pca954x power-on default is channel 0 connected. If multiple pca954x muxes are connected to the same physical I2C bus, the parent bus will see channel 0 devices behind both muxes by default. This is bad. Scenario: -- pca954x @ 0x70 -- ch 0 (I2C-bus-101) -- EEPROM @ 0x50 | I2C-bus-1 --- | -- pca954x @ 0x71 -- ch 0 (I2C-bus-111) -- EEPROM @ 0x50 1. Load I2C bus driver: creates I2C-bus-1 2. Load pca954x driver: creates virtual I2C-bus-101 and I2C-bus-111 3. Load eeprom driver 4. Try to read EEPROM @ 0x50 on I2C-bus-101. The transaction will also bleed onto I2C-bus-111 because pca954x @ 0x71 channel 0 is connected by default. Fix: Initialize pca954x to disconnected state in pca954x_probe() Signed-off-by: Petri Gynther <pgynther@google.com> Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: stable@kernel.org
2011-01-10i2c: Add generic I2C multiplexer using GPIO APIPeter Korsgaard
Add an i2c mux driver providing access to i2c bus segments using a hardware MUX sitting on a master bus and controlled through gpio pins. E.G. something like: ---------- ---------- Bus segment 1 - - - - - | | SCL/SDA | |-------------- | | | |------------| | | | | | Bus segment 2 | | | Linux | GPIO 1..N | MUX |--------------- Devices | |------------| | | | | | | | Bus segment M | | | |---------------| | ---------- ---------- - - - - - SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M according to the settings of the GPIO pins 1..N. Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-10-24i2c/pca954x: Remove __devinit and __devexit from probe and remove functionsGuenter Roeck
The underlying I2C adapter may or may not be present when this driver gets initialized, and may disappear later, so there is no safe time at which the probe and remove functions can be discarded. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-10-24i2c/mux: Driver for PCA9541 I2C Master SelectorGuenter Roeck
This patch adds support for PCA9541, an I2C Bus Master Selector. The driver is modeled as single channel I2C Multiplexer to be able to utilize the I2C multiplexer framework. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Reviewed-by: Tom Grennan <tom.grennan@ericsson.com> Acked-by: Jean Delvare <khali@linux-fr.org>
2010-10-24i2c: Change to new flag variablematt mooney
Replace EXTRA_CFLAGS with ccflags-y. Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-08-11i2c: I2C bus multiplexer driver pca954xMichael Lawnick
I2C driver for PCA954x I2C multiplexer series. Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de> Acked-by: Rodolfo Giometti <giometti@linux.it> Signed-off-by: Jean Delvare <khali@linux-fr.org>