linux/drivers/i2c/muxes
Ionut Nicu 8c0ec2500e i2c: mux: gpio: use reg value for i2c_add_mux_adapter
The i2c-mux driver requires that the chan_id parameter
passed to the i2c_add_mux_adapter() function is equal
to the reg value for that adapter:

for_each_child_of_node(mux_dev->of_node, child) {
	ret = of_property_read_u32(child, "reg", &reg);
	if (ret)
		continue;
	if (chan_id == reg) {
		priv->adap.dev.of_node = child;
		break;
	}
}

The i2c-mux-gpio driver uses an internal logical index
for chan_id when calling i2c_add_mux_adapter() instead
of using the reg value.

Because of this, there will problems in selecting the
right adapter when the i2c-mux-gpio's index into
mux->data.values doesn't match the reg value.

An example of such a case:

mux->data.values = { 1, 0 }

For chan_id = 0, i2c-mux will bind the adapter to the
of_node with reg = <0>, but when it will call the
select() callback with chan_id set to 0, the i2c-mux-gpio
will use it as an index into mux->data.values and it will
actually select the bus with reg = <1>.

Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2013-10-30 17:29:46 +01:00
..
i2c-arb-gpio-challenge.c i2c: remove redundant of_match_ptr 2013-10-03 22:00:41 +02:00
i2c-mux-gpio.c i2c: mux: gpio: use reg value for i2c_add_mux_adapter 2013-10-30 17:29:46 +01:00
i2c-mux-pca954x.c i2c: use dev_get_platdata() 2013-08-19 19:46:30 +02:00
i2c-mux-pca9541.c i2c: use dev_get_platdata() 2013-08-19 19:46:30 +02:00
i2c-mux-pinctrl.c i2c: Include linux/of.h header 2013-10-30 16:46:30 +01:00
Kconfig Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
Makefile i2c: mux: Add i2c-arb-gpio-challenge 'mux' driver 2013-04-17 11:31:03 +02:00