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i2c: mux: gpio: use reg value for i2c_add_mux_adapter

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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
This commit is contained in:
Ionut Nicu 2013-10-11 12:09:57 +02:00 committed by Wolfram Sang
parent 250ad590d6
commit 8c0ec2500e
1 changed files with 2 additions and 2 deletions
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4
drivers/i2c/muxes/i2c-mux-gpio.c
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@ -38,7 +38,7 @@ static int i2c_mux_gpio_select(struct i2c_adapter *adap, void *data, u32 chan)
{
struct gpiomux *mux = data;
i2c_mux_gpio_set(mux, mux->data.values[chan]);
i2c_mux_gpio_set(mux, chan);
return 0;
}
@ -224,7 +224,7 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
unsigned int class = mux->data.classes ? mux->data.classes[i] : 0;
mux->adap[i] = i2c_add_mux_adapter(parent, &pdev->dev, mux, nr,
i, class,
mux->data.values[i], class,
i2c_mux_gpio_select, deselect);
if (!mux->adap[i]) {
ret = -ENODEV;