| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 036/212] i2c: mux: gpio: use reg value for i2c_add_mux_adapter | Date | Mon, 2 Dec 2013 11:13:47 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: Ionut Nicu <ioan.nicu.ext@nsn.com>
commit 8c0ec2500eeb89749341884a972860d7f9e56f9c upstream.
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", ®); 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/i2c/muxes/i2c-mux-gpio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -38,7 +38,7 @@ static int i2c_mux_gpio_select(struct i2 { struct gpiomux *mux = data; - i2c_mux_gpio_set(mux, mux->data.values[chan]); + i2c_mux_gpio_set(mux, chan); return 0; } @@ -228,7 +228,7 @@ static int i2c_mux_gpio_probe(struct pla 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;
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