Re: [PATCH 08/12] i2c: core: Add support for 'i2c-bus' subnode

Jon Hunter
2016-08-02T06:49:08Z

On 02/08/16 07:26, Tomeu Vizoso wrote:
> On 23 June 2016 at 17:59, Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:
>> If the 'i2c-bus' device-tree node is present for an I2C adapter then
>> parse this subnode for I2C slaves.
>>
>> Signed-off-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> ---
>> drivers/i2c/i2c-core.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
>> index 952d2f0c02c5..71ad532be1d8 100644
>> --- a/drivers/i2c/i2c-core.c
>> +++ b/drivers/i2c/i2c-core.c
>> @@ -1452,7 +1452,7 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
>>
>> static void of_i2c_register_devices(struct i2c_adapter *adap)
>> {
>> - struct device_node *node;
>> + struct device_node *bus, *node;
>>
>> /* Only register child devices if the adapter has a node pointer set */
>> if (!adap->dev.of_node)
>> @@ -1460,11 +1460,17 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
>>
>> dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
>>
>> - for_each_available_child_of_node(adap->dev.of_node, node) {
>> + bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
>> + if (!bus)
>> + bus = of_node_get(adap->dev.of_node);
>> +
>> + for_each_available_child_of_node(bus, node) {
>> if (of_node_test_and_set_flag(node, OF_POPULATED))
>> continue;
>> of_i2c_register_device(adap, node);
>> }
>> +
>> + of_node_put(bus);
>> }
>
> Sorry for not commenting earlier, but I only found the issue yesterday.
>
> I'm bothered as well by the "modalias failure" error message but in my
> case the node doesn't have any i2c devices, so this patch isn't a
> complete solution to that problem.

But it is a i2c adapter correct? I guess I don't completely understand
the problem?

> Has this been considered already?

Why can't you add a place-holder 'i2c-bus' node for i2c devices so when
they are adding in the future they are placed under this node? This is
what I did for dpaux. See patch 12/12 of this series.

Jon

--
nvpublic