[PATCH] i2c: i2c-gpio: fix issue when DT node greater than 1
Stephen Warren
swarren at wwwdotorg.org
Thu Sep 20 01:28:04 EST 2012
On 09/18/2012 07:15 PM, Bo Shen wrote:
> Hi Stephen Warren,
>
> On 9/18/2012 22:51, Stephen Warren wrote:
>> On 09/18/2012 03:02 AM, Bo Shen wrote:
>>> When i2c-gpio node number is greater than 1, the second can not
>>> sucessfully
>>> regiter
>>>
>>> Using alias method to get the pdev->id, or else the second device
>>> will use
>>> the same id which will cause fail to register
>>
>> pdev->id shouldn't be used at all with device tree. Why does
>> registration fail without this change?
>
> I add the debug info, and it give the following error without this patch.
>
> --<8----------------------------------
> adap->name = i2c-gpio-1
> i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
> adap->name = i2c-gpio-1
> i2c-gpio: probe of i2c.3 failed with error -16
> -->8----------------------------------
>
> With this patch, it successfully registered.
> --<8----------------------------------
> adap->name = i2c-gpio0
> i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
> adap->name = i2c-gpio1
> i2c-gpio i2c.3: using pins 90 (SDA) and 91 (SCL)
> -->8----------------------------------
Yes, that explains why the registration fails, but not why this patch is
the correct solution to the problem.
The problematic code appears to be:
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
Instead, I think that should be something more like:
adap->name = dev_name(&pdev->dev);
or perhaps:
if (pdev->dev.of_node)
/* named will be based on DT node name */
adap->name = dev_name(&pdev->dev);
else
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
?
More information about the devicetree-discuss
mailing list