Ben Dooks wrote:
> On Tue, Jun 02, 2009 at 07:52:40PM +0200, Richard R????jfors wrote:
>> There is sometimes a need for the ocores driver to add devices to the bus when installed.
>
> please wrap to 72 characters per line.
>
>> i2c_register_board_info can not always be used, because the I2C devices are not known at an early state,
>> they could for instance be connected on a I2C bus on a PCI device which has the Open Cores IP.
>
> Maybe i2c_register_board_info() needs to check if the bus is extant
> or not. Anyone else have any feedback on this suggestion?
>
>> i2c_new_device can not be used in all cases either since the resulting bus nummer might be unknown.
>>
>> The solution is the pass a list of I2C devices in the platform data to the Open Cores driver. Is
>> useful for MFD drivers for instance.
>
> Possibly, but most systems I see know what devices they have before
> instantiation so can hard-fix the bus numbering when supplying the MFD
> drivers with their data.
I agree, but we have a case here where PCI device(s) are plugged in to a
standard system so we really don't know the bus numbering.
>
>> Signed-off-by: Richard R??jfors <richard.rojfors.ext@xxxxxxxxxxxxxxx>
>> ---
>> Index: linux-2.6.30-rc7/drivers/i2c/busses/i2c-ocores.c
>> ===================================================================
>> --- linux-2.6.30-rc7/drivers/i2c/busses/i2c-ocores.c (revision 861)
>> +++ linux-2.6.30-rc7/drivers/i2c/busses/i2c-ocores.c (revision 862)
>> @@ -216,6 +216,7 @@
>> struct ocores_i2c_platform_data *pdata;
>> struct resource *res, *res2;
>> int ret;
>> + u8 i;
>
> really, an int will do here, you might find compilers on !x86 archs
> will spend time contracting this variable to an u8.
Agreed.
>
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> if (!res)
>> @@ -271,6 +272,10 @@
>> goto add_adapter_failed;
>> }
>>
>> + /* add in known devices to the bus */
>> + for (i = 0; i < pdata->num_devices; i++)
>> + i2c_new_device(&i2c->adap, pdata->devices + i);
>> +
>> return 0;
>>
>> add_adapter_failed:
>> Index: linux-2.6.30-rc7/include/linux/i2c-ocores.h
>> ===================================================================
>> --- linux-2.6.30-rc7/include/linux/i2c-ocores.h (revision 861)
>> +++ linux-2.6.30-rc7/include/linux/i2c-ocores.h (revision 862)
>> @@ -14,6 +14,8 @@
>> struct ocores_i2c_platform_data {
>> u32 regstep; /* distance between registers */
>> u32 clock_khz; /* input clock in kHz */
>> + u8 num_devices; /* number of devices in the devices list */
>> + struct i2c_board_info const *devices; /* devices connected to the bus */
>> };
>
> anyone want to kerneldoc this?
If you accept the patch, I will send an updated one with updated docs.
>
>> #endif /* _LINUX_I2C_OCORES_H */
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