[U-Boot] [PATCH v3 01/12] drivers: core: device: add support to check dt compatible for a device/machine

[Mugunthan V N]

On Monday 02 May 2016 12:24 AM, Simon Glass wrote:
> Hi Mugunthan,
> 
> On 28 April 2016 at 04:06, Mugunthan V N <mugunthanvnm at ti.com> wrote:
>> Provide an api to check whether the given device or machine is
>> compatible with the given compat string which helps in making
>> decisions in drivers based on device or machine compatible.
>>
>> Idea taken from Linux.
>>
>> Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
>> Reviewed-by: Joe Hershberger <joe.hershberger at ni.com>
>> ---
>>  drivers/core/device.c | 14 ++++++++++++++
>>  include/dm/device.h   | 23 +++++++++++++++++++++++
>>  2 files changed, 37 insertions(+)
>>
>> diff --git a/drivers/core/device.c b/drivers/core/device.c
>> index 1322991..8fdd193 100644
>> --- a/drivers/core/device.c
>> +++ b/drivers/core/device.c
>> @@ -715,3 +715,17 @@ int device_set_name(struct udevice *dev, const char *name)
>>
>>         return 0;
>>  }
>> +
>> +bool of_device_is_compatible(struct udevice *dev, const char *compat)
> 
> This function is in device.h, so I think device_is_compatible() is a
> better name. Where does compat come from? Is it another device, or
> something else entirely?

I have used the funtion names as is from the kernel so that porting
kernel driver to U-boot will be easier.

The compat comes from the driver which uses the API, compat is the
device compatible string like "ti,am3517-emac"

> 
>> +{
>> +       const void *fdt = gd->fdt_blob;
>> +
>> +       return !fdt_node_check_compatible(fdt, dev->of_offset, compat);
>> +}
>> +
>> +bool of_machine_is_compatible(const char *compat)
> 
> This should go in fdtdec.h I think. It doesn't have anything to do
> with devices. So fdtdec_machine_is_compatible().

I have used the funtion names as is from the kernel so that porting
kernel driver to U-boot will be easier.

> 
>> +{
>> +       const void *fdt = gd->fdt_blob;
>> +
>> +       return !fdt_node_check_compatible(fdt, 0, compat);
>> +}
>> diff --git a/include/dm/device.h b/include/dm/device.h
>> index 8970fc0..cd18e82 100644
>> --- a/include/dm/device.h
>> +++ b/include/dm/device.h
>> @@ -532,6 +532,29 @@ bool device_is_last_sibling(struct udevice *dev);
>>  int device_set_name(struct udevice *dev, const char *name);
>>
>>  /**
>> + * of_device_is_compatible() - check if the device is compatible with the compat
>> + *
>> + * This allows to check whether the device is comaptible with the compat.
>> + *
>> + * @dev:       udevice pointer for which compatible needs to be verified.
>> + * @compat:    Compatible string which needs to verified in the given
>> + *             device
>> + * @return true if OK, false if the compatible is not found
> 
> Does this mean false if @compat is not found in the device's
> compatible string list? Can you beef up the comment a bit to be
> specific?

Yes, return true if compatible is found. Will modify like below.

@return true if the compatible is found, false if the compatible is not
found

> 
>> + */
>> +bool of_device_is_compatible(struct udevice *dev, const char *compat);
>> +
>> +/**
>> + * of_machine_is_compatible() - check if the machine is compatible with
>> + *                             the compat
>> + *
>> + * This allows to check whether the machine is comaptible with the compat.
> 
> Again can you beef up the comment? What is machine? Where does it actually look?
> 

Will do.

>> + *
>> + * @compat:    Compatible string which needs to verified
>> + * @return true if OK, false if the compatible is not found
>> + */
>> +bool of_machine_is_compatible(const char *compat);
>> +
>> +/**
>>   * device_is_on_pci_bus - Test if a device is on a PCI bus
>>   *
>>   * @dev:       device to test
>> --
>> 2.8.1.339.g3ad15fd
>>
> 

Regards
Mugunthan V N