[U-Boot] [PATCH v3 1/6] dm: i2c: Add u8 read/write i2c functions

[Simon Glass]

Hi,

On 20 September 2016 at 06:42, Keerthy <a0393675 at ti.com> wrote:
>
>
> On Tuesday 20 September 2016 05:23 PM, Simon Glass wrote:
>>
>> Hi,
>>
>> On 19 September 2016 at 00:17, Keerthy <j-keerthy at ti.com> wrote:
>>>
>>> Add u8 i2c read/write hooks.
>>>
>>> Signed-off-by: Keerthy <j-keerthy at ti.com>
>>> ---
>>>  drivers/i2c/i2c-uclass.c | 10 ++++++++++
>>>  include/i2c.h            | 24 ++++++++++++++++++++++++
>>>  2 files changed, 34 insertions(+)
>>>
>>> diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
>>> index dbd3789..6ce5d9a 100644
>>> --- a/drivers/i2c/i2c-uclass.c
>>> +++ b/drivers/i2c/i2c-uclass.c
>>> @@ -231,6 +231,16 @@ int dm_i2c_reg_write(struct udevice *dev, uint
>>> offset, uint value)
>>>         return dm_i2c_write(dev, offset, &val, 1);
>>>  }
>>>
>>> +int dm_i2c_u8_read(struct udevice *dev, uint offset, u8 *val)
>>> +{
>>> +       return dm_i2c_read(dev, offset, val, 1);
>>> +}
>>> +
>>> +int dm_i2c_u8_write(struct udevice *dev, uint offset, u8 *val)
>>> +{
>>> +       return dm_i2c_write(dev, offset, val, 1);
>>> +}
>>
>>
>> These look almost the same as dm_i2c_reg_read/write(), but IMO those
>> are easier to use since they don't require a pointer to be passed. How
>> do you intend to use these two new functions?
>
>
> Simon,
>
> I see a kind of issue in the current implementation of
> int dm_i2c_reg_read(struct udevice *dev, uint offset)
> int dm_i2c_reg_write(struct udevice *dev, uint offset, uint value)
>
> In the current set up my need is to read and then write a 1 byte I2C
> register. It is best to have consistency with read and write.
> In the current case(dm_i2c_reg_read/write) i read an integer and now when i
> want to write i need to convert it to an unsigned integer.
>
> Instead of all this i made a patch which keeps u8 across read and write:
>
> int dm_i2c_reg_read(struct udevice *dev, uint offset, u8 *val)
> returns error/success with the return value and value is passed by reference
> in val variable.
>
> int dm_i2c_reg_write(struct udevice *dev, uint offset, u8 *val)
> returns error/success using the return value and the value to be written is
> sent in val.

Well I really don't see why you can use the other functions. But if
you prefer these, then OK.

>
> Regards,
> Keerthy
>
>
[...]

Regards,
Simon