[PATCH RFC/RFT 0/3] omap24xx_i2c: Enable Repeated Start functionality

[Aniket Limaye]

Hello Tom, Heiko,

On 06/03/25 11:15, Heiko Schocher wrote:
> Hello Tom, Aniket,
> 
> On 05.03.25 16:50, Tom Rini wrote:
>> On Wed, Mar 05, 2025 at 03:34:08AM +0530, Aniket Limaye wrote:
>>> This series implements Repeated Start functionality for the DM_I2C xfer
>>> API (omap_i2c_xfer())
>>>
>>> First, split out the actual implementation for each individual i2c msg
>>> transfer into a new function __omap24_i2c_xfer_msg() and use this to
>>> implement omap_i2c_xfer().
>>>
>>> Then, add support for the Repeated Start condition in omap_i2c_xfer()
>>> through the CONFIG_I2C_REPEATED_START option.
>>>
>>> Also add this config to Kconfig and enable it for ARCH_K3 platforms by
>>> default.
>>>
>>> Test logs (On AM68-SK with additional debug prints):
>>> https://gist.github.com/aniket-l/8c64c5bc81246751a02836a96510df14
>>>
>>> Requesting reviews/testing on specifically the CONFIG_I2C_REPEATED_START
>>> addition:
>>> - Is the Kconfig needed or should we simply always default to not
>>>    sending Stop bit? Drivers can use i2c_msg.flags to request Stop bit
>>>    for each msg, same as in the Linux Kernel i2c-omap driver[0].
>>
>> Yes, a Kconfig is needed as this driver works (as implied by the name)
>> on so much old and differently buggy IP.
>>
>>> - If yes, Should we re-use CONFIG_I2C_REPEATED_START from the legacy
>>>    implementation of the driver or define a new config
>>
>> Lets pick a new option, under the SYS_I2C_OMAP24XX namespace (and remove
>> the legacy and unused variant).
>>

I will update the patch with the proper namespace for this config.

The legacy one (CONFIG_I2C_REPEATED_START) was never added to Kconfig at 
all... So will just leave it be ( unless you meant remove support for it 
from the legacy driver code as well and use this new one instead? )

>>> - Default enable it for K3 devices?
>>
>> I'm fine with that.
>>
> 
> Yep, fully aggree, we need the Kconfig symbol for backward compatibility.
> 
> Thanks!
> 
> bye,
> Heiko


Thanks for your reviews!

Regards,
Aniket