Re: [EXT] I2C_IMX support for i.MX8MP

David Wolfson
2022-08-18T12:54:09Z

On Thu, Aug 18, 2022 at 11:59:41AM +0000, Shenwei Wang wrote:
>Hi Richard,
>
>Nothing is hidden here. That is PAD control register, and should be documented in the IOMUXC and PIN Control section in the RM.
>

Checking the IOMUX and PADs' settings is the first step when enabling
an interface.

David

>Regards,
>Shenwei
>
>> -----Original Message-----
>> From: Richard Leitner <richard.leitner@linux.dev>
>> Sent: Thursday, August 18, 2022 3:41 AM
>> To: Shenwei Wang <shenwei.wang@nxp.com>
>> Cc: imx@lists.linux.dev
>> Subject: Re: [EXT] I2C_IMX support for i.MX8MP
>>
>> Caution: EXT Email
>>
>> On Wed, Aug 17, 2022 at 02:14:53PM +0000, Shenwei Wang wrote:
>> >
>> > The support for imx8mp-evk board has already pushed to mainline. That
>> includes the usage of i2c-imx.
>> > For example, a GPIO expander is connected to I2C3 on evk board.
>>
>> Thanks again. It now works with linux v6.0-rc1.
>>
>> The missing piece was setting the 0x40000000 bit in the SW_PAD_CTL registers
>> of SCL and SDA.
>> Unfortunately this bit seems to be undocumented in the RefManual and also the
>> driver documentation doesn't state anything about it.
>>
>> Can you please shed some light in this "magic" bit? Would be really helpful,
>> thanks!
>>
>> Furthermore I guess documenting it somewhere in the driver or setting it
>> implicitely (if that's possible) would be a good idea?
>>
>> regards;rl