Re: [PATCH v8 4/4] i2c: qcom-geni: Support multi-owner controllers in GPI mode

On 7/15/2026 5:54 PM, Konrad Dybcio wrote:
> On 7/8/26 7:10 AM, Mukesh Kumar Savaliya wrote:
>> Some platforms use a QUP-based I2C controller in a configuration where the
>> controller is shared with another system processor. In this setup the
>> operating system must not assume exclusive ownership of the controller or
>> its associated pins.
>>
>> Add support for enabling multi-owner operation when DeviceTree specifies
>> qcom,qup-multi-owner. When enabled, mark the underlying serial engine as
>> shared so the common GENI resource handling avoids selecting the "sleep"
>> pinctrl state, which could disrupt transfers initiated by the other
>> processor.
>>
>> For GPI mode transfers, request lock/unlock TRE sequencing from the GPI
>> driver by setting a single lock_action selector per message, emitting lock
>> before the first message and unlock after the last message (handling the
>> single-message case as well). This serializes access to the shared
>> controller without requiring message-position flags to be passed into the
>> DMA engine layer.
>>
>> Signed-off-by: Mukesh Kumar Savaliya <[email protected]>
>> ---
> 
> [...]
> 
> 
>> +		if (gi2c->se.multi_owner)
>> +			return dev_err_probe(gi2c->se.dev, -EINVAL,
>> +					     "I2C sharing not supported in non GSI mode\n");
> 
> ultra nit: "non-GSI"
> 
Will update in next patch.
>> +
>>   		tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
>>   
>>   		/* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
>> @@ -1098,6 +1115,11 @@ static int geni_i2c_probe(struct platform_device *pdev)
>>   		gi2c->clk_freq_out = I2C_MAX_STANDARD_MODE_FREQ;
>>   	}
>>   
>> +	if (of_property_read_bool(pdev->dev.of_node, "qcom,qup-multi-owner")) {
> 
> Let's use device_property_present() instead.
> 
Sure, Thanks for the suggestion and review. Will update in next patch.
> with that:
> 
> Reviewed-by: Konrad Dybcio <[email protected]>
> 
> Konrad