Re: [PATCH v3 2/2] i2c: qcom-target: Add driver for Qualcomm I2C target controller

From: Konrad Dybcio

Date: Wed Aug 26 2026 - 09:06:16 EST


On 8/26/26 2:52 PM, Viken Dadhaniya wrote:
>
>
> On 8/25/2026 3:11 PM, Konrad Dybcio wrote:
>> On 8/13/26 5:52 PM, Viken Dadhaniya wrote:
>>> QDU1000 and related Qualcomm SoCs include a dedicated I2C target
>>> controller that operates exclusively in target mode. The existing
>>> Qualcomm I2C controller drivers (GENI, QUP) are master-only and cannot
>>> serve systems where the SoC must respond as an I2C target on the bus.
>>
>> [...]
>>
>>> + ret = clk_prepare_enable(target->xo_clk);
>>> + if (ret)
>>> + return dev_err_probe(dev, ret, "failed to enable XO clock\n");
>>> +
>>> + ret = clk_prepare_enable(target->ahb_clk);
>>> + if (ret) {
>>> + clk_disable_unprepare(target->xo_clk);
>>> + return dev_err_probe(dev, ret, "failed to enable AHB clock\n");
>>> + }
>>
>> Does this need an OPP table? Presumably we need a power vote for each bus
>> frequency
>
> The xo and ahb are simple gate clocks with no rate states —
> xo runs at a fixed 19.2 MHz and the ahb rate is fabric-managed.
> Since this is a target-only controller the master drives bus speed,
> so there is nothing for us to scale. OPP is not needed here

OK, thanks for confirming.

Konrad