Re: [PATCH 2/4] clk: qcom: gcc: Add support for Global Clock controller found on MSM8940

From: Konrad Dybcio
Date: Mon Nov 17 2025 - 09:19:26 EST


On 11/17/25 3:02 PM, barnabas.czeman@xxxxxxxxxxxxxx wrote:
> On 2025-11-17 13:17, Konrad Dybcio wrote:
>> On 11/17/25 9:51 AM, Barnabás Czémán wrote:
>>>
>>>
>>> On 17 November 2025 09:03:53 CET, Taniya Das <taniya.das@xxxxxxxxxxxxxxxx> wrote:
>>>>
>>>>
>>>> On 11/17/2025 3:05 AM, Barnabás Czémán wrote:
>>>>>
>>>>> +static struct clk_branch gcc_ipa_tbu_clk = {
>>>>> +    .halt_reg = 0x120a0,
>>>>> +    .halt_check = BRANCH_VOTED,
>>>>> +    .clkr = {
>>>>> +        .enable_reg = 0x4500c,
>>>>> +        .enable_mask = BIT(16),
>>>>> +        .hw.init = &(struct clk_init_data){
>>>>> +            .name = "gcc_ipa_tbu_clk",
>>>>> +            .ops = &clk_branch2_ops,
>>>>> +        },
>>>>> +    },
>>>>> +};
>>>>> +
>>>>
>>>> Is the TBU clock used on 8940 by a SMMU driver?
>>> As far as I know no MSM8940 is using same smmu driver and bindings like MSM8937.
>>
>> On msm8939, the clock needed to be turned on for the GPU SMMU
> I have not got any qcom-iommu issues on 8940 but i think it could come when i try to add ipa2 driver
> for the SoC until i do not know where to check it.

I can't find a definitive answer, but it's most certainly going to be
necessary to turn it on

Konrad