linux-kernel - Re: [PATCH v2 1/3] clk: qcom: branch: Extend invert logic for branch2 mem clocks

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Message-ID: <0ec3b848-3fb0-4522-af1a-159fd7dc5dd4@oss.qualcomm.com>
Date: Wed, 3 Sep 2025 12:18:31 +0530
From: Taniya Das <taniya.das@....qualcomm.com>
To: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: Bjorn Andersson <andersson@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd
 <sboyd@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley
 <conor+dt@...nel.org>,
        Ajit Pandey <quic_ajipan@...cinc.com>,
        Imran Shaik <quic_imrashai@...cinc.com>,
        Jagadeesh Kona <quic_jkona@...cinc.com>, linux-arm-msm@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v2 1/3] clk: qcom: branch: Extend invert logic for branch2
 mem clocks



On 8/30/2025 5:47 AM, Dmitry Baryshkov wrote:
> On Fri, Aug 29, 2025 at 03:45:17PM +0530, Taniya Das wrote:
>> Some clock branches require inverted logic for memory gating, where
>> disabling the memory involves setting a bit and enabling it involves
>> clearing the same bit. This behavior differs from the standard approach
>> memory branch clocks ops where enabling typically sets the bit.
>>
>> Introducing the mem_enable_invert to allow conditional handling of
>> these sequences of the inverted control logic for memory operations
>> required on those memory clock branches.
>>
>> Signed-off-by: Taniya Das <taniya.das@....qualcomm.com>
>> ---
>>  drivers/clk/qcom/clk-branch.c | 14 +++++++++++---
>>  drivers/clk/qcom/clk-branch.h |  4 ++++
>>  2 files changed, 15 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/clk-branch.c b/drivers/clk/qcom/clk-branch.c
>> index 0f10090d4ae681babbdbbb1b6c68ffe77af7a784..90da1c94b4736f65c87aec92303d511c4aa9a173 100644
>> --- a/drivers/clk/qcom/clk-branch.c
>> +++ b/drivers/clk/qcom/clk-branch.c
>> @@ -142,8 +142,12 @@ static int clk_branch2_mem_enable(struct clk_hw *hw)
>>  	u32 val;
>>  	int ret;
>>  
>> -	regmap_update_bits(branch.clkr.regmap, mem_br->mem_enable_reg,
>> -			   mem_br->mem_enable_ack_mask, mem_br->mem_enable_ack_mask);
>> +	if (mem_br->mem_enable_invert)
>> +		regmap_update_bits(branch.clkr.regmap, mem_br->mem_enable_reg,
>> +				  mem_br->mem_enable_mask, 0);
>> +	else
>> +		regmap_update_bits(branch.clkr.regmap, mem_br->mem_enable_reg,
>> +				  mem_br->mem_enable_ack_mask, mem_br->mem_enable_ack_mask);
> 
> Please check that your lines are properly indented.
> 

Sorry, sure will fix in the next patch.

>>  
>>  	ret = regmap_read_poll_timeout(branch.clkr.regmap, mem_br->mem_ack_reg,
>>  				       val, val & mem_br->mem_enable_ack_mask, 0, 200);
>> @@ -159,7 +163,11 @@ static void clk_branch2_mem_disable(struct clk_hw *hw)
>>  {
>>  	struct clk_mem_branch *mem_br = to_clk_mem_branch(hw);
>>  
>> -	regmap_update_bits(mem_br->branch.clkr.regmap, mem_br->mem_enable_reg,
>> +	if (mem_br->mem_enable_invert)
>> +		regmap_update_bits(mem_br->branch.clkr.regmap, mem_br->mem_enable_reg,
>> +			   mem_br->mem_enable_mask, mem_br->mem_enable_mask);
> 
> This creates assymmetry. The drivers uses mem_enable_mask in one case
> and mem_enable_ack_mask in another.

Will try to use the common mask.

> 
>> +	else
>> +		regmap_update_bits(mem_br->branch.clkr.regmap, mem_br->mem_enable_reg,
>>  			   mem_br->mem_enable_ack_mask, 0);
> 
> And here.
> 

Will fix here too.

>>  
>>  	return clk_branch2_disable(hw);
>> diff --git a/drivers/clk/qcom/clk-branch.h b/drivers/clk/qcom/clk-branch.h
>> index 292756435f53648640717734af198442a315272e..6bc2ba2b5350554005b7f0c84f933580b7582fc7 100644
>> --- a/drivers/clk/qcom/clk-branch.h
>> +++ b/drivers/clk/qcom/clk-branch.h
>> @@ -44,6 +44,8 @@ struct clk_branch {
>>   * @mem_enable_reg: branch clock memory gating register
>>   * @mem_ack_reg: branch clock memory ack register
>>   * @mem_enable_ack_mask: branch clock memory enable and ack field in @mem_ack_reg
>> + * @mem_enable_mask: branch clock memory enable mask
>> + * @mem_enable_invert: branch clock memory enable and disable has invert logic
>>   * @branch: branch clock gating handle
>>   *
>>   * Clock which can gate its memories.
>> @@ -52,6 +54,8 @@ struct clk_mem_branch {
>>  	u32	mem_enable_reg;
>>  	u32	mem_ack_reg;
>>  	u32	mem_enable_ack_mask;
>> +	u32	mem_enable_mask;
>> +	bool	mem_enable_invert;
>>  	struct clk_branch branch;
>>  };
>>  
>>
>> -- 
>> 2.34.1
>>
> 

-- 
Thanks,
Taniya Das