diff mbox series

[2/2] clk: qcom: gcc-msm8996: Use read-only RCG ops for RPM bus clocks

Message ID 20230612-topic-rcg2_ro-v1-2-e7d824aeb628@linaro.org
State New
Headers show
Series Add read-only RCG2 ops | expand

Commit Message

Konrad Dybcio June 12, 2023, 9:22 a.m. UTC
The config/periph/system NoC clocks are wholly controlled by the
RPM firmware and Linux should never ever alter their configuration.

Switch them over to read-only ops to avoid that.

Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/clk/qcom/gcc-msm8996.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Konrad Dybcio June 13, 2023, 5:54 p.m. UTC | #1
On 13.06.2023 19:56, Bjorn Andersson wrote:
> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>> The config/periph/system NoC clocks are wholly controlled by the
>> RPM firmware and Linux should never ever alter their configuration.
>>
> 
> Does Linux need to know about them?
Not really, but it allows us to get rates of their children.

We can get rid of them if one can argue debugcc is enough. Unless
we need clk_get_rate for some reason.

Konrad
> 
> Regards,
> Bjorn
> 
>> Switch them over to read-only ops to avoid that.
>>
>> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>  drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
>> index 5e44d1bcca9e..588e3b67657a 100644
>> --- a/drivers/clk/qcom/gcc-msm8996.c
>> +++ b/drivers/clk/qcom/gcc-msm8996.c
>> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>>  		.name = "system_noc_clk_src",
>>  		.parent_data = gcc_xo_gpll0_gpll0_early_div,
>>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
>> -		.ops = &clk_rcg2_ops,
>> +		.ops = &clk_rcg2_ro_ops,
>>  	},
>>  };
>>  
>> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>>  		.name = "config_noc_clk_src",
>>  		.parent_data = gcc_xo_gpll0,
>>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> -		.ops = &clk_rcg2_ops,
>> +		.ops = &clk_rcg2_ro_ops,
>>  	},
>>  };
>>  
>> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>>  		.name = "periph_noc_clk_src",
>>  		.parent_data = gcc_xo_gpll0,
>>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> -		.ops = &clk_rcg2_ops,
>> +		.ops = &clk_rcg2_ro_ops,
>>  	},
>>  };
>>  
>>
>> -- 
>> 2.41.0
>>
Bjorn Andersson June 13, 2023, 5:56 p.m. UTC | #2
On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
> The config/periph/system NoC clocks are wholly controlled by the
> RPM firmware and Linux should never ever alter their configuration.
> 

Does Linux need to know about them?

Regards,
Bjorn

> Switch them over to read-only ops to avoid that.
> 
> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>  drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
> index 5e44d1bcca9e..588e3b67657a 100644
> --- a/drivers/clk/qcom/gcc-msm8996.c
> +++ b/drivers/clk/qcom/gcc-msm8996.c
> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>  		.name = "system_noc_clk_src",
>  		.parent_data = gcc_xo_gpll0_gpll0_early_div,
>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
> -		.ops = &clk_rcg2_ops,
> +		.ops = &clk_rcg2_ro_ops,
>  	},
>  };
>  
> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>  		.name = "config_noc_clk_src",
>  		.parent_data = gcc_xo_gpll0,
>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> -		.ops = &clk_rcg2_ops,
> +		.ops = &clk_rcg2_ro_ops,
>  	},
>  };
>  
> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>  		.name = "periph_noc_clk_src",
>  		.parent_data = gcc_xo_gpll0,
>  		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> -		.ops = &clk_rcg2_ops,
> +		.ops = &clk_rcg2_ro_ops,
>  	},
>  };
>  
> 
> -- 
> 2.41.0
>
Konrad Dybcio July 31, 2023, 11:01 a.m. UTC | #3
On 13.06.2023 19:54, Konrad Dybcio wrote:
> 
> 
> On 13.06.2023 19:56, Bjorn Andersson wrote:
>> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>>> The config/periph/system NoC clocks are wholly controlled by the
>>> RPM firmware and Linux should never ever alter their configuration.
>>>
>>
>> Does Linux need to know about them?
> Not really, but it allows us to get rates of their children.
> 
> We can get rid of them if one can argue debugcc is enough. Unless
> we need clk_get_rate for some reason.
> 
Any opinions?

Konrad
Dmitry Baryshkov Aug. 24, 2023, 11:32 a.m. UTC | #4
On Thu, 24 Aug 2023 at 13:28, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>
> On 31.07.2023 13:01, Konrad Dybcio wrote:
> > On 13.06.2023 19:54, Konrad Dybcio wrote:
> >>
> >>
> >> On 13.06.2023 19:56, Bjorn Andersson wrote:
> >>> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
> >>>> The config/periph/system NoC clocks are wholly controlled by the
> >>>> RPM firmware and Linux should never ever alter their configuration.
> >>>>
> >>>
> >>> Does Linux need to know about them?
> >> Not really, but it allows us to get rates of their children.
> >>
> >> We can get rid of them if one can argue debugcc is enough. Unless
> >> we need clk_get_rate for some reason.
> >>
> > Any opinions?
> So, do we drop them?

My opinion would be to drop the NoC clocks unless there is any extra
value (like child clocks).
diff mbox series

Patch

diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
index 5e44d1bcca9e..588e3b67657a 100644
--- a/drivers/clk/qcom/gcc-msm8996.c
+++ b/drivers/clk/qcom/gcc-msm8996.c
@@ -264,7 +264,7 @@  static struct clk_rcg2 system_noc_clk_src = {
 		.name = "system_noc_clk_src",
 		.parent_data = gcc_xo_gpll0_gpll0_early_div,
 		.num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
-		.ops = &clk_rcg2_ops,
+		.ops = &clk_rcg2_ro_ops,
 	},
 };
 
@@ -284,7 +284,7 @@  static struct clk_rcg2 config_noc_clk_src = {
 		.name = "config_noc_clk_src",
 		.parent_data = gcc_xo_gpll0,
 		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
-		.ops = &clk_rcg2_ops,
+		.ops = &clk_rcg2_ro_ops,
 	},
 };
 
@@ -306,7 +306,7 @@  static struct clk_rcg2 periph_noc_clk_src = {
 		.name = "periph_noc_clk_src",
 		.parent_data = gcc_xo_gpll0,
 		.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
-		.ops = &clk_rcg2_ops,
+		.ops = &clk_rcg2_ro_ops,
 	},
 };