diff mbox series

[6/6] clk: qcom: Fix APSS PLL and RCG Configuration

Message ID 20230113143647.14961-7-quic_devipriy@quicinc.com
State New
Headers show
Series Add APSS clock controller support for IPQ9574 | expand

Commit Message

Devi Priya Jan. 13, 2023, 2:36 p.m. UTC
Included CLK_IS_CRITICAL flag which helps to properly enable
the APSS PLL during bootup.
clk_rcg2_ops should be used for APSS clock RCG, as other ops
will not configure the RCG register

Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
Signed-off-by: devi priya <quic_devipriy@quicinc.com>
---
 drivers/clk/qcom/apss-ipq-pll.c | 1 +
 drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

Comments

Konrad Dybcio Jan. 13, 2023, 3:20 p.m. UTC | #1
On 13.01.2023 15:36, devi priya wrote:
> Included CLK_IS_CRITICAL flag which helps to properly enable
> the APSS PLL during bootup.
Please describe the issue and not only the user-visible impact it
makes. Does the PLL get shut down by clk_ignore_unused? Maybe you
would be interested in the sync_state changes that landed in recent
-next that may solve it for you?

I don't think it should be always-on, as you have an alternate source
for low power modes, adding CLK_IS_CRITICAL will keep the PLL enabled
even if you're not using it.

> clk_rcg2_ops should be used for APSS clock RCG, as other ops
> will not configure the RCG register
RCG register meaning RCG register*s*, meaning in this case M/N/D
which would be required for proper rate setting and not only input
switching (which arguably doesn't seem to be of much concern on a
single-parent clock)? This all is not obvious..

Konrad
> 
> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
> Signed-off-by: devi priya <quic_devipriy@quicinc.com>
> ---
>  drivers/clk/qcom/apss-ipq-pll.c | 1 +
>  drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/qcom/apss-ipq-pll.c b/drivers/clk/qcom/apss-ipq-pll.c
> index dd0c01bf5a98..75486a124fcd 100644
> --- a/drivers/clk/qcom/apss-ipq-pll.c
> +++ b/drivers/clk/qcom/apss-ipq-pll.c
> @@ -33,6 +33,7 @@ static struct clk_alpha_pll ipq_pll = {
>  			},
>  			.num_parents = 1,
>  			.ops = &clk_alpha_pll_huayra_ops,
> +			.flags = CLK_IS_CRITICAL,
>  		},
>  	},
>  };
> diff --git a/drivers/clk/qcom/apss-ipq6018.c b/drivers/clk/qcom/apss-ipq6018.c
> index f2f502e2d5a4..0d0e7196a4dc 100644
> --- a/drivers/clk/qcom/apss-ipq6018.c
> +++ b/drivers/clk/qcom/apss-ipq6018.c
> @@ -33,15 +33,21 @@ static const struct parent_map parents_apcs_alias0_clk_src_map[] = {
>  	{ P_APSS_PLL_EARLY, 5 },
>  };
>  
> +static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
> +	{ .src = P_APSS_PLL_EARLY, .pre_div = 1 },
> +	{ }
> +};
> +
>  static struct clk_rcg2 apcs_alias0_clk_src = {
>  	.cmd_rcgr = 0x0050,
> +	.freq_tbl = ftbl_apcs_alias0_clk_src,
>  	.hid_width = 5,
>  	.parent_map = parents_apcs_alias0_clk_src_map,
>  	.clkr.hw.init = &(struct clk_init_data){
>  		.name = "apcs_alias0_clk_src",
>  		.parent_data = parents_apcs_alias0_clk_src,
>  		.num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
> -		.ops = &clk_rcg2_mux_closest_ops,
> +		.ops = &clk_rcg2_ops,
>  		.flags = CLK_SET_RATE_PARENT,
>  	},
>  };
Devi Priya Jan. 31, 2023, 9:17 a.m. UTC | #2
Thanks for taking time to review the patch

On 1/13/2023 8:50 PM, Konrad Dybcio wrote:
> 
> 
> On 13.01.2023 15:36, devi priya wrote:
>> Included CLK_IS_CRITICAL flag which helps to properly enable
>> the APSS PLL during bootup.
> Please describe the issue and not only the user-visible impact it
> makes. Does the PLL get shut down by clk_ignore_unused? Maybe you
> would be interested in the sync_state changes that landed in recent
> -next that may solve it for you?
> 
> I don't think it should be always-on, as you have an alternate source
> for low power modes, adding CLK_IS_CRITICAL will keep the PLL enabled
> even if you're not using it.
Yeah, got it. Will drop the critical flag
> 
>> clk_rcg2_ops should be used for APSS clock RCG, as other ops
>> will not configure the RCG register
> RCG register meaning RCG register*s*, meaning in this case M/N/D
> which would be required for proper rate setting and not only input
> switching (which arguably doesn't seem to be of much concern on a
> single-parent clock)? This all is not obvious..
> 
> Konrad
The source selection is done by configuring the RCGR config register 
with the source entry (P_APSS_PLL_EARLY) added to the frequency table. 
Proper rate is achieved by configuring the PLL and hence M/N/D values 
are not configured
>>
>> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>> Signed-off-by: devi priya <quic_devipriy@quicinc.com>
>> ---
>>   drivers/clk/qcom/apss-ipq-pll.c | 1 +
>>   drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
>>   2 files changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/qcom/apss-ipq-pll.c b/drivers/clk/qcom/apss-ipq-pll.c
>> index dd0c01bf5a98..75486a124fcd 100644
>> --- a/drivers/clk/qcom/apss-ipq-pll.c
>> +++ b/drivers/clk/qcom/apss-ipq-pll.c
>> @@ -33,6 +33,7 @@ static struct clk_alpha_pll ipq_pll = {
>>   			},
>>   			.num_parents = 1,
>>   			.ops = &clk_alpha_pll_huayra_ops,
>> +			.flags = CLK_IS_CRITICAL,
>>   		},
>>   	},
>>   };
>> diff --git a/drivers/clk/qcom/apss-ipq6018.c b/drivers/clk/qcom/apss-ipq6018.c
>> index f2f502e2d5a4..0d0e7196a4dc 100644
>> --- a/drivers/clk/qcom/apss-ipq6018.c
>> +++ b/drivers/clk/qcom/apss-ipq6018.c
>> @@ -33,15 +33,21 @@ static const struct parent_map parents_apcs_alias0_clk_src_map[] = {
>>   	{ P_APSS_PLL_EARLY, 5 },
>>   };
>>   
>> +static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
>> +	{ .src = P_APSS_PLL_EARLY, .pre_div = 1 },
>> +	{ }
>> +};
>> +
>>   static struct clk_rcg2 apcs_alias0_clk_src = {
>>   	.cmd_rcgr = 0x0050,
>> +	.freq_tbl = ftbl_apcs_alias0_clk_src,
>>   	.hid_width = 5,
>>   	.parent_map = parents_apcs_alias0_clk_src_map,
>>   	.clkr.hw.init = &(struct clk_init_data){
>>   		.name = "apcs_alias0_clk_src",
>>   		.parent_data = parents_apcs_alias0_clk_src,
>>   		.num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
>> -		.ops = &clk_rcg2_mux_closest_ops,
>> +		.ops = &clk_rcg2_ops,
>>   		.flags = CLK_SET_RATE_PARENT,
>>   	},
>>   };
Best Regards,
Devi Priya
Devi Priya Jan. 31, 2023, 9:23 a.m. UTC | #3
Thanks for taking time to review the patch!

On 1/13/2023 9:47 PM, Robert Marko wrote:
> 
> On 13. 01. 2023. 16:20, Konrad Dybcio wrote:
>>
>> On 13.01.2023 15:36, devi priya wrote:
>>> Included CLK_IS_CRITICAL flag which helps to properly enable
>>> the APSS PLL during bootup.
>> Please describe the issue and not only the user-visible impact it
>> makes. Does the PLL get shut down by clk_ignore_unused? Maybe you
>> would be interested in the sync_state changes that landed in recent
>> -next that may solve it for you?
>>
>> I don't think it should be always-on, as you have an alternate source
>> for low power modes, adding CLK_IS_CRITICAL will keep the PLL enabled
>> even if you're not using it.
> 
> I have the same opinion, as this is working fine on IPQ6018 and IPQ8074
> and I have not experienced any issues with it.
> 
Sure, will drop the critical flag
>>
>>> clk_rcg2_ops should be used for APSS clock RCG, as other ops
>>> will not configure the RCG register
>> RCG register meaning RCG register*s*, meaning in this case M/N/D
>> which would be required for proper rate setting and not only input
>> switching (which arguably doesn't seem to be of much concern on a
>> single-parent clock)? This all is not obvious..
> Same question from me as well, why do you need clk_rcg2_ops with
> a dummy frequency table since this is just a mux using RCG2 control
> bits?
> 
> Regards,
> Robert
>>
The RCGR is used for source selection whereas the rate setting is done 
by configuring the PLL. The source is configured in the RCGR using the 
source entry (P_APSS_PLL_EARLY) added to the frequency table.

>> Konrad
>>> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>> Signed-off-by: devi priya <quic_devipriy@quicinc.com>
>>> ---
>>>   drivers/clk/qcom/apss-ipq-pll.c | 1 +
>>>   drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
>>>   2 files changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clk/qcom/apss-ipq-pll.c 
>>> b/drivers/clk/qcom/apss-ipq-pll.c
>>> index dd0c01bf5a98..75486a124fcd 100644
>>> --- a/drivers/clk/qcom/apss-ipq-pll.c
>>> +++ b/drivers/clk/qcom/apss-ipq-pll.c
>>> @@ -33,6 +33,7 @@ static struct clk_alpha_pll ipq_pll = {
>>>               },
>>>               .num_parents = 1,
>>>               .ops = &clk_alpha_pll_huayra_ops,
>>> +            .flags = CLK_IS_CRITICAL,
>>>           },
>>>       },
>>>   };
>>> diff --git a/drivers/clk/qcom/apss-ipq6018.c 
>>> b/drivers/clk/qcom/apss-ipq6018.c
>>> index f2f502e2d5a4..0d0e7196a4dc 100644
>>> --- a/drivers/clk/qcom/apss-ipq6018.c
>>> +++ b/drivers/clk/qcom/apss-ipq6018.c
>>> @@ -33,15 +33,21 @@ static const struct parent_map 
>>> parents_apcs_alias0_clk_src_map[] = {
>>>       { P_APSS_PLL_EARLY, 5 },
>>>   };
>>> +static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
>>> +    { .src = P_APSS_PLL_EARLY, .pre_div = 1 },
>>> +    { }
>>> +};
>>> +
>>>   static struct clk_rcg2 apcs_alias0_clk_src = {
>>>       .cmd_rcgr = 0x0050,
>>> +    .freq_tbl = ftbl_apcs_alias0_clk_src,
>>>       .hid_width = 5,
>>>       .parent_map = parents_apcs_alias0_clk_src_map,
>>>       .clkr.hw.init = &(struct clk_init_data){
>>>           .name = "apcs_alias0_clk_src",
>>>           .parent_data = parents_apcs_alias0_clk_src,
>>>           .num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
>>> -        .ops = &clk_rcg2_mux_closest_ops,
>>> +        .ops = &clk_rcg2_ops,
>>>           .flags = CLK_SET_RATE_PARENT,
>>>       },
>>>   };
>>
Best Regards,
Devi Priya
Dmitry Baryshkov Jan. 31, 2023, 9:40 a.m. UTC | #4
On 31/01/2023 11:17, Devi Priya wrote:
> Thanks for taking time to review the patch
> 
> On 1/13/2023 8:50 PM, Konrad Dybcio wrote:
>>
>>
>> On 13.01.2023 15:36, devi priya wrote:
>>> Included CLK_IS_CRITICAL flag which helps to properly enable
>>> the APSS PLL during bootup.
>> Please describe the issue and not only the user-visible impact it
>> makes. Does the PLL get shut down by clk_ignore_unused? Maybe you
>> would be interested in the sync_state changes that landed in recent
>> -next that may solve it for you?
>>
>> I don't think it should be always-on, as you have an alternate source
>> for low power modes, adding CLK_IS_CRITICAL will keep the PLL enabled
>> even if you're not using it.
> Yeah, got it. Will drop the critical flag
>>
>>> clk_rcg2_ops should be used for APSS clock RCG, as other ops
>>> will not configure the RCG register
>> RCG register meaning RCG register*s*, meaning in this case M/N/D
>> which would be required for proper rate setting and not only input
>> switching (which arguably doesn't seem to be of much concern on a
>> single-parent clock)? This all is not obvious..
>>
>> Konrad
> The source selection is done by configuring the RCGR config register 
> with the source entry (P_APSS_PLL_EARLY) added to the frequency table. 
> Proper rate is achieved by configuring the PLL and hence M/N/D values 
> are not configured

But the clk_rcg2_mux_closest_ops also programs the parent for the clock. 
So from your description it isn't obvious what is wrong with the current 
_ops used for the clock.

>>>
>>> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>> Signed-off-by: devi priya <quic_devipriy@quicinc.com>
>>> ---
>>>   drivers/clk/qcom/apss-ipq-pll.c | 1 +
>>>   drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
>>>   2 files changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clk/qcom/apss-ipq-pll.c 
>>> b/drivers/clk/qcom/apss-ipq-pll.c
>>> index dd0c01bf5a98..75486a124fcd 100644
>>> --- a/drivers/clk/qcom/apss-ipq-pll.c
>>> +++ b/drivers/clk/qcom/apss-ipq-pll.c
>>> @@ -33,6 +33,7 @@ static struct clk_alpha_pll ipq_pll = {
>>>               },
>>>               .num_parents = 1,
>>>               .ops = &clk_alpha_pll_huayra_ops,
>>> +            .flags = CLK_IS_CRITICAL,
>>>           },
>>>       },
>>>   };
>>> diff --git a/drivers/clk/qcom/apss-ipq6018.c 
>>> b/drivers/clk/qcom/apss-ipq6018.c
>>> index f2f502e2d5a4..0d0e7196a4dc 100644
>>> --- a/drivers/clk/qcom/apss-ipq6018.c
>>> +++ b/drivers/clk/qcom/apss-ipq6018.c
>>> @@ -33,15 +33,21 @@ static const struct parent_map 
>>> parents_apcs_alias0_clk_src_map[] = {
>>>       { P_APSS_PLL_EARLY, 5 },
>>>   };
>>> +static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
>>> +    { .src = P_APSS_PLL_EARLY, .pre_div = 1 },
>>> +    { }
>>> +};
>>> +
>>>   static struct clk_rcg2 apcs_alias0_clk_src = {
>>>       .cmd_rcgr = 0x0050,
>>> +    .freq_tbl = ftbl_apcs_alias0_clk_src,
>>>       .hid_width = 5,
>>>       .parent_map = parents_apcs_alias0_clk_src_map,
>>>       .clkr.hw.init = &(struct clk_init_data){
>>>           .name = "apcs_alias0_clk_src",
>>>           .parent_data = parents_apcs_alias0_clk_src,
>>>           .num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
>>> -        .ops = &clk_rcg2_mux_closest_ops,
>>> +        .ops = &clk_rcg2_ops,
>>>           .flags = CLK_SET_RATE_PARENT,
>>>       },
>>>   };
> Best Regards,
> Devi Priya
Devi Priya Feb. 1, 2023, 2:40 p.m. UTC | #5
On 1/31/2023 3:10 PM, Dmitry Baryshkov wrote:
> On 31/01/2023 11:17, Devi Priya wrote:
>> Thanks for taking time to review the patch
>>
>> On 1/13/2023 8:50 PM, Konrad Dybcio wrote:
>>>
>>>
>>> On 13.01.2023 15:36, devi priya wrote:
>>>> Included CLK_IS_CRITICAL flag which helps to properly enable
>>>> the APSS PLL during bootup.
>>> Please describe the issue and not only the user-visible impact it
>>> makes. Does the PLL get shut down by clk_ignore_unused? Maybe you
>>> would be interested in the sync_state changes that landed in recent
>>> -next that may solve it for you?
>>>
>>> I don't think it should be always-on, as you have an alternate source
>>> for low power modes, adding CLK_IS_CRITICAL will keep the PLL enabled
>>> even if you're not using it.
>> Yeah, got it. Will drop the critical flag
>>>
>>>> clk_rcg2_ops should be used for APSS clock RCG, as other ops
>>>> will not configure the RCG register
>>> RCG register meaning RCG register*s*, meaning in this case M/N/D
>>> which would be required for proper rate setting and not only input
>>> switching (which arguably doesn't seem to be of much concern on a
>>> single-parent clock)? This all is not obvious..
>>>
>>> Konrad
>> The source selection is done by configuring the RCGR config register 
>> with the source entry (P_APSS_PLL_EARLY) added to the frequency table. 
>> Proper rate is achieved by configuring the PLL and hence M/N/D values 
>> are not configured
> 
> But the clk_rcg2_mux_closest_ops also programs the parent for the clock. 
> So from your description it isn't obvious what is wrong with the current 
> _ops used for the clock.
> 
Okay, understood & agreed.
Will re-verify it once and update it accordingly in V2
>>>>
>>>> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>>> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
>>>> Signed-off-by: devi priya <quic_devipriy@quicinc.com>
>>>> ---
>>>>   drivers/clk/qcom/apss-ipq-pll.c | 1 +
>>>>   drivers/clk/qcom/apss-ipq6018.c | 8 +++++++-
>>>>   2 files changed, 8 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/clk/qcom/apss-ipq-pll.c 
>>>> b/drivers/clk/qcom/apss-ipq-pll.c
>>>> index dd0c01bf5a98..75486a124fcd 100644
>>>> --- a/drivers/clk/qcom/apss-ipq-pll.c
>>>> +++ b/drivers/clk/qcom/apss-ipq-pll.c
>>>> @@ -33,6 +33,7 @@ static struct clk_alpha_pll ipq_pll = {
>>>>               },
>>>>               .num_parents = 1,
>>>>               .ops = &clk_alpha_pll_huayra_ops,
>>>> +            .flags = CLK_IS_CRITICAL,
>>>>           },
>>>>       },
>>>>   };
>>>> diff --git a/drivers/clk/qcom/apss-ipq6018.c 
>>>> b/drivers/clk/qcom/apss-ipq6018.c
>>>> index f2f502e2d5a4..0d0e7196a4dc 100644
>>>> --- a/drivers/clk/qcom/apss-ipq6018.c
>>>> +++ b/drivers/clk/qcom/apss-ipq6018.c
>>>> @@ -33,15 +33,21 @@ static const struct parent_map 
>>>> parents_apcs_alias0_clk_src_map[] = {
>>>>       { P_APSS_PLL_EARLY, 5 },
>>>>   };
>>>> +static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
>>>> +    { .src = P_APSS_PLL_EARLY, .pre_div = 1 },
>>>> +    { }
>>>> +};
>>>> +
>>>>   static struct clk_rcg2 apcs_alias0_clk_src = {
>>>>       .cmd_rcgr = 0x0050,
>>>> +    .freq_tbl = ftbl_apcs_alias0_clk_src,
>>>>       .hid_width = 5,
>>>>       .parent_map = parents_apcs_alias0_clk_src_map,
>>>>       .clkr.hw.init = &(struct clk_init_data){
>>>>           .name = "apcs_alias0_clk_src",
>>>>           .parent_data = parents_apcs_alias0_clk_src,
>>>>           .num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
>>>> -        .ops = &clk_rcg2_mux_closest_ops,
>>>> +        .ops = &clk_rcg2_ops,
>>>>           .flags = CLK_SET_RATE_PARENT,
>>>>       },
>>>>   };
>> Best Regards,
>> Devi Priya
> 
Best Regards,
Devi Priya
diff mbox series

Patch

diff --git a/drivers/clk/qcom/apss-ipq-pll.c b/drivers/clk/qcom/apss-ipq-pll.c
index dd0c01bf5a98..75486a124fcd 100644
--- a/drivers/clk/qcom/apss-ipq-pll.c
+++ b/drivers/clk/qcom/apss-ipq-pll.c
@@ -33,6 +33,7 @@  static struct clk_alpha_pll ipq_pll = {
 			},
 			.num_parents = 1,
 			.ops = &clk_alpha_pll_huayra_ops,
+			.flags = CLK_IS_CRITICAL,
 		},
 	},
 };
diff --git a/drivers/clk/qcom/apss-ipq6018.c b/drivers/clk/qcom/apss-ipq6018.c
index f2f502e2d5a4..0d0e7196a4dc 100644
--- a/drivers/clk/qcom/apss-ipq6018.c
+++ b/drivers/clk/qcom/apss-ipq6018.c
@@ -33,15 +33,21 @@  static const struct parent_map parents_apcs_alias0_clk_src_map[] = {
 	{ P_APSS_PLL_EARLY, 5 },
 };
 
+static const struct freq_tbl ftbl_apcs_alias0_clk_src[] = {
+	{ .src = P_APSS_PLL_EARLY, .pre_div = 1 },
+	{ }
+};
+
 static struct clk_rcg2 apcs_alias0_clk_src = {
 	.cmd_rcgr = 0x0050,
+	.freq_tbl = ftbl_apcs_alias0_clk_src,
 	.hid_width = 5,
 	.parent_map = parents_apcs_alias0_clk_src_map,
 	.clkr.hw.init = &(struct clk_init_data){
 		.name = "apcs_alias0_clk_src",
 		.parent_data = parents_apcs_alias0_clk_src,
 		.num_parents = ARRAY_SIZE(parents_apcs_alias0_clk_src),
-		.ops = &clk_rcg2_mux_closest_ops,
+		.ops = &clk_rcg2_ops,
 		.flags = CLK_SET_RATE_PARENT,
 	},
 };