[v8,0/3] clk: qcom: clk-rcg2: introduce support for multiple conf for same freq

This small series fix a current problem with ipq8074 where the 2 uniphy
port doesn't work in some corner case with some clk configuration. The
port to correctly work require a specific frequency, using the wrong one
results in the port not transmitting data.

With the current code with a requested freq of 125MHz, the frequency is
set to 105MHz. This is caused by the fact that there are 2 different
configuration to set 125MHz and it's always selected the first one that
results in 105MHz.

In the original QSDK code, the frequency configuration selection is
different and the CEIL FLOOR logic is not present. Instead it's used a
BEST approach where the frequency table is checked and then it's checked
if there are duplicate entry.

This proposed implementation is more specific and introduce an entire new
set of ops and a specific freq table to support this special configuration.

A union is introduced in rcg2 struct to not duplicate the struct.
A new set of ops clk_rcg2_fm_ops are introduced to support this new kind
of frequency table.

Changes v8:
- Add Tested-by tag
- Fix typo in commit description
- Address requested fixup for Stephen
Changes v7:
- Improve handling of exit condition on missing parent.
Changes v6:
- Small rework of best_conf selection to mute Sparse warn.
Changes v5:
- Rework selection logic with suggestion from Konrad
- Return -EINVAL and WARN if we fail to find a correct conf
Changes v4:
- Drop suggested but wrong re-search patch
- Move everything to separate ops and struct to not affect current rcg2
  users.
Changes v3:
- Add qcom_find_freq_exact
- Drop re-search on rcg2_set_rate
- Rework multiple conf patch to follow new implementation
Changes v2:
- Out of RFC
- Fix compile warning from buildbot related to F redefinition

Christian Marangi (3):
  clk: qcom: clk-rcg: introduce support for multiple conf for same freq
  clk: qcom: clk-rcg2: add support for rcg2 freq multi ops
  clk: qcom: gcc-ipq8074: rework nss_port5/6 clock to multiple conf

 drivers/clk/qcom/clk-rcg.h     |  24 ++++-
 drivers/clk/qcom/clk-rcg2.c    | 166 +++++++++++++++++++++++++++++++++
 drivers/clk/qcom/common.c      |  18 ++++
 drivers/clk/qcom/common.h      |   2 +
 drivers/clk/qcom/gcc-ipq8074.c | 120 +++++++++++++++---------
 5 files changed, 285 insertions(+), 45 deletions(-)

Quoting Kathiravan Thirumoorthy (2024-01-22 09:46:23)
> 
> 
> On 12/21/2023 3:47 AM, Christian Marangi wrote:
> > This small series fix a current problem with ipq8074 where the 2 uniphy
> > port doesn't work in some corner case with some clk configuration. The
> > port to correctly work require a specific frequency, using the wrong one
> > results in the port not transmitting data.
> > 
> > With the current code with a requested freq of 125MHz, the frequency is
> > set to 105MHz. This is caused by the fact that there are 2 different
> > configuration to set 125MHz and it's always selected the first one that
> > results in 105MHz.
> > 
> > In the original QSDK code, the frequency configuration selection is
> > different and the CEIL FLOOR logic is not present. Instead it's used a
> > BEST approach where the frequency table is checked and then it's checked
> > if there are duplicate entry.
> > 
> > This proposed implementation is more specific and introduce an entire new
> > set of ops and a specific freq table to support this special configuration.
> > 
> > A union is introduced in rcg2 struct to not duplicate the struct.
> > A new set of ops clk_rcg2_fm_ops are introduced to support this new kind
> > of frequency table.
> > 
> 
> 
> Bjorn / Stephen Boyd,
> 
> I would like to know if there are any comments on this series. To enable 
> the clocks required for the Ethernet interfaces on the IPQ platforms, 
> these patches are needed. If no concerns, can this be picked up for v6.9?
> 

I'm fine if Bjorn wants to pick it up.

Acked-by: Stephen Boyd <sboyd@kernel.org>

On 4/11/2024 10:31 AM, Stephen Boyd wrote:
> Quoting Kathiravan Thirumoorthy (2024-01-22 09:46:23)
>>
>>
>> On 12/21/2023 3:47 AM, Christian Marangi wrote:
>>> This small series fix a current problem with ipq8074 where the 2 uniphy
>>> port doesn't work in some corner case with some clk configuration. The
>>> port to correctly work require a specific frequency, using the wrong one
>>> results in the port not transmitting data.
>>>
>>> With the current code with a requested freq of 125MHz, the frequency is
>>> set to 105MHz. This is caused by the fact that there are 2 different
>>> configuration to set 125MHz and it's always selected the first one that
>>> results in 105MHz.
>>>
>>> In the original QSDK code, the frequency configuration selection is
>>> different and the CEIL FLOOR logic is not present. Instead it's used a
>>> BEST approach where the frequency table is checked and then it's checked
>>> if there are duplicate entry.
>>>
>>> This proposed implementation is more specific and introduce an entire new
>>> set of ops and a specific freq table to support this special configuration.
>>>
>>> A union is introduced in rcg2 struct to not duplicate the struct.
>>> A new set of ops clk_rcg2_fm_ops are introduced to support this new kind
>>> of frequency table.
>>>
>>
>>
>> Bjorn / Stephen Boyd,
>>
>> I would like to know if there are any comments on this series. To enable
>> the clocks required for the Ethernet interfaces on the IPQ platforms,
>> these patches are needed. If no concerns, can this be picked up for v6.9?
>>
> 
> I'm fine if Bjorn wants to pick it up.
> 
> Acked-by: Stephen Boyd <sboyd@kernel.org>


Thanks Stephen. Bjorn, can this series picked up for v6.10, if no 
concerns from your side?

Thanks,
Kathiravan.

On Wed, 20 Dec 2023 23:17:21 +0100, Christian Marangi wrote:
> This small series fix a current problem with ipq8074 where the 2 uniphy
> port doesn't work in some corner case with some clk configuration. The
> port to correctly work require a specific frequency, using the wrong one
> results in the port not transmitting data.
> 
> With the current code with a requested freq of 125MHz, the frequency is
> set to 105MHz. This is caused by the fact that there are 2 different
> configuration to set 125MHz and it's always selected the first one that
> results in 105MHz.
> 
> [...]

Applied, thanks!

[1/3] clk: qcom: clk-rcg: introduce support for multiple conf for same freq
      commit: d06b1043644a1831ab141bbee2669002bba15b0f
[2/3] clk: qcom: clk-rcg2: add support for rcg2 freq multi ops
      commit: 89da22456af0762477d8c1345fdd17961b3ada80
[3/3] clk: qcom: gcc-ipq8074: rework nss_port5/6 clock to multiple conf
      commit: e88f03230dc07aa3293b6aeb078bd27370bb2594

Best regards,