[v3,0/8] Enable cpufreq for IPQ5332 & IPQ9574

Depends On:
https://lore.kernel.org/lkml/20230913-gpll_cleanup-v2-6-c8ceb1a37680@quicinc.com/T/

This patch series aims to enable cpufreq for IPQ5332 and IPQ9574.
For IPQ5332, a minor enhancement to Stromer Plus ops and a safe
source switch is needed before cpu freq can be enabled.

These are also included in this series. Posting this as a single
series. Please let me know if this is not correct, will split in
the subsequent revisions.

Passed the following DT related validations
make W=1 ARCH=arm64 -j16 DT_CHECKER_FLAGS='-v -m' dt_binding_check DT_SCHEMA_FILES=qcom
make W=1 ARCH=arm64 -j16 CHECK_DTBS=y DT_SCHEMA_FILES=qcom dtbs_check

For IPQ5332:
~~~~~~~~~~~
	* This patch series introduces stromer plus ops which
	  builds on stromer ops and implements a different
	  set_rate and determine_rate.

	  A different set_rate is needed since stromer plus PLLs
	  do not support dynamic frequency scaling. To switch
	  between frequencies, we have to shut down the PLL,
	  configure the L and ALPHA values and turn on again. So
	  introduce the separate set of ops for Stromer Plus PLL.

	* Update ipq_pll_stromer_plus to use clk_alpha_pll_stromer_plus_ops
	  instead of clk_alpha_pll_stromer_ops.

	* Set 'l' value to a value that is supported on all SKUs.

	* Provide safe source switch for a53pll

	* Include IPQ5332 in cpufreq nvmem framework

	* Add OPP details to device tree

For IPQ9574:
~~~~~~~~~~~
	* Include IPQ9574 in cpufreq nvmem framework

	* Add OPP details to device tree

Removed 2 patches from V1 as they have been merged
	* dt-bindings: cpufreq: qcom-cpufreq-nvmem: document IPQ5332
	* dt-bindings: cpufreq: qcom-cpufreq-nvmem: document IPQ9574

Varadarajan Narayanan (8):
  clk: qcom: clk-alpha-pll: introduce stromer plus ops
  clk: qcom: apss-ipq-pll: Use stromer plus ops for stromer plus pll
  clk: qcom: apss-ipq-pll: Fix 'l' value for ipq5332_pll_config
  clk: qcom: apss-ipq6018: ipq5332: add safe source switch for a53pll
  cpufreq: qti: Enable cpufreq for ipq53xx
  arm64: dts: qcom: ipq5332: populate the opp table based on the eFuse
  cpufreq: qti: Introduce cpufreq for ipq95xx
  arm64: dts: qcom: ipq9574: populate the opp table based on the eFuse

 arch/arm64/boot/dts/qcom/ipq5332.dtsi | 19 ++++++++++--
 arch/arm64/boot/dts/qcom/ipq9574.dtsi | 21 ++++++++++++-
 drivers/clk/qcom/apss-ipq-pll.c       |  4 +--
 drivers/clk/qcom/apss-ipq6018.c       | 58 ++++++++++++++++++++++++++++++++++-
 drivers/clk/qcom/clk-alpha-pll.c      | 57 ++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-alpha-pll.h      |  1 +
 drivers/cpufreq/cpufreq-dt-platdev.c  |  2 ++
 drivers/cpufreq/qcom-cpufreq-nvmem.c  | 16 ++++++++++
 8 files changed, 171 insertions(+), 7 deletions(-)

On 10/18/23 11:29, Varadarajan Narayanan wrote:
> IPQ95xx SoCs have different OPPs available for the CPU based on
> SoC variant. This can be determined from an eFuse register
> present in the silicon.
> 
> Add support to read the eFuse and populate the OPPs based on it.
> 
> Frequency	1.2GHz	1.8GHz	1.5GHz	No	opp-supported-hw
> 					Limit
> ------------------------------------------------------------
> 936000000	1	1	1	1	0xf
> 1104000000	1	1	1	1	0xf
> 1200000000	1	1	1	1	0xf
> 1416000000	0	1	1	1	0x7
> 1488000000	0	1	1	1	0x7
> 1800000000	0	1	0	1	0x5
> 2208000000	0	0	0	1	0x1
> -----------------------------------------------------------
> 
> Signed-off-by: Kathiravan T <quic_kathirav@quicinc.com>
> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> ---
> v2:	cpu_speed_bin -> cpu-speed-bin in node name
> 	Move comment to commit log
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad

Quoting Varadarajan Narayanan (2023-10-18 02:29:14)
> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
> index 4edbf77..f839a31 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.c
> +++ b/drivers/clk/qcom/clk-alpha-pll.c
> @@ -2508,3 +2508,60 @@ const struct clk_ops clk_alpha_pll_stromer_ops = {
>         .set_rate = clk_alpha_pll_stromer_set_rate,
>  };
>  EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_ops);
> +
> +static int clk_alpha_pll_stromer_plus_set_rate(struct clk_hw *hw,
> +                                              unsigned long rate,
> +                                              unsigned long prate)
> +{
> +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> +       u32 l, alpha_width = pll_alpha_width(pll);
> +       int ret;
> +       u64 a;
> +
> +       rate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
> +
> +       regmap_write(pll->clkr.regmap, PLL_MODE(pll), 0);

It still assumes the clk is always enabled. Please read back the
register value and make sure the PLL was already enabled before
restoring the enable state of the clk.

> +
> +       /* Delay of 2 output clock ticks required until output is disabled */
> +       udelay(1);

Quoting Varadarajan Narayanan (2023-10-18 02:29:16)
> The earlier 'l' value of 0x3e is for 1.5GHz. Not all SKUs support
> this frequency. Hence set it to 0x2d to get 1.1GHz which is
> supported in all SKUs.

Maybe also add the detail to the commit text that the frequency can
still increase above this initial configuration made here when the
cpufreq driver picks a different OPP.

> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> Fixes: c7ef7fbb1ccf ("clk: qcom: apss-ipq-pll: add support for IPQ5332")
> Signed-off-by: Kathiravan T <quic_kathirav@quicinc.com>
> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>