Re: [PATCH V3 2/2] phy: qcom-qmp-ufs: Add regulator loads for SM8650 and SM8750

[Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>]

On 21/08/2025 19:02, Nitin Rawat wrote:
> 
> 
> On 8/20/2025 5:24 PM, Dmitry Baryshkov wrote:
>> On Wed, Aug 20, 2025 at 12:07:57PM +0530, Nitin Rawat wrote:
>>>
>>>
>>> On 8/20/2025 6:19 AM, Dmitry Baryshkov wrote:
>>>> On Wed, Aug 20, 2025 at 03:58:26AM +0530, Nitin Rawat wrote:
>>>>> Add regulator load voting support for SM8650 and SM8750 platforms by
>>>>> introducing dedicated regulator bulk data arrays with their load
>>>>> values.
>>>>>
>>>>> The load requirements are:
>>>>> - SM8650: vdda-phy (205mA), vdda-pll (17.5mA)
>>>>> - SM8750: vdda-phy (213mA), vdda-pll (18.3mA)
>>>>>
>>>>> This ensures stable operation and proper power management for these
>>>>> platforms where regulators are shared between the QMP USB PHY and
>>>>> other IP blocks by setting appropriate regulator load currents 
>>>>> during PHY
>>>>> operations.
>>>>>
>>>>> Configurations without specific load requirements will continue to 
>>>>> work
>>>>> unchanged, as init_load_uA remains zero-initialized when .init_load_uA
>>>>> is not provided.
>>>>
>>>> Can we please get configuration for the rest of the platforms?
>>>
>>> Hi Dmitry,
>>>
>>> If you're okay with it, can I merge the configuration for the remaining
>>> platforms in the next patch series after I complete testing on all 
>>> remaining
>>> platforms.
>>
>> You don't need to test, finding MSM8996 or 98 might be troublesome. Just
>> fill in the values from the hardware documentation.
> 
> Hi Dmitry,
> 
> While implementing changes for all remaining platform, I noticed that 
> the "regulator-allow-set-load" property is defined only for SM8750 and 
> SM8850 within the PMIC PHY and PLL device tree nodes which means that 
> even if the UFS PHY driver is updated to vote for this configuration on 
> other platforms, it will have no impact.

If I remember correctly, on other platforms we don't allow setting the 
load exactly because consumers were not voting on the current/power 
requirements.

> 
> Should I still proceed with applying the change across all platform, or 
> limit it to just the SM8750 and SM8850 drivers? What’s your recommendation?

I think, we should proceed, then once all PHYs get those votes we can 
enable load toggling on those platforms too.

> 
> ===========================================================================
> // Device tree:
> vreg_l1j_0p91: ldo1 {
>      regulator-name = "vreg_l1j_0p91";
>      regulator-min-microvolt = <880000>;
>      regulator-max-microvolt = <920000>;
>      regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
>      regulator-allow-set-load;
>      regulator-allowed-modes = <RPMH_REGULATOR_MODE_LPM 
> RPMH_REGULATOR_MODE_HPM>;
> };
> 
> ===========================================================================
> drivers/regulator/of_regulator.c
> 
> 
> if (of_property_read_bool(np, "regulator-allow-set-load"))
>          constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
> 
> ===========================================================================
> //drivers/regulator/core.c
> static int drms_uA_update(struct regulator_dev *rdev)
> {
>      ...
>      if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_DRMS)) {
>          rdev_dbg(rdev, "DRMS operation not allowed\n");
>          return 0;
>      }
>      ...
> }
> 
> 
> Regards,
> Nitin
> 
> 
> 
> 
>>
> 


-- 
With best wishes
Dmitry