Re: [PATCH 8/8] PCI: qcom: Add support to PCIe slot power supplies

[Qiang Yu <quic_qianyu@quicinc.com>]

On 9/11/2024 11:32 PM, Manivannan Sadhasivam wrote:
> On Wed, Sep 11, 2024 at 04:17:41PM +0800, Qiang Yu wrote:
>> On 8/28/2024 12:58 AM, Manivannan Sadhasivam wrote:
>>> On Tue, Aug 27, 2024 at 02:44:09PM +0300, Dmitry Baryshkov wrote:
>>>> On Tue, 27 Aug 2024 at 09:36, Qiang Yu <quic_qianyu@quicinc.com> wrote:
>>>>> On platform x1e80100 QCP, PCIe3 is a standard x8 form factor. Hence, add
>>>>> support to use 3.3v, 3.3v aux and 12v regulators.
>>>> First of all, I don't see corresponding bindings change.
>>>>
>>>> Second, these supplies power up the slot, not the host controller
>>>> itself. As such these supplies do not belong to the host controller
>>>> entry. Please consider using the pwrseq framework instead.
>>>>
>>> Indeed. For legacy reasons, slot power supplies were populated in the host
>>> bridge node itself until recently Rob started objecting it [1]. And it makes
>>> real sense to put these supplies in the root port node and handle them in the
>>> relevant driver.
>>>
>>> I'm still evaluating whether the handling should be done in the portdrv or
>>> pwrctl driver, but haven't reached the conclusion. Pwrctl seems to be the ideal
>>> choice, but I see a few issues related to handling the OF node for the root
>>> port.
>>>
>>> Hope I'll come to a conclusion in the next few days and will update this thread.
>>>
>>> - Mani
>>>
>>> [1] https://lore.kernel.org/lkml/20240604235806.GA1903493-robh@kernel.org/
>> Hi Mani, do you have any updates?
>>
> I'm working with Bartosz to add a new pwrctl driver for rootports. And we are
> debugging an issue currently. Unfortunately, the progress is very slow as I'm on
> vacation still.
>
> Will post the patches once it got resolved.
>
> - Mani
OK, thanks for your update.

Thanks,
Qiang
>> Thanks,
>> Qiang
>>>>> Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
>>>>> ---
>>>>>    drivers/pci/controller/dwc/pcie-qcom.c | 52 +++++++++++++++++++++++++-
>>>>>    1 file changed, 50 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>>>>> index 6f953e32d990..59fb415dfeeb 100644
>>>>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>>>>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>>>>> @@ -248,6 +248,8 @@ struct qcom_pcie_cfg {
>>>>>           bool no_l0s;
>>>>>    };
>>>>>
>>>>> +#define QCOM_PCIE_SLOT_MAX_SUPPLIES                    3
>>>>> +
>>>>>    struct qcom_pcie {
>>>>>           struct dw_pcie *pci;
>>>>>           void __iomem *parf;                     /* DT parf */
>>>>> @@ -260,6 +262,7 @@ struct qcom_pcie {
>>>>>           struct icc_path *icc_cpu;
>>>>>           const struct qcom_pcie_cfg *cfg;
>>>>>           struct dentry *debugfs;
>>>>> +       struct regulator_bulk_data slot_supplies[QCOM_PCIE_SLOT_MAX_SUPPLIES];
>>>>>           bool suspended;
>>>>>           bool use_pm_opp;
>>>>>    };
>>>>> @@ -1174,6 +1177,41 @@ static int qcom_pcie_link_up(struct dw_pcie *pci)
>>>>>           return !!(val & PCI_EXP_LNKSTA_DLLLA);
>>>>>    }
>>>>>
>>>>> +static int qcom_pcie_enable_slot_supplies(struct qcom_pcie *pcie)
>>>>> +{
>>>>> +       struct dw_pcie *pci = pcie->pci;
>>>>> +       int ret;
>>>>> +
>>>>> +       ret = regulator_bulk_enable(ARRAY_SIZE(pcie->slot_supplies),
>>>>> +                                   pcie->slot_supplies);
>>>>> +       if (ret < 0)
>>>>> +               dev_err(pci->dev, "Failed to enable slot regulators\n");
>>>>> +
>>>>> +       return ret;
>>>>> +}
>>>>> +
>>>>> +static void qcom_pcie_disable_slot_supplies(struct qcom_pcie *pcie)
>>>>> +{
>>>>> +       regulator_bulk_disable(ARRAY_SIZE(pcie->slot_supplies),
>>>>> +                              pcie->slot_supplies);
>>>>> +}
>>>>> +
>>>>> +static int qcom_pcie_get_slot_supplies(struct qcom_pcie *pcie)
>>>>> +{
>>>>> +       struct dw_pcie *pci = pcie->pci;
>>>>> +       int ret;
>>>>> +
>>>>> +       pcie->slot_supplies[0].supply = "vpcie12v";
>>>>> +       pcie->slot_supplies[1].supply = "vpcie3v3";
>>>>> +       pcie->slot_supplies[2].supply = "vpcie3v3aux";
>>>>> +       ret = devm_regulator_bulk_get(pci->dev, ARRAY_SIZE(pcie->slot_supplies),
>>>>> +                                     pcie->slot_supplies);
>>>>> +       if (ret < 0)
>>>>> +               dev_err(pci->dev, "Failed to get slot regulators\n");
>>>>> +
>>>>> +       return ret;
>>>>> +}
>>>>> +
>>>>>    static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
>>>>>    {
>>>>>           struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>>>> @@ -1182,10 +1220,14 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
>>>>>
>>>>>           qcom_ep_reset_assert(pcie);
>>>>>
>>>>> -       ret = pcie->cfg->ops->init(pcie);
>>>>> +       ret = qcom_pcie_enable_slot_supplies(pcie);
>>>>>           if (ret)
>>>>>                   return ret;
>>>>>
>>>>> +       ret = pcie->cfg->ops->init(pcie);
>>>>> +       if (ret)
>>>>> +               goto err_disable_slot;
>>>>> +
>>>>>           ret = phy_set_mode_ext(pcie->phy, PHY_MODE_PCIE, PHY_MODE_PCIE_RC);
>>>>>           if (ret)
>>>>>                   goto err_deinit;
>>>>> @@ -1216,7 +1258,8 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
>>>>>           phy_power_off(pcie->phy);
>>>>>    err_deinit:
>>>>>           pcie->cfg->ops->deinit(pcie);
>>>>> -
>>>>> +err_disable_slot:
>>>>> +       qcom_pcie_disable_slot_supplies(pcie);
>>>>>           return ret;
>>>>>    }
>>>>>
>>>>> @@ -1228,6 +1271,7 @@ static void qcom_pcie_host_deinit(struct dw_pcie_rp *pp)
>>>>>           qcom_ep_reset_assert(pcie);
>>>>>           phy_power_off(pcie->phy);
>>>>>           pcie->cfg->ops->deinit(pcie);
>>>>> +       qcom_pcie_disable_slot_supplies(pcie);
>>>>>    }
>>>>>
>>>>>    static void qcom_pcie_host_post_init(struct dw_pcie_rp *pp)
>>>>> @@ -1602,6 +1646,10 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>>>>>                           goto err_pm_runtime_put;
>>>>>           }
>>>>>
>>>>> +       ret = qcom_pcie_get_slot_supplies(pcie);
>>>>> +       if (ret)
>>>>> +               goto err_pm_runtime_put;
>>>>> +
>>>>>           ret = pcie->cfg->ops->get_resources(pcie);
>>>>>           if (ret)
>>>>>                   goto err_pm_runtime_put;
>>>>> --
>>>>> 2.34.1
>>>>>
>>>> -- 
>>>> With best wishes
>>>> Dmitry