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Date:   Fri, 7 Jul 2023 11:40:05 +0530
From:   Manivannan Sadhasivam <mani@kernel.org>
To:     Krishna chaitanya chundru <quic_krichai@quicinc.com>
Cc:     manivannan.sadhasivam@linaro.org, helgaas@kernel.org,
        linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, quic_vbadigan@quicinc.com,
        quic_nitegupt@quicinc.com, quic_skananth@quicinc.com,
        quic_ramkri@quicinc.com, krzysztof.kozlowski@linaro.org,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH v2 6/8] PCI: qcom: ep: Add wake up host op to
 dw_pcie_ep_ops
Message-ID: <20230707061005.GE6001@thinkpad>
References: <1688122331-25478-1-git-send-email-quic_krichai@quicinc.com>
 <1688122331-25478-7-git-send-email-quic_krichai@quicinc.com>
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On Fri, Jun 30, 2023 at 04:22:09PM +0530, Krishna chaitanya chundru wrote:

Subject prefix should be "PCI: qcom-ep:"

> Add wakeup host op to dw_pcie_ep_ops to wake up host.
> If the EPF asks to send PME trigger the inband PME by writing
> into the parf registers otherwise toggle wake signal.
> 

If the wakeup type is PME, then trigger inband PME by writing to the PARF
PARF_PM_CTRL register, otherwise toggle #WAKE.

> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index e75aec4..e382b4b 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -89,6 +89,7 @@
>  /* PARF_PM_CTRL register fields */
>  #define PARF_PM_CTRL_REQ_EXIT_L1		BIT(1)
>  #define PARF_PM_CTRL_READY_ENTR_L23		BIT(2)
> +#define PARF_PM_CTRL_XMT_PME			BIT(4)
>  #define PARF_PM_CTRL_REQ_NOT_ENTR_L1		BIT(5)
>  
>  /* PARF_MHI_CLOCK_RESET_CTRL fields */
> @@ -729,10 +730,40 @@ static void qcom_pcie_ep_init(struct dw_pcie_ep *ep)
>  		dw_pcie_ep_reset_bar(pci, bar);
>  }
>  
> +static int qcom_pcie_ep_wakeup_host(struct dw_pcie_ep *ep, u8 func_no,
> +					enum pci_epc_wakeup_host_type type)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +	struct device *dev = pci->dev;
> +	u32 val;
> +
> +	if (type == PCI_WAKEUP_TOGGLE_WAKE) {
> +		dev_dbg(dev, "Waking up the host by toggling WAKE#\n");
> +		gpiod_set_value_cansleep(pcie_ep->wake, 1);
> +		usleep_range(WAKE_DELAY_US, WAKE_DELAY_US + 500);
> +		gpiod_set_value_cansleep(pcie_ep->wake, 0);
> +		return 0;
> +
> +	} else if (type == PCI_WAKEUP_SEND_PME) {
> +		dev_dbg(dev, "Waking up the host using PME\n");
> +		val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
> +		val |= PARF_PM_CTRL_XMT_PME;
> +		writel_relaxed(val, pcie_ep->parf + PARF_PM_CTRL);
> +
> +	} else {
> +		dev_err(dev, "Device is not in D3 state wakeup is not supported\n");
> +		return -EOPNOTSUPP;

This is not needed if you use bool. And this debug message is wrong btw since
you are not checking whether the device is in D3 state or not.

- Mani

> +	}
> +
> +	return 0;
> +}
> +
>  static const struct dw_pcie_ep_ops pci_ep_ops = {
>  	.ep_init = qcom_pcie_ep_init,
>  	.raise_irq = qcom_pcie_ep_raise_irq,
>  	.get_features = qcom_pcie_epc_get_features,
> +	.wakeup_host = qcom_pcie_ep_wakeup_host,
>  };
>  
>  static int qcom_pcie_ep_probe(struct platform_device *pdev)
> -- 
> 2.7.4
> 

-- 
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