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Message-ID: <9b8c0bcb-dcaf-ffe2-f2a2-1fa2da0f2f18@quicinc.com>
Date:   Fri, 7 Jul 2023 16:28:54 +0530
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Subject: Re: [PATCH v2 6/8] PCI: qcom: ep: Add wake up host op to
 dw_pcie_ep_ops
Content-Language: en-US
To:     Manivannan Sadhasivam <mani@kernel.org>
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>,
        =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>
References: <1688122331-25478-1-git-send-email-quic_krichai@quicinc.com>
 <1688122331-25478-7-git-send-email-quic_krichai@quicinc.com>
 <20230707061005.GE6001@thinkpad>
From:   Krishna Chaitanya Chundru <quic_krichai@quicinc.com>
In-Reply-To: <20230707061005.GE6001@thinkpad>
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On 7/7/2023 11:40 AM, Manivannan Sadhasivam wrote:
> 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

I will change it bool and will remove these.

- KC

>
>> +	}
>> +
>> +	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
>>