Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <fdf697c1-16a3-6b8c-90fa-51ef7137d546@linaro.org>
Date:   Mon, 8 May 2023 14:39:40 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH V3 5/6] arm64: dts: qcom: ipq9574: Enable PCIe PHYs and
 controllers
Content-Language: en-GB
To:     Devi Priya <quic_devipriy@quicinc.com>
Cc:     agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org,
        lpieralisi@kernel.org, kw@linux.com, robh@kernel.org,
        bhelgaas@google.com, krzysztof.kozlowski+dt@linaro.org,
        mturquette@baylibre.com, sboyd@kernel.org, mani@kernel.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-clk@vger.kernel.org, quic_srichara@quicinc.com,
        quic_sjaganat@quicinc.com, quic_kathirav@quicinc.com,
        quic_arajkuma@quicinc.com, quic_anusha@quicinc.com,
        quic_ipkumar@quicinc.com
References: <20230421124938.21974-1-quic_devipriy@quicinc.com>
 <20230421124938.21974-6-quic_devipriy@quicinc.com>
 <CAA8EJpqx1jv_xEnS-2rOOGCtEB=1vo477H7XLGGvH=o7NHJD7w@mail.gmail.com>
 <6c962760-d81c-af52-bce2-49090f66f4ee@quicinc.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <6c962760-d81c-af52-bce2-49090f66f4ee@quicinc.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 08/05/2023 13:55, Devi Priya wrote:
> 
> 
> On 4/22/2023 5:43 AM, Dmitry Baryshkov wrote:
>> On Fri, 21 Apr 2023 at 15:51, Devi Priya <quic_devipriy@quicinc.com> 
>> wrote:
>>>
>>> Enable the PCIe controller and PHY nodes corresponding to
>>> RDP 433.
>>>
>>> Signed-off-by: Devi Priya <quic_devipriy@quicinc.com>
>>> ---
>>>   Changes in V3:
>>>          - No change
>>>
>>>   arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts | 62 +++++++++++++++++++++
>>>   1 file changed, 62 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts 
>>> b/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
>>> index 7be578017bf7..3ae38cf327ea 100644
>>> --- a/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
>>> +++ b/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
>>> @@ -8,6 +8,7 @@
>>>
>>>   /dts-v1/;
>>>
>>> +#include <dt-bindings/gpio/gpio.h>
>>>   #include "ipq9574.dtsi"
>>>
>>>   / {
>>> @@ -43,6 +44,42 @@
>>>          };
>>>   };
>>>
>>> +&pcie1_phy {
>>> +       status = "okay";
>>> +};
>>> +
>>> +&pcie1 {
>>> +       pinctrl-names = "default";
>>> +       pinctrl-0 = <&pcie_1_pin>;
>>> +
>>> +       perst-gpios = <&tlmm 26 GPIO_ACTIVE_LOW>;
>>
>> Usually qcom PCIe hosts also define wake-gpios.
> In IPQ9574, we do not have hot plug support and host always starts the
> enumeration for the device. Hence no wake pin is required.

None of the qcom PCIe hosts support hotplug, if I remember correctly. 
This is not a reason not to describe the hardware.

>>
>>> +       status = "okay";
>>> +};
>>> +
>>> +&pcie2_phy {
>>> +       status = "okay";
>>> +};
>>> +
>>> +&pcie2 {
>>> +       pinctrl-names = "default";
>>> +       pinctrl-0 = <&pcie_2_pin>;
>>> +
>>> +       perst-gpios = <&tlmm 29 GPIO_ACTIVE_LOW>;
>>> +       status = "okay";
>>> +};
>>> +
>>> +&pcie3_phy {
>>> +       status = "okay";
>>> +};
>>> +
>>> +&pcie3 {
>>> +       pinctrl-names = "default";
>>> +       pinctrl-0 = <&pcie_3_pin>;
>>> +
>>> +       perst-gpios = <&tlmm 32 GPIO_ACTIVE_LOW>;
>>> +       status = "okay";
>>> +};
>>> +
>>>   &sdhc_1 {
>>>          pinctrl-0 = <&sdc_default_state>;
>>>          pinctrl-names = "default";
>>> @@ -60,6 +97,31 @@
>>>   };
>>>
>>>   &tlmm {
>>> +
>>> +       pcie_1_pin: pcie-1-state {
>>> +               pins = "gpio26";
>>> +               function = "gpio";
>>> +               drive-strength = <8>;
>>> +               bias-pull-down;
>>> +               output-low;
>>
>> No clkreq and no wake gpios?
> We do not use any PCIe low power states and link is always in L0.

Again. We = software. Please describe the hardware here.

> 
> Thanks,
> Devi Priya
>>
>>> +       };
>>> +
>>> +       pcie_2_pin: pcie-2-state {
>>> +               pins = "gpio29";
>>> +               function = "gpio";
>>> +               drive-strength = <8>;
>>> +               bias-pull-down;
>>> +               output-low;
>>> +       };
>>> +
>>> +       pcie_3_pin: pcie-3-state {
>>> +               pins = "gpio32";
>>> +               function = "gpio";
>>> +               drive-strength = <8>;
>>> +               bias-pull-up;
>>> +               output-low;
>>> +       };
>>> +
>>>          sdc_default_state: sdc-default-state {
>>>                  clk-pins {
>>>                          pins = "gpio5";
>>> -- 
>>> 2.17.1
>>>
>>
>>

-- 
With best wishes
Dmitry