Message-ID: <c766648f-c3a5-b842-2164-c3f480dee129@quicinc.com>
Date:   Mon, 20 Feb 2023 19:11:52 +0530
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Subject: Re: [PATCH 2/7] PCI: qcom: Add IPQ9574 PCIe support
Content-Language: en-US
To:     Sricharan Ramabadhran <quic_srichara@quicinc.com>,
        <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>, <vkoul@kernel.org>,
        <kishon@kernel.org>, <mturquette@baylibre.com>, <sboyd@kernel.org>,
        <mani@kernel.org>, <p.zabel@pengutronix.de>,
        <svarbanov@mm-sol.com>, <linux-arm-msm@vger.kernel.org>,
        <linux-pci@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-phy@lists.infradead.org>,
        <linux-clk@vger.kernel.org>
CC:     <quic_gokulsri@quicinc.com>, <quic_sjaganat@quicinc.com>,
        <quic_kathirav@quicinc.com>, <quic_arajkuma@quicinc.com>,
        <quic_anusha@quicinc.com>
References: <20230214164135.17039-1-quic_devipriy@quicinc.com>
 <20230214164135.17039-3-quic_devipriy@quicinc.com>
 <6ea43d8d-7b9c-5a11-097f-906e10ac3627@quicinc.com>
From:   Devi Priya <quic_devipriy@quicinc.com>
In-Reply-To: <6ea43d8d-7b9c-5a11-097f-906e10ac3627@quicinc.com>
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Hi Sri,
Thanks for taking time to review the patch!

On 2/16/2023 5:08 PM, Sricharan Ramabadhran wrote:
> Hi Devi,
> 
> On 2/14/2023 10:11 PM, Devi Priya wrote:
>> Adding PCIe support for IPQ9574 SoC
>>
>> Co-developed-by: Anusha Rao <quic_anusha@quicinc.com>
>> Signed-off-by: Anusha Rao <quic_anusha@quicinc.com>
>> Signed-off-by: Devi Priya <quic_devipriy@quicinc.com>
>> ---
>>   drivers/pci/controller/dwc/pcie-qcom.c | 119 +++++++++++++++++++++++++
>>   1 file changed, 119 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c 
>> b/drivers/pci/controller/dwc/pcie-qcom.c
>> index a232b04af048..57606c113d45 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -193,6 +193,12 @@ struct qcom_pcie_resources_2_9_0 {
>>       struct reset_control *rst;
>>   };
>> +struct qcom_pcie_resources_1_27_0 {
>> +    struct clk_bulk_data *clks;
>> +    struct reset_control *rst;
>> +    int num_clks;
>> +};
>> +
>>   union qcom_pcie_resources {
>>       struct qcom_pcie_resources_1_0_0 v1_0_0;
>>       struct qcom_pcie_resources_2_1_0 v2_1_0;
>> @@ -201,6 +207,7 @@ union qcom_pcie_resources {
>>       struct qcom_pcie_resources_2_4_0 v2_4_0;
>>       struct qcom_pcie_resources_2_7_0 v2_7_0;
>>       struct qcom_pcie_resources_2_9_0 v2_9_0;
>> +    struct qcom_pcie_resources_1_27_0 v1_27_0;
>>   };
>>   struct qcom_pcie;
>> @@ -1409,6 +1416,104 @@ static int qcom_pcie_post_init_2_9_0(struct 
>> qcom_pcie *pcie)
>>       return 0;
>>   }
>> +static int qcom_pcie_get_resources_1_27_0(struct qcom_pcie *pcie)
>> +{
>> +    struct qcom_pcie_resources_1_27_0 *res = &pcie->res.v1_27_0;
>> +    struct dw_pcie *pci = pcie->pci;
>> +    struct device *dev = pci->dev;
>> +
>> +    res->num_clks = devm_clk_bulk_get_all(dev, &res->clks);
>> +    if (res->clks < 0)
>> +        return res->num_clks;
>> +
>> +    res->rst = devm_reset_control_array_get_exclusive(dev);
>> +    if (IS_ERR(res->rst))
>> +        return PTR_ERR(res->rst);
>> +
>> +    return 0;
>> +}
>> +
>> +static void qcom_pcie_deinit_1_27_0(struct qcom_pcie *pcie)
>> +{
>> +    struct qcom_pcie_resources_1_27_0 *res = &pcie->res.v1_27_0;
>> +
>> +    clk_bulk_disable_unprepare(res->num_clks, res->clks);
>> +}
>> +
>> +static int qcom_pcie_init_1_27_0(struct qcom_pcie *pcie)
>> +{
>> +    struct qcom_pcie_resources_1_27_0 *res = &pcie->res.v1_27_0;
>> +    struct device *dev = pcie->pci->dev;
>> +    int ret;
>> +
>> +    ret = reset_control_assert(res->rst);
>> +    if (ret) {
>> +        dev_err(dev, "reset assert failed (%d)\n", ret);
>> +        return ret;
>> +    }
>> +
>> +    /*
>> +     * Delay periods before and after reset deassert are working values
>> +     * from downstream Codeaurora kernel
>> +     */
>> +    usleep_range(2000, 2500);
>> +
>> +    ret = reset_control_deassert(res->rst);
>> +    if (ret) {
>> +        dev_err(dev, "reset deassert failed (%d)\n", ret);
>> +        return ret;
>> +    }
>> +
>> +    usleep_range(2000, 2500);
>> +
>> +    return clk_bulk_prepare_enable(res->num_clks, res->clks);
>> +}
>> +
>> +static int qcom_pcie_post_init_1_27_0(struct qcom_pcie *pcie)
>> +{
>> +    struct dw_pcie *pci = pcie->pci;
>> +    u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> +    u32 val;
>> +    int i;
>> +
>> +    writel(0x8000000, pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
>> +
>> +    val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
>> +    val &= ~BIT(0);
>> +    writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
>> +
>> +    writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
>> +
>> +    writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
>> +    writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
>> +           pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
>> +    writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS |
>> +           GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
>> +           pci->dbi_base + GEN3_RELATED_OFF);
>> +
>> +    writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS |
>> +           SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
>> +           AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
>> +           pcie->parf + PCIE20_PARF_SYS_CTRL);
>> +
>> +    writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
>> +
>> +    dw_pcie_dbi_ro_wr_en(pci);
>> +    writel(PCIE_CAP_SLOT_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
>> +
>> +    val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
>> +    val &= ~PCI_EXP_LNKCAP_ASPMS;
>> +    writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
>> +
>> +    writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
>> +           PCI_EXP_DEVCTL2);
>> +
>> +    for (i = 0; i < 256; i++)
>> +        writel(0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N + (4 * 
>> i));
>> +
>> +    return 0;
>> +}
>> +
>>   static int qcom_pcie_link_up(struct dw_pcie *pci)
>>   {
>>       u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> @@ -1620,6 +1725,15 @@ static const struct qcom_pcie_ops ops_2_9_0 = {
>>       .ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
>>   };
>> +/* Qcom IP rev.: 1.27.0 Synopsys IP rev.: 5.80a */
>> +static const struct qcom_pcie_ops ops_1_27_0 = {
>> +    .get_resources = qcom_pcie_get_resources_1_27_0,
>> +    .init = qcom_pcie_init_1_27_0,
>> +    .post_init = qcom_pcie_post_init_1_27_0,
>> +    .deinit = qcom_pcie_deinit_1_27_0,
>> +    .ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
>> +};
>> +
>>   static const struct qcom_pcie_cfg cfg_1_0_0 = {
>>       .ops = &ops_1_0_0,
>>   };
>> @@ -1652,6 +1766,10 @@ static const struct qcom_pcie_cfg cfg_2_9_0 = {
>>       .ops = &ops_2_9_0,
>>   };
>> +static const struct qcom_pcie_cfg cfg_1_27_0 = {
>> +    .ops = &ops_1_27_0,
>> +};
>> +
>>   static const struct dw_pcie_ops dw_pcie_ops = {
>>       .link_up = qcom_pcie_link_up,
>>       .start_link = qcom_pcie_start_link,
>> @@ -1829,6 +1947,7 @@ static const struct of_device_id 
>> qcom_pcie_match[] = {
>>       { .compatible = "qcom,pcie-ipq8064-v2", .data = &cfg_2_1_0 },
>>       { .compatible = "qcom,pcie-ipq8074", .data = &cfg_2_3_3 },
>>       { .compatible = "qcom,pcie-ipq8074-gen3", .data = &cfg_2_9_0 },
>> +    { .compatible = "qcom,pcie-ipq9574", .data = &cfg_1_27_0 },
> 
>    I do not see much difference between 2_9_0 and 1_27_0. Is this patch
>    really required. Can you check if it works with 2_9_0 itself ?
Yes right Sri, Only the clocks seem to differ between 2_9_0 and 1_27_0.
Will update 2_9_0 ops to get the clocks from the DT and use the same for 
ipq9574 in the next spin.

Best Regards,
Devi Priya
> 
> Regards,
>   Sricharan