Re: [PATCH 2/7] PCI: qcom: Add IPQ9574 PCIe support

From: Devi Priya
Date: Mon Feb 20 2023 - 08:42:41 EST


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@xxxxxxxxxxx>
Signed-off-by: Anusha Rao <quic_anusha@xxxxxxxxxxx>
Signed-off-by: Devi Priya <quic_devipriy@xxxxxxxxxxx>
---
  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