[PATCH 3/3] PCI: qcom: Add D3cold support
From: Krishna Chaitanya Chundru <hidden>
Date: 2026-01-28 11:41:06
Also in:
linux-arm-msm, linux-pci, lkml
Subsystem:
arm/qualcomm mailing list, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for qualcomm msm, the rest · Maintainers:
Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
Add pme_turn_off() support and use DWC common suspend resume methods for device D3cold entry & exit. If the device is not kept in D3cold use existing methods like keeping icc votes, opp votes etc.. intact. In qcom_pcie_deinit_2_7_0(), explicitly disable PCIe clocks and resets in the controller. Remove suspended flag from qcom_pcie structure as it is no longer needed. Signed-off-by: Krishna Chaitanya Chundru <redacted> --- drivers/pci/controller/dwc/pcie-qcom.c | 114 ++++++++++++++++++++------------- 1 file changed, 68 insertions(+), 46 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 7b92e7a1c0d9364a9cefe1450818f9cbfc7fd3ac..bb4e5a29c452a6c0d4b31b2a9ff3aa62b984fb64 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c@@ -150,6 +150,7 @@ /* ELBI_SYS_CTRL register fields */ #define ELBI_SYS_CTRL_LT_ENABLE BIT(0) +#define ELBI_SYS_CTRL_PME_TURNOFF_MSG BIT(4) /* AXI_MSTR_RESP_COMP_CTRL0 register fields */ #define CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K 0x4
@@ -283,7 +284,6 @@ struct qcom_pcie { const struct qcom_pcie_cfg *cfg; struct dentry *debugfs; struct list_head ports; - bool suspended; bool use_pm_opp; };
@@ -1075,6 +1075,12 @@ static void qcom_pcie_host_post_init_2_7_0(struct qcom_pcie *pcie) static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie) { struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0; + u32 val; + + /* Disable PCIe clocks and resets */ + val = readl(pcie->parf + PARF_PHY_CTRL); + val |= PHY_TEST_PWR_DOWN; + writel(val, pcie->parf + PARF_PHY_CTRL); clk_bulk_disable_unprepare(res->num_clks, res->clks);
@@ -1355,10 +1361,18 @@ static void qcom_pcie_host_post_init(struct dw_pcie_rp *pp) pcie->cfg->ops->host_post_init(pcie); } +static void qcom_pcie_host_pme_turn_off(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + + writel(ELBI_SYS_CTRL_PME_TURNOFF_MSG, pci->elbi_base + ELBI_SYS_CTRL); +} + static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { .init = qcom_pcie_host_init, .deinit = qcom_pcie_host_deinit, .post_init = qcom_pcie_host_post_init, + .pme_turn_off = qcom_pcie_host_pme_turn_off, }; /* Qcom IP rev.: 2.1.0 Synopsys IP rev.: 4.01a */
@@ -2016,53 +2030,51 @@ static int qcom_pcie_suspend_noirq(struct device *dev) if (!pcie) return 0; - /* - * Set minimum bandwidth required to keep data path functional during - * suspend. - */ - if (pcie->icc_mem) { - ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1)); - if (ret) { - dev_err(dev, - "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n", - ret); - return ret; - } - } + ret = dw_pcie_suspend_noirq(pcie->pci); + if (ret) + return ret; - /* - * Turn OFF the resources only for controllers without active PCIe - * devices. For controllers with active devices, the resources are kept - * ON and the link is expected to be in L0/L1 (sub)states. - * - * Turning OFF the resources for controllers with active PCIe devices - * will trigger access violation during the end of the suspend cycle, - * as kernel tries to access the PCIe devices config space for masking - * MSIs. - * - * Also, it is not desirable to put the link into L2/L3 state as that - * implies VDD supply will be removed and the devices may go into - * powerdown state. This will affect the lifetime of the storage devices - * like NVMe. - */ - if (!dw_pcie_link_up(pcie->pci)) { - qcom_pcie_host_deinit(&pcie->pci->pp); - pcie->suspended = true; - } + if (pcie->pci->suspended) { + ret = icc_disable(pcie->icc_mem); + if (ret) + dev_err(dev, "Failed to disable PCIe-MEM interconnect path: %d\n", ret); - /* - * Only disable CPU-PCIe interconnect path if the suspend is non-S2RAM. - * Because on some platforms, DBI access can happen very late during the - * S2RAM and a non-active CPU-PCIe interconnect path may lead to NoC - * error. - */ - if (pm_suspend_target_state != PM_SUSPEND_MEM) { ret = icc_disable(pcie->icc_cpu); if (ret) dev_err(dev, "Failed to disable CPU-PCIe interconnect path: %d\n", ret); if (pcie->use_pm_opp) dev_pm_opp_set_opp(pcie->pci->dev, NULL); + } else { + /* + * Set minimum bandwidth required to keep data path functional during + * suspend. + */ + if (pcie->icc_mem) { + ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1)); + if (ret) { + dev_err(dev, + "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n", + ret); + return ret; + } + } + + /* + * Only disable CPU-PCIe interconnect path if the suspend is non-S2RAM. + * Because on some platforms, DBI access can happen very late during the + * S2RAM and a non-active CPU-PCIe interconnect path may lead to NoC + * error. + */ + if (pm_suspend_target_state != PM_SUSPEND_MEM) { + ret = icc_disable(pcie->icc_cpu); + if (ret) + dev_err(dev, "Failed to disable CPU-PCIe interconnect path: %d\n", + ret); + + if (pcie->use_pm_opp) + dev_pm_opp_set_opp(pcie->pci->dev, NULL); + } } return ret; }
@@ -2076,20 +2088,30 @@ static int qcom_pcie_resume_noirq(struct device *dev) if (!pcie) return 0; - if (pm_suspend_target_state != PM_SUSPEND_MEM) { + if (pcie->pci->suspended) { ret = icc_enable(pcie->icc_cpu); if (ret) { dev_err(dev, "Failed to enable CPU-PCIe interconnect path: %d\n", ret); return ret; } - } - if (pcie->suspended) { - ret = qcom_pcie_host_init(&pcie->pci->pp); + ret = icc_enable(pcie->icc_mem); + if (ret) { + dev_err(dev, "Failed to enable PCIe-MEM interconnect path: %d\n", ret); + return ret; + } + ret = dw_pcie_resume_noirq(pcie->pci); if (ret) return ret; - - pcie->suspended = false; + } else { + if (pm_suspend_target_state != PM_SUSPEND_MEM) { + ret = icc_enable(pcie->icc_cpu); + if (ret) { + dev_err(dev, "Failed to enable CPU-PCIe interconnect path: %d\n", + ret); + return ret; + } + } } qcom_pcie_icc_opp_update(pcie);
--
2.34.1