From 3445d3820770377c3e7dc96875ac0e928e497fd5 Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Sat, 1 Nov 2025 09:29:34 +0530 Subject: PCI: dwc: Implement .assert_perst() for dwc glue drivers Add .assert_perst() hook for dwc glue drivers to register with assert_perst() of pci ops, allowing for better control over the link initialization and shutdown process. Implement assert_perst() function op for dwc drivers. Signed-off-by: Krishna Chaitanya Chundru [bhelgaas: squash dwc host support] Signed-off-by: Bjorn Helgaas Acked-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20251101-tc9563-v9-3-de3429f7787a@oss.qualcomm.com Link: https://patch.msgid.link/20251101-tc9563-v9-4-de3429f7787a@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-designware-host.c | 9 +++++++++ drivers/pci/controller/dwc/pcie-designware.h | 9 +++++++++ 2 files changed, 18 insertions(+) (limited to 'drivers/pci/controller/dwc') diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 20c9333bcb1c..b56dd1d51fa4 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -842,10 +842,19 @@ void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn, } EXPORT_SYMBOL_GPL(dw_pcie_own_conf_map_bus); +static int dw_pcie_op_assert_perst(struct pci_bus *bus, bool assert) +{ + struct dw_pcie_rp *pp = bus->sysdata; + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + + return dw_pcie_assert_perst(pci, assert); +} + static struct pci_ops dw_pcie_ops = { .map_bus = dw_pcie_own_conf_map_bus, .read = pci_generic_config_read, .write = pci_generic_config_write, + .assert_perst = dw_pcie_op_assert_perst, }; static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index e995f692a1ec..99a02f052e1c 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -485,6 +485,7 @@ struct dw_pcie_ops { enum dw_pcie_ltssm (*get_ltssm)(struct dw_pcie *pcie); int (*start_link)(struct dw_pcie *pcie); void (*stop_link)(struct dw_pcie *pcie); + int (*assert_perst)(struct dw_pcie *pcie, bool assert); }; struct debugfs_info { @@ -787,6 +788,14 @@ static inline void dw_pcie_stop_link(struct dw_pcie *pci) pci->ops->stop_link(pci); } +static inline int dw_pcie_assert_perst(struct dw_pcie *pci, bool assert) +{ + if (pci->ops && pci->ops->assert_perst) + return pci->ops->assert_perst(pci, assert); + + return 0; +} + static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci) { u32 val; -- cgit v1.2.3 From 8bf3ad767587c0744fdf4a1eec02b5487baa82d3 Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Sat, 1 Nov 2025 09:29:36 +0530 Subject: PCI: qcom: Implement .assert_perst() Add support for assert_perst() for switches like TC9563, which require configuration before the PCIe link is established. Such devices use this function op to assert PERST# before configuring the device and once the configuration is done they de-assert PERST#. Signed-off-by: Krishna Chaitanya Chundru Signed-off-by: Bjorn Helgaas Acked-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20251101-tc9563-v9-5-de3429f7787a@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/pci/controller/dwc') diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 805edbbfe7eb..cdc605b44e19 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -696,6 +696,18 @@ static int qcom_pcie_post_init_1_0_0(struct qcom_pcie *pcie) return 0; } +static int qcom_pcie_assert_perst(struct dw_pcie *pci, bool assert) +{ + struct qcom_pcie *pcie = to_qcom_pcie(pci); + + if (assert) + qcom_ep_reset_assert(pcie); + else + qcom_ep_reset_deassert(pcie); + + return 0; +} + static void qcom_pcie_2_3_2_ltssm_enable(struct qcom_pcie *pcie) { u32 val; @@ -1516,6 +1528,7 @@ static const struct qcom_pcie_cfg cfg_fw_managed = { static const struct dw_pcie_ops dw_pcie_ops = { .link_up = qcom_pcie_link_up, .start_link = qcom_pcie_start_link, + .assert_perst = qcom_pcie_assert_perst, }; static int qcom_pcie_icc_init(struct qcom_pcie *pcie) -- cgit v1.2.3