From 8bf3ad767587c0744fdf4a1eec02b5487baa82d3 Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Sat, 1 Nov 2025 09:29:36 +0530 Subject: [PATCH] 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(+) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 805edbbfe7eba..cdc605b44e19e 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) -- 2.47.3