From: Manivannan Sadhasivam Date: Wed, 25 Oct 2023 13:00:29 +0000 (+0530) Subject: PCI: qcom-ep: Add dedicated callback for writing to DBI2 registers X-Git-Tag: v6.6.7~699 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bf9a8870ad507c42dbf5568a27c889d79e4a50de;p=platform%2Fkernel%2Flinux-starfive.git PCI: qcom-ep: Add dedicated callback for writing to DBI2 registers commit a07d2497ed657eb2efeb967af47e22f573dcd1d6 upstream. The DWC core driver exposes the write_dbi2() callback for writing to the DBI2 registers in a vendor-specific way. On the Qcom EP platforms, the DBI_CS2 bit in the ELBI region needs to be asserted before writing to any DBI2 registers and deasserted once done. So, let's implement the callback for the Qcom PCIe EP driver so that the DBI2 writes are correctly handled in the hardware. Without this callback, the DBI2 register writes like BAR size won't go through and as a result, the default BAR size is set for all BARs. [kwilczynski: commit log, renamed function to match the DWC convention] Fixes: f55fee56a631 ("PCI: qcom-ep: Add Qualcomm PCIe Endpoint controller driver") Suggested-by: Serge Semin Link: https://lore.kernel.org/linux-pci/20231025130029.74693-2-manivannan.sadhasivam@linaro.org Signed-off-by: Manivannan Sadhasivam Signed-off-by: Krzysztof Wilczyński Reviewed-by: Serge Semin Cc: stable@vger.kernel.org # 5.16+ Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c index 8bd8107..9b62ee6 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -123,6 +123,7 @@ /* ELBI registers */ #define ELBI_SYS_STTS 0x08 +#define ELBI_CS2_ENABLE 0xa4 /* DBI registers */ #define DBI_CON_STATUS 0x44 @@ -263,6 +264,21 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci) disable_irq(pcie_ep->perst_irq); } +static void qcom_pcie_dw_write_dbi2(struct dw_pcie *pci, void __iomem *base, + u32 reg, size_t size, u32 val) +{ + struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci); + int ret; + + writel(1, pcie_ep->elbi + ELBI_CS2_ENABLE); + + ret = dw_pcie_write(pci->dbi_base2 + reg, size, val); + if (ret) + dev_err(pci->dev, "Failed to write DBI2 register (0x%x): %d\n", reg, ret); + + writel(0, pcie_ep->elbi + ELBI_CS2_ENABLE); +} + static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep) { struct dw_pcie *pci = &pcie_ep->pci; @@ -519,6 +535,7 @@ static const struct dw_pcie_ops pci_ops = { .link_up = qcom_pcie_dw_link_up, .start_link = qcom_pcie_dw_start_link, .stop_link = qcom_pcie_dw_stop_link, + .write_dbi2 = qcom_pcie_dw_write_dbi2, }; static int qcom_pcie_ep_get_io_resources(struct platform_device *pdev,