From aeeebdadc56ea2fde479e8b890019ca8cdbc9073 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Mon, 25 Nov 2024 10:46:16 +0100 Subject: [PATCH] pci: pcie_dw_common: introduce pcie_dw_find_capability() Add PCIe config space capability search function specific for the host controller, which are bridges *to* PCI devices but are not PCI devices themselves. Signed-off-by: Neil Armstrong Link: https://lore.kernel.org/r/20241125-topic-pcie-controller-v1-1-45c20070dd53@linaro.org Signed-off-by: Caleb Connolly --- drivers/pci/pcie_dw_common.c | 42 ++++++++++++++++++++++++++++++++++++ drivers/pci/pcie_dw_common.h | 2 ++ 2 files changed, 44 insertions(+) diff --git a/drivers/pci/pcie_dw_common.c b/drivers/pci/pcie_dw_common.c index 0673e516c6f..78961271a8e 100644 --- a/drivers/pci/pcie_dw_common.c +++ b/drivers/pci/pcie_dw_common.c @@ -267,6 +267,48 @@ int pcie_dw_write_config(struct udevice *bus, pci_dev_t bdf, pcie->io.bus_start, pcie->io.size); } +/* + * These interfaces resemble the pci_find_*capability() interfaces, but these + * are for configuring host controllers, which are bridges *to* PCI devices but + * are not PCI devices themselves. + */ +static u8 pcie_dw_find_next_cap(struct pcie_dw *pci, u8 cap_ptr, u8 cap) +{ + u8 cap_id, next_cap_ptr; + u32 val; + u16 reg; + + if (!cap_ptr) + return 0; + + val = readl(pci->dbi_base + (cap_ptr & ~0x3)); + reg = pci_conv_32_to_size(val, cap_ptr, 2); + cap_id = (reg & 0x00ff); + + if (cap_id > PCI_CAP_ID_MAX) + return 0; + + if (cap_id == cap) + return cap_ptr; + + next_cap_ptr = (reg & 0xff00) >> 8; + return pcie_dw_find_next_cap(pci, next_cap_ptr, cap); +} + +u8 pcie_dw_find_capability(struct pcie_dw *pci, u8 cap) +{ + u8 next_cap_ptr; + u32 val; + u16 reg; + + val = readl(pci->dbi_base + (PCI_CAPABILITY_LIST & ~0x3)); + reg = pci_conv_32_to_size(val, PCI_CAPABILITY_LIST, 2); + + next_cap_ptr = (reg & 0x00ff); + + return pcie_dw_find_next_cap(pci, next_cap_ptr, cap); +} + /** * pcie_dw_setup_host() - Setup the PCIe controller for RC opertaion * diff --git a/drivers/pci/pcie_dw_common.h b/drivers/pci/pcie_dw_common.h index e0f7796f2a8..8cb99a12ea1 100644 --- a/drivers/pci/pcie_dw_common.h +++ b/drivers/pci/pcie_dw_common.h @@ -139,6 +139,8 @@ int pcie_dw_read_config(const struct udevice *bus, pci_dev_t bdf, uint offset, u int pcie_dw_write_config(struct udevice *bus, pci_dev_t bdf, uint offset, ulong value, enum pci_size_t size); +u8 pcie_dw_find_capability(struct pcie_dw *pci, u8 cap); + static inline void dw_pcie_dbi_write_enable(struct pcie_dw *pci, bool en) { u32 val; -- 2.39.5