diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 7818b4febb08..181449e342f1 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap) } EXPORT_SYMBOL_GPL(dw_pcie_find_capability); +static u16 dw_pcie_find_next_ext_capability(struct dw_pcie *pci, u16 start, + u8 cap) +{ + u32 header; + int ttl; + int pos = PCI_CFG_SPACE_SIZE; + + /* minimum 8 bytes per capability */ + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; + + if (start) + pos = start; + + header = dw_pcie_readl_dbi(pci, pos); + /* + * If we have no capabilities, this is indicated by cap ID, + * cap version and next pointer all being 0. + */ + if (header == 0) + return 0; + + while (ttl-- > 0) { + if (PCI_EXT_CAP_ID(header) == cap && pos != start) + return pos; + + pos = PCI_EXT_CAP_NEXT(header); + if (pos < PCI_CFG_SPACE_SIZE) + break; + + header = dw_pcie_readl_dbi(pci, pos); + } + + return 0; +} + +u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap) +{ + return dw_pcie_find_next_ext_capability(pci, 0, cap); +} +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability); + int dw_pcie_read(void __iomem *addr, int size, u32 *val) { if (!IS_ALIGNED((uintptr_t)addr, size)) { |