[PATCH V8 05/15] PCI: dwc: Add ext config space capability search API
From: Vidya Sagar <hidden>
Date: 2019-05-26 04:38:40
Also in:
linux-devicetree, linux-pci, linux-tegra, lkml
Subsystem:
pci driver for synopsys designware, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Jingoo Han, Manivannan Sadhasivam, Lorenzo Pieralisi, Krzysztof Wilczyński, Bjorn Helgaas, Linus Torvalds
Add extended configuration space capability search API using struct dw_pcie * pointer Signed-off-by: Vidya Sagar <redacted> Acked-by: Gustavo Pimentel <redacted> --- Changes since [v7]: * Changed data types of return and arguments to be inline with data being returned and passed. Changes since [v6]: * None Changes since [v5]: * None Changes since [v4]: * None Changes since [v3]: * None Changes since [v2]: * None Changes since [v1]: * This is a new patch in v2 series drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++ drivers/pci/controller/dwc/pcie-designware.h | 1 + 2 files changed, 42 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 38d76bd63b8f..d8be6c3339fa 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)) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 6cb978132469..45cd7c88d28a 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h@@ -252,6 +252,7 @@ struct dw_pcie { container_of((endpoint), struct dw_pcie, ep) u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap); +u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap); int dw_pcie_read(void __iomem *addr, int size, u32 *val); int dw_pcie_write(void __iomem *addr, int size, u32 val);
--
2.17.1
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