[RFC PATCH 07/30] PCI: cadence: Add read and write accessors to perform only 32-bit accesses
From: Kishon Vijay Abraham I <hidden>
Date: 2019-06-04 13:17:52
Also in:
linux-devicetree, linux-omap, linux-pci, linux-rockchip, lkml
Subsystem:
pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
Certain platforms like TI's J721E allows only 32-bit register accesses. Add read and write accessor to perform only 32-bit accesses in order to support platfroms like TI's J721E. Signed-off-by: Kishon Vijay Abraham I <redacted> --- drivers/pci/controller/pcie-cadence.c | 40 +++++++++++++++++++++++++++ drivers/pci/controller/pcie-cadence.h | 2 ++ 2 files changed, 42 insertions(+)
diff --git a/drivers/pci/controller/pcie-cadence.c b/drivers/pci/controller/pcie-cadence.c
index cd795f6fc1e2..de5b3b06f2d0 100644
--- a/drivers/pci/controller/pcie-cadence.c
+++ b/drivers/pci/controller/pcie-cadence.c@@ -7,6 +7,46 @@ #include "pcie-cadence.h" +u32 cdns_pcie_read32(void __iomem *addr, int size) +{ + void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4); + unsigned int offset = (unsigned long)addr & 0x3; + u32 val = readl(aligned_addr); + + if (!IS_ALIGNED((uintptr_t)addr, size)) { + pr_err("Invalid Address in function:%s\n", __func__); + return 0; + } + + if (size > 2) + return val; + + return (val >> (8 * offset)) & ((1 << (size * 8)) - 1); +} + +void cdns_pcie_write32(void __iomem *addr, int size, u32 value) +{ + void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4); + unsigned int offset = (unsigned long)addr & 0x3; + u32 mask; + u32 val; + + if (!IS_ALIGNED((uintptr_t)addr, size)) { + pr_err("Invalid Address in function:%s\n", __func__); + return; + } + + if (size > 2) { + writel(value, addr); + return; + } + + mask = ~(((1 << (size * 8)) - 1) << (offset * 8)); + val = readl(aligned_addr) & mask; + val |= value << (offset * 8); + writel(val, aligned_addr); +} + void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 fn, u32 r, bool is_io, u64 cpu_addr, u64 pci_addr, size_t size)
diff --git a/drivers/pci/controller/pcie-cadence.h b/drivers/pci/controller/pcie-cadence.h
index 0134c1b1ad65..d157bf5eabd5 100644
--- a/drivers/pci/controller/pcie-cadence.h
+++ b/drivers/pci/controller/pcie-cadence.h@@ -406,6 +406,8 @@ void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r); void cdns_pcie_disable_phy(struct cdns_pcie *pcie); int cdns_pcie_enable_phy(struct cdns_pcie *pcie); int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie); +u32 cdns_pcie_read32(void __iomem *addr, int size); +void cdns_pcie_write32(void __iomem *addr, int size, u32 value); extern const struct dev_pm_ops cdns_pcie_pm_ops; #endif /* _PCIE_CADENCE_H */
--
2.17.1
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