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Direktori : /usr/src/linux-headers-5.15.0-125-generic/include/linux/ |
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/* SPDX-License-Identifier: GPL-2.0 */ /* * Common LiteX header providing * helper functions for accessing CSRs. * * Copyright (C) 2019-2020 Antmicro <www.antmicro.com> */ #ifndef _LINUX_LITEX_H #define _LINUX_LITEX_H #include <linux/io.h> static inline void _write_litex_subregister(u32 val, void __iomem *addr) { writel((u32 __force)cpu_to_le32(val), addr); } static inline u32 _read_litex_subregister(void __iomem *addr) { return le32_to_cpu((__le32 __force)readl(addr)); } /* * LiteX SoC Generator, depending on the configuration, can split a single * logical CSR (Control&Status Register) into a series of consecutive physical * registers. * * For example, in the configuration with 8-bit CSR Bus, a 32-bit aligned, * 32-bit wide logical CSR will be laid out as four 32-bit physical * subregisters, each one containing one byte of meaningful data. * * For Linux support, upstream LiteX enforces a 32-bit wide CSR bus, which * means that only larger-than-32-bit CSRs will be split across multiple * subregisters (e.g., a 64-bit CSR will be spread across two consecutive * 32-bit subregisters). * * For details see: https://github.com/enjoy-digital/litex/wiki/CSR-Bus */ static inline void litex_write8(void __iomem *reg, u8 val) { _write_litex_subregister(val, reg); } static inline void litex_write16(void __iomem *reg, u16 val) { _write_litex_subregister(val, reg); } static inline void litex_write32(void __iomem *reg, u32 val) { _write_litex_subregister(val, reg); } static inline void litex_write64(void __iomem *reg, u64 val) { _write_litex_subregister(val >> 32, reg); _write_litex_subregister(val, reg + 4); } static inline u8 litex_read8(void __iomem *reg) { return _read_litex_subregister(reg); } static inline u16 litex_read16(void __iomem *reg) { return _read_litex_subregister(reg); } static inline u32 litex_read32(void __iomem *reg) { return _read_litex_subregister(reg); } static inline u64 litex_read64(void __iomem *reg) { return ((u64)_read_litex_subregister(reg) << 32) | _read_litex_subregister(reg + 4); } #endif /* _LINUX_LITEX_H */