> It provides helper CSR access functions used by all > LiteX drivers. > > Signed-off-by: Mateusz Holenko <mholenko@xxxxxxxxxxxx> > --- > This commit has been introduced in v2 of the patchset. > > MAINTAINERS | 6 +++++ > include/linux/litex.h | 59 +++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 65 insertions(+) > create mode 100644 include/linux/litex.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 296de2b51c83..eaa51209bfb2 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -9493,6 +9493,12 @@ F: Documentation/misc-devices/lis3lv02d.rst > F: drivers/misc/lis3lv02d/ > F: drivers/platform/x86/hp_accel.c > > +LITEX PLATFORM > +M: Karol Gugala <kgugala@xxxxxxxxxxxx> > +M: Mateusz Holenko <mholenko@xxxxxxxxxxxx> > +S: Maintained > +F: include/linux/litex.h > + > LIVE PATCHING > M: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > M: Jiri Kosina <jikos@xxxxxxxxxx> > diff --git a/include/linux/litex.h b/include/linux/litex.h > new file mode 100644 > index 000000000000..e793d2d7c881 > --- /dev/null > +++ b/include/linux/litex.h > @@ -0,0 +1,59 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Common LiteX header providing > + * helper functions for accessing CSRs. > + * > + * Copyright (C) 2019 Antmicro <www.antmicro.com> > + */ > + > +#ifndef _LINUX_LITEX_H > +#define _LINUX_LITEX_H > + > +#include <linux/io.h> > +#include <linux/types.h> > +#include <linux/compiler_types.h> > + > +#define LITEX_REG_SIZE 0x4 > +#define LITEX_SUBREG_SIZE 0x1 > +#define LITEX_SUBREG_SIZE_BIT (LITEX_SUBREG_SIZE * 8) Please be aware that LiteX supports "LITEX_SUBREG_SIZE" of up to 4, and might go even as far as 8 in the near future. Hard coding this here might be short sighted. A good alternative might be to have "litex_subreg_size" or "mmio-dw-bytes" passed in via a DT property of the SoC node, as illustrated here: https://github.com/litex-hub/linux-on-litex-vexriscv/pull/60 Thanks, --Gabriel > + > +#ifdef __LITTLE_ENDIAN > +# define LITEX_READ_REG(addr) ioread32(addr) > +# define LITEX_READ_REG_OFF(addr, off) ioread32(addr + off) > +# define LITEX_WRITE_REG(val, addr) iowrite32(val, addr) > +# define LITEX_WRITE_REG_OFF(val, addr, off) iowrite32(val, addr + off) > +#else > +# define LITEX_READ_REG(addr) ioread32be(addr) > +# define LITEX_READ_REG_OFF(addr, off) ioread32be(addr + off) > +# define LITEX_WRITE_REG(val, addr) iowrite32be(val, addr) > +# define LITEX_WRITE_REG_OFF(val, addr, off) iowrite32be(val, addr + off) > +#endif > + > +/* Helper functions for manipulating LiteX registers */ > + > +static inline void litex_set_reg(void __iomem *reg, u32 reg_size, u32 val) > +{ > + u32 shifted_data, shift, i; > + > + for (i = 0; i < reg_size; ++i) { > + shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); > + shifted_data = val >> shift; > + LITEX_WRITE_REG(shifted_data, reg + (LITEX_REG_SIZE * i)); > + } > +} > + > +static inline u32 litex_get_reg(void __iomem *reg, u32 reg_size) > +{ > + u32 shifted_data, shift, i; > + u32 result = 0; > + > + for (i = 0; i < reg_size; ++i) { > + shifted_data = LITEX_READ_REG(reg + (LITEX_REG_SIZE * i)); > + shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); > + result |= (shifted_data << shift); > + } > + > + return result; > +} > + > +#endif /* _LINUX_LITEX_H */
