[PATCH v4 0/3] drivers/soc/litex: support 32-bit subregisters, 64-bit CPUs

From: Gabriel Somlo
Date: Fri Dec 25 2020 - 19:17:44 EST


This series expands on commit 22447a99c97e ("drivers/soc/litex: add LiteX
SoC Controller driver"), adding support for handling both 8- and 32-bit
LiteX CSR (MMIO) subregisters, on both 32- and 64-bit CPUs.

Notes v4:
- improved "eloquence" of some 3/3 commit blurb paragraphs
- fixed instance of "disgusting" comment style :)
- litex_[get|set]_reg() now using size_t for 'reg_size' argument
- slightly tighter shift calculation in litex_set_reg()

Notes v3:
- split into smaller, more self-explanatory patches
- more detailed commit blurb for "main payload" (3/3) patch
- eliminate compiler warning on 32-bit architectures

Notes v2:
- fix typo (s/u32/u64/) in litex_read64().

Notes v1:
- LITEX_SUBREG_SIZE now provided by Kconfig.
- it's not LITEX_REG_SIZE, but rather LITEX_SUBREG_ALIGN!
- move litex_[get|set]_reg() to include/linux/litex.h and mark
them as "static inline";
- redo litex_[read|write][8|16|32|64]() using litex_[get|set]_reg()
(compiler should produce code as efficient as hardcoded shifts,
but also automatically matching LITEX_SUBREG_SIZE).

Gabriel Somlo (3):
drivers/soc/litex: move generic accessors to litex.h
drivers/soc/litex: separate MMIO from subregister offset calculation
drivers/soc/litex: support 32-bit subregisters, 64-bit CPUs

drivers/soc/litex/Kconfig | 12 +++
drivers/soc/litex/litex_soc_ctrl.c | 76 +--------------
include/linux/litex.h | 151 +++++++++++++++++++----------
3 files changed, 115 insertions(+), 124 deletions(-)

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2.26.2