| 3706f9f7 | 19-Jan-2021 |
Geert Uytterhoeven <geert@linux-m68k.org> |
drivers/soc/litex: Add restart handler
Let the LiteX SoC Controller register a restart handler, which resets
the LiteX SoC by writing 1 to CSR_CTRL_RESET_ADDR.
Signed-off-by: Geert Uytterhoeven <ge
drivers/soc/litex: Add restart handler
Let the LiteX SoC Controller register a restart handler, which resets
the LiteX SoC by writing 1 to CSR_CTRL_RESET_ADDR.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Stafford Horne <shorne@gmail.com>
show more ...
|
| 4f70d150 | 12-Jan-2021 |
Gabriel Somlo <gsomlo@gmail.com> |
drivers/soc/litex: make 'litex_[set|get]_reg()' methods private
The 'litex_[set|get]_reg()' methods use the 'reg_size' parameter to
specify the width of the LiteX CSR (MMIO) register being accessed.
drivers/soc/litex: make 'litex_[set|get]_reg()' methods private
The 'litex_[set|get]_reg()' methods use the 'reg_size' parameter to
specify the width of the LiteX CSR (MMIO) register being accessed.
Since 'u64' is the widest data being supported, the value of 'reg_size'
MUST be between 1 and sizeof(u64), which SHOULD be checked at runtime
if these methods are publicly available for use by other LiteX device
drivers.
At the same time, none of the existing (or foreseeable) LiteX device
drivers have a need to access registers whose size is unknown during
compilation. As such, all LiteX device drivers should use fixed-width
accessor methods such as 'litex_[write|read][8|16|32|64]()'.
This patch renames 'litex_[set|get]_reg()' to '_litex_[set|get]_reg()',
indicating that they should NOT be directly called from outside of
the 'include/linux/litex.h' header file.
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
show more ...
|
| 51f10922 | 12-Jan-2021 |
Gabriel Somlo <gsomlo@gmail.com> |
drivers/soc/litex: support 32-bit subregisters, 64-bit CPUs
Upstream LiteX now defaults to using 32-bit CSR subregisters
(see https://github.com/enjoy-digital/litex/commit/a2b71fde).
This patch exp
drivers/soc/litex: support 32-bit subregisters, 64-bit CPUs
Upstream LiteX now defaults to using 32-bit CSR subregisters
(see https://github.com/enjoy-digital/litex/commit/a2b71fde).
This patch 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, as determined by the
LITEX_SUBREG_SIZE Kconfig option.
NOTE that while LITEX_SUBREG_SIZE could theoretically be a device
tree property, defining it as a compile-time constant allows for
much better optimization of the resulting code. This is further
supported by the low expected usefulness of deploying the same
kernel across LiteX SoCs built with different CSR-Bus data widths.
Finally, the litex_[read|write][8|16|32|64]() accessors are
redefined in terms of litex_[get|set]_reg(), which, after compiler
optimization, will result in code as efficient as hardcoded shifts,
but with the added benefit of automatically matching the appropriate
LITEX_SUBREG_SIZE.
NOTE that litex_[get|set]_reg() nominally operate on 64-bit data,
but that will also be optimized by the compiler in situations where
narrower data is used from a call site.
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
show more ...
|