Since upstream LiteX recommends that Linux support be limited to
designs configured with 32-bit CSR subregisters (see commit a2b71fde
in upstream LiteX, https://github.com/enjoy-digital/litex), remove
the option to select 8-bit subregisters, significantly reducing the
complexity of LiteX CSR (MMIO register) accessor methods.
NOTE: for details on the underlying mechanics of LiteX CSR registers,
see https://github.com/enjoy-digital/litex/wiki/CSR-Bus or the original
LiteX accessors (litex/soc/software/include/hw/common.h in the upstream
repository).
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Florent Kermarrec <florent@enjoy-digital.fr>
Cc: Mateusz Holenko <mholenko@antmicro.com>
Cc: Joel Stanley <joel@jms.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Stafford Horne <shorne@gmail.com>
The header file <linux/errno.h> is already included above and can be
removed here.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Mateusz Holenko <mholenko@antmicro.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Pickup fixes that went upstream already in order to resolve conflicts in
litex_soc_ctrl.c between 5.11 fixes that went upstream and the
or1k-5.12-updates linux-next queue.
Signed-off-by: Stafford Horne <shorne@gmail.com>
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>
Upstream LiteX now defaults to using 32-bit CSR subregisters
(see https://github.com/enjoy-digital/litex/commit/a2b71fde).
This patch expands on commit 22447a99c9 ("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>
Move generic LiteX CSR (MMIO) register accessors to litex.h and
declare them as "static inline", in preparation for supporting
32-bit CSR subregisters and 64-bit CPUs.
NOTE: this is a non-functional change.
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
The test robot reported:
drivers/soc/litex/litex_soc_ctrl.c:143:34: warning: unused variable 'litex_soc_ctrl_of_match' [-Wunused-const-variable]
static const struct of_device_id litex_soc_ctrl_of_match[] = {
^
1 warning generated.
As per the random config device tree is not configured causing the
litex_soc_ctrl_of_match match list to not be used. This would usually
mean that we cannot even use this driver as it depends on device tree,
but as we also have COMPILE_TEST configured we allow it.
Fix the warning by surrounding the unused variable with an ifdef
CONFIG_OF.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Gabriel Somlo