Commit Graph

6 Commits

Author SHA1 Message Date
Stafford Horne 2261352157 Merge remote-tracking branch 'openrisc/or1k-5.11-fixes' into or1k-5.12-updates
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>
2021-01-25 11:16:06 +09:00
Geert Uytterhoeven 3706f9f76a 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>
2021-01-21 21:40:05 +09:00
Gabriel Somlo 51f1092283 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 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>
2021-01-14 09:52:54 +09:00
Gabriel Somlo 9d93a9e8aa drivers/soc/litex: move generic accessors to litex.h
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>
2021-01-14 09:52:54 +09:00
Stafford Horne e6dc077b7d soc: litex: Fix compile warning when device tree is not configured
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>
2021-01-14 09:34:00 +09:00
Pawel Czarnecki 22447a99c9 drivers/soc/litex: add LiteX SoC Controller driver
This commit adds driver for the FPGA-based LiteX SoC
Controller from LiteX SoC builder.

Co-developed-by: Mateusz Holenko <mholenko@antmicro.com>
Signed-off-by: Mateusz Holenko <mholenko@antmicro.com>
Signed-off-by: Pawel Czarnecki <pczarnecki@internships.antmicro.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
2020-11-09 21:07:00 +09:00