Commit Graph

5 Commits (master)

Author SHA1 Message Date
Anton Blanchard ebdddcc402 Remove some FPGA style signal inits
These don't work on the ASIC flow, so remove them and initialise
them explicitly where required.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
2 years ago
Anton Blanchard 3f1e2b3a4f
Merge pull request #265 from antonblanchard/another-spi-rxtx-reset-issu
Fix another reset issue in spi_rxtx
4 years ago
Anton Blanchard a0eb4eec17 Fix another reset issue in spi_rxtx
counter was X state after reset, initialize it.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
4 years ago
Anton Blanchard bf9a446e3f Reset cmd_ready_o in spi_txrx
Initialize bit_count so that cmd_ready_o isn't X state immediately
after reset.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
4 years ago
Benjamin Herrenschmidt cc4dcb3597 spi: Add SPI Flash controller
This adds an SPI flash controller which supports direct
memory-mapped access to the flash along with a manual
mode to send commands.

The direct mode can be set via generic to default to single
wire or quad mode. The controller supports normal, dual and quad
accesses with configurable commands, clock divider, dummy clocks
etc...

The SPI clock can be an even divider of sys_clk starting at 2
(so max 50Mhz with our typical Arty designs).

A flash offset is carried via generics to syscon to tell SW about
which portion of the flash is reserved for the FPGA bitfile. There
is currently no plumbing to make the CPU reset past that address (TBD).

Note: Operating at 50Mhz has proven unreliable without adding some
delay to the sampling of the input data. I'm working in improving
this, in the meantime, I'm leaving the default set at 25 Mhz.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
4 years ago