Set the speed requested through mpc8xx_spi_set_speed() instead
of hardcoding a fixed speed.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
On CPM, the RISC core is a lot more efficiant when doing transfers
in 16-bits chunks than in 8-bits chunks, but unfortunately the
words need to be byte swapped.
So, for large tranfers with an even size, allocate a temporary
buffer and byte-swap data before and after transfer.
This change allows setting higher speed for transfer. For instance
on an MPC 8xx (CPM1 comms RISC processor), the documentation tells
that transfer in byte mode at 1 kbit/s uses 0.200% of CPM load
at 25 MHz while a word transfer at the same speed uses 0.032%
of CPM load. This means the speed can be 6 times higher in
word mode for the same CPM load.
For small transfers, the load reduction is not worth the CPU load
required to allocate the temporary buffer, so do it only when data
size is over 64 bytes.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Perform multiple transfer of size MAX_BUFFER when the data to be
transferred is longer than MAX_BUFFER.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
SDMA configuration register needs to be set up only once and doesn't
belong to drivers. Also, the value to be used is different on mpc885.
So do the init in cpu_init_f() with 0x40 for mpc885 and 0x1 for others.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
xfer ops can be passed a NULL input or output buffer. At the
time being the driver ignores it and overwrites memory at 0.
Define a dummy buffer and use it when either input or output
buffer is NULL. Bail out when both are NULL as it shouldn't.
Also increase MAX_BUFFER len to 32k as the current is pretty
low.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
With relocation, CPM parameter RAM can be anywhere in the
dual port RAM, so don't split dual port RAM.
Remove dparam and dparam16 members of struct comm_proc
PROFF_XXX become offsets from the start of dual port RAM,
then they are now consistant with the offsets in RPBASE
registers.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
This patch fixes the mpc8xx SPI driver:
- A stub callbacks for mode and speed,
- Use chip selects defined as GPIOs,
- Write proper value to disable relocation, other it fails on mpc885,
- Don't modify ports setup, ports can be different from one board to
another and are already set by board_early_init_r().
This patch was originally written by Charles Frey who's
email address is not valid anymore as he left the company.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: FRANJOU Stephane <stephane.franjou@csgroup.eu>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
include/commproc.h is dedicated to the 8xx, rename it cpm_8xx.h and
move it into arch/powerpc/include/asm
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
