Remove a lot of older cruft not needed.
Improve ISR support, but it is still unused since polling is faster
Properly initalize the speed register to get 90kb/s, not 400b/s.
Try to catch NACK
Allow 0 length read transfers to generate start/top pairs.
o Don't delay when checking the done bits. There's no gain other
than a small performance hit.
o calculate the clock divisors better (things are still way slow,
so maybe there's more here?)
o don't always fail reset. Always succeed instead.
o fix inverted logic around at91_twi_wait() return value
o remove debug code
o remove unneeded, unworking junk
o Fix the packet statistics
o Make sure we set the FD bit when in full duplex
o Improve TX side efficency by eliminating a data copy for
unfragmented mbufs (the hardware can't do s/g).
o Minor busdma pedantry
o better comments in some places, more XXX in others
o Minor style nits.
This solves a problem I was seeing where I'd get no ethernet when not
booting with a NFS root. Well, unless I unplugged the cable and
plugged it back in first so I'd get the same up down up messages I get
for NFS root...
Thanks to sam and scottl for suggestions on making this driver more
efficient through better use of approrpiate APIs.
This interface also appears in the AT91SAM9260 and '61 as well as the
AVR32 based micros from Atmel. We don't yet support write protect or
hot-swap in this bridge driver.
whole the physical memory, cached, using 1MB section mappings. This reduces
the address space available for user processes a bit, but given the amount of
memory a typical arm machine has, it is not (yet) a big issue.
It then provides a uma_small_alloc() that works as it does for architectures
which have a direct mapping.
The core uart code expects the receive method to actually puts the
characters read into its buffers. For AT91, it's done in the ipend routine,
so also check if we have the alternate break sequence here.
MFC after: 3 days
Introduce framework to configure the multiplexed pins on boot.
Since the USART supprots RS-485 multidrop mode, it allows the
TX pins to float. However, for RS-232 operations, we don't
want these pins to float. Instead, they should be pulled up
to avoid mismatches. Linux does something similar when it
configures the TX lines. This implies that we also allow the
RX lines to float rather than be in the state they are left in
by the boot loader. Since they are input pins, I think that
this is the right thing to do.
Plus minor for our board.
address is in the userland address space. The proper thing is either to choose
a virtual address in the kernel address space beyond the KVA, or to use
pmap_mapdev().
Make serial ports more robust and reliable. Make non-console ports
work. This might have broken skyeye stuff.
o Introduce ping-pong receive buffers.
o Use DMA to copy characters directly into memory.
o Support baud rates other than 115200
o Use 1 stop bit when 1 stop bit is requested (otherwise 2 were used,
which caused dropped characters when received in bursts).
o Use 1.5 stop bits for 5-bit bytes, and 2 stop bits otherwise when 2
stop bits were requested.
o Actually update line parameters.
o Fix comments
o Move init into attach
o Tweaks to TX interrupt registers to get them reliable and non-storming.
o harvest data in ipend since the latency between it and the callback
was too long. This likely is how it should be, I don't know why I deferred
things to the callback before.
o disable all interrupts in console init. We don't want interrupts until
we turn on an ISR.
o cosmetic tweaks
o Automatically detect of the TIMEOUT interrupt is supported. If so, use
it so we get better CPU utilization. Otherwise do a character at a time
RX. Good news here is that it seems we have enough CPU and low enough
fast interrupt latency to do this reliably.
o Don't read USART_CR. It is a write-only register.
o start to implement bus_ioctl. Do BAUD now...
number of banks, rows and columns the SDRAMC is programmed to access
to determine the RAM size for the board, rather than hard-wiring it to
be 32MB. My company's board with 64MB now probes correctly, as does
the KB9202 with only 32MB. This means that to detect the right memory
size, our boot loader must correctly initialize these values. This is
a fairly safe assumption because the boot loader has to initialize
SDRAM already, and it isn't really possible to change this register
after we've accessed SDRAM.
The boot loader is supposed to leave this bit set to the right value
for the board. If this bit was set at attach time, use it to init the
config register correctly.
Note: this means the boot loader has to properly initialize it.
