src/sys/dev/uart/uart_dev_z8530.c, branch upstream/11.1.0

Add support for the uart classes to set their default register shift value.

2015-04-11T17:16:23+00:00

This is needed with the pl011 driver. Before this change it would default
to a shift of 0, however the hardware places the registers at 4-byte
addresses meaning the value should be 2.

This patch fixes this for the pl011 when configured using the fdt. The
other drivers have a default value of 0 to keep this a no-op.

MFC after:	1 week

Introduce grab and ungrab upcalls. When the kernel desires to grab the

2014-01-19T19:39:13+00:00

console, it calls the grab functions. These functions should turn off
the RX interrupts, and any others that interfere. This makes mountroot
prompt work again. If there's more generalized need other than
prompting, many of these routines should be expanded to do those new
things.

Should have been part of r260889, but waasn't due to command line typo.

Reviewed by:	bde (with reservations)

Fix low-level uart drivers that set their fifo sizes in the softc too late.

2013-04-01T00:44:20+00:00

uart(4) allocates send and receiver buffers in attach() before it calls
the low-level driver's attach routine.  Many low-level drivers set the
fifo sizes in their attach routine, which is too late.  Other drivers set
them in the probe() routine, so that they're available when uart(4)
allocates buffers.  This fixes the ones that were setting the values too
late by moving the code to probe().

Don't expose the uart_ops structure directly, but instead have

2007-04-02T22:00:22+00:00

it obtained through the uart_class structure. This allows us
to declare the uart_class structure as weak and as such allows
us to reference it even when it's not compiled-in.
It also allows is to get the uart_ops structure by name, which
makes it possible to implement the dt tag handling in uart_getenv().
The side-effect of all this is that we're using the uart_class
structure more consistently which means that we now also have
access to the size of the bus space block needed by the hardware
when we map the bus space, eliminating any hardcoding.

- Add a uart_rxready() and corresponding device-specific implementations

2007-01-18T22:01:19+00:00

  that can be used to check whether receive data is ready, i.e. whether
  the subsequent call of uart_poll() should return a char, and unlike
  uart_poll() doesn't actually receive data.
- Remove the device-specific implementations of uart_poll() and implement
  uart_poll() in terms of uart_getc() and the newly added uart_rxready()
  in order to minimize code duplication.
- In sunkbd(4) take advantage of uart_rxready() and use it to implement
  the polled mode part of sunkbd_check() so we don't need to buffer a
  potentially read char in the softc.
- Fix some mis-indentation in sunkbd_read_char().

Discussed with:	marcel

On PowerPC the clock for the BRG comes from RTxC, not PCLK. Add a

2006-07-26T17:29:37+00:00

quick hack to deal with this. We may need to formalize this better
and have this information come from the bus attachments.

Implement UART_IOCTL_BAUD for the Z8530. This allows a serial console

2006-07-26T17:21:59+00:00

on PowerPC use the current setting of the hardware and not second
guess what the OFW does on various machines.

o A divisor of 0 is perfectly valid. Reserve -1 for an invalid

2006-05-12T23:24:45+00:00

   divisor. This allows us to set the line speed to the maximum
   of 1/4 of the device clock.
o  Disable the baudrate generator before programming the line
   settings, including baudrate, and enable it afterwards.

In z8530_divisor() return 0 if the calculated divisor is less than 0.

2006-04-04T01:16:16+00:00

This happens when the baudrate is too high for the given RCLK.

Don't hold the hardware mutex across getc(). It can wait indefinitely

2006-04-01T19:04:54+00:00

for a character to be received. Instead let getc() do any necesary
locking.