Commit Graph

12 Commits

Author SHA1 Message Date
Marcel Moolenaar
f8100ce2a7 Don't expose the uart_ops structure directly, but instead have
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.
2007-04-02 22:00:22 +00:00
Warner Losh
fbd68c4b4c Make uart_getenv() not be ns8250 dependent. This will allow, in the future,
compilation of kernels without ns8250 support but using the uart framework.
These kernels will be for machines where size matters more, so including code
that can never be executed is undesriable...
2005-12-12 21:00:58 +00:00
Warner Losh
098ca2bda9 Start each of the license/copyright comments with /*-, minor shuffle of lines 2005-01-06 01:43:34 +00:00
Marius Strobl
37f37506de Remove the whole uart_cpu_identify() stuff again. Now that it's no longer
used on sparc64 they are only stubs on all architectures and it doesn't
look like if we would need it in the near future again.

Ok'ed by:	marcel
2004-11-17 20:01:43 +00:00
Marius Strobl
efa79eb77e - Introduce an uart_cpu_identify() which is implemented in uart_cpu_<arch>.c
and that can be used as an identify function for all kinds of busses on a
  certain platform. Expect for sparc64 these are only stubs right now. [1]
- For sparc64, add code to its uart_cpu_identify() for registering the on-
  board ISA UARTs and their resources based on information obtained from
  Open Firmware.
  It would be better if this would be done in the OFW ISA code. However, due
  to the common FreeBSD ISA code and PNP-IDs not always being present in the
  properties of the ISA nodes there seems to be no good way to implement that.
  Therefore special casing UARTs as the sole really relevant ISA devices on
  sparc64 seemed reasonable. [2]

Approved by:	marcel
Discussed with:	marcel [1], tmm [2]
Tested by:	make universe
2004-08-14 23:54:27 +00:00
Marcel Moolenaar
2ae4f1fd16 Introduce the hw.uart.console and hw.uart.dbgport environment variables
to select a serial console and debug port (resp). On ia64 these replace
the use of hints completely and take precedence over hints on alpha,
amd64 and i386. On sparc64 these variables are not yet recognised.

The reasons for introducing these variables are:
1.  Hints have side-effects. They reserve the unit number for use by
    isa or acpi devices and therefore cannot be used to select a pci
    device. Also, the use of a unit number to select a device prior
    to bus enumeration is nonsense. The new variables have no side-
    effects and are not based on unit numbers.
2.  Hints don't have the expression power to allow the sysadmin to
    select UARTs that are not legacy PC devices and need the support
    of compile-time constants to give the sysadmin some level of
    flexibility.

The hw.uart.console and hw.uart.dbgport variables specify a list of
attributes. An attribute is a tag-value pair, seperated by a colon.
Attributes are seperated by a comma. Where possible, tags are the
same as those in /etc/remote (only br and pa in practice). Details
can be found in the manpage (not part of this commit).

Not tested on: amd64, pc98
2004-03-20 02:14:02 +00:00
Marcel Moolenaar
875f70dba4 Revert the introduction of iobase in struct uart_bas. Both the SAB82532
and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizing this by
introducing iobase is not a solution. How for example would a driver
know which channel it controls for a multi-channel UART that only has a
single I/O range?

Instead, add an explicit field, called chan, to struct uart_bas that
holds the channel within a device, or 0 otherwise. The chan field is
initialized both by the system device probing (i.e. a system console)
or it is passed down to uart_bus_probe() by any of the bus front-ends.
As such, it impacts all platforms and bus drivers and makes it a rather
large commit.

Remove the use of iobase in uart_cpu_eqres() for pc98. It is expected
that platforms have the capability to compare tag and handle pairs for
equality; as to determine whether two pairs access the same device or
not. The use of iobase for pc98 makes it impossible to formalize this
and turn it into a real newbus function later. This commit reverts
uart_cpu_eqres() for pc98 to an unimplemented function. It has to be
reimplemented using only the tag and handle fields in struct uart_bas.

Rewrite the SAB82532 and Z8530 drivers to use the chan field in struct
uart_bas. Remove the IS_CHANNEL_A and IS_CHANNEL_B macros. We don't
need to abstract anything anymore.

Discussed with: nyan
Tested on: i386, ia64, sparc64
2003-09-26 05:14:56 +00:00
Yoshihiro Takahashi
312ebe0323 Don't return to search another ports even if bus_space_map() fails. 2003-09-23 13:03:22 +00:00
Yoshihiro Takahashi
c423dba334 - Keep the base address in struct uart_bas for sab82532 and z8530 modules.
- Remove buggy uart_cpu_busaddr() function.
2003-09-23 09:25:38 +00:00
Yoshihiro Takahashi
81a11def25 Use bus_space_map() to initialize a bus_handle. 2003-09-23 08:38:49 +00:00
Marcel Moolenaar
5cc705512d Remove the assumption that a bus_space_handle_t is an I/O address
from the SAB82532 and the Z8530 hardware drivers by introducing
uart_cpu_busaddr(). The assumption is not true on pc98 where
bus_space_handle_t is a pointer to a structure.
The uart_cpu_busaddr() function will return the bus address
corresponding the tag and handle given to it by the BAS.

WARNING: the intend of the function is STRICTLY to allow hardware
drivers to determine which logical channel they control and is NOT
to be used for actual I/O. It is therefore EXPLICITLY allowed that
uart_cpu_busaddr() returns only the lower 8 bits of the address
and garbage in all other bits. No mistakes...
2003-09-07 21:51:03 +00:00
Marcel Moolenaar
27d5dc189c The uart(4) driver is an universal driver for various UART hardware.
It improves on sio(4) in the following areas:
o  Fully newbusified to allow for memory mapped I/O. This is a must
   for ia64 and sparc64,
o  Machine dependent code to take full advantage of machine and firm-
   ware specific ways to define serial consoles and/or debug ports.
o  Hardware abstraction layer to allow the driver to be used with
   various UARTs, such as the well-known ns8250 family of UARTs, the
   Siemens sab82532 or the Zilog Z8530. This is especially important
   for pc98 and sparc64 where it's common to have different UARTs,
o  The notion of system devices to unkludge low-level consoles and
   remote gdb ports and provides the mechanics necessary to support
   the keyboard on sparc64 (which is UART based).
o  The notion of a kernel interface so that a UART can be tied to
   something other than the well-known TTY interface. This is needed
   on sparc64 to present the user with a device and ioctl handling
   suitable for a keyboard, but also allows us to cleanly hide an
   UART when used as a debug port.

Following is a list of features and bugs/flaws specific to the ns8250
family of UARTs as compared to their support in sio(4):
o  The uart(4) driver determines the FIFO size and automaticly takes
   advantages of larger FIFOs and/or additional features. Note that
   since I don't have sufficient access to 16[679]5x UARTs, hardware
   flow control has not been enabled. This is almost trivial to do,
   provided one can test. The downside of this is that broken UARTs
   are more likely to not work correctly with uart(4). The need for
   tunables or knobs may be large enough to warrant their creation.
o  The uart(4) driver does not share the same bumpy history as sio(4)
   and will therefore not provide the necessary hooks, tweaks, quirks
   or work-arounds to deal with once common hardware. To that extend,
   uart(4) supports a subset of the UARTs that sio(4) supports. The
   question before us is whether the subset is sufficient for current
   hardware.
o  There is no support for multiport UARTs in uart(4). The decision
   behind this is that uart(4) deals with one EIA RS232-C interface.
   Packaging of multiple interfaces in a single chip or on a single
   expansion board is beyond the scope of uart(4) and is now mostly
   left for puc(4) to deal with. Lack of hardware made it impossible
   to actually implement such a dependency other than is present for
   the dual channel SAB82532 and Z8350 SCCs.

The current list of missing features is:
o  No configuration capabilities. A set of tunables and sysctls is
   being worked out. There are likely not going to be any or much
   compile-time knobs. Such configuration does not fit well with
   current hardware.
o  No support for the PPS API. This is partly dependent on the
   ability to configure uart(4) and partly dependent on having
   sufficient information to implement it properly.

As usual, the manpage is present but lacks the attention the
software has gotten.
2003-09-06 23:13:47 +00:00