lalal

["Uwe Kleine-König" <ukleinek@informatik.uni-freiburg.de>]

Hello,

I'm reimplementing a driver for the serial ports of the NetSilicon 9360
processor and have a few questions concerning this.

For your information, I'm using v2.6.21-rc3 and if your interested in
the specs of the UART, you can find it at

	http://ftp1.digi.com/support/documentation/90000675_C.pdf

- I cannot find anything about out1 and out2 in the HRM.  Are these
  signals optional?  (set_mctrl)

- The UART has two different loopback modes.  Citing the HRM:

	- Remote loopback (RL)
	  Provides a remote loopback feature.  When RL is set to 1, the
	  TXD transmit output is connected to the RXD receive input. The
	  RL field immediately echoes receive data back as transmit
	  data.
	  This field is used primarily as a test vehicle for external
	  data equipment.

	- Local loopback (LL)
	  Provides an internal local loopback feature.  When LL is set
	  to 1, the internal receive data stream is connected to the TXD
	  output signal. LL connects the serial channel receiver
	  directly to the serial channel transmitter.
	  This field is used primarily as a test vehicle for the serial
	  channel driver firmware.

  I think I should set at least LL in set_mctrl, if mctrl has TIOCM_LOOP
  set.  What about RL, should I set that, too?

- Documentation/serial/driver lists the bits relevant for get_mctrl.
  One of them is TIOCM_DCD.  When grepping for that in the linux tree,
  the only match is Documentation/serial/driver itself.  The reference
  implementation (amba_pl011.c) uses TIOCM_CAR instead.  Probably the
  documentation should be fixed?

- grepping for TIOCM_RI shows that for all architectures this is defined
  as follows:

  	#define TIOCM_RI   TIOCM_RNG

  For me it looks as if TIOCM_RI were deprecated?  If so,
  Documentation/serial/driver should better use TIOCM_RNG?  amba_pl011.c
  uses TIOCM_RNG, too.

For now that's it, but I expect to have some more questions as the
driver is far from being complete.

Best regards
Uwe

-- 
Uwe Kleine-König

http://www.google.com/search?q=half+a+cup+in+teaspoons
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