[PATCH 0/2] tty slave devices support - version 2

From: NeilBrown
Date: Fri Dec 19 2014 - 19:11:00 EST


Thanks for all the great feedback. I have incorporated a lot of it,
though not all ... partly because there was not yet unanimity on some
issues.

Big changes:
- children of a uart are no longer automatically managed.
The driver for the child device must register with the tty
after which it will be told when the tty is opened or closed.
The driver can then do whatever it likes, which may involve
powering the device on.

- I am now only providing a single drivers: serial-power-manager.
It can be used for devices which only want power management.
Currently it can provide this using a regulator and/or a
toggle GPIO. This one driver supports both of my devices.

non-changes:
- The interface functionality is still provided by the 'tty'
layer, not the 'serial' layer. I have no strong feelings on
this and doubt that I would have until some other user
appeared for this functionality. That would help show
if the current arrangement was helpful or inconvenient.

- We still treat any child node of a tty device which has a
'compatible' field gets allocated a device. If there is no
platform driver which supports that 'compatible' value, then
the device will be inactive. Specific action will only be
taken if there is a child node with a 'compatible' field for which
there is a supporting driver.

small changes:
- proper 'compatible' names are used
- switch to use 'gpiod' instead of 'gpio'
- no longer misuse the 'tty_' prefix.


Comments and suggestions always welcome,
Thanks,
NeilBrown

---

NeilBrown (2):
TTY: add support for "tty slave" devices.
misc: add a driver to power on/off UART attached devices.


.../devicetree/bindings/misc/wi2wi,w2cbw003.txt | 19 +
.../devicetree/bindings/misc/wi2wi,w2sg0004.txt | 37 +
.../devicetree/bindings/serial/of-serial.txt | 4
.../devicetree/bindings/vendor-prefixes.txt | 1
drivers/misc/Kconfig | 12
drivers/misc/Makefile | 1
drivers/misc/serial-power-manager.c | 494 ++++++++++++++++++++
drivers/tty/tty_io.c | 73 +++
include/linux/tty.h | 16 +
9 files changed, 654 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/misc/wi2wi,w2cbw003.txt
create mode 100644 Documentation/devicetree/bindings/misc/wi2wi,w2sg0004.txt
create mode 100644 drivers/misc/serial-power-manager.c

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