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Author	SHA1	Message	Date
David Brownell	8ae12a0d85	[PATCH] spi: simple SPI framework This is the core of a small SPI framework, implementing the model of a queue of messages which complete asynchronously (with thin synchronous wrappers on top). - It's still less than 2KB of ".text" (ARM). If there's got to be a mid-layer for something so simple, that's the right size budget. :) - The guts use board-specific SPI device tables to build the driver model tree. (Hardware probing is rarely an option.) - This version of Kconfig includes no drivers. At this writing there are two known master controller drivers (PXA/SSP, OMAP MicroWire) and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML mentions of other drivers in development. - No userspace API. There are several implementations to compare. Implement them like any other driver, and bind them with sysfs. The changes from last version posted to LKML (on 11-Nov-2005) are minor, and include: - One bugfix (removes a FIXME), with the visible effect of making device names be "spiB.C" where B is the bus number and C is the chipselect. - The "caller provides DMA mappings" mechanism now has kerneldoc, for DMA drivers that want to be fancy. - Hey, the framework init can be subsys_init. Even though board init logic fires earlier, at arch_init ... since the framework init is for driver support, and the board init support uses static init. - Various additional spec/doc clarifications based on discussions with other folk. It adds a brief "thank you" at the end, for folk who've helped nudge this framework into existence. As I've said before, I think that "protocol tweaking" is the main support that this driver framework will need to evolve. From: Mark Underwood <basicmark@yahoo.com> Update the SPI framework to remove a potential priority inversion case by reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>	2006-01-13 16:29:54 -08:00

Author

SHA1

Message

Date

David Brownell

8ae12a0d85

[PATCH] spi: simple SPI framework

This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).

  - It's still less than 2KB of ".text" (ARM).  If there's got to be a
    mid-layer for something so simple, that's the right size budget.  :)

  - The guts use board-specific SPI device tables to build the driver
    model tree.  (Hardware probing is rarely an option.)

  - This version of Kconfig includes no drivers.  At this writing there
    are two known master controller drivers (PXA/SSP, OMAP MicroWire)
    and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
    mentions of other drivers in development.

  - No userspace API.  There are several implementations to compare.
    Implement them like any other driver, and bind them with sysfs.

The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:

  - One bugfix (removes a FIXME), with the visible effect of making device
    names be "spiB.C" where B is the bus number and C is the chipselect.

  - The "caller provides DMA mappings" mechanism now has kerneldoc, for
    DMA drivers that want to be fancy.

  - Hey, the framework init can be subsys_init.  Even though board init
    logic fires earlier, at arch_init ... since the framework init is
    for driver support, and the board init support uses static init.

  - Various additional spec/doc clarifications based on discussions
    with other folk.  It adds a brief "thank you" at the end, for folk
    who've helped nudge this framework into existence.

As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.

From: Mark Underwood <basicmark@yahoo.com>

  Update the SPI framework to remove a potential priority inversion case by
  reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2006-01-13 16:29:54 -08:00

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