Commit Graph

193 Commits

Author SHA1 Message Date
Stephen Street 8d94cc50aa [PATCH] spi: stabilize PIO mode transfers on PXA2xx systems
Stabilize PIO mode transfers against a range of word sizes and FIFO
thresholds and fixes word size setup/override issues.

1) 16 and 32 bit DMA/PIO transfers broken due to timing differences.
2) Potential for bad transfer counts due to transfer size assumptions.
3) Setup function broken is multiple ways.
4) Per transfer bit_per_word changes break DMA setup in pump_tranfers.
5) False positive timeout are not errors.
6) Changes in pxa2xx_spi_chip not effective in calls to setup.
7) Timeout scaling wrong for PXA255 NSSP.
8) Driver leaks memory while busy during unloading.

Known issues:

SPI_CS_HIGH and SPI_LSB_FIRST settings in struct spi_device are not handled.

Testing:

This patch has been test against the "random length, random bits/word,
random data (verified on loopback) and stepped baud rate by octaves
(3.6MHz to 115kHz)" test.  It is robust in PIO mode, using any
combination of tx and rx thresholds, and also in DMA mode (which
internally computes the thresholds).

Much thanks to Ned Forrester for exhaustive reviews, fixes and testing.
The driver is substantially better for his efforts.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:40 -08:00
Akinobu Mita 7b92ff01c2 [PATCH] spi: check platform_device_register_simple() error
Check the return value of platform_device_register_simple().

Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:42 -08:00
Hans-Christian Egtvedt 3bd0f69435 [PATCH] spi: set kset of master class dev explicitly
<quote Imre Deak from Thu, 12 Jan 2006 21:18:54 +0200>
  In order for spi_busnum_to_master to work spi master devices must be linked
  into the spi_master_class.subsys.kset list.  At the moment the default
  class_obj_subsys.kset is used and we can't enumerate the master devices.
</quote>

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:33 -08:00
Hans-Christian Egtvedt 4740d387f3 [PATCH] spi: correct bus_num and buffer bug in spi core
Correct the following in driver/spi/spi.c in function spi_busnum_to_master:

 * must allow bus_num 0, the if is really not needed.
 * correct the name buffer which is too small for bus_num >= 10000. It

should be 9 bytes big, not 8.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:32 -08:00
Jeff Garzik 89fc9a1a79 [PATCH] SPI: improve sysfs compiler complaint handling
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:31 -08:00
Christoph Lameter e94b176609 [PATCH] slab: remove SLAB_KERNEL
SLAB_KERNEL is an alias of GFP_KERNEL.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:24 -08:00
David Howells 6d5aefb8ea WorkQueue: Fix up arch-specific work items where possible
Fix up arch-specific work items where possible to use the new work_struct and
delayed_work structs.

Three places that enqueue bits of their stack and then return have been marked
with #error as this is not permitted.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-12-05 19:36:26 +00:00
David Howells 9db7372445 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	drivers/ata/libata-scsi.c
	include/linux/libata.h

Futher merge of Linus's head and compilation fixups.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-12-05 17:01:28 +00:00
David Howells 4c1ac1b491 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	drivers/infiniband/core/iwcm.c
	drivers/net/chelsio/cxgb2.c
	drivers/net/wireless/bcm43xx/bcm43xx_main.c
	drivers/net/wireless/prism54/islpci_eth.c
	drivers/usb/core/hub.h
	drivers/usb/input/hid-core.c
	net/core/netpoll.c

Fix up merge failures with Linus's head and fix new compilation failures.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-12-05 14:37:56 +00:00
Al Viro 914e26379d [PATCH] severing fs.h, radix-tree.h -> sched.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-12-04 02:00:24 -05:00
Matt LaPlante 3cb2fccc5f Fix misc Kconfig typos
Fix various Kconfig typos.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-11-30 05:22:59 +01:00
David Howells c4028958b6 WorkStruct: make allyesconfig
Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22 14:57:56 +00:00
Andrew Morton d3e5a938e7 [PATCH] spi section fix
WARNING: vmlinux - Section mismatch: reference to .init.text:spi_register_board_info from __ksymtab_gpl between '__ksymtab_spi_register_board_info' (at offset 0xc032f7d0) and '__ksymtab_spi_alloc_master'

Fix this by removing the export.

Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03 12:27:58 -08:00
Jeff Garzik c7bec5aba5 Various drivers' irq handlers: kill dead code, needless casts
- Eliminate casts to/from void*

- Eliminate checks for conditions that never occur.  These typically
  fall into two classes:

	1) Checking for 'dev_id == NULL', then it is never called with
	NULL as an argument.

	2) Checking for invalid irq number, when the only caller (the
	system) guarantees the irq handler is called with the proper
	'irq' number argument.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-06 15:00:58 -04:00
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Dave Jones 038b0a6d8d Remove all inclusions of <linux/config.h>
kbuild explicitly includes this at build time.

Signed-off-by: Dave Jones <davej@redhat.com>
2006-10-04 03:38:54 -04:00
Ingo Molnar 60be6b9a41 [PATCH] lockdep: annotate on-stack completions
lockdep needs to have the waitqueue lock initialized for on-stack waitqueues
implicitly initialized by DECLARE_COMPLETION().  Annotate on-stack completions
accordingly.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:09 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
David Brownell 980a01c9bf [PATCH] SPI: infrastructure to initialize spi_device.mode early
This patch adds earlier initialization of spi_device.mode, as needed
on boards using nondefault chipselect polarity.  An example would be
ones using the RS5C348 RTC without an external signal inverter between
the RTC chipselect and the SPI controller.

Without this mechanism, the first setup() call for that chip would
wrongly enable chips, corrupting transfers to/from other chips sharing
that SPI bus.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 15:51:01 -07:00
Ben Dooks ac88bcff2f [PATCH] s3c24xx: fix spi driver with CONFIG_PM
Fix compile bug with the S3C24XX SPI driver when CONFIG_PM is set.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-26 11:55:46 -07:00
Stephen Street 5daa3ba0c6 [PATCH] pxa2xx-spi update
Fix some outstanding issues with the pxa2xx_spi driver when running on a
PXA270:

- Wrong timeout calculation in the setup function due to different
  peripheral clock rates in the PXAxxx family.

- Bad handling of SSSR_TFS interrupts in interrupt_transfer function.

- Added locking to interface between the pump_messages workqueue and the
  pump_transfers tasklet.

Much thanks to Juergen Beisert for the extensive testing on the PXA270.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:20 -07:00
Ben Dooks 7fba53402e [PATCH] S3C24XX: hardware SPI driver
Hardware based SPI driver for Samsung S3C24XX SoC systems

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:19 -07:00
Ben Dooks 1fc7547d4b [PATCH] S3C24XX: GPIO based SPI driver
SPI driver for SPI by GPIO on the Samsung S3C24XX series of SoC processors.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: Greg KH <greg@kroah.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:19 -07:00
Kumar Gala ccf06998fe [PATCH] spi: add spi master driver for Freescale MPC83xx SPI controller
This driver supports the SPI controller on the MPC83xx SoC devices from
Freescale.  Note, this driver supports only the simple shift register SPI
controller and not the descriptor based CPM or QUICCEngine SPI controller.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:19 -07:00
dmitry pervushin ba1a051319 [PATCH] minor SPI doc fix
Because several developers asked me about referenced but missing
spi_add_master(), I think that this patch should be applied ...  it
corrects comments so they refer to spi_register_master() instead.

Signed-off-by: dmitry pervushin <dpervushin@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:19 -07:00
David Brownell 1e316d7566 [PATCH] SPI: spi_bitbang: clocking fixes
This fixes two problems triggered by the MMC stack updating clocks:

 - SPI masters driver should accept a max clock speed of zero; that's one
   convention for marking idle devices.  (Presumably that helps controllers
   that don't autogate clocks to "off" when not in use.)

 - There are more than 1000 nanoseconds per millisecond; setting the clock
   down to 125 KHz now works properly.

Showing once again that Zero (http://en.wikipedia.org/wiki/Zero) is still
an inexhaustible number of bugs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:58 -07:00
Stephen Street 9708c121c3 [PATCH] spi: Update to PXA2xx SPI Driver
Fix two outstanding issues with the pxa2xx_spi driver:

1) Bad cast in the function u32_writer. Thanks to Henrik Bechmann
2) Adds support for per transfer changes to speed and bits per word

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:58 -07:00
David Brownell a020ed7521 [PATCH] SPI: busnum == 0 needs to work
We need to be able to have a "SPI bus 0" matching chip numbering; but
that number was wrongly used to flag dynamic allocation of a bus number.

This patch resolves that issue; now negative numbers trigger dynamic alloc.

It also updates the how-to-write-a-controller-driver overview to mention
this stuff.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:57 -07:00
David Brownell ccf77cc4af [PATCH] SPI: devices can require LSB-first encodings
Add spi_device hook for LSB-first word encoding, and update all the
(in-tree) controller drivers to reject such devices.  Eventually,
some controller drivers will be updated to support lsb-first encodings
on the wire; no current drivers need this.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:57 -07:00
Kumar Gala ff9f4771b5 [PATCH] SPI: Renamed bitbang_transfer_setup to spi_bitbang_setup_transfer and export it
Renamed bitbang_transfer_setup to follow convention of other exported symbols
from spi-bitbang.  Exported spi_bitbang_setup_transfer to allow users of
spi-bitbang to use the function in their own setup_transfer.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:57 -07:00
David Brownell a9948b6194 [PATCH] SPI: spi bounce buffer has a minimum length
Make sure that spi_write_then_read() can always handle at least 32 bytes
of transfer (total, both directions), minimizing one portability issue.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:57 -07:00
Stephen Street e0c9905e87 [PATCH] SPI: add PXA2xx SSP SPI Driver
This driver turns a PXA2xx synchronous serial port (SSP) into a SPI master
controller (see Documentation/spi/spi_summary).  The driver has the following
features:

- Support for any PXA2xx SSP
- SSP PIO and SSP DMA data transfers.
- External and Internal (SSPFRM) chip selects.
- Per slave device (chip) configuration.
- Full suspend, freeze, resume support.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:56 -07:00
Imre Deak 4cff33f94f [PATCH] SPI: per-transfer overrides for wordsize and clocking
Some protocols (like one for some bitmap displays) require different clock
speed or word size settings for each transfer in an SPI message. This adds
those parameters to struct spi_transfer.  They are to be used when they are
nonzero; otherwise the defaults from spi_device are to be used.

The patch also adds a setup_transfer callback to spi_bitbang, uses it for
messages that use those overrides, and implements it so that the pure
bitbanging code can help resolve any questions about how it should work.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16 14:33:56 -07:00
Stephen Street d2799f083d [PATCH] spi: Fix modular master driver remove and device suspend/remove
Fix two problems in the spi subsystem:

1) spi subsystem core dumps when modular spi master is unloaded.
2) spi subsystem core dumps when spi slave device is suspended/resumed and
   module slave driver is not loaded.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:09 -08:00
David Brownell 9c1da3cb46 [PATCH] SPI: spi_butterfly, restore lost deltas
This resolves some minor version skew glitches that accumulated for the AVR
Butterfly adapter driver, which caused among other things the existence of
a duplicate Kconfig entry.  Most of it boils down to comment updates, but in
one case it removes some now-superfluous code that would be better if not
copied into other controller-level drivers.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
2006-02-06 12:17:17 -08:00
David Brownell 2e10c84b9c [PATCH] SPI: add spi_butterfly driver
This adds a bitbanging parport based adaptor cable for AVR Butterfly, giving
SPI links to its DataFlash chip and (eventually) firmware running in the card.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 16:29:56 -08:00
Andrew Morton 5d870c8e21 [PATCH] spi: remove fastcall crap
gcc4 generates warnings when a non-FASTCALL function pointer is assigned to a
FASTCALL one.  Perhaps it has taste.

Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 16:29:56 -08:00
David Brownell 7111763d39 [PATCH] spi: misc fixes
This collects some small SPI patches that seem to be missing from the MM tree:

  - spi_butterfly kbuild hooks got dropped somehow; this restores them
  - quick fix for a (theoretical?) m25p80_write() oops noted by Andrew
  - quick fix for a potential config-specific oops for mtd_dataflash()
  - minor doc tweaks

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 16:29:56 -08:00
Vitaly Wool 8275c642cc [PATCH] spi: use linked lists rather than an array
This makes the SPI core and its users access transfers in the SPI message
structure as linked list not as an array, as discussed on LKML.

From: David Brownell <dbrownell@users.sourceforge.net>

  Updates including doc, bugfixes to the list code, add
  spi_message_add_tail().  Plus, initialize things _before_ grabbing the
  locks in some cases (in case it grows more expensive).  This also merges
  some bitbang updates of mine that didn't yet make it into the mm tree.

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Dmitry Pervushin <dpervushin@gmail.com>
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 16:29:56 -08:00
David Brownell 9904f22a72 [PATCH] spi: add spi_bitbang driver
This adds a bitbanging spi master, hooking up to board/adapter-specific glue
code which knows how to set and read the signals (gpios etc).

This code kicks in after the glue code creates a platform_device with the
right platform_data.  That data includes I/O loops, which will usually
come from expanding an inline function (provided in the header).  One goal
is that the I/O loops should be easily optimized down to a few GPIO register
accesses, in common cases, for speed and minimized overhead.

This understands all the currently defined protocol tweaking options in the
SPI framework, and might eventually serve as as reference implementation.

  - different word sizes (1..32 bits)
  - differing clock rates
  - SPI modes differing by CPOL (affecting chip select and I/O loops)
  - SPI modes differing by CPHA (affecting I/O loops)
  - delays (usecs) after transfers
  - temporarily deselecting chips in mid-transfer

A lot of hardware could work with this framework, though common types of
controller can't reach peak performance without switching to a driver
structure that supports pipelining of transfers (e.g.  DMA queues) and maybe
controllers (e.g.  IRQ driven).

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 16:29:55 -08:00
David Brownell 0c868461fc [PATCH] SPI core tweaks, bugfix
This includes various updates to the SPI core:

  - Fixes a driver model refcount bug in spi_unregister_master() paths.

  - The spi_master structures now have wrappers which help keep drivers
    from needing class-level get/put for device data or for refcounts.

  - Check for a few setup errors that would cause oopsing later.

  - Docs say more about memory management.  Highlights the use of DMA-safe
    i/o buffers, and zero-initializing spi_message and such metadata.

  - Provide a simple alloc/free for spi_message and its spi_transfer;
    this is only one of the possible memory management policies.

Nothing to break code that already works.

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 16:29:55 -08:00
David Brownell b885244eb2 [PATCH] spi: add spi_driver to SPI framework
This is a refresh of the "Simple SPI Framework" found in 2.6.15-rc3-mm1
which makes the following changes:

  * There's now a "struct spi_driver".  This increase the footprint
    of the core a bit, since it now includes code to do what the driver
    core was previously handling directly.  Documentation and comments
    were updated to match.

  * spi_alloc_master() now does class_device_initialize(), so it can
    at least be refcounted before spi_register_master().  To match,
    spi_register_master() switched over to class_device_add().

  * States explicitly that after transfer errors, spi_devices will be
    deselected.  We want fault recovery procedures to work the same
    for all controller drivers.

  * Minor tweaks:  controller_data no longer points to readonly data;
    prevent some potential cast-from-null bugs with container_of calls;
    clarifies some existing kerneldoc,

And a few small cleanups.

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
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