This is a doc-only patch which I hope will reduce the number of
spi_master controller driver patches starting out with a common
implementation bug.
(As in: almost every spi_master driver I see starts out with its
version of this bug. Sigh.)
It just re-emphasizes that the setup() method may be called for one
device while a transfer is active on another ... which means that most
driver implementations shouldn't touch any registers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a byteswap bug in the LM70 temperature sensor driver,
which was previously covered up by a converse bug in the driver
for the LM70EVAL-LLP board (which is also fixed).
Other fixes: doc updates, remove an annoying msleep(), and improve
three-wire protocol handling.
Signed-off-by: Kaiwan N Billimoria <kaiwan@designergraphix.com>
[ dbrownell@users.sourceforge.net: doc and whitespace tweaks ]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Use __initdata for data, not __init.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the chip info structure data optional by providing reasonable
defaults. Improve corresponding documentation, and highlight the drawback
of not providing explicit chipselect control.
DMA can determine appropriate dma_burst_size and thresholds automatically
so use DMA even if dma_burst_size is not specified.
Signed-off-by: Vernon Sauder <VernonInHand@gmail.com>
Reviewed-by: Ned Forrester <nforrester@whoi.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently source files in the Documentation/ sub-dir can easily bit-rot
since they are not generally buildable, either because they are hidden in
text files or because there are no Makefile rules for them. This needs to
be fixed so that the source files remain usable and good examples of code
instead of bad examples.
Add the ability to build source files that are in the Documentation/ dir.
Add to Kconfig as "BUILD_DOCSRC" config symbol.
Use "CONFIG_BUILD_DOCSRC=1 make ..." to build objects from the
Documentation/ sources. Or enable BUILD_DOCSRC in the *config system.
However, this symbol depends on HEADERS_CHECK since the header files need
to be installed (for userspace builds).
Built (using cross-tools) for x86-64, i386, alpha, ia64, sparc32,
sparc64, powerpc, sh, m68k, & mips.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move sample source code to its own source file so that it can be used
easier and build-tested/check/maintained by anyone.
(Makefile changes are in a separate patch for all of Documentation/.)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update SPI documentation to clarify some areas of recent confusion: clock
polarity takes effect when chipselect goes active; and zero length buffers are
OK in certain cases.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Convert files to UTF-8.
* Also correct some people's names
(one example is Eißfeldt, which was found in a source file.
Given that the author used an ß at all in a source file
indicates that the real name has in fact a 'ß' and not an 'ss',
which is commonly used as a substitute for 'ß' when limited to
7bit.)
* Correct town names (Goettingen -> Göttingen)
* Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Make the SPI framework and drivers stop using class_device. Update docs
accordingly ... highlighting just which sysfs paths should be
"safe"/stable.
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Constify two char pointers and a struct in Documentation/spi/spidev_test.c.
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a simple utility used to test SPI functionality. It could stand
growing options to support using other test data patterns; this initial
version only issues full duplex transfers, which rules out 3WIRE or
Microwire links.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a driver for the LM70-LLP parport adapter, which is an eval board
for the LM70 temperature sensor. For those without that board, it may be a
simpler example of a parport-to-SPI adapter then spi_butterfly.
Signed-off-by: Kaiwan N Billimoria <kaiwan@designergraphix.com>
Doc, coding style, and interface updates; build fixes. Minor rename.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update the SPI documentation to cover a few points that have proven to be
confusing or unclear; most notably the two clock mode bits.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various documentation updates for the SPI infrastructure, to clarify things
that may not have been clear, to cope with lack of editing, and fix
omissions.
Also, plug SPI into the kernel-api DocBook template, and fix all the
resulting glitches in document generation.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a filesystem API for <linux/spi/spi.h> stack. The initial version of
this interface is purely synchronous.
dbrownell@users.sourceforge.net:
Cleaned up, bugfixed; much simplified; added preliminary documentation.
Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.
Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
groups of one or more transfers (each of which may be full duplex if
desired).
This is marked as EXPERIMENTAL with an explicit disclaimer that the API
(notably the ioctls) is subject to change.
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes the unnecessary bit number from CKENnn_XXXX
definitions for PXA, so that
CKEN0_PWM0 --> CKEN_PWM0
CKEN1_PWM1 --> CKEN_PWM1
...
CKEN24_CAMERA --> CKEN_CAMERA
The reasons for the change of these defitions are:
1. they do not scale - they are currently valid for pxa2xx, but
definitely not valid for pxa3xx, e.g., pxa3xx has bit 3 for camera
instead of bit 24
2. they are unnecessary - the peripheral name within the definition
has already announced its usage, we don't need those bit numbers
to know which peripheral we are going to enable/disable clock for
3. they are inconvenient - think about this: a driver programmer
for pxa has to remember which bit in the CKEN register to turn
on/off
Another change in the patch is to make the definitions equal to its
clock bit index, so that
#define CKEN_CAMERA (24)
instead of
#define CKEN_CAMERA (1 << 24)
this change, however, will add a run-time bit shift operation in
pxa_set_cken(), but the benefit of this change is that it scales
when bit index exceeds 32, e.g., pxa3xx has two registers CKENA
and CKENB, totally 64 bit for this, suppose CAMERA clock enabling
bit is CKENB:10, one can simply define CKEN_CAMERA to be (32 + 10)
and so that pxa_set_cken() need minimum change to adapt to that.
Signed-off-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The spi_register_driver() sets the bus_type field of the spi_driver being
registered, so there is no need to have it set in the driver itself.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add wrappers for getting and setting the driver data using spi_device
instead of using dev_{get|set}_drvdata with &spi->dev, to mirror the
platform_{get|set}_drvdata.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Remove many duplicated words under Documentation/ and do other small
cleanups.
Examples:
"and and" --> "and"
"in in" --> "in"
"the the" --> "the"
"the the" --> "to the"
...
Signed-off-by: Paolo Ornati <ornati@fastwebnet.it>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
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>
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>
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>
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>
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>
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>
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>
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>
