Update chipselect handling for atmel_spi:
* Teach it how to leave chipselect active between messages; this
helps various drivers work better.
* Cope with at91rm0200 errata: nCS0 can't be managed with GPIOs.
The MR.PCS value is now updated whenever a chipselect changes.
(This requires SPI pinmux init for that controller to change,
and also testing on rm9200; doesn't break at91sam9 or avr32.)
* Fix minor glitches: spi_setup() must leave chipselects inactive,
as must removal of the spi_device.
Also tweak diagnostic messaging to be a bit more useful.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minor updates to atmel_spi:
- DMA:
* Comments to explain the DMA policies
* Report any mapping errors from spi_transfer()
* Remove extra loop for DMA mapping
- Diagnostics: report minimum clock rate, if we need to reject a
spi_setup() request because that rate is too low.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The MPC83xx SPI controller clock divider can divide the system clock by not
more then 1024. The spi_mpc83xx driver does not check this and silently
writes garbage to the SPI controller registers when asked to run at lower
frequencies. I've tried to run the SPI on a 266MHz MPC8349E with 100kHz
for debugging a bus problem and suddenly was confronted with a 2nd problem
to debug.. ;-)
The patch adds an additional check which avoids writing garbage to the SPI
controller registers and warn the user about it. This might help others to
avoid simmilar problems.
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: David Brownell <david-b@pacbell.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>
Get rid of annoying GCC warning on 32-bit platforms.
drivers/spi/spidev.c: In function 'spidev_message':
drivers/spi/spidev.c:184: warning: cast to pointer from integer of different size
drivers/spi/spidev.c:216: warning: cast to pointer from integer of different size
The trick is to add an extra cast using "ptrdiff_t" to convert the u64 to
the correct size integer, and only then casting it into a "void *" pointer.
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>
Minor SPI controller driver updates: make the setup() methods reject
spi->mode bits they don't support, by masking aginst the inverse of bits
they *do* support. This insures against misbehavior later when new mode
bits get added.
Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH.
Support for all four SPI clock/transfer modes is routine.
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>
Well, first of all, I don't want to change so many files either.
What I do:
Adding a new parameter "struct bin_attribute *" in the
.read/.write methods for the sysfs binary attributes.
In fact, only the four lines change in fs/sysfs/bin.c and
include/linux/sysfs.h do the real work.
But I have to update all the files that use binary attributes
to make them compatible with the new .read and .write methods.
I'm not sure if I missed any. :(
Why I do this:
For a sysfs attribute, we can get a pointer pointing to the
struct attribute in the .show/.store method,
while we can't do this for the binary attributes.
I don't know why this is different, but this does make it not
so handy to use the binary attributes as the regular ones.
So I think this patch is reasonable. :)
Who benefits from it:
The patch that exposes ACPI tables in sysfs
requires such an improvement.
All the table binary attributes share the same .read method.
Parameter "struct bin_attribute *" is used to get
the table signature and instance number which are used to
distinguish different ACPI table binary attributes.
Without this parameter, we need to offer different .read methods
for different ACPI table binary attributes.
This is impossible as there are various ACPI tables on different
platforms, and we don't know what they are until they are loaded.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs is now completely out of driver/module lifetime game. After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners. Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.
This patch kills now unnecessary attribute->owner. Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.
For more info regarding lifetime rule cleanup, please read the
following message.
http://article.gmane.org/gmane.linux.kernel/510293
(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix SPI dynamic bus ID assignment to start at 2^15-1 rather than a negative
number. Valid bus ids are supposed to be positive, and are (now) stored in
an 's16' value.
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>
Fix 2 bugs:
- SPI_DMA_RHDMA bad value.
- Missing return value in setup() function (lost passing from
patch-2.6.20-rc4-spi_imx to patch-2.6.20-rc6-spi_imx).
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When either rx_buf or tx_buf is not being used, i.e. for plain read- or
write operations, the atmel_spi uses a fixed-size DMA buffer instead. If
the transfer is longer than the size of this buffer, it is split into
multiple DMA transfers.
When the transfer is split like this, the atmel_spi driver ends up using
the same DMA address again and again even for the buffer that came from the
user, which is of course wrong. Fix this by adding the number of bytes
already transferred to the DMA address so that the data ends up in the
right place.
Thanks to Wu Xuan for discovering this bug.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.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>
The omap_uwire controller driver handles SPI_CPHA incorrectly;
It should mean:
CPHA=0 ... sample at leading edge of clock
CPHA=1 ... sample at trailing edge of clock
This bug has been masked by inverse bugs in layered drivers;
and was uncovered by running some of them on non-OMAP hardware.
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>
'ioc' should be deallocated if __copy_from_user fails (found by Coverity
- CID 1644).
Signed-off-by: Florin Malita <fmalita@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>
Message size needs to be checked before copying, or bad things could
happen.
Signed-off-by: Domen Puncer <domen.puncer@telargo.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>
Fix mpc5200 PSC SPI driver to actually work for CONFIG_PPC_MERGE
- s/mpc52xx/mpc5200/, as this was changed in device tree some time ago
- fix spi id detection
The move from 'ppc' to 'powerpc' didn't quite match the latest
kernel.org code.
Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Acked-by: Dragos Carp <dragos.carp@toptica.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>
a) platorm_driver_probe(...) instead of platform_driver_register(&driver);
b) set bfin_spi_enable and bfin_spi_disable static
c) Why is the width flag a u32?
d) maybe use dev_dbg() instead of pr_debug()
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_first_zero_bit accepts number of bits, not longs.
Signed-off-by: Domen Puncer <domen.puncer@telargo.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>
SPI master driver for MPC52xx using its Programmable Serial Controller.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dragos Carp <dragos.carp@toptica.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add "depends on HAS_IOMEM" to a number of menus to make them
disappear for s390 which does not have I/O memory.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Now that the cpu_is_xxx() macros are available both on AVR32 and AT91, we can
remove a couple of #ifdefs from this driver. One of them is actually wrong --
new_1 should be set on AVR32 but isn't. This causes the bus clock to run at
twice the speed it is configured to.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is a driver for the Alchemy au1550 PSC (Programmable Serial
Controller) in SPI master mode.
It supports dma transfers using the Alchemy descriptor based dma controller
for 4-8 bits per word SPI transfers. For 9-24 bits per word transfers, pio
irq based mode is used to avoid setup of dma channels from scratch on each
number of bits per word change.
Tested with au1550; this may also work on other MIPS Alchemy cpus, like
au1200/au1210/au1250. Used extensively with SD card connected via SPI;
this handles 8.1MHz SPI clock transfers using dma without any problem (the
highest SPI clock freq possible with au1550 running on 324MHz).
The driver supports sharing of SPI bus by multiple devices. All features
of Alchemy SPI mode are supported (all SPI modes, msb/lsb first, bits per
word in 4-24 range).
As the SPI clock of the controller depends on main input clock that shall
be configured externally, platform data structure for au1550 SPI controller
driver contains mainclk_hz attribute to define the input clock rate. From
this value, dividers of the controller for SPI clock are set up for
required frequency.
Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
Whitespace and section fixups. Remove partial workaround for platform
setup bug in dma_mask setup; it couldn't work with multiple controllers.
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>
Simplify the spi_butterfly driver by removing incomplete/unused support for
the second SPI bus, implemented by the USI controller. This should make
this a clearer example of how to write a parport bitbang driver.
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 some of the layered parport_driver code to use parport->dev:
- i2c-parport (parent of i2c_adapter)
- spi_butterfly (parent of spi_master, allowing cruft removal)
- lp (creating class_device)
- ppdev (parent of parportN device)
- tipar (creating class_device)
There are still drivers that should be updated, like some of the input
drivers; but they won't be any worse off than they are today.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a836f5856a removes the shutdown
member of the bitbang structure, breaking the build of spi_s3c24xx.c.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.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>
This patch implements the driver necessary use the Analog Devices Blackfin
processor's SPI Port.
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It turns out that the last patch to change set_cs to be kept in the
controller's structure instead of the platform data was an incomplete
change, and did not change the references to platfrom data in the setup
xfer code. (This can prevent an oops.)
Reported-by: <Ling.Alex@iac.com.tw>
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>
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:spi_register_master from .text between 'spi_bitbang_start' (at offset 0x84e11a) and 'bitbang_work'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:spi_alloc_master from .text between 'butterfly_attach' (at offset 0x84e681) and 'at25_remove'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:spi_new_device from .text between 'butterfly_attach' (at offset 0x84e7e4) and 'at25_remove'
Signed-off-by: Adrian Bunk <bunk@stusta.de>
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>
The set_cs field of struct s3c24xx_spi is declared as returning a int but
the value returned but set_cs is never fixed. Moreover, the default
function for set_cs and the set_cs defintion in the platform data are
returning void.
I'm proposing to change the prototype to void (*set_cs)(...). By doing
this, I'm also fixing 2 build warnings:
drivers/spi/spi_s3c24xx.c: In function 's3c24xx_spi_probe':
drivers/spi/spi_s3c24xx.c:330: warning: assignment from incompatible pointer type
drivers/spi/spi_s3c24xx.c:335: warning: assignment from incompatible pointer type
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.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>
Prevents a potential oops with CONFIG_SPI_DEBUG given flakey hardware or
incorrect configuration.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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>
It's been pointed out that output GPIOs should have an initial value, to
avoid signal glitching ... among other things, it can be some time before
a driver is ready. This patch corrects that oversight, fixing
- documentation
- platforms supporting the GPIO interface
- users of that call (just one for now, others are pending)
There's only one user of this call for now since most platforms are still
using non-generic GPIO setup code, which in most cases already couples the
initial value with its "set output mode" request.
Note that most platforms are clear about the hardware letting the output
value be set before the pin direction is changed, but the s3c241x docs are
vague on that topic ... so those chips might not avoid the glitches.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Acked-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a bug in the cleanup of an spi_bitbang bus.
The workqueue associated with the bus was destroyed before the call to
spi_unregister_master. That meant that spi devices on that bus would be
unable to do IO in their remove method. The shutdown flag should have been
able to prevent a segfault, but was never getting set. By waiting to
destroy the workqueue until after the master is unregistered, devices are
able to do IO in their remove methods. An added benefit is that neither
the shutdown flag nor a wait for the queue of messages to empty is needed.
Signed-off-by: Chris Lesiak <chris.lesiak@licor.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>
Add transfer modes 2 and 3 to the S3C24XX gpio SPI driver
Signed-off-by: Harald Welte <laforge@openmoko.org>
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>
The signature of the per-device cleanup() routine changed to remove its
const-ness. Three new SPI controller drivers now need that change, to
eliminate build warnings.
This also fixes a build bug with atmel_spi on AT91 systems.
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>
Driver for the Atmel on-chip SPI master controller.
Tested primarily on AVR32/AT32AP7000/ATSTK1000 using mtd_dataflash and the
jffs2 filesystem. Should also work fine on various AT91 ARM-based chips
like AT91SAM926x and AT91RM9200.
Hardware documentation can be found in the AT32AP7000 data sheet, or its
AT91 siblings, which can be downloaded from
http://www.atmel.com/dyn/products/datasheets.asp?family_id=682
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.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 is adds a simple SPI EEPROM driver, providing access to the EEPROM
through sysfs much like the I2C "eeprom" driver ... except this driver
supports write access, and multiple EEPROM sizes.
From: "Tuppa, Walter" <walter.tuppa@siemens.com>
Since I have EEPROMs on SPI with different address sizing, I made some
changes to your at25.c to support them. Works perfectly. (Also includes a
small bugfix for the "what size address" test.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Walter Tuppa <walter.tuppa@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'd like to assign NULL to kfree()d members of a structure. I can't do
that without ugly casting (see the PXA patch) when the structure pointed to
is const-qualified. I don't really see a reason why the cleanup method
isn't allowed to alter the object it should clean up. :-)
No, I didn't test the PXA patch, but I verified that the NULL-assignment
doesn't stop me from doing rmmod/insmodding my own spi_bitbang-based
driver.
Signed-off-by: Hans-Peter Nilsson <hp@axis.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>
A small bug-fix for spi_bitbang: it must always call the setup_transfer
function via the overridable pointer, not assume that its
spi_bitbang_setup_transfer is sufficient. Otherwise, if all options in the
transfers are default (0), the overrided function will never be called.
Granted, the function replacing it must call spi_bitbang_setup_transfer,
but it might also have other important things to do, even if the second
argument (the spi_transfer) is NULL. Tested together with the other
patches on the spi_crisv32_sser and spi_crisv32_gpio drivers (not yet in
the kernel, will IIUC be submitted as part of the usual
arch-maintainer-pushes).
Signed-off-by: Hans-Peter Nilsson <hp@axis.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>
Add the SPI controller driver for Freescale i.MX(S/L/1).
Main features summary:
> Per chip setup via board specific code and/or protocol driver.
> Per transfer setup.
> PIO transfers.
> DMA transfers.
> Managing of NULL tx / rx buffer for rd only / wr only transfers.
This patch replace patch-2.6.20-rc4-spi_imx with the following changes:
> Few cosmetic changes.
> Function map_dma_buffers now return 0 for success and -1 for failure.
> Solved a bug inside spi_imx_probe function (wrong error path).
> Solved a bug inside setup function (bad undo setup for max_speed_hz).
> For read-only transfers, always write zero bytes.
This is almost the same as the 'BIS' version sent by Andrea, except for
updating the 'DUMMY' byte so that read-only transfers shift out zeroes.
That part of the API changed recently, since some half duplex peripheral
chips require that semantic.
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
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 SPI driver for the Microwire controller on OMAP1 chips. This
driver has been used in the Linux-OMAP tree for some time now, including
with some of those displays using standardized 9-bit commands followed by
data with 8-bit words.
Microwire only supports half duplex transfers, but that's all that most SPI
protocols need. When full duplex, or higher speeds, are needed there are
several other controllers that can be used on OMAP.
[akpm@osdl.org: cleanups]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Imre Deak <imre.deak@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minor Kconfig cleanup ... put the SPI_S3C24XX entry in the
correct location (alphabetical order).
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 reverts commit 2943ecf2ed.
This should go through the SPI maintainer, it was my fault that it did
not. Especially as it conflicts with other patches he has pending.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Cc: <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If a SPI master device exists, udev (udevtrigger) causes kernel crash, due
to wrong kobj pointer in kobject_uevent_env(). This problem was not in
2.6.19.
The backtrace (on MIPS) was:
[<8024db6c>] kobject_uevent_env+0x54c/0x5e8
[<802a8264>] store_uevent+0x1c/0x3c (in drivers/class.c)
[<801cb14c>] subsys_attr_store+0x2c/0x50
[<801cb80c>] flush_write_buffer+0x38/0x5c
[<801cb900>] sysfs_write_file+0xd0/0x190
[<80181444>] vfs_write+0xc4/0x1a0
[<80181cdc>] sys_write+0x54/0xa0
[<8010dae4>] stack_done+0x20/0x3c
flush_write_buffer() passes kobject of spi_master_class.subsys to
subsys_addr_store(), then subsys_addr_store() passes a pointer to a struct
subsystem to store_uevent() which expects a pointer to a struct
class_device. The problem seems subsys_attr_store() called instead of
class_device_attr_store().
This mismatch was caused by commit
3bd0f69435, which overrides kset of master
class. This made spi_master_class.subsys.kset.ktype NULL so
subsys_sysfs_ops is used instead of class_dev_sysfs_ops.
The commit was to fix spi_busnum_to_master(). Here is a patch fixes
this function in other way, just searching children list of
class_device.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the spi mode can be set to the wrong mode if you are switching
from any mode other than mode 0. This is because the mode is set using a
bitwise or on uncleared bits. The following patch clears the mode bits
before setting the new mode. I've also modified it to use the appropriate
defines from pxa-regs.h for readability.
Signed-off-by: Justin Clacherty <justin@redfish-group.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It turns out that the spi chipselect was not being passed to the set_cs
routine if one was specified in the platform data.
As part of the fix, change to using a set_cs field in the controller state,
and put a default gpio routine in if the data passed does not specify it.
Also remove the //#define DEBUG
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Russel King recently reminded us that one shouldn't use asm/arch/hardware.h
but one should use asm/hardware.h. Unfortunately, the spi_s3c24xx_gpio
driver is using the wrong header. This patch is fixing that.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
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>
Some issues were recently turned up with the current specification of what
it means for spi_transfer.tx_buf to be null, as part of transfers which are
(from the SPI protocol driver perspective) pure reads.
Specifically, that it seems better to change the TX behaviour there from
"undefined" to "will shift zeroes". This lets protocol drivers (like the
ads7846 driver) depend on that behavior. It's what most controller drivers
in the tree are already doing (with one exception and one case of driver
wanting-to-oops), it's what Microwire hardware will necessarily be doing,
and it removes an issue whereby certain security audits would need to
define such a value anyway as part of removing covert channels.
This patch changes the specification to require shifting zeroes, and
updates all currently merged SPI controller drivers to do so.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The general gpio driver includes seem to now depend on having
<linux/workqueue.h> included before they are.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
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>
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>
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>
<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>
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>
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>
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>
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>
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>
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>
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>
- 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>
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)
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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 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>
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>
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>
