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path: root/drivers/spi/spi.c
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* spi: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers2009-01-06
| | | | | | Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spi: core and gpio expanders use subsys_initDavid Brownell2008-10-16
| | | | | | | | | | | | | | | Make the SPI external GPIO expander drivers register themselves at subsys_initcall() time when they're statically linked, and make the SPI core do its driver model initialization earlier so that's safe. SOC-integrated GPIOs are available starting very early -- often before initcalls start to run, or earily in arch_initcall() at latest -- so this improves consistency, letting more subsystems rely on GPIOs being usable by their own subsys_initcall() code. 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: simplify spi_write_then_read()Vernon Sauder2008-10-16
| | | | | | | | | | Modify spi_write_then_read() to use one transfer. This speeds up all callers, and is a minor code shrink. Signed-off-by: Vernon Sauder <Vernon.Sauder@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>
* spi: bugfix spi_add_device() with duplicate chipselectsDavid Brownell2008-08-15
| | | | | | | | | | | | | | | | | | | | | | | When reviewing a recent patch I noticed a potential trouble spot in the registration of new SPI devices. The SPI master driver is told to set the device up before adding it to the driver model, so that it's always properly set up when probe() is called. (This is important, because in the case of inverted chipselects, this device can make the bus misbehave until it's properly deselected. It's got to be set up even if no driver binds to the device.) The trouble spot is that it doesn't first verify that no other device has been added using that chipselect. If such a device has been added, its configuration gets trashed. (Fortunately this has not been a common error!) The fix here adds an explicit check, and a mutex to protect the relevant critical region. [akpm@linux-foundation.org: make the lock local to spi_add_device()] 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: split up spi_new_device() to allow two stage registration.Grant Likely2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | spi_new_device() allocates and registers an spi device all in one swoop. If the driver needs to add extra data to the spi_device before it is registered, then this causes problems. This is needed for OF device tree support so that the SPI device tree helper can add a pointer to the device node after the device is allocated, but before the device is registered. OF aware SPI devices can then retrieve data out of the device node to populate a platform data structure. This patch splits the allocation and registration portions of code out of spi_new_device() and creates two new functions; spi_alloc_device() and spi_register_device(). spi_new_device() is modified to use the new functions for allocation and registration. None of the existing users of spi_new_device() should be affected by this change. Drivers using the new API can forego the use of spi_board_info structure to describe the device layout and populate data into the spi_device structure directly. This change is in preparation for adding an OF device tree parser to generate spi_devices based on data in the device tree. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David Brownell <dbrownell@users.sourceforge.net>
* spi: make spi_board_info.modalias a char arrayGrant Likely2008-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, 'modalias' in the spi_device structure is a 'const char *'. The spi_new_device() function fills in the modalias value from a passed in spi_board_info data block. Since it is a pointer copy, the new spi_device remains dependent on the spi_board_info structure after the new spi_device is registered (no other fields in spi_device directly depend on the spi_board_info structure; all of the other data is copied). This causes a problem when dynamically propulating the list of attached SPI devices. For example, in arch/powerpc, the list of SPI devices can be populated from data in the device tree. With the current code, the device tree adapter must kmalloc() a new spi_board_info structure for each new SPI device it finds in the device tree, and there is no simple mechanism in place for keeping track of these allocations. This patch changes modalias from a 'const char *' to a fixed char array. By copying the modalias string instead of referencing it, the dependency on the spi_board_info structure is eliminated and an outside caller does not need to maintain a separate spi_board_info allocation for each device. If searched through the code to the best of my ability for any references to modalias which may be affected by this change and haven't found anything. It has been tested with the lite5200b platform in arch/powerpc. [dbrownell@users.sourceforge.net: cope with linux-next changes: KOBJ_NAME_LEN obliterated, etc] Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 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 Core: add ability for class_find_device to start in middle of listGreg Kroah-Hartman2008-07-22
| | | | | | | | | | | | | | | This mirrors the functionality that driver_find_device has as well. We add a start variable, and all callers of the function are fixed up at the same time. The block layer will be using this new functionality in a follow-on patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spi core: stop updating dev->power.power_stateDavid Brownell2008-02-06
| | | | | | | | | | Don't update dev->power.power_state any more in the SPI core. The only reason to update this scheduled-to-be-removed field was to make the already-removed /sys/devices/.../power/state files work better. 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>
* Remove inclusions of <linux/autoconf.h>Ralf Baechle2008-02-06
| | | | | | | | | | Nothing should ever include this file. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: "Mike Frysinger" <vapier.adi@gmail.com> Acked-by: "Bryan Wu" <cooloney.lkml@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* spi: use class iteration apiDave Young2008-01-24
| | | | | | | | | Convert to use the class iteration api. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Acked-by: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spi: simplify spi_sync() calling conventionMarc Pignat2007-12-05
| | | | | | | | | | | | Simplify spi_sync calling convention, eliminating the need to check both the return value AND the message->status. In consequence, this corrects misbehaviours of spi_read and spi_write (which only checked the former) and their callers. Signed-off-by: Marc Pignat <marc.pignat@hevs.ch> 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: use mutex not semaphoreDavid Brownell2007-12-05
| | | | | | | | Make spi_write_then_read() use a mutex not a binary semaphore. 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: fix double-free on spi_unregister_masterAtsushi Nemoto2007-11-14
| | | | | | | | | | | | After 49dce689ad4ef0fd1f970ef762168e4bd46f69a3, device_for_each_child iteration hits the master device itself. Do not call spi_unregister_device() for the master device. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Acked-by: David Brownell <david-b@pacbell.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* spi doesn't need class_deviceTony Jones2007-10-16
| | | | | | | | | | | | 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>
* Driver core: change add_uevent_var to use a structKay Sievers2007-10-12
| | | | | | | | | | | | | | | | | | This changes the uevent buffer functions to use a struct instead of a long list of parameters. It does no longer require the caller to do the proper buffer termination and size accounting, which is currently wrong in some places. It fixes a known bug where parts of the uevent environment are overwritten because of wrong index calculations. Many thanks to Mathieu Desnoyers for finding bugs and improving the error handling. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spi device setup gets better error checkingDavid Brownell2007-07-31
| | | | | | | | | | | | | | | | | | | | | | | This updates some error reporting paths in SPI device setup: - Move validation logic for SPI chipselects to spi_new_device(), which is where it should always have been. - In spi_new_device(), emit error messages if the device can't be created. This is LOTS better than a silent failure; though eventually, the calling convention should probably change to use the <linux/err.h> conventions. - Includes one previously-missing check: SPI masters must always have at least one chipselect, even for dedicated busses which always keep it selected! It also adds a FIXME (IDR for dynamic ID allocation) so the issue doesn't live purely in my mailbox. 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.c:scan_boardinfo() mustn't be __init_or_moduleAdrian Bunk2007-07-21
| | | | | | | | | WARNING: drivers/built-in.o(.text+0x889735): Section mismatch: reference to .init.text:scan_boardinfo (between 'spi_register_master' and '__unregister') Signed-off-by: Adrian Bunk <bunk@stusta.de> 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>
* use mutex instead of semaphore in SPI core/init codeMatthias Kaehlcke2007-07-17
| | | | | | | | | | The SPI core/init code uses a semaphore as mutex. Use the mutex API instead of the (binary) semaphore. Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Acked-by: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SPI dynamic busid generation bugfixDavid Brownell2007-06-04
| | | | | | | | | | 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>
* SPI kerneldocDavid Brownell2007-05-08
| | | | | | | | | | | | | | 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>
* [PATCH] drivers/spi/: fix section mismatchesAdrian Bunk2007-03-27
| | | | | | | | | | | 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>
* [PATCH] SPI cleanup() method param becomes non-constHans-Peter Nilsson2007-02-12
| | | | | | | | | | | | | | | | 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>
* Revert "Driver core: convert SPI code to use struct device"Greg Kroah-Hartman2007-02-08
| | | | | | | | | This reverts commit 2943ecf2ed32632473c06f1975db47a7aa98c10f. 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>
* Driver core: convert SPI code to use struct deviceGreg Kroah-Hartman2007-02-07
| | | | | | | | | 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>
* [PATCH] SPI: alternative fix for spi_busnum_to_masterAtsushi Nemoto2007-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 3bd0f6943520e459659d10f3282285e43d3990f1, 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>
* [PATCH] spi: set kset of master class dev explicitlyHans-Christian Egtvedt2006-12-07
| | | | | | | | | | | | | <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>
* [PATCH] spi: correct bus_num and buffer bug in spi coreHans-Christian Egtvedt2006-12-07
| | | | | | | | | | | | | | 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>
* [PATCH] SPI: improve sysfs compiler complaint handlingJeff Garzik2006-12-07
| | | | | | | 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>
* [PATCH] slab: remove SLAB_KERNELChristoph Lameter2006-12-07
| | | | | | | | 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>
* [PATCH] spi section fixAndrew Morton2006-11-03
| | | | | | | | | | 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>
* [PATCH] lockdep: annotate on-stack completionsIngo Molnar2006-07-03
| | | | | | | | | | | | 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>
* [PATCH] SPI: infrastructure to initialize spi_device.mode earlyDavid Brownell2006-06-28
| | | | | | | | | | | | | | 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>
* [PATCH] minor SPI doc fixdmitry pervushin2006-05-21
| | | | | | | | | | | 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>
* [PATCH] SPI: busnum == 0 needs to workDavid Brownell2006-05-16
| | | | | | | | | | | | | 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>
* [PATCH] SPI: spi bounce buffer has a minimum lengthDavid Brownell2006-05-16
| | | | | | | | 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>
* [PATCH] spi: Fix modular master driver remove and device suspend/removeStephen Street2006-02-20
| | | | | | | | | | | | | | 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>
* [PATCH] spi: remove fastcall crapAndrew Morton2006-01-13
| | | | | | | | | 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>
* [PATCH] spi: use linked lists rather than an arrayVitaly Wool2006-01-13
| | | | | | | | | | | | | | | | | | 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>
* [PATCH] SPI core tweaks, bugfixDavid Brownell2006-01-13
| | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] spi: add spi_driver to SPI frameworkDavid Brownell2006-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] spi: simple SPI frameworkDavid Brownell2006-01-13
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>
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