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2006-12-10[PATCH] spi: stabilize PIO mode transfers on PXA2xx systemsStephen Street
Stabilize PIO mode transfers against a range of word sizes and FIFO thresholds and fixes word size setup/override issues. 1) 16 and 32 bit DMA/PIO transfers broken due to timing differences. 2) Potential for bad transfer counts due to transfer size assumptions. 3) Setup function broken is multiple ways. 4) Per transfer bit_per_word changes break DMA setup in pump_tranfers. 5) False positive timeout are not errors. 6) Changes in pxa2xx_spi_chip not effective in calls to setup. 7) Timeout scaling wrong for PXA255 NSSP. 8) Driver leaks memory while busy during unloading. Known issues: SPI_CS_HIGH and SPI_LSB_FIRST settings in struct spi_device are not handled. Testing: This patch has been test against the "random length, random bits/word, random data (verified on loopback) and stepped baud rate by octaves (3.6MHz to 115kHz)" test. It is robust in PIO mode, using any combination of tx and rx thresholds, and also in DMA mode (which internally computes the thresholds). Much thanks to Ned Forrester for exhaustive reviews, fixes and testing. The driver is substantially better for his efforts. Signed-off-by: Stephen Street <stephen@streetfiresound.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03Documentation: remove duplicated wordsPaolo Ornati
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>
2006-05-16[PATCH] SPI: busnum == 0 needs to workDavid Brownell
We need to be able to have a "SPI bus 0" matching chip numbering; but that number was wrongly used to flag dynamic allocation of a bus number. This patch resolves that issue; now negative numbers trigger dynamic alloc. It also updates the how-to-write-a-controller-driver overview to mention this stuff. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16[PATCH] SPI: add PXA2xx SSP SPI DriverStephen Street
This driver turns a PXA2xx synchronous serial port (SSP) into a SPI master controller (see Documentation/spi/spi_summary). The driver has the following features: - Support for any PXA2xx SSP - SSP PIO and SSP DMA data transfers. - External and Internal (SSPFRM) chip selects. - Per slave device (chip) configuration. - Full suspend, freeze, resume support. Signed-off-by: Stephen Street <stephen@streetfiresound.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-06[PATCH] SPI: spi_butterfly, restore lost deltasDavid Brownell
This resolves some minor version skew glitches that accumulated for the AVR Butterfly adapter driver, which caused among other things the existence of a duplicate Kconfig entry. Most of it boils down to comment updates, but in one case it removes some now-superfluous code that would be better if not copied into other controller-level drivers. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
2006-01-13[PATCH] SPI: add spi_butterfly driverDavid Brownell
This adds a bitbanging parport based adaptor cable for AVR Butterfly, giving SPI links to its DataFlash chip and (eventually) firmware running in the card. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: misc fixesDavid Brownell
This collects some small SPI patches that seem to be missing from the MM tree: - spi_butterfly kbuild hooks got dropped somehow; this restores them - quick fix for a (theoretical?) m25p80_write() oops noted by Andrew - quick fix for a potential config-specific oops for mtd_dataflash() - minor doc tweaks Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] SPI core tweaks, bugfixDavid Brownell
This includes various updates to the SPI core: - Fixes a driver model refcount bug in spi_unregister_master() paths. - The spi_master structures now have wrappers which help keep drivers from needing class-level get/put for device data or for refcounts. - Check for a few setup errors that would cause oopsing later. - Docs say more about memory management. Highlights the use of DMA-safe i/o buffers, and zero-initializing spi_message and such metadata. - Provide a simple alloc/free for spi_message and its spi_transfer; this is only one of the possible memory management policies. Nothing to break code that already works. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: add spi_driver to SPI frameworkDavid Brownell
This is a refresh of the "Simple SPI Framework" found in 2.6.15-rc3-mm1 which makes the following changes: * There's now a "struct spi_driver". This increase the footprint of the core a bit, since it now includes code to do what the driver core was previously handling directly. Documentation and comments were updated to match. * spi_alloc_master() now does class_device_initialize(), so it can at least be refcounted before spi_register_master(). To match, spi_register_master() switched over to class_device_add(). * States explicitly that after transfer errors, spi_devices will be deselected. We want fault recovery procedures to work the same for all controller drivers. * Minor tweaks: controller_data no longer points to readonly data; prevent some potential cast-from-null bugs with container_of calls; clarifies some existing kerneldoc, And a few small cleanups. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: simple SPI frameworkDavid Brownell
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>