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path: root/drivers/spi/pxa2xx_spi.c
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2009-04-07pxa2xx_spi: set spi_master.dma_alignment = 8Mike Rapoport
Signed-off-by: Mike Rapoport <mike@compulab.co.il> Cc: 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>
2009-04-07spi: pxa2xx_spi: introduce chipselect GPIO to simplify the common casesEric Miao
Most SPI peripherals use GPIOs as their chip selects, introduce .gpio_cs for this. Signed-off-by: Eric Miao <eric.miao@marvell.com> Cc: David Brownell <david-b@pacbell.net> 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>
2009-03-28Merge branch 'origin' into develRussell King
Conflicts: sound/soc/pxa/pxa2xx-i2s.c
2009-03-24spi: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Cc: dbrownell@users.sourceforge.net Cc: spi-devel-general@lists.sourceforge.net Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
2009-03-09[ARM] pxa: move DMA registers definitions into <mach/dma.h>Eric Miao
1. Driver code where pxa_request_dma() is called will most likely reference DMA registers as well, and it is really unnecessary to include pxa-regs.h just for this. Move the definitions into <mach/dma.h> and make relevant drivers include it instead of <mach/pxa-regs.h>. 2. Introduce DMAC_REGS_VIRT as the virtual address base for these DMA registers. This allows later processors to re-use the same IP while registers may start at different I/O address. Signed-off-by: Eric Miao <eric.miao@marvell.com>
2009-01-06drivers/spi: move a dereference below a NULL testJulia Lawall
In each case, if the NULL test is necessary, then the dereference should be moved below the NULL test. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ type T; expression E; identifier i,fld; statement S; @@ - T i = E->fld; + T i; ... when != E when != i if (E == NULL) S + i = E->fld; // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> 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>
2008-11-29[ARM] Hide ISA DMA API when ISA_DMA_API is unsetRussell King
When ISA_DMA_API is unset, we're not implementing the ISA DMA API, so there's no point in publishing the prototypes via asm/dma.h, nor including the machine dependent parts of that API. This allows us to remove a lot of mach/dma.h files which don't contain any useful code. Unfortunately though, some platforms put their own private non-ISA definitions into mach/dma.h, so we leave these behind and fix the appropriate #include statments. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-19pxa2xx_spi: bugfix full duplex dma data corruptionNed Forrester
Fixes a data corruption bug in pxa2xx_spi.c when operating in full duplex mode with DMA and using buffers that overlap. SPI transmit and receive buffers are allowed to be the same or to overlap. However, this driver fails if such overlap is attempted in DMA mode because it maps the rx and tx buffers in the wrong order. By mapping DMA_FROM_DEVICE (read) before DMA_TO_DEVICE (write), it invalidates the cache before flushing it, thus discarding data which should have been transmitted. The patch corrects the order of mapping. This bug exists in all versions of pxa2xx_spi.c; similar bugs are in the drivers for two other SPI controllers (au1500, imx). A version of this patch has been tested on kernel 2.6.20 using verification of loopback data with: random transfer length, random bits-per-word, random positive offsets (both larger and smaller than transfer length) between the start of the rx and tx buffers, and varying clock rates. Signed-off-by: Ned Forrester <nforrester@whoi.edu> Cc: Vernon Sauder <vernoninhand@gmail.com> Cc: J. Scott Merritt <merrij3@rpi.edu> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> [2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16pxa2xx_spi: fix chip_info defaults and documentation.Vernon Sauder
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>
2008-10-16pxa2xx_spi: minor cleanupGuennadi Liakhovetski
Minor fixes: remove redundant local variable initialization, fix "can not" to what I _think_ is a preferred spelling, output IRQ number if requesting it failed. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.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>
2008-10-01pxa2xx_spi: fix build breakageMike Rapoport
This patch fixes a build error in the pxa2xx-spi driver, introduced by commit 7e96445533ac3f4f7964646a202ff3620602fab4 ("pxa2xx_spi: dma bugfixes") CC drivers/spi/pxa2xx_spi.o drivers/spi/pxa2xx_spi.c: In function 'map_dma_buffers': drivers/spi/pxa2xx_spi.c:331: error: invalid operands to binary & drivers/spi/pxa2xx_spi.c:331: error: invalid operands to binary & drivers/spi/pxa2xx_spi.c: In function 'pump_transfers': drivers/spi/pxa2xx_spi.c:897: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'unsigned int' [dbrownell@users.sourceforge.net: fix warning too ] Signed-off-by: Mike Rapoport <mike@compulab.co.il> Acked-by: Eric Miao <eric.miao@marvell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-13pxa2xx_spi: dma bugfixesNed Forrester
Fixes two DMA bugs in the pxa2xx_spi driver. The first bug is in all versions of this driver; the second was introduced in the 2.6.20 kernel, and prevents using the driver with chips like m25p16 flash (which can issue large DMA reads). 1. Zero length transfers are permitted for use to insert timing, but pxa2xx_spi.c will fail if this is requested in DMA mode. Fixed by using programmed I/O (PIO) mode for such transfers. 2. Transfers larger than 8191 are not permitted in DMA mode. A test for length rejects all large transfers regardless of DMA or PIO mode. Worked around by rejecting only large transfers with DMA mapped buffers, and forcing all other transfers larger than 8191 to use PIO mode. A rate limited warning is issued for DMA transfers forced to PIO mode. This patch should apply to all kernels back to and including 2.6.20; it was test patched against 2.6.20. An additional patch would be required for older kernels, but those versions are very buggy anyway. Signed-off-by: Ned Forrester <nforrester@whoi.edu> Cc: Vernon Sauder <vernoninhand@gmail.com> Cc: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-13pxa2xx_spi: chipselect bugfixesNed Forrester
Fixes several chipselect bugs in the pxa2xx_spi driver. These bugs are in all versions of this driver and prevent using it with chips like m25p16 flash. 1. The spi_transfer.cs_change flag is handled too early: before spi_transfer.delay_usecs applies, thus making the delay ineffective at holding chip select. 2. spi_transfer.delay_usecs is ignored on the last transfer of a message (likewise not holding chipselect long enough). 3. If spi_transfer.cs_change is set on the last transfer, the chip select is always disabled, instead of the intended meaning: optionally holding chip select enabled for the next message. Those first three bugs were fixed with a relocation of delays and chip select de-assertions. 4. If a message has the cs_change flag set on the last transfer, and had the chip select stayed enabled as requested (see 3, above), it would not have been disabled if the next message is for a different chip. Fixed by dropping chip select regardless of cs_change at end of a message, if there is no next message or if the next message is for a different chip. This patch should apply to all kernels back to and including 2.6.20; it was test patched against 2.6.20. An additional patch would be required for older kernels, but those versions are very buggy anyway. Signed-off-by: Ned Forrester <nforrester@whoi.edu> Cc: Vernon Sauder <vernoninhand@gmail.com> Cc: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-07[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/machRussell King
This just leaves include/asm-arm/plat-* to deal with. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-07[ARM] Remove asm/hardware.h, use asm/arch/hardware.h insteadRussell King
Remove includes of asm/hardware.h in addition to asm/arch/hardware.h. Then, since asm/hardware.h only exists to include asm/arch/hardware.h, update everything to directly include asm/arch/hardware.h and remove asm/hardware.h. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-07-26dma-mapping: add the device argument to dma_mapping_error()FUJITA Tomonori
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13spi: pxa2xx_spi clock resume bugfixEric BENARD
There is a typo in pxa2xx_spi.c, comment says "Enable the SSP clock", code says: clk_disable ... so after resume, the SSP is dead. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Ned Forrester <nforrester@whoi.edu> Cc: Stephen Street <stephen@streetfiresound.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28spi: pxa2xx_spi "sparse" fixesDavid Brownell
Various cleanups to pxa2xx_spi suggested by "sparse": make sure that register addresess are "void __iomem *", and make a few functions properly static. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Ned Forrester <nforrester@whoi.edu> Cc: Stephen Street <stephen@streetfiresound.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-11spi: fix platform driver hotplug/coldplugKay Sievers
Since 43cc71eed1250755986da4c0f9898f9a635cb3bf, the platform modalias is prefixed with "platform:". Add MODULE_ALIAS() to the hotpluggable SPI platform drivers, to allow module auto loading. [dbrownell@users.sourceforge.net: more drivers: registration fixes] Signed-off-by: Kay Sievers <kay.sievers@vrfy.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>
2008-02-23spi: pxa2xx_spi clock polarity fixNed Forrester
Fixes a sequencing bug in spi driver pxa2xx_spi.c in which the chip select for a transfer may be asserted before the clock polarity is set on the interface. As a result of this bug, the clock signal may have the wrong polarity at transfer start, so it may need to make an extra half transition before the intended clock/data signals begin. (This probably means all transfers are one bit out of sequence.) This only occurs on the first transfer following a change in clock polarity in systems using more than one more than one such polarity. The fix assures that the clock mode is properly set before asserting chip select. This bug was introduced in a patch merged on 2006/12/10, kernel 2.6.20. The patch defines an additional bit in: include/asm-arm/arch-pxa/regs-ssp.h for 2.6.25 and newer kernels but this addition must be made in: include/asm-arm/arch-pxa/pxa-regs.h for kernels between 2.6.20 and 2.6.24, inclusive Signed-off-by: Ned Forrester <nforrester@whoi.edu> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Russell King <rmk@arm.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06spi: remove more dev->power.power_state usageDavid Brownell
Remove some more references to dev->power.power_state. That field is overdue for removal, but we can't do that while it's still referenced in the kernel. The only reason to update it was to make the /sys/devices/.../power/state files (now removed) 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>
2008-01-26[ARM] pxa: make pxa2xx_spi driver use ssp_request()/ssp_free()eric miao
1. make pxa2xx_spi.c use ssp_request() and ssp_free() to get the common information of the designated SSP port. 2. remove those IRQ/memory request code, ssp_request() has done that for the driver 3. the SPI platform device is thus made psuedo, no resource (memory/IRQ) has to be defined, all will be retreived by ssp_request() 4. introduce ssp_get_clk_div() to handle controller difference in clock divisor setting 5. use clk_xxx() API for clock enable/disable, and clk_get_rate() to handle the different SSP clock frequency between different processors Signed-off-by: eric miao <eric.miao@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-26[ARM] pxa: move SSP register definitions from pxa-regs.h to regs-ssp.heric miao
Signed-off-by: eric miao <eric.miao@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-12-10pxa2xx_spi: fix typo in descriptionWill Newton
Signed-off-by: Will Newton <will.newton@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>
2007-10-16spi doesn't need class_deviceTony Jones
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>
2007-10-16SPI driver runtime footprint shrinkageDavid Brownell
Shrink the runtime footprint of various SPI drivers: - Move the probe() routine into the init section where practical, using platform_driver_probe() to make that safe. This often saves around 1KB. Using platform_driver_probe() can also be a correctness fix, if the probe routine is already marked __init but the driver struct keeps a dangling pointer to it after init section removal. - Likewise move remove() routines into the exit sections. These changes would be inappropriate iff the platform devices were actually hotpluggable (e.g. they're found on optional addon cards, or in an FPGA that's dynamically reprogrammed). In these cases, that's not the situation; it's an SOC controller and the only device is initialized before these drivers. 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>
2007-10-16Clean up duplicate includes in drivers/spi/Jesper Juhl
This patch cleans up duplicate includes in drivers/spi/ Signed-off-by: Jesper Juhl <jesper.juhl@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>
2007-07-17SPI controller drivers: check for unsupported modesDavid Brownell
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>
2007-02-12[PATCH] SPI cleanup() method param becomes non-constHans-Peter Nilsson
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>
2007-02-07Revert "Driver core: convert SPI code to use struct device"Greg Kroah-Hartman
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>
2007-02-07Driver core: convert SPI code to use struct deviceGreg Kroah-Hartman
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>
2007-01-26[PATCH] spi: fix error setting the spi mode in pxa2xx_spi.cJustin Clacherty
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>
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>
2006-12-05WorkQueue: Fix up arch-specific work items where possibleDavid Howells
Fix up arch-specific work items where possible to use the new work_struct and delayed_work structs. Three places that enqueue bits of their stack and then return have been marked with #error as this is not permitted. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-06Various drivers' irq handlers: kill dead code, needless castsJeff Garzik
- Eliminate casts to/from void* - Eliminate checks for conditions that never occur. These typically fall into two classes: 1) Checking for 'dev_id == NULL', then it is never called with NULL as an argument. 2) Checking for invalid irq number, when the only caller (the system) guarantees the irq handler is called with the proper 'irq' number argument. Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-05-21[PATCH] pxa2xx-spi updateStephen Street
Fix some outstanding issues with the pxa2xx_spi driver when running on a PXA270: - Wrong timeout calculation in the setup function due to different peripheral clock rates in the PXAxxx family. - Bad handling of SSSR_TFS interrupts in interrupt_transfer function. - Added locking to interface between the pump_messages workqueue and the pump_transfers tasklet. Much thanks to Juergen Beisert for the extensive testing on the PXA270. Signed-off-by: Stephen Street <stephen@streetfiresound.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-16[PATCH] spi: Update to PXA2xx SPI DriverStephen Street
Fix two outstanding issues with the pxa2xx_spi driver: 1) Bad cast in the function u32_writer. Thanks to Henrik Bechmann 2) Adds support for per transfer changes to speed and bits per word Signed-off-by: Stephen Street <stephen@streetfiresound.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-16[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>