Commit Graph

20 Commits

Author SHA1 Message Date
Ned Forrester b97c74bddc spi: pxa2xx_spi clock polarity fix
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>
2008-02-23 17:12:14 -08:00
David Brownell 5beec4aa2a spi: remove more dev->power.power_state usage
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>
2008-02-06 10:41:11 -08:00
eric miao 2f1a74e5a2 [ARM] pxa: make pxa2xx_spi driver use ssp_request()/ssp_free()
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 15:07:52 +00:00
eric miao 0aea1fd565 [ARM] pxa: move SSP register definitions from pxa-regs.h to regs-ssp.h
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-26 15:07:51 +00:00
Will Newton 037cdafe42 pxa2xx_spi: fix typo in description
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>
2007-12-10 19:43:54 -08:00
Tony Jones 49dce689ad spi doesn't need class_device
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>
2007-10-16 09:43:10 -07:00
David Brownell d1e44d9ce8 SPI driver runtime footprint shrinkage
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>
2007-10-16 09:43:09 -07:00
Jesper Juhl 8b7f9b81c8 Clean up duplicate includes in drivers/spi/
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>
2007-10-16 09:43:09 -07:00
David Brownell dccd573bb0 SPI controller drivers: check for unsupported modes
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>
2007-07-17 10:23:04 -07:00
Hans-Peter Nilsson 0ffa028505 [PATCH] SPI cleanup() method param becomes non-const
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>
2007-02-12 09:48:31 -08:00
Greg Kroah-Hartman 07b2463046 Revert "Driver core: convert SPI code to use struct device"
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>
2007-02-07 21:34:08 -08:00
Greg Kroah-Hartman 2943ecf2ed Driver core: convert SPI code to use struct device
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>
2007-02-07 10:37:11 -08:00
Justin Clacherty 7f6ee1adc7 [PATCH] spi: fix error setting the spi mode in pxa2xx_spi.c
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>
2007-01-26 13:50:57 -08:00
Stephen Street 8d94cc50aa [PATCH] spi: stabilize PIO mode transfers on PXA2xx systems
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>
2006-12-10 09:55:40 -08:00
David Howells 6d5aefb8ea WorkQueue: Fix up arch-specific work items where possible
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>
2006-12-05 19:36:26 +00:00
Jeff Garzik c7bec5aba5 Various drivers' irq handlers: kill dead code, needless casts
- 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>
2006-10-06 15:00:58 -04:00
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
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)
2006-10-05 15:10:12 +01:00
Stephen Street 5daa3ba0c6 [PATCH] pxa2xx-spi update
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>
2006-05-21 12:59:20 -07:00
Stephen Street 9708c121c3 [PATCH] spi: Update to PXA2xx SPI Driver
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 14:33:58 -07:00
Stephen Street e0c9905e87 [PATCH] SPI: add PXA2xx SSP SPI Driver
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>
2006-05-16 14:33:56 -07:00