linux-toradex.git/drivers/i2c/chips, branch v2.6.19.2

[PATCH] i2c: fix broken ds1337 initialization

2007-01-10T19:05:19+00:00

On a custom board with ds1337 RTC I found that upgrade from 2.6.15 to
2.6.18 broke RTC support.

The main problem are changes to ds1337_init_client().
When a ds1337 recognizes a problem (e.g. power or clock failure) bit 7
in status register is set. This has to be reset by writing 0 to status
register. But since there are only 16 byte written to the chip and the
first byte is interpreted as an address, the status register (which is
the 16th) is never written.
The other problem is, that initializing all registers to zero is not
valid for day, date and month register. Funny enough this is checked by
ds1337_detect(), which depends on this values not being zero. So then
treated by ds1337_init_client() the ds1337 is not detected anymore,
whereas the failure bit in the status register is still set.

Broken by commit f9e8957937ebf60d22732a5ca9130f48a7603f60 (2.6.16-rc1,
2006-01-06). This fix is in Linus' tree since 2.6.20-rc1 (commit
763d9c046a2e511ec090a8986d3f85edf7448e7e).

Signed-off-by: Dirk Stieler 
Signed-off-by: Dirk Eibach 
Signed-off-by: Jean Delvare 
Signed-off-by: Chris Wright

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

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 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

USB: move to

2006-09-27T18:58:48+00:00

Move  to .

Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

[PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private

2006-09-27T15:26:17+00:00

The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86.  (It would be more on an x86_64 system).  This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).

This patch:

The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer.  Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer.  This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.

[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Judith Lebzelter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

i2c: __must_check fixes (chip drivers)

2006-09-26T22:38:51+00:00

i2c: __must_check fixes (chip drivers)

Check for error on sysfs file creation.
Delete sysfs files on device removal.

The approach taken for the most complex case (pcf8591) is similar to
what Mark M. Hoffman proposed for hardware monitoring chip drivers.

Signed-off-by: Jean Delvare 
Cc: Ben Gardner 
Cc: Aurelien Jarno 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: tps65010 build fixes

2006-08-26T20:05:12+00:00

The tps65010.c driver in the main tree never got updated with
build fixes since the last batch of I2C driver changes; and the
genirq trigger flags were updated wierdly too.

This also includes a minor tweak to reduce the frequency used to
poll for unplug-the-AC-power on the TPS chips that don't provide
relevant IRQs.  It _would_ be nice to sense whether there's even
a battery, but that'd normally be an HDQ/1-wire interface to a
smart battery, and such APIs aren't standardized.

Signed-off-by: David Brownell 
Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

[PATCH] pca9539: Honor the force parameter

2006-07-12T22:43:07+00:00

The pca9539 driver doesn't honor the force parameter; it always does
detection. This patch will skip detection if forced.

Signed-off-by: Ben Gardner 
Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

[PATCH] irq-flags: misc drivers: Use the new IRQF_ constants

2006-07-02T20:58:50+00:00

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[PATCH] i2c: Suggest N for rare devices in Kconfig

2006-06-22T18:10:33+00:00

Improve the Kconfig help text of the follwing i2c drivers:
* busses/i2c-pca-isa.c
* chips/pcf8574.c
* chips/pcf8591.c
These are hard to detect and building them into the kernel
results in long delays at boot.

March 2006, thread "I2C_PCA_ISA causes boot delays"
http://marc.theaimsgroup.com/?l=linux-kernel&m=114360399415744&w=2

April 2006, thread "i2c-related 1-minute hang during bootup"
http://marc.theaimsgroup.com/?l=linux-kernel&m=114640992330721&w=2

Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman