linux.git/drivers/spi, branch v2.6.23

spi_mpc83xx: hang fix

2007-09-12T00:21:19+00:00

When the spi_mpc83xx driver receives a tx_buf pointer which is NULL, it
only writes one zero filled word to the transmit register.  If the driver
expects to receive more than one word it will wait forever for a second
receive interrupt.  With this patch the controller will shift out zeroes
until all words have been received.

Signed-off-by: Jan Andersson 
Tested-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Acked-by: Kumar Gala 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix typo in atmel_spi.c

2007-08-31T08:42:23+00:00

Fix cut 'n paste bug in Atmel SPI driver.

Signed-off-by: Andrew Victor 
Acked-by: David Brownell 
Acked-by: Haavard Skinnemoen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: correct name for spi_txx9

2007-08-31T08:42:22+00:00

Correct the name of the spi_txx9 driver (and their in-tree user)
instead of MODULE_ALIAS workaround.  This would be preferable in the
long term.

Signed-off-by: Atsushi Nemoto 
Acked-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

SPI driver hotplug/coldplug fixes

2007-08-31T08:42:22+00:00

Update various SPI drivers so they properly support

  - coldplug through "modprobe $(cat /sys/devices/.../modalias)"

  - hotplug through "modprobe $(MODALIAS)"

The basic rule for platform, SPI, and (new style) I2C drivers is just
to make sure that modprobing the driver name works.  In this case, all
the relevant drivers are platform drivers, and this patch either

  (a)	Changes the driver name, if no in-tree code would break;
	this is simpler and thus preferable in the long term.

  (b)	Adds MODULE_ALIAS directives, when in-tree platforms declare
	devices using the current driver name; less desirable.

Most systems will link SPI controller drivers statically, but
there's no point in being needlessly broken.

Signed-off-by: David Brownell 
Cc: Jean Delvare 
Acked-by: Andrei Konovalov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spidev warning fix

2007-08-11T22:47:42+00:00

Git rid of "warning: passing arg 2 of `access_ok' makes pointer from integer
without a cast" reported on SH ...  most architectures use macros in that
test, SH uses inlined functions.

Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc83xx: fix prescale modulus calculation

2007-08-11T22:47:41+00:00

Long ago I've noticed (but didn't pay much attention) that
spi_mpc83xx using PM calculations that differs from what
specs describe. I.e.

u8 pm = mpc83xx_spi->spibrg / (spi->max_speed_hz * 4);

While specs says: "The SPI baud rate generator clock source (either
system clock or system clock divided by 16, depending on DIV16 bit) is
divided by 4 * ([PM] + 1), a range from 4 to 64.".

Thus " - 1" is missing in the spi_mpc83xx's formula.

Why nobody noticed that bug? Probably because sysclk usually less then
user expects, e.g. you expect 200 MHz, but real clock is 198 MHz,
and integer rounding helps when this formula is used.

Suppose it's SPI in QE, SYSCLK at 198 MHz, thus SPIBRG at 99MHz, 25 MHz
requested.

PM = (99MHz / ( 25 MHz * 4 )), PM == 0, output SPICLK will be 24.75 MHz

At lower frequencies this bug is more noticeable, though.

And this bug shows itself in all its beauty if SYSCLK is equal or a bit
more than you expect (200 MHz SYSCLK, 100 MHz SPIBRG):
PM = (100MHz / ( 25 MHz * 4 )), PM == 1, output SPICLK will be 12.625 MHz!

Signed-off-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc83xx: in "QE mode", use sysclk/2

2007-08-11T22:47:41+00:00

For MPC8349E input to the SPI Baud Rate Generator is SYSCLK, but it's
SYSCLK/2 for MPC8323E (SPI in QE).  Fix this, and remove confusion by
renaming the mpc83xx_spi->sysclk member as mpc83xx_spi->spibrg.

Signed-off-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi device setup gets better error checking

2007-07-31T22:39:44+00:00

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  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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc83xx: support loopback mode

2007-07-31T22:39:40+00:00

This exposes the hardware loopback mode to drivers, primarily for testing.

Signed-off-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spidev supports more communications modes

2007-07-31T22:39:40+00:00

The spidev driver doesn't currently expose all SPI communications modes to
userspace.  This passes them all through to the driver.

Two of them are potentially troublesome, in the sense that they could cause
hardware conflicts on shared busses.  It might be appropriate to add some
privilege checks for for those modes.

Signed-off-by: Anton Vorontsov 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds