linux.git/drivers/spi, branch v2.6.31

spi_s3c24xx: fix transfer setup code

2009-08-18T23:31:13+00:00

Since the changes to the bitbang driver, there is the possibility we will
be called with either the speed_hz or bpw values zero.  We take these to
mean that the default values (8 bits per word, or maximum bus speed).

Signed-off-by: Ben Dooks 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_s3c24xx: fix clock rate calculation

2009-08-18T23:31:13+00:00

Currently the clock rate calculation may round as pleased, which means
that it is possible that we will round down and end up with a faster clock
rate than intended.

Change the calculation to use DIV_ROUND_UP() to ensure that we end up with
a clock rate either the same as or lower than the user requested one.

Signed-off-by: Ben Dooks 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: omap2_mcspi rxdma bugfix

2009-07-30T02:10:35+00:00

When data is read through DMA, the last element must be read separately
through the RX register.  It cannot be transferred by the DMA.  For
further details see e.g.  OMAP35x TRM (table 19-16).

Without the fix the driver causes extra clocks to be clocked to the bus
after DMA RX operations.  This can cause interesting behaviour with some
devices.

Signed-off-by: Juuso Oikarinen 
Signed-off-by: Eero Nurkkala 
[aaro.koskinen@nokia.com: Simplified the patch while keeping the idea.]
Signed-off-by: Aaro Koskinen 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: omap2_mcspi supports wake events

2009-07-30T02:10:35+00:00

Currently mcspi wake-ups are not enabled.  This might cause cases where
OMAP is not waking up on mcspi events.

Signed-off-by: Jouni Hogander 
Signed-off-by: Tony Lindgren 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: bitbang bugfix in message setup

2009-07-01T01:56:00+00:00

Bugfix to spi_bitbang infrastructure: make sure to always set transfer
parameters on the first pass through the message's per-transfer loop.
This can matter with drivers that replace the per-word or per-buffer
transfer primitives, on busses with multiple SPI devices.

Previously, this could have started messages using the settings left after
previous messages.  The problem was observed when a high speed chip
(m25p80 type flash) was running very slowly because a low speed device
(avr8 microcontroller) had previously used the bus.  Similar faults could
have driven the low speed device too fast, or used an unexpected word
size.

Acked-by: Steven A. Falco 
Signed-off-by: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: add spi_master flag word

2009-07-01T01:56:00+00:00

Add a new spi_master.flags word listing constraints relevant to that
controller.  Define the first constraint bit: a half duplex restriction.
Include that constraint in the OMAP1 MicroWire controller driver.

Have the mmc_spi host be the first customer of this flag.  Its coding
relies heavily on full duplex transfers, so it must fail when the
underlying controller driver won't perform them.

(The spi_write_then_read routine could use it too: use the
temporarily-withdrawn full-duplex speedup unless this flag is set, in
which case the existing code applies.  Similarly, any spi_master
implementing only SPI_3WIRE should set the flag.)

Signed-off-by: David Brownell 
Cc: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi: new spi->mode bits

2009-07-01T01:56:00+00:00

Add two new spi_device.mode bits to accomodate more protocol options, and
pass them through to usermode drivers:

 * SPI_NO_CS ... a second 3-wire variant, where the chipselect
   line is removed instead of a data line; transfers are still
   full duplex.

   This obviously has STRONG protocol implications since the
   chipselect transitions can't be used to synchronize state
   transitions with the SPI master.

 * SPI_READY ... defines open drain signal that's pulled low
   to pause the clock.  This defines a 5-wire variant (normal
   4-wire SPI plus READY) and two 4-wire variants (READY plus
   each of the 3-wire flavors).

   Such hardware flow control can be a big win.  There are ADC
   converters and flash chips that expose READY signals, but not
   many host controllers support it today.

The spi_bitbang code should be changed to use SPI_NO_CS instead of its
current nonportable hack.  That's a mode most hardware can easily support
(unlike SPI_READY).

Signed-off-by: David Brownell 
Cc: "Paulraj, Sandeep" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc8xxx: s/83xx/8xxx/g

2009-06-19T23:46:05+00:00

Since we renamed the file, we might want to rename the file internals too.

Though we don't bother with changing platform driver name and platform
module alias.  The stuff is legacy and hopefully we'll remove it soon.

Suggested-by: Kumar Gala 
Signed-off-by: Anton Vorontsov 
Cc: David Brownell 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc83xx: rename spi_83xx.c to spi_8xxx.c

2009-06-19T23:46:05+00:00

The driver handles MPC83xx, MPC85xx and MPC86xx SPI controllers, so rename
the file for clarity.

Suggested-by: Kumar Gala 
Signed-off-by: Anton Vorontsov 
Cc: Kumar Gala 
Cc: David Brownell 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spi_mpc83xx: remove dead code

2009-06-19T23:46:05+00:00

This patch removes #if 0'ed code, and spi_mpc83xx->busy variable that is
used by that dead snippet only.

Signed-off-by: Anton Vorontsov 
Cc: Kumar Gala 
Cc: David Brownell 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds