ppc4xx: Add PPC4xx SPI driver

This patch adds an SPI driver for the 440EPx processor.

Tested on Sequoia.

---
Thanks for the comments.

I've added the in/out accessors, and included the other comments made by reviewers (inlines, etc). The patch passes a checkpatch test.

 drivers/spi/Makefile         |    1 +
 drivers/spi/ppc4xx_spi.c     |  141 ++++++++++++++++++++++++++++++++++++++++++
 include/asm-ppc/ppc4xx_spi.h |   58 +++++++++++++++++
 3 files changed, 200 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/ppc4xx_spi.c
 create mode 100644 include/asm-ppc/ppc4xx_spi.h

index 15e0f7a..a699760 100644
@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi.a
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
+COBJS-$(CONFIG_PPC4xx_SPI) += ppc4xx_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 
 COBJS	:= $(COBJS-y)

1.6.0.2

Dear "Steven A. Falco",

Stefan, I vote to put this driver on hold until there are any users for it.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Do not simplify the design of a program if a way can be found to make
it complex and wonderful.

I would prefer to include it now (next merge window) since it *can* be used on Sequoia actually. So it may serve as an example for other 4xx boards as well.

But it's your decision in the end.

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================

Dear Stefan,

Well, we had similar examples before - things that can be used but did not get checked in (for example the dummy EEPROM driver, etc. The policy so far has always been not to add dead code.

Well, you are the 4xx custodian, and if you really think it's useful to add such dead code...

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I perceive a possibility of an immediate  chronological  sequence  of
events which includes a violence.
                        - Terry Pratchett, _The Dark Side of the Sun_