[PATCH] i2c: devtree-aware iic support for PPC4xx
david at gibson.dropbear.id.au
Mon Sep 17 11:31:13 EST 2007
On Sun, Sep 16, 2007 at 11:53:30AM -0700, Eugene Surovegin wrote:
> On Sun, Sep 16, 2007 at 01:52:02PM +0200, Stefan Roese wrote:
> > This patch reworks existing ibm-iic driver to an of_platform_device
> > and enables it to talk to device tree directly. The ocp quirks are
> > completely removed by this patch.
> > This is done to enable I2C support for the PPC4xx platforms now
> > being moved from arch/ppc (OCP) to arch/powerpc (of). The first board
> > using this driver will be the AMCC Sequoia (PPC440EPx).
> > Signed-off-by: Stefan Roese <sr at denx.de>
> > ---
> > 2nd try with some cleanups. Please let me know if there still are some
> > problems.
> > Thanks.
> > commit 5748f81ff53277fa5c16de815b7d6b172ca284e9
> > tree 8284b3f1c836eb6eb06ee6882ee13b9e8f6cbb6b
> > parent d0174640eedc1cd756754f03afe2dbb3d56de74e
> > author Stefan Roese <sr at denx.de> Sun, 16 Sep 2007 13:46:40 +0200
> > committer Stefan Roese <sr at denx.de> Sun, 16 Sep 2007 13:46:40 +0200
> > drivers/i2c/busses/Kconfig | 12 -
> > drivers/i2c/busses/Makefile | 1
> > drivers/i2c/busses/i2c-ibm_iic.h | 3
> > drivers/i2c/busses/i2c-ibm_of.c | 858 ++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 873 insertions(+), 1 deletions(-)
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index 9f3a4cd..12453e2 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -220,7 +220,17 @@ config I2C_PIIX4
> > config I2C_IBM_IIC
> > tristate "IBM PPC 4xx on-chip I2C interface"
> > - depends on IBM_OCP
> > + depends on !PPC_MERGE
> > + help
> > + Say Y here if you want to use IIC peripheral found on
> > + embedded IBM PPC 4xx based systems.
> > +
> > + This driver can also be built as a module. If so, the module
> > + will be called i2c-ibm_iic.
> > +
> > +config I2C_IBM_OF
> > + tristate "IBM PPC 4xx on-chip I2C interface"
> > + depends on PPC_MERGE
> > help
> > Say Y here if you want to use IIC peripheral found on
> > embedded IBM PPC 4xx based systems.
> > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> > index 5b752e4..0cd0bac 100644
> > --- a/drivers/i2c/busses/Makefile
> > +++ b/drivers/i2c/busses/Makefile
> > @@ -17,6 +17,7 @@ obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
> > obj-$(CONFIG_I2C_I801) += i2c-i801.o
> > obj-$(CONFIG_I2C_I810) += i2c-i810.o
> > obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
> > +obj-$(CONFIG_I2C_IBM_OF) += i2c-ibm_of.o
> > obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
> > obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o
> > obj-$(CONFIG_I2C_IXP4XX) += i2c-ixp4xx.o
> Hmm, I just noticed that you basically added a copy of existing
> driver with small changes to support OF while keeping OCP one.
> Why not just add OF support to the existing code (under some ifdef),
> and then remove OCP support as soon as ppc -> powerpc transition is
> finished? Why have two almost identical code in the tree?
> I also personally don't like this _iic -> _of name change (you
> removed peripheral name and added something which has nothing to do
> with iic, I never heard of OF peripheral in 4xx chips). Whether you
> use OCP or OF to pass a little information is quite irrelevant to the
> iic driver operation.
I concur on this point. Especially since on 4xx the device tree will
generally be a flattened device tree which is vaguely OF-like, but not
from an actual Open Firmware.
> If you insist on this approach, please add yourself as a maintainer of
> this code, because I'm not going to support two identical copies of my
> code in the kernel tree.
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
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