[RFC PATCH 1/2] ARM: CSR: add rtc i/o bridge interface for SiRFprimaII

[Jamie Iles]

On Fri, Aug 05, 2011 at 07:28:05PM +0800, Barry Song wrote:
> Hi Jamie,
> Thanks.
> 
> 2011/8/5 Jamie Iles <jamie at jamieiles.com>:
> > Hi Barry, Zhiwu,
> >
> > A couple of minor comments inline.
> >
> > Jamie
> >
> > On Thu, Aug 04, 2011 at 07:54:47PM -0700, Barry Song wrote:
> >> From: Zhiwu Song <zhiwu.song at csr.com>
> >>
> >> The module is a bridge between the RTC clock domain and the CPU interface
> >> clock domain. ARM access the register of SYSRTC, GPSRTC and PWRC through
> >> this module.
> >>
> >> Signed-off-by: Zhiwu Song <zhiwu.song at csr.com>
> >> Signed-off-by: Barry Song <baohua.song at csr.com>
> >> ---
> >>  arch/arm/mach-prima2/Makefile        |    1 +
> >>  arch/arm/mach-prima2/rtciobrg.c      |  118 ++++++++++++++++++++++++++++++++++
> >>  include/linux/rtc/sirfsoc_rtciobrg.h |   18 +++++
> >>  3 files changed, 137 insertions(+), 0 deletions(-)
> >>  create mode 100644 arch/arm/mach-prima2/rtciobrg.c
> >>  create mode 100644 include/linux/rtc/sirfsoc_rtciobrg.h
> >>
> >> diff --git a/arch/arm/mach-prima2/Makefile b/arch/arm/mach-prima2/Makefile
> >> index 7af7fc0..f49d70b 100644
> >> --- a/arch/arm/mach-prima2/Makefile
> >> +++ b/arch/arm/mach-prima2/Makefile
> >> @@ -3,5 +3,6 @@ obj-y += irq.o
> >>  obj-y += clock.o
> >>  obj-y += rstc.o
> >>  obj-y += prima2.o
> >> +obj-y += rtciobrg.o
> >>  obj-$(CONFIG_DEBUG_LL) += lluart.o
> >>  obj-$(CONFIG_CACHE_L2X0) += l2x0.o
> >> diff --git a/arch/arm/mach-prima2/rtciobrg.c b/arch/arm/mach-prima2/rtciobrg.c
> >> new file mode 100644
> >> index 0000000..0dc29f8
> >> --- /dev/null
> >> +++ b/arch/arm/mach-prima2/rtciobrg.c
> >> @@ -0,0 +1,118 @@
> >> +/*
> >> + * RTC I/O Bridge interfaces for CSR SiRFprimaII
> >> + * ARM access the registers of SYSRTC, GPSRTC and PWRC through this module
> >> + *
> >> + * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
> >> + *
> >> + * Licensed under GPLv2 or later.
> >> + */
> >> +
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/io.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_address.h>
> >> +
> >> +#define SIRFSOC_CPUIOBRG_CTRL           0x00
> >> +#define SIRFSOC_CPUIOBRG_WRBE           0x04
> >> +#define SIRFSOC_CPUIOBRG_ADDR           0x08
> >> +#define SIRFSOC_CPUIOBRG_DATA           0x0c
> >> +
> >> +void __iomem *sirfsoc_rtciobrg_base;
> >
> > static void __iomem?
> 
> this var will be accessed by sleep.S in patch 2/2.

OK, but then shouldn't these be in a header file somewhere?  I think 
sparse will warn about this otherwise saying it could be declared as 
static.

[...]
> >> +u32 __sirfsoc_rtc_iobrg_readl(u32 addr)
> >> +{
> >
> > Maybe for clarity have offset rather than address for these accessors to
> > indicate the nature of their use?
> 
> it should be an address not an offset. the address is local address
> againest rtciobrg. it is not an address in memory bus againest CPU
> core.
> if it is an offset, than its memory address is:
> MEMORY_BASE + addr.
> 
> but here its address is addr in local bus.

OK, I guess it's a terminology thing, but I don't particularly mind 
either way.

Jamie