clk_{un}prepare() routines are required for required on some platforms to run
part of clk enable/disable() routines from contexts that can schedule.

This patch adds support for these routines in sp805 driver.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This patch converts existing sp805 watchdog driver to use already in place
common infrastructure present in watchdog core. With this lot of code goes away.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

sp805 driver currently uses normal kzalloc, ioremap, etc routines. This patch
replaces these routines with devm_kzalloc and devm_request_mem_region etc, so
that we don't need to handle freeing of resources for error cases and module
removal routine.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

readl/writel versions for ARM contain memory barrier instruction for
synchronizing DMA buffers.  These are not required at least on this
module.  So use lighter _relaxed variants.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

@ was missing before variables names, in their description. Also adev is
mentioned as dev in comment. Fix both these issues.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

nowayout is actually a boolean value.
So make it bool for all watchdog device drivers.
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

For simple modules that contain a single amba_driver without any
additional setup code then ends up being a block of duplicated
boilerplate. This patch adds a new macro, module_amba_driver(),
which replaces the module_init()/module_exit() registrations with
template functions.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The AMBA ID table is marked as __initdata, yet it is referenced by the
driver struct which is not.  This causes a (somewhat unhelpful) section
mismatch warning:

  WARNING: drivers/watchdog/sp805_wdt.o(.data+0x4c): Section mismatch in
           reference from the variable sp805_wdt_driver to the (unknown
           reference) .init.data:(unknown)

Fix this by removing the annotation.
Signed-off-by: NNick Bowler <nbowler@elliptictech.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NDave Martin <dave.martin@linaro.org>

There are no reads in these functions, so if MMIO writes are posted,
the writes in enable/disable may not have completed by the time these
functions return.  If the functions run from different CPUs, it's
in theory possible for the writes to be interleaved, which would be
disastrous for this driver.

At the very least, we need an mmiowb() before releasing the lock, but
since it seems desirable for the watchdog timer to be actually stopped
or reset when these functions return, read the lock register to force
the writes out.
Signed-off-by: NNick Bowler <nbowler@elliptictech.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

At least on the Versatile Express' V2M, calling wdt_disable followed by
wdt_enable, for instance by running the following sequence:

  echo V > /dev/watchdog; echo V > /dev/watchdog

results in an immediate reset.  The wdt_disable function writes 0 to the
load register; while the watchdog interrupts are disabled at this point,
this special value is defined to trigger an interrupt immediately.  It
appears that in this instance, the reset happens when the interrupts
are subsequently enabled by wdt_enable.

Putting in a short delay after writing a new load value in wdt_enable
solves the issue, but it seems cleaner to simply never write 0 to the
load register at all: according to the hardware docs, writing 0 to the
control register suffices to stop the counter, and the write of 0 to
the load register is questionable anyway since this register resets to
0xffffffff.
Signed-off-by: NNick Bowler <nbowler@elliptictech.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Make Primecell driver probe functions take a const pointer to their
ID tables.  Drivers should never modify their ID tables in their
probe handler.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Technical Reference Manual can be found at:
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0270b/DDI0270.pdfSigned-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>