On some platforms, bootloaders are known to do some interesting RTC
programming. Without going into the obscurities as to why this may be
the case, suffice it to say the the driver should not make any
assumptions about the state of the RTC when the driver loads. In
particular, the driver probe should be sure that all interrupts are
disabled until otherwise programmed.
This was discovered when finding bursty I2C traffic every second on
Overo platforms. This I2C overhead was keeping the SoC from hitting
deep power states. The cause was found to be the RTC firing every
second on the I2C-connected TWL PMIC.
Special thanks to Felipe Balbi for suggesting to look for a rogue driver
as the source of the I2C traffic rather than the I2C driver itself.
Special thanks to Steve Sakoman for helping track down the source of the
continuous RTC interrups on the Overo boards.
Signed-off-by: Kevin Hilman <khilman@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Tested-by: Steve Sakoman <steve@sakoman.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Tested-by: Shubhrajyoti Datta <omaplinuxkernel@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Requesting a threaded interrupt without a primary handler and without
IRQF_ONESHOT is dangerous, and after commit 1c6c6952 ("genirq: Reject
bogus threaded irq requests"), these requests are rejected. This causes
->probe() to fail, and the RTC driver not to be availble.
To fix, add IRQF_ONESHOT to the IRQ flags.
Tested on OMAP3730/OveroSTORM and OMAP4430/Panda board using rtcwake to
wake from system suspend multiple times.
Signed-off-by: Kevin Hilman <khilman@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RTC stores time and date in several registers. Due to the fact that
these registers can't be read instantaneously, there is a chance that
reading from counting registers gives an error of one minute, one hour,
one day, etc.
To address this issue, the RTC has hardware support to copy the RTC
counting registers to static shadowed registers. The current
implementation does not use this feature, and in a stress test, we can
reproduce this error at a rate of around two times per 300000 readings.
Fix the implementation to ensure that the right snapshot of time is
captured.
Signed-off-by: Konstantin Shlyakhovoy <x0155534@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: linux-omap <linux-omap@vger.kernel.org>
Acked-by: Mykola Oleksiienko <x0174904@ti.com>
Acked-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@ti.com>
Acked-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following changes are made as part of this change:
1. As TWL RTC supports periodic interrupt, the correct event should be
RTC_PF instead of RTC_UF.
2. No need to initialize variable "events" to 0 & then OR it with the
event values. Hence fixing it.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For clearing RTC interrupt, programming ALARM bit only is sufficient, as
all other bits are any way not affected by writing 0 to them.
Hence removed unwanted OR operation.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As part of probe, before enabling RTC, RTC_CTRL register is read to check
if it is already running. If RTC is used by kernel alone, then this read
is not required. Even if RTC was enabled already by boot loader, setting
STOP_RTC bit again should not harm. Hence removed unwanted read
operation.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As the TWL RTC driver has a cached copy of enabled RTC interrupt bits in
variable rtc_irq_bits, that can be checked before really setting or
masking any of the interrupt bits.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the DT support for the TI rtc-twl present in the twl4030 and twl6030
devices.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Only register as an RTC device after the hardware has been
successfully initialized. The RTC class driver will call
back to this driver to read a pending alarm, and other
drivers watching for new devices on the RTC class may
read the RTC time upon registration. Such access might
occur while the RTC is stopped, prior to clearing
pending alarms, etc.
The new ordering also avoids leaving the platform
device drvdata set to an unregistered struct rtc_device *
on probe errors.
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Now that the irq is properly threaded (due to it needing i2c access)
we should also remove the local_irq_enable() call in twl_rtc_interrupt.
Testing this with Pandaboard, the RTC is still working.
[Reworked commit message -jstultz]
Signed-off-by: John Stultz <john.stultz@linaro.org>
The driver is accessing to i2c bus in interrupt handler.
Therefore, it should use threaded irq.
Signed-off-by: Ilkka Koskinen <ilkka.koskinen@nokia.com>
Acked-by: Balaji T K <balajitk@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
We forget to save the return value of the call to
twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG); in 'ret', making the
test of 'ret < 0' dead code since 'ret' then couldn't possibly have
changed since the last test just a few lines above. It also makes us not
detect failures from that specific twl_rtc_write_u8() call.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Rusev <source@mvista.com>
Cc: "George G. Davis" <gdavis@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the generic code handles UIE mode irqs via periodic
alarm interrupts, no one calls the
rtc_class_ops->update_irq_enable() method anymore.
This patch removes the driver hooks and implementations of
update_irq_enable if no one else is calling it.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the beginning of
the declaration specifiers in a declaration is an obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds support for RTC in phoenix TWL6030.
Register offset addresses have changed in TWL6030
rtc-twl.c will hence forth support all twl RTC (4030, 5030, 6030 ..)
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This patch renames all twl4030_ functions to twl_ so that RTC driver can be
shared between Triton and Phoenix.
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Nayak Rajendra <rnayak@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This patch renames function names like twl4030_i2c_write_u8,
twl4030_i2c_read_u8 to twl_i2c_write_u8, twl_i2c_read_u8
and also common variable in twl-core.c
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The upcoming TWL6030 is companion chip for OMAP4 like the current TWL4030
for OMAP3. The common modules like RTC, Regulator creates opportunity
to re-use the most of the code from twl4030.
This patch renames few common drivers twl4030* files to twl* to enable
the code re-use.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
