The bindings have been updated to expose the RTC's internal oscillator,
for some SoCs that have it directly feeding the PRCM block. The changes
include the index 2 for the clock outputs, as well as the clock output
names.
This patch adds the internal oscillator to the list of clocks exposed
through of_clk_add_hw_provider(), and also have the driver optionally
fetch the name of the clock from the device tree if it's available.
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
There are different variants to the RTC hardware first seen on sun6i
(A31). The differences we care about in this driver are the clock rate
for the internal oscillator, prescalers, and the presence of an external
clock output.
This patch adds support for all the known pre-H6 base compatibles using
the variants data structure previously introduced.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Amongst the Allwinner SoCs that have seen some kind of coverage by the
linux-sunxi community, whether it be mainline Linux or U-boot support,
or just available datasheets, most newer chips use the RTC design first
seen in the A31 (sun6i).
Overall there have been some minor differences. This patch covers the
following:
- average clock rate of the internal RC oscillator
+ presence of fixed and adjustable prescaler for this clock
- availability of an external (to the SoC) clock output
One major difference regarding the H6 is the 24 MHz crystal is now
routed through the RTC, as a digitally compensated oscillator (DCXO).
This is not covered in this patch and will be supported later.
Other differences are either unrelated to RTC or clock functionality,
such as boot or crypto related registers, or the driver simply doesn't
use the feature in question. One example of the latter is the
calibration function for the RC oscillator. We consider this clock to
be very bad and avoid using it.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The RTC's main clock, used internally and exported to the rest of the
SoC, is called "LOSC" (low speed oscillator) through the hardware
documentation.
This patch adds a default name for this clock, in case the device tree
does not provide one. This shouldn't happen, but lets play it safe.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
clk-gate core will take bit_idx through clk_register_gate
and then do clk_gate_ops by using BIT(bit_idx), but rtc-sun6i
is passing bit_idx as BIT(bit_idx) it becomes BIT(BIT(bit_idx)
which is wrong and eventually external gate clock is not enabling.
This patch fixed by passing bit index and the original change
introduced from below commit.
"rtc: sun6i: Add support for the external oscillator gate"
(sha1: 17ecd24641)
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Fixes: 17ecd24641 ("rtc: sun6i: Add support for the external oscillator gate")
Cc: stable@vger.kernel.org
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The error return path on clk_data allocation failure does not kfree
the allocated rtc object. Fix this with a kfree of rtc on the error
exit path.
Detected by CoverityScan, CID#1452264 ("Resource Leak")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The RTC can output its 32kHz clock outside of the SoC, for example to clock
a WiFi chip.
Create a new clock that other devices will be able to retrieve, while
maintaining the DT stability by providing a default name for that clock if
clock-output-names doesn't list one.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
There are two error return paths that do not kfree clk_data and
we end up with a memory leak. Fix these with a kfree error exit
path.
Detected by CoverityScan, CID#1402959 ("Resource Leak")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
In case of error, the function of_io_request_and_map() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should
be replaced with IS_ERR().
Fixes: 847b8bf62eb4 ("rtc: sun6i: Expose the 32kHz oscillator")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Commit 847b8bf62eb4 ("rtc: sun6i: Expose the 32kHz oscillator") adds
a new clock for the rtc block with a 2 step probe mechanism. To share
the register region between both the clock and rtc instance, a static
pointer is used to keep the related data structure.
To preserve compatibility with the old binding, the data structure
should be saved as soon as the registers are mapped in, regardless
of the presence of the clock bindings, so that the rtc device can
retrieve it when it is probed.
This fixes the rtc device not probing when we use the updated driver
with an old device tree blob.
Fixes: 847b8bf62eb4 ("rtc: sun6i: Expose the 32kHz oscillator")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Now that we have a devm variant of rtc_device_register, switch to it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The RTC controls the input source of the main 32kHz oscillator in the
system, feeding it to the clock unit too.
By default, this is using an internal, very inaccurate (+/- 30%)
oscillator with a divider to make it roughly around 32kHz. This is however
quite impractical for the RTC, since our time will not be tracked properly.
Since this oscillator is an input of the main clock unit, and since that
clock unit will be probed using CLK_OF_DECLARE, we have to use it as well,
leading to a two stage probe: one to enable the clock, the other one to
enable the RTC.
There is also a slight change in the binding that is required (and should
have been from the beginning), since we'll need a phandle to the external
oscillator used on that board. We support the old binding by not allowing
to switch to the external oscillator and only using the internal one (which
was the previous behaviour) in the case where we're missing that phandle.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The RTC is clocked from either an internal, imprecise, oscillator or an
external one, which is usually much more accurate.
The difference perceived between the time elapsed and the time reported by
the RTC is in a 10% scale, which prevents the RTC from being useful at all.
Fortunately, the external oscillator is reported to be mandatory in the
Allwinner datasheet, so we can just switch to it.
Cc: stable@vger.kernel.org
Fixes: 9765d2d943 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Some registers have a read-modify-write access pattern that are not atomic.
Add some locking to prevent from concurrent accesses.
Cc: stable@vger.kernel.org
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Since we have to provide the clock very early on, the RTC driver cannot be
built as a module. Make sure that won't happen.
Cc: stable@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This patch introduces the driver for the RTC in the Allwinner A31 and
A23 SoCs.
Unlike the RTC found in A10/A20 SoCs, which was part of the timer, the
RTC in A31/A23 are a separate hardware block, which also contain a few
controls for the RTC block hardware (a regulator and RTC block GPIO pin
latches), while also having separate interrupts for the alarms.
The hardware is different enough to make a different driver for it.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
