The Renesas OS Timer (OSTM) driver contains two probe points, of which
only one should complete:
1. Early probe, using TIMER_OF_DECLARE(), to provide the sole
clocksource on (arm32) RZ/A1 and RZ/A2 SoCs,
2. Normal probe, using a platform driver, to provide additional timers
on (arm64 + riscv) RZ/G2L and similar SoCs.
The latter is needed because using OSTM on RZ/G2L requires manipulation
of its reset signal, which is not yet available at the time of early
probe, causing early probe to fail with -EPROBE_DEFER. It is only
enabled when building a kernel with support for the RZ/G2L family, so it
does not impact RZ/A1 and RZ/A2. Hence only one probe method can
complete on all affected systems.
As relying on the order of initialization of subsystems inside the
kernel is fragile, set the DT node's OF_POPULATED flag after a succesful
early probe. This makes sure the platform driver's probe is never
called after a successful early probe.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviwed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/bd027379713cbaafa21ffe9e848ebb7f475ca0e7.1710930542.git.geert+renesas@glider.be
The RZ/V2H(P) (R9A09G057) SoC is equipped with the Generic Timer Module,
also known as OSTM. Similar to the RZ/G2L SoC, the OSTM on the RZ/V2H(P)
SoC requires the reset line to be deasserted before accessing any
registers.
Early call to ostm_init() happens through TIMER_OF_DECLARE() which always
fails with -EPROBE_DEFER, as resets are not available that early in the
boot process. To address this issue on the RZ/V2H(P) SoC, enable the OSTM
driver to be reprobed through the platform driver probe mechanism.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240322151219.885832-3-prabhakar.mahadev-lad.rj@bp.renesas.com
The OSTM block is identical on Renesas RZ/G2L and RZ/V2L SoC's, so instead
of adding dependency for each SoC's add dependency on ARCH_RZG2L. The
ARCH_RZG2L config option is already selected by ARCH_R9A07G044 and
ARCH_R9A07G054.
With the above change OSTM will be enabled on RZ/V2L SoC.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220907080056.3460-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
RZ/G2L SoC has Generic Timer Module(a.k.a OSTM) which needs to
deassert the reset line before accessing any registers.
This patch adds an entry point for RZ/G2L so that we can deassert
the reset line in probe callback.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20211112184413.4391-4-biju.das.jz@bp.renesas.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Currently all OSTM devices are called "ostm", also in kernel messages.
As there can be multiple instances in an SoC, this can confuse the user.
Hence construct a unique name from the DT node name, like is done for
platform devices.
On RSK+RZA1, the boot log changes like:
-clocksource: ostm: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
+clocksource: timer@fcfec000: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
sched_clock: 32 bits at 33MHz, resolution 30ns, wraps every 64440619504ns
-ostm: used for clocksource
-ostm: used for clock events
+/soc/timer@fcfec000: used for clocksource
+/soc/timer@fcfec400: used for clock events
...
-clocksource: Switched to clocksource ostm
+clocksource: Switched to clocksource timer@fcfec000
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191016144747.29538-5-geert+renesas@glider.be
Convert the Renesas OSTM driver to use the timer_of framework.
This reduces the driver object size by 367 bytes (with gcc 7.4.0).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191016144747.29538-4-geert+renesas@glider.be
Use the DIV_ROUND_CLOSEST() helper instead of open-coding the same
operation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This patch updates license to use SPDX-License-Identifier instead of verbose
license text.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.
It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.
On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.
So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.
The patch has not functional changes.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
This patch adds a OSTM driver for the Renesas architecture.
The OS Timer (OSTM) has independent channels that can be
used as a freerun or interval times.
This driver uses the first probed device as a clocksource
and then any additional devices as clock events.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
