The recent changes to genpd makes a genpd OF provider that is powered-on at
initialization to stay powered-on, until the ->sync_state() callback is
invoked for it.
This may not happen at all, if we wait for a consumer device to be probed,
leading to wasting energy. There are ways to enforce the ->sync_state()
callback to be invoked, through sysfs or via the probe-defer-timeout, but
none of them in its current form are a good fit for rmobile-sysc PM
domains.
Let's therefore opt-out from this behaviour of genpd for now, by using the
GENPD_FLAG_NO_STAY_ON.
Link: https://lore.kernel.org/all/20250701114733.636510-1-ulf.hansson@linaro.org/
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 0e789b491b ("pmdomain: core: Leave powered-on genpds on until sync_state")
Fixes: 13a4b7fb62 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The recent changes to genpd makes a genpd OF provider that is powered-on at
initialization to stay powered-on, until the ->sync_state() callback is
invoked for it.
This may not happen at all, if we wait for a consumer device to be probed,
leading to wasting energy. There are ways to enforce the ->sync_state()
callback to be invoked, through sysfs or via the probe-defer-timeout, but
none of them in its current form are a good fit for rcar-gen4-sysc PM
domains.
Let's therefore opt-out from this behaviour of genpd for now, by using the
GENPD_FLAG_NO_STAY_ON.
Link: https://lore.kernel.org/all/20250701114733.636510-1-ulf.hansson@linaro.org/
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 0e789b491b ("pmdomain: core: Leave powered-on genpds on until sync_state")
Fixes: 13a4b7fb62 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The recent changes to genpd makes a genpd OF provider that is powered-on at
initialization to stay powered-on, until the ->sync_state() callback is
invoked for it.
This may not happen at all, if we wait for a consumer device to be probed,
leading to wasting energy. There are ways to enforce the ->sync_state()
callback to be invoked, through sysfs or via the probe-defer-timeout, but
none of them in its current form are a good fit for rcar-sysc PM domains.
Let's therefore opt-out from this behaviour of genpd for now, by using the
GENPD_FLAG_NO_STAY_ON.
Link: https://lore.kernel.org/all/20250701114733.636510-1-ulf.hansson@linaro.org/
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 0e789b491b ("pmdomain: core: Leave powered-on genpds on until sync_state")
Fixes: 13a4b7fb62 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Subsequent changes to genpd adds a limitation that registering a genpd OF
providers must be done after its bus registration, which is at
core_initcall.
To adopt to this, let's split the initialization into two steps. The first
part keep registering the PM domains with genpd at early_initcall, as this
is needed to bringup the CPUs for R-Car H1, by calling
rcar_sysc_power_up_cpu(). The second and new part, moves the registration
of the genpd OF provider to a postcore_initcall().
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250701114733.636510-2-ulf.hansson@linaro.org
Renesas Kconfig is using "SoC chip number" for CONFIG symbol, but is
using "SoC chip name" for menu description. Because of it, it looks
random order when we run "make menuconfig".
commit 6d5aded8d5 ("soc: renesas: Sort driver description title")
sorted Renesas Kconfig by "menu description title order" (= SoC chip
name), but it makes confusable to add new config, because developer
usually checks CONFIG symbols (= SoC chip number).
Let's indicate both "SoC chip number" and "SoC chip name" in description
and sort it again.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/87ikkacacf.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Until commit 7e8a50df26 ("soc: renesas: rcar-sysc: Drop legacy
handling") in v4.19, the rcar_sysc_ch structure was part of the API for
legacy board code not yet using DT. Since then, there is no longer a
reason to keep it as a separate structure.
Moreover, a future quirk handling will need access to the rcar_sysc_pd
structure's flags member in rcar_sysc_pwr_on_off(). Hence absorb the
rcar_sysc_ch structure into the rcar_sysc_pd structure, and pass around
the latter instead of the former.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/672805a8c52ce63200e342212bbe6f84a445397b.1713348705.git.geert+renesas@glider.be
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The delays used with the various atomic polling loops are already at the
maximum value of ~10µs, as documented for read_poll_timeout_atomic().
Hence reduce the delays from 10 to 1 µs. Increase PDRESR_RETRIES
accordingly, to retain the old (generous) timeout value.
Measurements on R-Car V3U, S4, V4H, and V4M show that the first three
polling loops rarely (never?) loop, so the actual delay does not matter.
The fourth loop (for SYSCISCR in rcar_gen4_sysc_power()) typically ran
for one or two cycles with the old delay. With the reduced delay, it
typically runs for two to 17 cycles, and finishes earlier than before,
which can reduce loop time up to a factor of three.
While at it, rename the SYSCISR_{TIMEOUT,DELAY_US} definitions to
SYSCISCR_{TIMEOUT,DELAY_US}, to match the register name they apply to.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/77f150522096d55c6da0ff983db61e0cf6309344.1709317289.git.geert+renesas@glider.be
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
It has been pointed out that naming a subsystem "genpd" isn't very
self-explanatory and the acronym itself that means Generic PM Domain, is
known only by a limited group of people.
In a way to improve the situation, let's rename the subsystem to pmdomain,
which ideally should indicate that this is about so called Power Domains or
"PM domains" as we often also use within the Linux Kernel terminology.
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230912221127.487327-1-ulf.hansson@linaro.org
