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authorLinus Walleij <linus.walleij@linaro.org>2019-10-27 00:47:32 +0300
committerLee Jones <lee.jones@linaro.org>2019-11-11 11:45:04 +0300
commit22fb3ad0cc5f578398953ddcab9c8239a08caccd (patch)
treead7ac7fab95c75124bc4471b735f282e3ed3b520 /arch/arm/mach-ux500
parent59dbc0e0d498c8bdb26a661ee080ee8d147c3c5d (diff)
downloadlinux-22fb3ad0cc5f578398953ddcab9c8239a08caccd.tar.xz
mfd: db8500-prcmu: Support U8420-sysclk firmware
There is a distinct version of the Ux500 U8420 variant with "sysclk", as can be seen from the vendor code that didn't make it upstream, this firmware lacks the ULPPLL (ultra-low power phase locked loop) which in effect means that the timer clock is instead wired to the 32768 Hz always-on clock. This has some repercussions when enabling the timer clock as the code as it stands will disable the timer clock on these platforms (lacking the so-called "doze mode") and obtaining the wrong rate of the timer clock. The timer frequency is of course needed very early in the boot, and as a consequence, we need to shuffle around the early PRCMU init code: whereas in the past we did not need to look up the PRCMU firmware version in the early init, but now we need to know the version before the core system timers are registered so we restructure the platform callbacks to the PRCMU so as not to take any arguments and instead look up the resources it needs directly from the device tree when initializing. As we do not yet support any platforms using this firmware it is not a regression, but as PostmarketOS is starting to support products with this firmware we need to fix this up. The low rate of 32kHz also makes the MTU timer unsuitable as delay timer but this needs to be fixed in a separate patch. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Stephan Gerhold <stephan@gerhold.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'arch/arm/mach-ux500')
-rw-r--r--arch/arm/mach-ux500/cpu-db8500.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mach-ux500/cpu-db8500.c b/arch/arm/mach-ux500/cpu-db8500.c
index 3875027ef8fc..e929aaa744c0 100644
--- a/arch/arm/mach-ux500/cpu-db8500.c
+++ b/arch/arm/mach-ux500/cpu-db8500.c
@@ -84,6 +84,7 @@ static void __init ux500_init_irq(void)
struct resource r;
irqchip_init();
+ prcmu_early_init();
np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
of_address_to_resource(np, 0, &r);
of_node_put(np);
@@ -91,7 +92,6 @@ static void __init ux500_init_irq(void)
pr_err("could not find PRCMU base resource\n");
return;
}
- prcmu_early_init(r.start, r.end-r.start);
ux500_pm_init(r.start, r.end-r.start);
/* Unlock before init */