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@@ -1,3 +1,56 @@
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+From 3cc8011171186d906c547bc6f0c1f8e350edc7cf Mon Sep 17 00:00:00 2001
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+From: Markus Stockhausen <[email protected]>
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+Date: Mon, 3 Oct 2022 14:45:21 +0200
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+Subject: [PATCH] realtek: resurrect timer driver
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+
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+Now that we provide a clock driver for the Reltek SOCs the CPU frequency might
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+change on demand. This has direct visible effects during operation
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+
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+- the CEVT 4K timer is no longer a stable clocksource
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+- after CPU frequencies changes time calculation works wrong
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+- sched_clock falls back to kernel default interval (100 Hz)
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+- timestamps in dmesg have only 2 digits left
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+
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+[ 0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns, wraps ...
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+[ 0.060000] pid_max: default: 32768 minimum: 301
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+[ 0.070000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
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+[ 0.070000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
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+[ 0.080000] dyndbg: Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build
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+[ 0.090000] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, ...
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+
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+Looking around where we can start the CEVT timer for RTL930X is a good basis.
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+Initially it was developed as a clocksource driver for the broken timer in that
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+specific SOC series. Afterwards it was shifted around to the CEVT location,
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+got SMP enablement and lost its clocksource feature. So we at least have
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+something to copy from. As the timers on these devices are well understood
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+the implementation follows this way:
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+
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+- leave the RTL930X implementation as is
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+- provide a new driver for RTL83XX devices only
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+- swap RTL930X driver at a later time
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+
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+Like the clock driver this patch contains a self contained module that is SOC
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+independet and already provides full support for the RTL838X, RTL839X and
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+RTL930X devices. Some of the new (or reestablished) features are:
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+
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+- simplified initialization routines
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+- SMP setup with CPU hotplug framework
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+- derived from LXB clock speed
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+- supplied clocksource
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+- dedicated register functions for better readability
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+- documentation about some caveats
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+
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+Signed-off-by: Markus Stockhausen <[email protected]>
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+[remove unused header includes, remove old CONFIG_MIPS dependency, add
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+REALTEK_ prefix to driver symbol]
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+Signed-off-by: Sander Vanheule <[email protected]>
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+
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+---
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+ drivers/clocksource/Kconfig | 12 +++
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+ drivers/clocksource/Makefile | 1 +
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+ include/linux/cpuhotplug.h | 1 +
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+ 3 files changed, 14 insertions(+)
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+
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--- a/drivers/clocksource/Kconfig
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+++ b/drivers/clocksource/Kconfig
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@@ -127,6 +127,17 @@ config RDA_TIMER
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