Commit Graph

4 Commits

Author SHA1 Message Date
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Tony Lindgren
2a296c8f89 ARM: OMAP: Make plat/omap_hwmod.h local to mach-omap2
Let's make omap_hwmod local to mach-omap2 for
ARM common zImage support.

Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-18 16:05:55 -07:00
Kevin Hilman
414e41286e ARM: OMAP2+: WDTIMER integration: fix !PM boot crash, disarm timer after hwmod reset
Without runtime PM enabled, hwmod needs to leave all IP blocks in an
enabled state by default so any driver access to the HW will succeed.
This is accomplished by seting the postsetup_state to enabled for all
hwmods during init when runtime PM is disabled.

Currently, we have a special case for WDT in that its postsetup_state
is always set to disabled.  This is done so that the WDT is disabled
and the timer is disarmed at boot in case there is no WDT driver.
This also means that when runtime PM is disabled, if a WDT driver *is*
built in the kernel, the kernel will crash on the first access to the
WDT hardware.

We can't simply leave the WDT module enabled, because the timer is
armed by default after reset. That means that if there is no WDT
driver initialzed or loaded before the timer expires, the kernel will
reboot.

To fix this, a custom reset method is added to the watchdog class of
omap_hwmod.  This method will *always* disarm the timer after hwmod
reset.  The WDT timer then will only be rearmed when/if the driver is
loaded for the WDT.  With the timer disarmed by default, we no longer
need a special-case for the postsetup_state of WDT during init, so it
is removed.

Any platforms wishing to ensure the watchdog remains armed across the
entire boot boot can simply disable the reset-on-init feature of the
watchdog hwmod using omap_hwmod_no_setup_reset().

Tested on 3530/Overo, 4430/Panda.

NOTE: on 4430, the hwmod OCP reset does not seem to rearm the timer as
documented in the TRM (and what happens on OMAP3.)  I noticed this
because testing the HWMOD_INIT_NO_RESET feature with no driver loaded,
I expected a reboot part way through the boot, but did not see a
reboot.  Adding some debug to read the counter, I verified that right
after OCP softreset, the counter is not firing.  After writing the
magic start sequence, the timer starts counting.  This means that the
timer disarm sequence added here does not seem to be needed for 4430,
but is technically the correct way to ensure the timer is disarmed, so
it is left in for OMAP4.

Special thanks to Paul Walmsley for helping brainstorm ideas to fix
this problem.

Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[paul@pwsan.com: updated the omap2_wd_timer_reset() function in the
 wake of commit 3c55c1baff ("ARM:
 OMAP2+: hwmod: Revert "ARM: OMAP2+: hwmod: Make omap_hwmod_softreset
 wait for reset status""); added kerneldoc; rolled in warning fix from Kevin]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2012-05-08 17:25:37 -06:00
Paul Walmsley
81fbc5ef9b OMAP2+: wd_timer: separate watchdog disable code from the rest of mach-omap2/devices.c
Split the wd_timer disable code out into its own file,
mach-omap2/wd_timer.c; it belongs in its own file rather than
cluttering up devices.c.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Charulatha Varadarajan <charu@ti.com>
2010-12-21 19:56:17 -07:00