Commit Graph

23 Commits

Author SHA1 Message Date
Alexandre Belloni 6ec8be251f clocksource/drivers/tcb_clksrc: Make IO endian agnostic
Now that AVR32 is gone, we can use the proper IO accessors that are
correctly handling endianness.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-06-27 11:25:20 +02:00
Alexandre Belloni 2a515e5d7c clocksource/drivers/tcb_clksrc: Save timer context on suspend/resume
On sama5d2, power to the core may be cut while entering suspend mode. It is
necessary to save and restore the TCB registers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-06-14 12:02:31 +02:00
Romain Izard 33d8c15559 Revert "clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock"
This reverts commit 7b9f1d16e6 ("clocksource/drivers/tcb_clksrc: Use
32 bit tcb as sched_clock"). In the current state, the kernel warns
against a late registration of the new sched_clock, the printk clock
resets after only a few minutes, and it seems that scheduling can be
affected as well.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-03-11 22:03:34 +01:00
David Engraf 7b9f1d16e6 clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock
On newer boards the TC can be read as single 32 bit value without locking.
Thus the clock can be used as reference for sched_clock which is much more
accurate than the jiffies implementation.

Tested on a Atmel SAMA5D2 board.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-07 20:58:30 +01:00
Thomas Gleixner a5a1d1c291 clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2016-12-25 11:04:12 +01:00
Alexandre Belloni f02b4b72d1 clockevents/tcb_clksrc: Prevent disabling an already disabled clock
clockevents_exchange_device is calling clockevents_shutdown() on the new
clockenvents device but it may have never been enabled in the first place.
This results in the tcb clock being disabled without being enabled first:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34()
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6
Hardware name: Atmel AT91SAM9
[<c000f2b8>] (unwind_backtrace) from [<c000d01c>] (show_stack+0x10/0x14)
[<c000d01c>] (show_stack) from [<c00172f0>] (warn_slowpath_common+0x78/0xa0)
[<c00172f0>] (warn_slowpath_common) from [<c00173a8>] (warn_slowpath_null+0x18/0x20)
[<c00173a8>] (warn_slowpath_null) from [<c0361528>] (clk_disable+0x28/0x34)
[<c0361528>] (clk_disable) from [<c034d560>] (tc_shutdown+0x38/0x4c)
[<c034d560>] (tc_shutdown) from [<c0059ad4>] (clockevents_switch_state+0x38/0x6c)
[<c0059ad4>] (clockevents_switch_state) from [<c0059b18>] (clockevents_shutdown+0x10/0x24)
[<c0059b18>] (clockevents_shutdown) from [<c005a458>] (tick_check_new_device+0x84/0xac)
[<c005a458>] (tick_check_new_device) from [<c0059660>] (clockevents_register_device+0x7c/0x108)
[<c0059660>] (clockevents_register_device) from [<c06b5a68>] (tcb_clksrc_init+0x390/0x3e8)
[<c06b5a68>] (tcb_clksrc_init) from [<c00097cc>] (do_one_initcall+0x114/0x1d4)
[<c00097cc>] (do_one_initcall) from [<c069bd54>] (kernel_init_freeable+0xfc/0x1b8)
[<c069bd54>] (kernel_init_freeable) from [<c04c3818>] (kernel_init+0x8/0xe0)
[<c04c3818>] (kernel_init) from [<c000a410>] (ret_from_fork+0x14/0x24)
---[ end trace 0000000000000001 ]---

Check what state we were in before trying to disable the clock.

Fixes: cf4541c101 ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1452854061-30370-1-git-send-email-alexandre.belloni@free-electrons.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-15 11:40:44 +01:00
Boris Brezillon 7d8d05d114 misc: atmel_tclib: get and use slow clock
Commit dca1a4b5ff ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the timer counters.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06 12:33:14 +02:00
Boris Brezillon eed9fb9df4 clocksource: tcb_clksrc: fix setup_clkevents error path
t2_clk is already disabled before request_irq(), it must not be disabled
again.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-10-06 12:25:39 +02:00
Viresh Kumar cf4541c101 clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface
Migrate tcb_clksrc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:40:52 +02:00
Gaël PORTAY d07a1ecdfb clocksource: tcb_clksrc: sanitize IRQ request
The clock is not unprepared in case of the request IRQ fails.

Also update to request_irq.

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08 10:54:03 +02:00
Gaël PORTAY 4930d247af ARM: at91/tclib: move initialization from alloc to probe
Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately
reporting resource related issues when a TC block user request a TC block.

Moreover, resources retrieval are usually done in the probe function,
thus moving them add some consistency with other drivers.

Initialization is done once, ie not every time a tc block is requested.
If it fails, the device is not appended to the list of tc blocks.

Furhermore, the device id is retrieved at probe as well, avoiding parsing
DT every time the user requests of tc block.

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08 10:54:03 +02:00
David Jander acbf6d21ac clocksource: tcb_clksrc: Make tc_mode interrupt safe
tc_mode() can be called from interrupt context and thus must not call
clk_*prepare*() functions.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-05-22 18:54:58 +02:00
Boris BREZILLON f51380a756 clocksource: tcb_clksrc: Remove IRQF_DISABLED
Remove the deprecated IRQF_DISABLED flag.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-10-03 16:28:40 +02:00
Boris BREZILLON 5b3c11da14 clocksource: tcb_clksrc: Improve driver robustness
Check function return values to avoid false positive driver init.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-10-03 16:28:30 +02:00
Boris BREZILLON 0e746ec558 clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare
Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-10-03 16:28:23 +02:00
Shawn Guo 77cc982f6a clocksource: use clockevents_config_and_register() where possible
The clockevent core is able to figure out the best mult and shift,
calculate min_delta_ns and max_delta_ns, with the necessary info passed
into clockevents_config_and_register().  Use this combined configure
and register function where possible to make the codes less error prone
and gain some positive diff stat.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-14 10:12:42 -08:00
Nicolas Ferre 8e315a7b0c ARM: at91/tc/clocksource: Add 32 bit variant to Timer Counter
Some SoC have a 32 bit variant of Timer Counter Blocks. We do not
need the chaining of two 16 bit counters anymore for them.

The SoC nature is deduced from the device tree "compatible" string.
For non-device-tree configurations, backward compatibility is maintained
by using the default 16 bit counter configuration.

This patch addresses both the atmel_tclib and its user: tcb_clksrc
clocksource.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2012-03-01 13:38:49 +01:00
John Stultz f5a54dd795 clocksource: Convert tcb_clksrc to use clocksource_register_hz/khz
Convert tcb_clksrc to use clocksource_register_hz.

CC: Nikolaus Voss <n.voss@weinmann.de>
CC: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Nikolaus Voss <n.voss@weinmann.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-11-21 19:01:42 -08:00
Voss, Nikolaus 1817dc0370 drivers/clocksource/tcb_clksrc.c: fix init sequence
setup_irq() was called before clockevents_register_device() which is
needed by the irq handler.  Bug was reproducible by restarting the
kernel using kexec (reliable crash).

Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:04 +10:00
Magnus Damm 8e19608e8b clocksource: pass clocksource to read() callback
Pass clocksource pointer to the read() callback for clocksources.  This
allows us to share the callback between multiple instances.

[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-21 13:41:47 -07:00
Rusty Russell 320ab2b0b1 cpumask: convert struct clock_event_device to cpumask pointers.
Impact: change calling convention of existing clock_event APIs

struct clock_event_timer's cpumask field gets changed to take pointer,
as does the ->broadcast function.

Another single-patch change.  For safety, we BUG_ON() in
clockevents_register_device() if it's not set.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
2008-12-13 21:20:26 +10:30
David Brownell 3ee08aea72 tclib: Fix compile warnings
Does that have something analagous to this "remove warnings" patch?
Seems setup_clkevents() no longer needs a t0_clk parameter either...

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-03-13 22:53:29 +01:00
David Brownell 4d243f92e4 atmel_tc clocksource/clockevent code
Clocksource and clockevent device based on the Atmel TC blocks.

The clockevent device handles both periodic and oneshot modes, so this
enables NO_HZ and high res timers on some platforms that previously
couldn't use those mechanisms.

This works on both AVR32 and AT91 chips, given relevant patches for
tclib support (always) and clockevents (or else this will only look
like a higher precision clocksource).  It's an updated and modularized
version of an AT91-only patch that has circulated for some time now.

Changes relative to the original patch:
  * Update to use new tclib API
  * Replace open-coded do-while loop using goto with a real do-while loop
  * Minor irq handler optimization: Load register base address from
    dev_id instead of a global variable.
  * Aggressively turn off clocks when the clockevent isn't being used
  * Include the clockevent code on AT91RM9200 as well. The rating is
    lower than the System Timer, so the clock will usually stay off.
  * Don't assume that the number of clocks is always equal to the
    number of irqs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-03-04 13:42:24 +01:00