linux-stable.git/drivers/clocksource/timer-ti-dm.c, branch linux-5.7.y

Merge branch 'timers/drivers/timer-ti-dm' into timers/drivers/next

2020-03-16T12:24:10+00:00

clocksource/drivers/timer-ti-dm: Enable autoreload in set_pwm

2020-03-16T11:40:51+00:00

dm timer ops set_load() api allows to configure the load value and to
set the auto reload feature. But auto reload feature is independent of
load value and should be part of configuring pwm. This way pwm can be
disabled by disabling auto reload feature using set_pwm() so that the
current pwm cycle will be completed. Else pwm disabling causes the
cycle to be stopped abruptly.

Signed-off-by: Lokesh Vutla 
Acked-by: Tony Lindgren 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200305082715.15861-7-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Add support to get pwm current status

2020-03-16T11:40:42+00:00

omap_dm_timer_ops provide support to configure the pwm but there is no
support to get the current status. For configuring pwm it is advised to
check the current hw status instead of relying on pwm framework. So
implement a new timer ops to get the current status of pwm.

Signed-off-by: Lokesh Vutla 
Acked-by: Tony Lindgen 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200305082715.15861-6-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Do not update counter on updating the period

2020-03-16T11:40:36+00:00

Write to trigger register(OMAP_TIMER_TRIGGER_REG) will load the value
in Load register(OMAP_TIMER_LOAD_REG) into Counter register
(OMAP_TIMER_COUNTER_REG).

omap_dm_timer_set_load() writes into trigger register every time load
register is updated. When timer is configured in pwm mode, this causes
disruption in current pwm cycle, which is not expected especially when
pwm is used as PPS signal for synchronized PTP clocks. So do not write
into trigger register on updating the period.

Tested-by: Tony Lindgren 
Signed-off-by: Lokesh Vutla 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200305082715.15861-5-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Implement cpu_pm notifier for context save and restore

2020-03-16T11:40:29+00:00

omap_dm_timer_enable() restores the entire context(including counter)
based on 2 conditions:
- If get_context_loss_count is populated and context is lost.
- If get_context_loss_count is not populated update unconditionally.

Case2 has a side effect of updating the counter register even though
context is not lost. When timer is configured in pwm mode, this is
causing undesired behaviour in the pwm period.

Instead of using get_context_loss_count call back, implement cpu_pm
notifier with context save and restore support. And delete the
get_context_loss_count callback all together.

Suggested-by: Tony Lindgren 
Signed-off-by: Lokesh Vutla 
[tony@atomide.com: removed pm_runtime calls from cpuidle calls]
Signed-off-by: Tony Lindgren 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200316111453.15441-1-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Prepare for using cpuidle

2020-03-16T11:40:21+00:00

Let's add runtime_suspend and resume functions and atomic enabled
flag. This way we can use these when converting to use cpuidle
for saving and restoring device context.

And we need to maintain the driver state in the driver as documented
in "9. Autosuspend, or automatically-delayed suspends" in the
Documentation/power/runtime_pm.rst document related to using driver
private lock and races with runtime_suspend().

Signed-off-by: Tony Lindgren 
Signed-off-by: Lokesh Vutla 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200305082715.15861-3-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Convert to SPDX identifier

2020-03-16T11:40:14+00:00

Use SPDX-License-Identifier instead of a verbose license text.

Signed-off-by: Lokesh Vutla 
Acked-by: Tony Lindgren 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200305082715.15861-2-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Drop bogus omap_dm_timer_of_set_source()

2020-02-27T09:32:11+00:00

The function omap_dm_timer_of_set_source() was originally added in
commit 31a7448f4fa8a ("ARM: OMAP: dmtimer: Add clock source from DT"),
and is designed to set a clock source from DT using the clocks property
of a timer node. This design choice is okay for clk provider nodes but
otherwise is a bad design as typically the clocks property is used to
specify the functional clocks for a device, and not its parents.

The timer nodes now all define a timer functional clock after the
conversion to ti-sysc and the new clkctrl layout, and this results
in an attempt to set the same functional clock as its parent when a
consumer driver attempts to acquire any of these timers in the
omap_dm_timer_prepare() function. This was masked and worked around
in commit 983a5a43ec25 ("clocksource: timer-ti-dm: Fix pwm dmtimer
usage of fck reparenting"). Fix all of this by simply dropping the
entire function.

Any DT configuration of clock sources should be achieved using
assigned-clocks and assigned-clock-parents properties provided
by the Common Clock Framework.

Cc: Tony Lindgren 
Cc: Tero Kristo 
Cc: Neil Armstrong 
Cc: H. Nikolaus Schaller 
Cc: Bartosz Golaszewski 
Cc: Keerthy 
Cc: Ladislav Michl 
Cc: Pavel Machek 
Cc: Sebastian Reichel 
Signed-off-by: Suman Anna 
Tested-by: Lokesh Vutla 
Tested-by: Tony Lindgren 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200213053504.22638-1-s-anna@ti.com

clocksource/drivers/timer-ti-dm: Do not update counter on updating the period

2020-02-27T09:26:23+00:00

Write to trigger register(OMAP_TIMER_TRIGGER_REG) will load the value
in Load register(OMAP_TIMER_LOAD_REG) into Counter register
(OMAP_TIMER_COUNTER_REG).

omap_dm_timer_set_load() writes into trigger register every time load
register is updated. When timer is configured in pwm mode, this causes
disruption in current pwm cycle, which is not expected especially when
pwm is used as PPS signal for synchronized PTP clocks. So do not write
into trigger register on updating the period.

Signed-off-by: Lokesh Vutla 
Tested-by: Tony Lindgren 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200224050753.17784-3-lokeshvutla@ti.com

clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access

2020-01-16T18:09:02+00:00

Clean-up commit 8c82723414d5 ("clocksource/drivers/timer-ti-dm: Switch to
platform_get_irq") caused a regression where we now try to access
uninitialized data for timer:

drivers/clocksource/timer-ti-dm.c: In function 'omap_dm_timer_probe':
drivers/clocksource/timer-ti-dm.c:798:13: warning: 'timer' may be used
uninitialized in this function [-Wmaybe-uninitialized]

On boot we now get:

Unable to handle kernel NULL pointer dereference at virtual address
00000004
...
(omap_dm_timer_probe) from [] (platform_drv_probe+0x48/0x98)
(platform_drv_probe) from [] (really_probe+0x1dc/0x348)
(really_probe) from [] (driver_probe_device+0x5c/0x160)

Let's fix the issue by moving platform_get_irq to happen after timer has
been allocated.

Fixes: bc83caddf17b ("clocksource/drivers/timer-ti-dm: Switch to platform_get_irq")
Cc: Yangtao Li 
Signed-off-by: Tony Lindgren 
Acked-by: Olof Johansson 
Acked-by: Yangtao Li 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200106203700.21009-1-tony@atomide.com