linux-toradex.git/drivers/spmi, branch v4.13-rc2

spmi: pmic-arb: Always allocate ppid_to_apid table

2017-07-17T13:00:47+00:00

After commit 7f1d4e58dabb ("spmi: pmic-arb: optimize table
lookups") we always need the ppid_to_apid table regardless of the
version of pmic arbiter we have. Otherwise, we will try to deref
the array when we don't allocate it on v2 hardware like the
msm8974 SoCs.

Cc: Abhijeet Dharmapurikar 
Cc: Kiran Gunda 
Fixes: 7f1d4e58dabb ("spmi: pmic-arb: optimize table lookups")
Signed-off-by: Stephen Boyd 
Tested-by: Luca Weiss 
Reviewed-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: Include OF based modalias in device uevent

2017-07-17T13:00:47+00:00

Include the OF-based modalias in the uevent sent when registering SPMI
devices, so that user space has a chance to autoload the kernel module
for the device.

Tested-by: Rob Clark 
Reported-by: Rob Clark 
Reviewed-by: Stephen Boyd 
Signed-off-by: Bjorn Andersson 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

spmi: spmi-pmic-arb: enable the SPMI interrupt as a wakeup source

2017-06-03T10:05:47+00:00

Currently the SPMI interrupt will not wake the device. Enable this
interrupt as a wakeup source.

Signed-off-by: Nicholas Troast 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic_arb: add support for PMIC bus arbiter v3

2017-06-03T10:05:47+00:00

PMIC bus arbiter v3 supports 512 SPMI peripherals. Add the v3 operators to
support this new arbiter version.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic-arb: check apid enabled before calling the handler

2017-06-03T10:05:47+00:00

The driver currently invokes the apid handler (periph_handler())
once it sees that the summary status bit for that apid is set.

However the hardware is designed to set that bit even if the apid
interrupts are disabled. The driver should check whether the apid
is indeed enabled before calling the apid handler.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic_arb: use appropriate flow handler

2017-06-03T10:05:47+00:00

The current code uses handle_level_irq flow handler even if the
trigger type of the interrupt is edge. This can lead to missing
of an edge transition that happens when the interrupt is being
handled. The level flow handler masks the interrupt while it is
being handled, so if an edge transition happens at that time,
that edge is lost.

Use an edge flow handler for edge type interrupts which ensures
that the interrupt stays enabled while being handled - at least
until it triggers at which point the flow handler sets the
IRQF_PENDING flag and only then masks the interrupt. That
IRQF_PENDING state indicates an edge transition happened while
the interrupt was being handled and the handler is called again.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic-arb: clear the latched status of the interrupt

2017-06-03T10:05:47+00:00

PMIC interrupts each have an internal latched status bit which is
not visible from any register.  This status bit is set as soon as
the conditions specified in the interrupt type and polarity
registers are met even if the interrupt is not enabled.  When it
is set, nothing else changes within the PMIC and no interrupt
notification packets are sent.  If the internal latched status
bit is set when an interrupt is enabled, then the value is
immediately propagated into the interrupt latched status register
and an interrupt notification packet is sent out from the PMIC
over SPMI.

This PMIC hardware behavior can lead to a situation where the
handler for a level triggered interrupt is called immediately
after enable_irq() is called even though the interrupt physically
triggered while it was disabled within the genirq framework.
This situation takes place if the the interrupt fires twice after
calling disable_irq().  The first time it fires, the level flow
handler will mask and disregard it.  Unfortunately, the second
time it fires, the internal latched status bit is set within the
PMIC and no further notification is received.  When enable_irq()
is called later, the interrupt is unmasked (enabled in the PMIC)
which results in the PMIC immediately sending an interrupt
notification packet out over SPMI.  This breaks the semantics
of level triggered interrupts within the genirq framework since
they should be completely ignored while disabled.

The PMIC internal latched status behavior also affects how
interrupts are treated during suspend.  While entering suspend,
all interrupts not specified as wakeup mode are masked.  Upon
resume, these interrupts are unmasked.  Thus if any of the
non-wakeup PMIC interrupts fired while the system was suspended,
then the PMIC will send interrupt notification packets out via
SPMI as soon as they are unmasked during resume.  This behavior
violates genirq semantics as well since non-wakeup interrupts
should be completely ignored during suspend.

Modify the qpnpint_irq_unmask() function so that the interrupt
latched status clear register is written immediately before the
interrupt enable register.  This clears the internal latched
status bit of the interrupt so that it cannot trigger spuriously
immediately upon being enabled.

Also, while resuming an irq, an unmask could be called even if it
was not previously masked.  So, before writing these registers,
check if the interrupt is already enabled within the PMIC. If it
is, then no further register writes are required.  This
condition check ensures that a valid latched status register bit
is not cleared until it is properly handled.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic-arb: fix missing interrupts

2017-06-03T10:05:47+00:00

irq_enable is called when the device resumes. Note that the
irq_enable is called regardless of whether the interrupt was
marked enabled/disabled in the descriptor or whether it was
masked/unmasked at the controller while resuming.

The current driver unconditionally clears the interrupt in its
irq_enable callback. This is dangerous as any interrupts that
happen right before the resume could be missed.
Remove the irq_enable callback and use mask/unmask instead.

Also remove struct pmic_arb_irq_spec as it serves no real purpose.
It is used only in the translate function and the code is much
cleaner without it.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic-arb: cleanup unrequested irqs

2017-06-03T10:05:47+00:00

We see a unmapped irqs trigger right around bootup. This could
likely be because the bootloader exited leaving the interrupts
in an unknown or unhandled state.  Ack and mask the interrupt
if one is found. A request_irq later will unmask it and also
setup proper mapping structures.

Also the current driver ensures that no read/write transaction
is in progress while it makes changes to the interrupt regions.
This is not necessary because read/writes over spmi and arbiter
interrupt control are independent operations. Hence, remove the
synchronized accesses to interrupt region.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman

spmi: pmic-arb: optimize table lookups

2017-06-03T10:05:47+00:00

The current driver uses a mix of radix tree and a fwd lookup
table to translate between apid and ppid. It is buggy and confusing.

Instead simply use a radix tree for v1 hardware and use the
forward lookup table for v2.

Signed-off-by: Abhijeet Dharmapurikar 
Signed-off-by: Kiran Gunda 
Signed-off-by: Greg Kroah-Hartman