spmi: Use devm_spmi_controller_alloc()

Convert to the device-managed version of spmi_controller_alloc() and
simplify the excess error handling code.

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-3-fshao@chromium.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-5-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: fix W=1 kernel-doc warnings

Fix all W=1 kernel-doc warnings in drivers/spmi/:

drivers/spmi/spmi.c:414: warning: expecting prototype for spmi_controller_alloc(). Prototype was for spmi_device_alloc() instead
drivers/spmi/spmi.c:592: warning: expecting prototype for spmi_driver_register(). Prototype was for __spmi_driver_register() instead
drivers/spmi/spmi.c:592: warning: Function parameter or member 'owner' not described in '__spmi_driver_register'
drivers/spmi/spmi-pmic-arb.c:155: warning: cannot understand function prototype: 'struct spmi_pmic_arb '
drivers/spmi/spmi-pmic-arb.c:203: warning: cannot understand function prototype: 'struct pmic_arb_ver_ops '
drivers/spmi/spmi-pmic-arb.c:219: warning: expecting prototype for struct pmic_arb_ver. Prototype was for struct pmic_arb_ver_ops instead

Link: https://lore.kernel.org/r/20230113064040.26801-1-rdunlap@infradead.org
Cc: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20230413223834.4084793-6-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/r/20230306073446.2194048-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20230413223834.4084793-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Add support for PMIC v7

PMIC v7 has different offset values and seqeunces, so add support for
this new version of PMIC

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # SM8450 HDK
Acked-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221110100755.4032505-3-vkoul@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: increase SPMI transaction timeout delay

Increase the SPMI transaction timeout delay from 100 us to
1000 us in order to account for the slower execution time
found on some simulator targets.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-11-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-10-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: block access for invalid PMIC arbiter v5 SPMI writes

The system crashes due to an access permission violation when
writing to a PMIC peripheral which is not owned by the current
ee. Add a check for PMIC arbiter version 5 for such invalid
write requests and return an error instead of crashing the
system.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-8-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-9-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: correct duplicate APID to PPID mapping logic

Correct the way that duplicate PPID mappings are handled for PMIC
arbiter v5. The final APID mapped to a given PPID should be the
one which has write owner = APPS EE, if it exists, or if not
that, then the first APID mapped to the PPID, if it exists.

Fixes: 40f318f0ed67 ("spmi: pmic-arb: add support for HW version 5")
Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-7-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-8-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: add support to dispatch interrupt based on IRQ status

Current implementation of SPMI arbiter dispatches interrupt based on the
Arbiter's accumulator status, in some cases the accumulator status may
remain zero and the interrupt remains un-handled. Add logic to dispatch
interrupts based Arbiter's IRQ status if the accumulator status is zero.

Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-6-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-7-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: check apid against limits before calling irq handler

Check that the apid for an SPMI interrupt falls between the
min_apid and max_apid that can be handled by the APPS processor
before invoking the per-apid interrupt handler:
periph_interrupt().

This avoids an access violation in rare cases where the status
bit is set for an interrupt that is not owned by the APPS
processor.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-5-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-6-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: do not ack and clear peripheral interrupts in cleanup_irq

Currently, cleanup_irq() is invoked when a peripheral's interrupt
fires and there is no mapping present in the interrupt domain of
spmi interrupt controller.

The cleanup_irq clears the arbiter bit, clears the pmic interrupt
and disables it at the pmic in that order. The last disable in
cleanup_irq races with request_irq() in that it stomps over the
enable issued by request_irq. Fix this by not writing to the pmic
in cleanup_irq. The latched bit will be left set in the pmic,
which will not send us more interrupts even if the enable bit
stays enabled.

When a client wants to request an interrupt, use the activate
callback on the irq_domain to clear latched bit. This ensures
that the latched, if set due to the above changes in cleanup_irq
or when the bootloader leaves it set, gets cleaned up, paving way
for upcoming interrupts to trigger.

With this, there is a possibility of unwanted triggering of
interrupt right after the latched bit is cleared - the interrupt
may be left enabled too. To avoid that, clear the enable first
followed by clearing the latched bit in the activate callback.

Fixes: 6bc546e71e50 ("spmi: pmic-arb: cleanup unrequested irqs")
Fixes: 02abec3616c1 ("spmi: pmic-arb: rename pa_xx to pmic_arb_xx and other cleanup")
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
[collinsd@codeaurora.org: fix merge conflict]
Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-4-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-5-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: handle spurious interrupt

Call handle_bad_irq() when the summary interrupt is fired spuriously.

Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-3-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: add a print in cleanup_irq

The cleanup_irq() was meant to clear and mask interrupts that were
left enabled in the hardware but there was no interrupt handler
registered for it. Add an error print when it gets invoked.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/1655004286-11493-2-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-3-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: spmi-pmic-arb: fix irq_set_type race condition

The qpnpint_irq_set_type() callback function configures the type
(edge vs level) and polarity (high, low, or both) of a particular
PMIC interrupt within a given peripheral. To do this, it reads
the three consecutive IRQ configuration registers, modifies the
specified IRQ bit within the register values, and finally writes
the three modified register values back to the PMIC. While a
spinlock is used to provide mutual exclusion on the SPMI bus
during the register read and write calls, there is no locking
around the overall read, modify, write sequence. This opens up
the possibility of a race condition if two tasks set the type of
a PMIC IRQ within the same peripheral simultaneously.

When the race condition is encountered, both tasks will read the
old value of the registers and IRQ bits set by one of the tasks
will be dropped upon the register write of the other task. This
then leads to PMIC IRQs being enabled with an incorrect type and
polarity configured. Such misconfiguration can lead to an IRQ
storm that overwhelms the system and causes it to crash.

This race condition and IRQ storm have been observed when using
a pair of pm8941-pwrkey devices to handle PMK8350 pwrkey and
resin interrupts. The independent devices probe asynchronously
in parallel and can simultaneously request and configure PMIC
IRQs in the same PMIC peripheral.

For a good case, the IRQ configuration calls end up serialized
due to timing deltas and the register read/write sequence looks
like this:

1. pwrkey probe: SPMI read(0x1311): 0x00, 0x00, 0x00
2. pwrkey probe: SPMI write(0x1311): 0x80, 0x80, 0x80
3. resin probe: SPMI read(0x1311): 0x80, 0x80, 0x80
4. resin probe: SPMI write(0x1311): 0xC0, 0xC0, 0xC0

The final register states after both devices have requested and
enabled their respective IRQs is thus:

0x1311: 0xC0
0x1312: 0xC0
0x1313: 0xC0
0x1314: 0x00
0x1315: 0xC0

For a bad case, the IRQ configuration calls end up occurring
simultaneously and the race condition is encountered. The
register read/write sequence then looks like this:

1. pwrkey probe: SPMI read(0x1311): 0x00, 0x00, 0x00
2. resin probe: SPMI read(0x1311): 0x00, 0x00, 0x00
3. pwrkey probe: SPMI write(0x1311): 0x80, 0x80, 0x80
4. resin probe: SPMI write(0x1311): 0x40, 0x40, 0x40

In this case, the final register states after both devices have
requested and enabled their respective IRQs is thus:

0x1311: 0x40
0x1312: 0x40
0x1313: 0x40
0x1314: 0x00
0x1315: 0xC0

This corresponds to the resin IRQ being configured for both
rising and falling edges, as expected. However, the pwrkey IRQ
is misconfigured as level type with both polarity high and low
set to disabled. The PMIC IRQ triggering hardware treats this
particular register configuration as if level low triggering is
enabled.

The raw pwrkey IRQ signal is low when the power key is not being
pressed. Thus, the pwrkey IRQ begins firing continuously in an
IRQ storm.

Fix the race condition by holding the spmi-pmic-arb spinlock for
the duration of the read, modify, write sequence performed in the
qpnpint_irq_set_type() function. Split the pmic_arb_read_cmd()
and pmic_arb_write_cmd() functions each into three parts so that
hardware register IO is decoupled from spinlock locking. This
allows a new function pmic_arb_masked_write() to be added which
locks the spinlock and then calls register IO functions to
perform SPMI read and write commands in a single atomic
operation.

Link: https://lore.kernel.org/r/20211118034719.28971-1-quic_collinsd@quicinc.com
Signed-off-by: David Collins <quic_collinsd@quicinc.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20211216190812.1574801-7-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Add sid and address to error messages

It's useful to know what particular device/component is having trouble
accessing the bus. Add the sid and address to error messages here so
that debugging is a little simpler.

Link: https://lore.kernel.org/r/20210920234849.3614036-1-swboyd@chromium.org
Cc: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Cc: satya priya <skakit@codeaurora.org>
Reviewed-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Reviewed-by: Satya Priya <skakit@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20211216190812.1574801-2-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: spmi-pmic-arb: Fix hw_irq overflow

Currently, when handling the SPMI summary interrupt, the hw_irq
number is calculated based on SID, Peripheral ID, IRQ index and
APID. This is then passed to irq_find_mapping() to see if a
mapping exists for this hw_irq and if available, invoke the
interrupt handler. Since the IRQ index uses an "int" type, hw_irq
which is of unsigned long data type can take a large value when
SID has its MSB set to 1 and the type conversion happens. Because
of this, irq_find_mapping() returns 0 as there is no mapping
for this hw_irq. This ends up invoking cleanup_irq() as if
the interrupt is spurious whereas it is actually a valid
interrupt. Fix this by using the proper data type (u32) for id.

Cc: stable@vger.kernel.org
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Link: https://lore.kernel.org/r/1612812784-26369-1-git-send-email-subbaram@codeaurora.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20210212031417.3148936-1-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Set lockdep class for hierarchical irq domains

I see the following lockdep splat in the qcom pinctrl driver when
attempting to suspend the device.

WARNING: possible recursive locking detected
5.4.11 #3 Tainted: G W
--------------------------------------------
cat/3074 is trying to acquire lock:
ffffff81f49804c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

but task is already holding lock:
ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&irq_desc_lock_class);
lock(&irq_desc_lock_class);

*** DEADLOCK ***

May be due to missing lock nesting notation

6 locks held by cat/3074:
#0: ffffff81f01d9420 (sb_writers#7){.+.+}, at: vfs_write+0xd0/0x1a4
#1: ffffff81bd7d2080 (&of->mutex){+.+.}, at: kernfs_fop_write+0x12c/0x1fc
#2: ffffff81f4c322f0 (kn->count#337){.+.+}, at: kernfs_fop_write+0x134/0x1fc
#3: ffffffe411a41d60 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x348
#4: ffffff81f1c5e970 (&dev->mutex){....}, at: __device_suspend+0x168/0x41c
#5: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

stack backtrace:
CPU: 5 PID: 3074 Comm: cat Tainted: G W 5.4.11 #3
Hardware name: Google Cheza (rev3+) (DT)
Call trace:
dump_backtrace+0x0/0x174
show_stack+0x20/0x2c
dump_stack+0xc8/0x124
__lock_acquire+0x460/0x2388
lock_acquire+0x1cc/0x210
_raw_spin_lock_irqsave+0x64/0x80
__irq_get_desc_lock+0x64/0x94
irq_set_irq_wake+0x40/0x144
qpnpint_irq_set_wake+0x28/0x34
set_irq_wake_real+0x40/0x5c
irq_set_irq_wake+0x70/0x144
pm8941_pwrkey_suspend+0x34/0x44
platform_pm_suspend+0x34/0x60
dpm_run_callback+0x64/0xcc
__device_suspend+0x310/0x41c
dpm_suspend+0xf8/0x298
dpm_suspend_start+0x84/0xb4
suspend_devices_and_enter+0xbc/0x620
pm_suspend+0x210/0x348
state_store+0xb0/0x108
kobj_attr_store+0x14/0x24
sysfs_kf_write+0x4c/0x64
kernfs_fop_write+0x15c/0x1fc
__vfs_write+0x54/0x18c
vfs_write+0xe4/0x1a4
ksys_write+0x7c/0xe4
__arm64_sys_write+0x20/0x2c
el0_svc_common+0xa8/0x160
el0_svc_handler+0x7c/0x98
el0_svc+0x8/0xc

Set a lockdep class when we map the irq so that irq_set_wake() doesn't
warn about a lockdep bug that doesn't exist.

Fixes: 12a9eeaebba3 ("spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips")
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200121183748.68662-1-swboyd@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284

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 version 2 and
only version 2 as published by the free software foundation this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: revert "validate type when mapping IRQ"

Validation of the IRQ type was added to spmi pmic-arb, however spmi-mpp
in device tree still uses IRQ_TYPE_NONE. This commit caused the
spmi-mpp probe to fail since platform_irq_count() would return 0.
Correct this by backing out the previous patch.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Fixes: 135ef21ab064 ("spmi: pmic-arb: validate type when mapping IRQ")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi: pmic-arb: revert "disassociate old virq if hwirq mapping already exists"

Now that spmi-gpio is a proper hierarchical IRQ chip, and all in-tree
users of device tree have been updated, we can now drop the hack that
was introduced to disassociate the old Linux virq if a hwirq mapping
already exists. That patch was introduced to not break git bisect for
any existing boards.

Driver was tested using gpio-keys and iadc/vadc on the LG Nexus 5
(hammerhead) phone.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi: pmic-arb: validate type when mapping IRQ

qpnpint_irq_domain_map did not validate the IRQ type and this can cause
IRQs to not work as expected if an unsupported type (such as
IRQ_TYPE_NONE) is passed in. Now that spmi-gpio is a hierarchical IRQ
controller, and all device tree bindings have been updated, add
additional validation to the type field.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi: pmic-arb: disassociate old virq if hwirq mapping already exists

Check to see if the hwirq is already associated with another virq on
this IRQ domain. If so, then disassociate it before associating the
hwirq with the new virq.

This is a temporary hack that is needed in order to not break git
bisect for existing boards. The next patch in this series converts
spmi-gpio to be a hierarchical IRQ chip, then there are several patches
to update all of the device tree files, and finally this patch will be
reverted within the same patch series.

IRQs for spmi-gpio are all initially setup without an IRQ hierarchy
on pmic-arb when mfd/qcom-spmi-pmic.c is probed (via the
devm_of_platform_populate call) due to the interrupts property in
device tree. Once spmi-gpio is converted to be a hierarchical IRQ chip
in the next patch, existing users of gpio[d]_to_irq() will call
pmic_gpio_to_irq(), and that will use the new IRQ chip code in
spmi-gpio that sets up the IRQ in an IRQ hierarchy. The hwirq is now
associated with two Linux virqs and interrupts will not work as
expected. This patch corrects that issue.

Driver was tested using gpio-keys and iadc/vadc on the LG Nexus 5
(hammerhead) phone.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips

Convert the spmi-pmic-arb IRQ code to use the version 2 IRQ interface
in order to support hierarchical IRQ chips. This is necessary so that
spmi-gpio can be setup as a hierarchical IRQ chip with pmic-arb as the
parent. IRQ chips in device tree should be usable from the start without
the consumer having to make an additional call to gpio[d]_to_irq() to
get the proper IRQ on the parent.

The old qpnpint_irq_domain_map function would hardcode the handler as
handle_level_irq, however qpnpint_irq_set_type would later override the
handler. Properly set the handler when the IRQ is mapped. This new code
doesn't return an error for IRQ_TYPE_NONE and preserves the existing
behavior of using handle_level_irq since there are some broken device
tree bindings that need to be corrected first.

Driver was tested on a LG Nexus 5 (hammerhead) phone.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi: pmic-arb: Move the ownership check to irq_chip callback

Check the irq ownership in the irq_request_resources callback
instead of checking it during the irq mapping. This can prevent
installing the flow handler for the interrupt that is not owned by the EE
and allow the irq translation during the gpio driver probe.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Tested-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Remove checking opc value not less than 0

The opc parameter in pmic_arb_write_cmd() function is defined with type
u8 and it's always greater than or equal to 0. Checking that it's not
less than 0 is redundant and it can cause a forbidden warning during
compilation. Remove the check.

Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: add support for HW version 5

Add support for version 5 of the SPMI PMIC arbiter. It utilizes
different offsets for registers than those found on version 3.
Also, the procedure to determine if writing and IRQ access is
allowed for a given PPID changes for version 5.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: fix a possible null pointer dereference

If "core" memory resource is not specified, then the driver could
end up dereferencing a null pointer. Fix this issue.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: return __iomem pointer instead of offset

Modify the pmic_arb version ops to return an __iomem pointer
to the address instead of an offset. That way we do not need to
care about the base address changes in the new HW version.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: use irq_chip callback to set spmi irq wakeup capability

Currently the driver sets the pmic arbiter core interrupt as wakeup capable
irrespective of the child irqs which causes the system to wakeup
unnecessarily. To fix this, set the core interrupt as wakeup capable
only if any of the child irqs request for it. Do this by marking it as
wakeup capable in the irq_set_wake callback.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: return the value instead of passing by pointer

Returning the output value from a function, when it is possible, is the
better and cleaner way than passing it by the pointer. Hence, modify
the ppid_to_apid mapping function to return apid instead of passing
it by a pointer. While at it, pass the ppid as function parameter to
ppid_to_apid mapping function instead of passing the sid and addr.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: replace the writel_relaxed with __raw_writel

Replace the writel_relaxed with __raw_writel to avoid byte swapping
in pmic_arb_write_data() function. That way the code is independent
of the CPU endianness.

Fixes: 111a10bf3e53 ("spmi: pmic-arb: rename spmi_pmic_arb_dev to
spmi_pmic_arb")
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: fix memory allocation for mapping_table

Allocate the correct memory size (max_pmic_peripherals) for the
mapping_table that holds the apid to ppid mapping. Also use a local
variable for mapping_table for better alignment of the code.

Fixes: 987a9f128b8a ("spmi: pmic-arb: Support more than 128 peripherals")
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: optimize qpnpint_irq_set_type function

Optimize the qpnpint_irq_set_type() by using a local variable
to hold the handler type. Also clean up other variable usage.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: clean up pmic_arb_find_apid function

Clean up the pmic_arb_find_apid() by using the local
variables to improve the code readability.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: rename pa_xx to pmic_arb_xx and other cleanup

This patch cleans up the following.

- Rename the "pa" to "pmic_arb".
- Rename the spmi_pmic_arb *dev to spmi_pmic_arb *pmic_arb.
- Rename the pa_{read,write}_data() functions to
pmic_arb_{read,write}_data().
- Rename channel to APID.
- Rename the HWIRQ_*() macros to hwirq_to_*().

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: remove the read/write access checks

The access mode checks for peripheral ownership for read/write
permissions should not be required. Every peripheral enabled for
this master is expected to have a read/write permissions. If there
is any such invalid access due to wrong configuration in boot loader
or device tree files, then it should be fixed in those locations.
Hence, remove the access mode checks from the driver.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Always allocate ppid_to_apid table

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 <adharmap@codeaurora.org>
Cc: Kiran Gunda <kgunda@codeaurora.org>
Fixes: 7f1d4e58dabb ("spmi: pmic-arb: optimize table lookups")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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

Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic_arb: add support for PMIC bus arbiter v3

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

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic_arb: use appropriate flow handler

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: fix missing interrupts

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: cleanup unrequested irqs

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: optimize table lookups

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 <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: fix inconsistent use of apid and chan

The driver currently uses "apid" and "chan" to mean apid. Remove
the use of chan and use only apid.

On a SPMI bus there is allocation to manage up to 4K peripherals.
However, in practice only few peripherals are instantiated
and only few among the instantiated ones actually interrupt.

APID is CPU's way of keeping track of peripherals that could interrupt.
There is a table that maps the 256 interrupting peripherals to
a number between 0 and 255. This number is called APID. Information about
that interrupting peripheral is stored in registers offset by its
corresponding apid.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: rename spmi_pmic_arb_dev to spmi_pmic_arb

Usually *_dev best used for structures that embed a struct device in
them. spmi_pmic_arb_dev doesn't embed one. It is simply a driver data
structure. Use an appropriate name for it.

Also there are many places in the driver that left shift the bit to
generate a bit mask. Replace it with the BIT() macro.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic_arb: block access of invalid read and writes

The system crashes due to bad access when reading from an non configured
peripheral and when writing to peripheral which is not owned by current
ee. This patch verifies ownership to avoid crashing on
write.
For reads, since the forward mapping table, data_channel->ppid, is
towards the end of the block, we use the core size to figure the
max number of ppids supported. The table starts at an offset of 0x800
within the block, so size - 0x800 will give us the area used by the
table. Since each table is 4 bytes long (core_size - 0x800) / 4 will
gives us the number of data_channel supported.
This new protection is functional on hw v2.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Return an error code if sanity check fails

If the test 'if (channel > 5)' is true, then we will return 'err' which
is known to be 0 at this point.
Return -EINVAL instead.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Support more than 128 peripherals

Add support for more than 128 peripherals by taking a lazy
caching approach to the mapping tables. Instead of reading and
caching the tables at boot given some fixed size, read them and
cache them on an as needed basis. We still assume a max size of
512 peripherals, trading off some space for simplicity.

Based on a patch by Gilad Avidov <gavidov@codeaurora.org> and
Sagar Dharia <sdharia@codeaurora.org>.

Cc: Gilad Avidov <gavidov@codeaurora.org>
Cc: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

irqdomain: Use irq_domain_get_of_node() instead of direct field access

The struct irq_domain contains a "struct device_node *" field
(of_node) that is almost the only link between the irqdomain
and the device tree infrastructure.

In order to prepare for the removal of that field, convert all
users to use irq_domain_get_of_node() instead.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

spmi: pmic-arb: u8 <= 0xff is always true

Silences this static checker warning:

drivers/spmi/spmi-pmic-arb.c:363
pmic_arb_write_cmd() warn: always true condition
'(opc <= 255) => (0-255 <= 255)'

Cc: Andy Gross <agross@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: pmic-arb: Don't byte swap when reading/writing FIFO

We don't want to swap bytes that we're reading and writing to the
FIFOs when we're running on a big-endian CPU. Doing so causes
problems like where the qcom-spmi-iadc driver can't detect the
type of device because the bytes are all mixed up. Use the raw IO
accessors for these API instead, and collapse pmic_arb_base_read()
into the byte reading API so that we aren't tempted to read non-FIFO
data like commands with that function.

Cc: Andy Gross <agross@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

genirq: Remove irq argument from irq flow handlers

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>

spmi: pmic-arb: add support for irq_get_irqchip_state

Reviewed-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Tested-by: Tim Bird <tim.bird@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi/pmic: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20150713151750.915477120@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

spmi/pmic_arb: Consolidate chained IRQ handler install/remove

Chained irq handlers usually set up handler data as well. We now have
a function to set both under irq_desc->lock. Replace the two calls
with one.

Search and conversion was done with coccinelle.

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Link: http://lkml.kernel.org/r/20150713151750.831790045@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

spmi: pmic_arb: add support for hw version 2

Qualcomm PMIC Arbiter version-2 changes from version-1 are:

- Some different register offsets.
- New channel register space, one per PMIC peripheral (ppid).
All tx traffic uses these channels.
- New observer register space. All rx trafic uses this space.
- Different command format for spmi command registers.

Reviewed-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

spmi: pmic_arb: add support for interrupt handling

The Qualcomm PMIC Arbiter, in addition to being a basic SPMI controller,
also implements interrupt handling for slave devices. Note, this is
outside the scope of SPMI, as SPMI leaves interrupt handling completely
unspecified.

Extend the driver to provide a irq_chip implementation and chained irq
handling which allows for these interrupts to be used.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spmi: Add MSM PMIC Arbiter SPMI controller

Qualcomm's PMIC Arbiter SPMI controller functions as a bus master and
is used to communication with one or more PMIC (slave) devices on the
SPMI bus. The PMIC Arbiter is actually a hardware wrapper around the
SPMI controller that provides concurrent and autonomous PMIC access
to various entities that need to communicate with the PMIC.

The SPMI controller hardware handles all of the SPMI bus activity (bus
arbitration, sequence start condition, transmission of frames, etc).
This software driver uses the PMIC Arbiter register interface to
initiate command sequences on the SPMI bus. The status register is
read to determine when the command sequence has completed and whether
or not it completed successfully.

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>