regulator: ti-abb: don't use devm_platform_ioremap_resource_byname for shared interrupt register

We can't use devm_platform_ioremap_resource_byname() to remap the
interrupt register that can be shared between
regulator-abb-{ivahd,dspeve,gpu} drivers instances.

The combined helper introduce a call to devm_request_mem_region() that
creates a new busy resource region on PRM_IRQSTATUS_MPU register
(0x4ae06010). The first devm_request_mem_region() call succeeds for
regulator-abb-ivahd but fails for the two other regulator-abb-dspeve
and regulator-abb-gpu.

# cat /proc/iomem | grep -i 4ae06
4ae06010-4ae06013 : 4ae07e34.regulator-abb-ivahd int-address
4ae06014-4ae06017 : 4ae07ddc.regulator-abb-mpu int-address

regulator-abb-dspeve and regulator-abb-gpu are missing due to
devm_request_mem_region() failure (EBUSY):

[ 1.326660] ti_abb 4ae07e30.regulator-abb-dspeve: can't request region for resource [mem 0x4ae06010-0x4ae06013]
[ 1.326660] ti_abb: probe of 4ae07e30.regulator-abb-dspeve failed with error -16
[ 1.327239] ti_abb 4ae07de4.regulator-abb-gpu: can't request region for resource [mem 0x4ae06010-0x4ae06013]
[ 1.327270] ti_abb: probe of 4ae07de4.regulator-abb-gpu failed with error -16

>From arm/boot/dts/dra7.dtsi:

The abb_mpu is the only instance using its own interrupt register:
(0x4ae06014) PRM_IRQSTATUS_MPU_2, ABB_MPU_DONE_ST (bit 7)

The other tree instances (abb_ivahd, abb_dspeve, abb_gpu) share
PRM_IRQSTATUS_MPU register (0x4ae06010) but use different bits
ABB_IVA_DONE_ST (bit 30), ABB_DSPEVE_DONE_ST( bit 29) and
ABB_GPU_DONE_ST (but 28).

The commit b36c6b1887ff ("regulator: ti-abb: Make use of the helper
function devm_ioremap related") overlooked the following comment
implicitly explaining why devm_ioremap() is used in this case:

/*
* We may have shared interrupt register offsets which are
* write-1-to-clear between domains ensuring exclusivity.
*/

Fixes and partially reverts commit b36c6b1887ff ("regulator: ti-abb:
Make use of the helper function devm_ioremap related").

Improve the existing comment to avoid further conversion to
devm_platform_ioremap_resource_byname().

Fixes: b36c6b1887ff ("regulator: ti-abb: Make use of the helper function devm_ioremap related")
Signed-off-by: Romain Naour <romain.naour@skf.com>
Reviewed-by: Yoann Congal <yoann.congal@smile.fr>
Link: https://msgid.link/r/20240123111456.739381-1-romain.naour@smile.fr
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Use device_get_match_data()

Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231017203442.2699322-1-robh@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that existed in 4.14

Probing of regulators can be a slow operation and can contribute to
slower boot times. This is especially true if a regulator is turned on
at probe time (with regulator-boot-on or regulator-always-on) and the
regulator requires delays (off-on-time, ramp time, etc).

While the overall kernel is not ready to switch to async probe by
default, as per the discussion on the mailing lists [1] it is believed
that the regulator subsystem is in good shape and we can move
regulator drivers over wholesale. There is no way to just magically
opt in all regulators (regulators are just normal drivers like
platform_driver), so we set PROBE_PREFER_ASYNCHRONOUS for all
regulators found in 'drivers/regulator' individually.

Given the number of drivers touched and the impossibility to test this
ahead of time, it wouldn't be shocking at all if this caused a
regression for someone. If there is a regression caused by this patch,
it's likely to be one of the cases talked about in [1]. As a "quick
fix", drivers involved in the regression could be fixed by changing
them to PROBE_FORCE_SYNCHRONOUS. That being said, the correct fix
would be to directly fix the problem that caused the issue with async
probe.

The approach here follows a similar approach that was used for the mmc
subsystem several years ago [2]. In fact, I ran nearly the same python
script to auto-generate the changes. The only thing I changed was to
search for "i2c_driver", "spmi_driver", and "spi_driver" in addition
to "platform_driver".

[1] https://lore.kernel.org/r/06db017f-e985-4434-8d1d-02ca2100cca0@sirena.org.uk
[2] https://lore.kernel.org/r/20200903232441.2694866-1-dianders@chromium.org/

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230316125351.1.I2a4677392a38db5758dee0788b2cea5872562a82@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: of: Fix kernel-doc

drivers/regulator/ti-abb-regulator.c:161: warning: expecting prototype for ti_abb_wait_tranx(). Prototype was for ti_abb_wait_txdone() instead.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2206
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220919024830.111874-2-jiapeng.chong@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_320.RULE

Based on the normalized pattern:

this program is free software you can redistribute it and/or modify it
under the terms of the gnu general public license version 2 as
published by the free software foundation this program is distributed
as is without any warranty of any kind whether express or implied
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.

Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

regulator: Fix parameter declaration and spelling mistake.

Use Complete data type declaration of 'sel' in ti_abb_set_voltage_sel().
Fix spelling of 'are'nt' in comments.

Signed-off-by: Zhang Jiaming <jiaming@nfschina.com>
Link: https://lore.kernel.org/r/20220705071445.21124-1-jiaming@nfschina.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: cleanup comments

For spdx
Remove leading space, add space after //

Replacements
overriden to overridden
Calulate to Calculate
addional to additional
regulatior to regulator
devive to device

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220305162438.689442-1-trix@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ti-abb: Make use of the helper function devm_ioremap related

Use the devm_platform_ioremap_resource_byname() helper instead of
calling platform_get_resource_byname() and devm_ioremap/devm_ioremap_resource()
separately

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20210908105745.1984-1-caihuoqing@baidu.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ti-abb: Fix array out of bound read access on the first transition

At the start of driver initialization, we do not know what bias
setting the bootloader has configured the system for and we only know
for certain the very first time we do a transition.

However, since the initial value of the comparison index is -EINVAL,
this negative value results in an array out of bound access on the
very first transition.

Since we don't know what the setting is, we just set the bias
configuration as there is nothing to compare against. This prevents
the array out of bound access.

NOTE: Even though we could use a more relaxed check of "< 0" the only
valid values(ignoring cosmic ray induced bitflips) are -EINVAL, 0+.

Fixes: 40b1936efebd ("regulator: Introduce TI Adaptive Body Bias(ABB) on-chip LDO driver")
Link: https://lore.kernel.org/linux-mm/CA+G9fYuk4imvhyCN7D7T6PMDH6oNp6HDCRiTUKMQ6QXXjBa4ag@mail.gmail.com/
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20201118145009.10492-1-nm@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: ti-abb: Constify ti_abb_reg_ops

The only usage of ti_abb_reg_ops is to assign its address to the ops
field in the regulator_desc struct, which is a const pointer. Make it
const to allow the compiler to put it in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200913084114.8851-6-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

remove ioremap_nocache and devm_ioremap_nocache

ioremap has provided non-cached semantics by default since the Linux 2.6
days, so remove the additional ioremap_nocache interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>

regulator: ti-abb: Fix timeout in ti_abb_wait_txdone/ti_abb_clear_all_txdone

ti_abb_wait_txdone() may return -ETIMEDOUT when ti_abb_check_txdone()
returns true in the latest iteration of the while loop because the timeout
value is abb->settling_time + 1. Similarly, ti_abb_clear_all_txdone() may
return -ETIMEDOUT when ti_abb_check_txdone() returns false in the latest
iteration of the while loop. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20190929095848.21960-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: devm_kzalloc() -> devm_kcalloc()

The devm_kzalloc() function has a 2-factor argument form, devm_kcalloc().
This patch replaces cases of:

devm_kzalloc(handle, a * b, gfp)

with:
devm_kcalloc(handle, a * b, gfp)

as well as handling cases of:

devm_kzalloc(handle, a * b * c, gfp)

with:

devm_kzalloc(handle, array3_size(a, b, c), gfp)

as it's slightly less ugly than:

devm_kcalloc(handle, array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

devm_kzalloc(handle, 4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

Some manual whitespace fixes were needed in this patch, as Coccinelle
really liked to write "=devm_kcalloc..." instead of "= devm_kcalloc...".

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
expression HANDLE;
type TYPE;
expression THING, E;
@@

(
devm_kzalloc(HANDLE,
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
devm_kzalloc(HANDLE,
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression HANDLE;
expression COUNT;
typedef u8;
typedef __u8;
@@

(
devm_kzalloc(HANDLE,
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(char) * COUNT
+ COUNT
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
expression HANDLE;
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
expression HANDLE;
identifier SIZE, COUNT;
@@

- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression HANDLE;
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
devm_kzalloc(HANDLE,
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression HANDLE;
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
devm_kzalloc(HANDLE,
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
devm_kzalloc(HANDLE,
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
expression HANDLE;
identifier STRIDE, SIZE, COUNT;
@@

(
devm_kzalloc(HANDLE,
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
devm_kzalloc(HANDLE,
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression HANDLE;
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
devm_kzalloc(HANDLE,
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
devm_kzalloc(HANDLE,
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
devm_kzalloc(HANDLE,
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
devm_kzalloc(HANDLE,
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression HANDLE;
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
devm_kzalloc(HANDLE, sizeof(THING) * C2, ...)
|
devm_kzalloc(HANDLE, sizeof(TYPE) * C2, ...)
|
devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
devm_kzalloc(HANDLE, C1 * C2, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- (E1) * E2
+ E1, E2
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- (E1) * (E2)
+ E1, E2
, ...)
|
- devm_kzalloc
+ devm_kcalloc
(HANDLE,
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

regulator: of: Add regulator desc param to of_get_regulator_init_data()

The of_get_regulator_init_data() function is used to extract the regulator
init_data but information on how to extract certain data is defined in the
static regulator descriptor (e.g: how to map the hardware operating modes).

Add a const struct regulator_desc * parameter to the function signature so
the parsing logic could use the information in the struct regulator_desc.

of_get_regulator_init_data() relies on of_get_regulation_constraints() to
actually extract the init_data so it has to pass the struct regulator_desc
but that is modified on a later patch.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: 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>

regulator: ti-abb: Remove redundant error message

kzalloc prints its own OOM message upon failure.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Do not hardcode return value

Propagate the error value returned by the function instead.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb-regulator: do not open-code counting and access of dt array elements

Open coding the counting of elements in a dt-property is abstracted by the newly
introduced of_property_count_uXX_elems functions. Additionally the raw iteration
over the states element exposes the endian conversion and dtb-format details,
which according to Mark Rutland "would be nice to limit [...] to of_ helper
functions".

Thus change ti-abb-regulator to use the helper for element counting and
of_property_read_u32_index for retrieval of individual values.

This makes it possible to remove the raw access to the property entirely.

Signed-off-by: Heiko Stuebner <heiko.stuebner@bqreaders.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Add support for interleaved LDO registers

Certain platforms such as DRA7 have quirky memory maps such as:
PRM_ABBLDO_DSPEVE_CTRL 0x4ae07e20
PRM_ABBLDO_IVA_CTRL 0x4ae07e24
other-registers
PRM_ABBLDO_DSPEVE_SETUP 0x4ae07e30
PRM_ABBLDO_IVA_SETUP 0x4ae07e34

These need the address range allocation to be either not reserved OR
unique allocation per register instance or use something like syscon
based solution.

By going with unique allocation per register, we are able to now have
a single compatible driver for all instances on all platforms which
use the IP block.

So, introduce a new "ti,abb-v3" compatible to allow for definitions
where explicit register definitions are provided, while maintaining
backward compatibility of older predefined register offsets provided
by "ti-abb-v1" and "ti-abb-v2".

As part of this change, we rename a few variables to indicate the
appropriate meaning.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Fix operator precedence typo

commit 40b1936e (regulator: Introduce TI Adaptive Body Bias(ABB) on-chip
LDO driver) missed a pair of brackets which cause the wrong vset data to be
picked up from efuse, resulting in bad VBB voltage values.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

regulator: ti-abb: skip optional parameter for ldo-address

On platforms like OMAP4460, LDO override is never used. Even though
efuse determines the ABB bias mode to operate at, ABB voltage is
preconfigured in internal efuse registers without the need for
LDO override for bias voltage. So skip optional parameter if
property is not present.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Fix bias voltage glitch in transition to bypass mode

As documented in Application Note SWPA117 v2.1(NDA), LDO override has a
requirement that when switching from Bias active + override active
mode(FBB/RBB) to Bypass(nominal) mode, LDO reset must be performed
*after* LDO transitions to Bypass(nominal) mode.

The same rule in reverse applies when switching from a ABB bypass mode
to ABB enabled - LDO override *must* be performed prior to transition to
required ABB mode, if we do not do that, the same glitch takes place.

Currently while transitioning to ABB bypass, we reset the LDO overide
prior to the transition which causes a few milliseconds where ABB LDO
voltage could go all the way to 800mV(based on SoC process node),
during this period, the delta voltage between VDD rail and VBB rail
could cause the system to improperly function.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

regulator: ti-abb: Use devm_regulator_register

devm_* simplifies the code.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: simplify platform_get_resource_byname/devm_ioremap_resource

Remove unneeded error handling on the result of a call to
platform_get_resource_byname when the value is passed to devm_ioremap_resource.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression pdev,res,e,e1;
expression ret != 0;
identifier l;
@@

res = platform_get_resource_byname(...);
- if (res == NULL) { ... \(goto l;\|return ret;\) }
e = devm_ioremap_resource(e1, res);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Convert to use devm_ioremap_resource

Commit 75096579c3ac ("lib: devres: Introduce devm_ioremap_resource()")
introduced devm_ioremap_resource() and deprecated the use of
devm_request_and_ioremap().

While at it, remove the error message as devm_ioremap_resource prints a similar
error message.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator: ti-abb: Fix off-by-one valid range checking for abb->current_info_idx

abb->current_info_idx is used as array subscript to access volt_table,
thus the valid value range should be 0 ... desc->n_voltages - 1.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regulator: Introduce TI Adaptive Body Bias(ABB) on-chip LDO driver

Adaptive Body Biasing (ABB) modulates transistor bias voltages
dynamically in order to optimize switching speed versus leakage.

Texas Instruments' SmartReflex 2 technology provides support for this
power management technique with Forward Body Biasing (FBB) and Reverse
Body Biasing (RBB). These modulate the body voltage of transistor
cells or blocks dynamically to gain performance and reduce leakage.
TI's SmartReflex white paper[1] has further information for usage in
conjunction with other power management techniques.

The application of FBB/RBB technique is determined for each unique
device in some process nodes, whereas, they are mandated on other
process nodes.

In a nutshell, ABB technique is implemented on TI SoC as an on-chip
LDO which has ABB module controlling the bias voltage. However, the
voltage is unique per device. These vary per SoC family and the manner
in which these techniques are used may vary depending on the Operating
Performance Point (OPP) voltage targeted. For example:
OMAP3630/OMAP4430: certain OPPs mandate usage of FBB independent of
devices.
OMAP4460/OMAP4470: certain OPPs mandate usage of FBB, while others may
optionally use FBB or optimization with RBB.
OMAP5: ALL OPPs may optionally use ABB, and ABB biasing voltage is
influenced by vset fused in s/w and requiring s/w override of
default values.

Further, two generations of ABB module are used in various TI SoCs.
They have remained mostly register field compatible, however the
register offset had switched between versions.

We introduce ABB LDO support in the form of a regulator which is
controlled by voltages denoting the desired Operating Performance
Point which is targeted. However, since ABB transition is part of OPP
change sequence, the sequencing required to ensure sane operation
w.r.t OPP change is left to the controlling driver (example: cpufreq
SoC driver) using standard regulator operations.

The driver supports all ABB modes and ability to override ABB LDO vset
control efuse based ABB mode detection etc.

Current implementation is heavily influenced by the original patch
series [2][3] from Mike Turquette. However, the current implementation
supports only device tree based information.

[1] http://www.ti.com/pdfs/wtbu/smartreflex_whitepaper.pdf
[2] http://marc.info/?l=linux-omap&m=134931341818379&w=2
[3] http://marc.info/?l=linux-arm-kernel&m=134931402406853&w=2

[nm@ti.com: co-developer]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrii.Tseglytskyi <andrii.tseglytskyi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>