power: supply: core: add power_supply_for_each_device()

Introduce power_supply_for_each_device(), which is a wrapper
for class_for_each_device() using the power_supply_class and
going through all devices.

This allows making the power_supply_class itself a local
variable, so that drivers cannot mess with it and simplifies
the code slightly.

Reviewed-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240301-psy-class-cleanup-v1-1-aebe8c4b6b08@collabora.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: core: make power_supply_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the power_supply_class structure to be declared at build
time placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240301-class_cleanup-power-v1-1-97e0b7bf9c94@marliere.net
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500_chargalg: 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 ignored (apart
from emitting a warning) 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. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

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

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230918133700.1254499-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Set typing and props

I had the following weird phenomena on a mobile phone: while
the capacity in /sys/class/power_supply/ab8500_fg/capacity
would reflect the actual charge and capacity of the battery,
only 1/3 of the value was shown on the battery status
indicator and warnings for low battery appeared.

It turns out that UPower, the Freedesktop power daemon,
will average all the power supplies of type "battery" in
/sys/class/power_supply/* if there is more than one battery.

For the AB8500, there was "battery" ab8500_fg, ab8500_btemp
and ab8500_chargalg. The latter two don't know anything
about the battery, and should not be considered. They were
however averaged and with the capacity of 0.

Flag ab8500_btemp and ab8500_chargalg with type "unknown"
so they are not averaged as batteries.

Remove the technology prop from ab8500_btemp as well, all
it does is snoop in on knowledge from another supply.

After this the battery indicator shows the right value.

Cc: Stefan Hansson <newbyte@disroot.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: remove unused static local variable

cpp_check reports
[drivers/power/supply/ab8500_chargalg.c:493]: (style) Variable 'ab8500_chargalg_ex_ac_enable_toggle' is assigned a value that is never used.

From inspection, this variable is never used. So remove it.

Fixes: 6c50a08d9dd3 ("power: supply: ab8500: Drop external charger leftovers")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Chen Lifu <chenlifu@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Remove unused struct ab8500_chargalg_sysfs_entry

After commit 75ee3f6f0c1a("power: supply: ab8500_chargalg: Drop enable/disable
sysfs"), no one use struct ab8500_chargalg_sysfs_entry, so remove it.

Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Remove flush_scheduled_work() call.

It seems to me that ab8500 driver is using dedicated workqueues and
is not calling schedule{,_delayed}_work{,_on}(). Then, there will be
no work to flush using flush_scheduled_work().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Drop external charger leftovers

Some leftover code for external chargers only used with
unreleased ASIC revisions and the header file for the
unsupported PM2301 was left behind in an earlier cleanup,
fix it by deleting the remnants.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Exit maintenance if too low voltage

The maintenance charging is supposedly designed such that the
maintenance current compensates for the battery discharge curve,
and as the charging progress from CC/CV -> maintenance A ->
maintenance B states, we end up on a reasonable voltage to
restart ordinary CC/CV charging after the safety timer at the
maintenance B state exits.

However: old batteries discharge quicker, and in an old
battery we might not get to the expiration of the maintenance B
timer before the battery is completely depleted and the system
powers off with an empty battery.

This is hardly the desire of anyone leaving their phone in the
charger for a few days!

Introduce a second clause in both maintenance states such that
we exit the state and return to ordinary CC/CV charging if
the voltage drops below charge_restart_voltage_uv or 95%
if this is not defined for the battery.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Respect charge_restart_voltage_uv

The battery info contains a voltage indicating when the voltage
is so low that it is time to restart the CC/CV charging.
Make the AB8500 respect and prioritize this setting over the
hardcoded 95% threshold.

Break out the check into its own function and add some safeguards
so we do not run into unpredictable side effects.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power_supply: ab8500: use default_groups in kobj_type

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the ab8500 power supply sysfs code to use default_groups
field which has been the preferred way since aa30f47cf666 ("kobject: Add
support for default attribute groups to kobj_type") so that we can soon
get rid of the obsolete default_attrs field.

Cc: Sebastian Reichel <sre@kernel.org>
Cc: linux-pm@vger.kernel.org
Link: https://lore.kernel.org/r/20211229140908.2523513-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

power: ab8500_chargalg: Use CLOCK_MONOTONIC

The HRTimer in the AB8500 charging code is using CLOCK_REALTIME
to set an alarm some hours forward in time +/- 5 min for a safety
timer.

I have observed that this will sometimes fire sporadically
early when charging a battery with the result that
charging stops.

As CLOCK_REALTIME can be subject to adjustments of time from
sources such as NTP, this cannot be trusted and will likely
for example fire events if the clock is set forward some hours
by say NTP.

Use CLOCK_MONOTONIC as indicated in other instances and the
problem goes away. Also initialize the timer to REL mode
as this is what will be used later.

Fixes: 257107ae6b9b ("ab8500-chargalg: Use hrtimer")
Cc: Lee Jones <lee.jones@linaro.org>
Suggested-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Remove unused variable

Kernel test robot reported below warning ->
drivers/power/supply/ab8500_chargalg.c:790:13: warning:
variable 'delta_i_ua' set but not used [-Wunused-but-set-variable]

Remove unused variable delta_i_ua.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: fix a handful of spelling mistakes

There are a few spelling mistakes in comments and in a dev_err
error message. Fix them.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize alert mode charging

The AB8500 code is using a special current and voltage setting
when the battery is in "alert mode", i.e. when it is starting
to go outside normal operating conditions so it is too
cold or too hot. This makes sense as a way for the charging
algorithm to deal with hostile environments.

Add the needed members to the struct power_supply_battery_info,
and switch the AB8500 charging code over to using this.

Reviewed-by: Matti Vaittineen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize maintenance charging

Maintenance charging is the phase of keeping up the charge
after the battery has charged fully using CC/CV charging.

This can be done in many successive phases and is usually
done with a slightly lower constant voltage than CV, and
a slightly lower allowed current.

Add an array of maintenance charging points each with a
current, voltage and safety timer, and add helper functions
to use these. Migrate the AB8500 code over.

This is used in several Samsung products using the AB8500
and these batteries and their complete parameters will
be added later as full examples, but the default battery
in the AB8500 code serves as a reasonable example so far.

Reviewed-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500_chargalg: Drop enable/disable sysfs

There is a sysfs ABI to enable/disable charging of different
types (AC/USB).

Since we don't have any userspace for this code, this sits
unused and it is not used on production products either.

Drop this code.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500_chargalg: Drop charging step

There is a sysfs ABI to change the "charging step" of the
charger i.e. limit how much we charge from userspace.

Since we don't have any userspace for this code, this sits
unused and it is not used on production products either.

Drop this code.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Swap max and overvoltage

We should terminate charging when we reach the voltage_max_design_uv
not overvoltage_limit_uv, this is an abuse of that struct member.

The overvoltage limit is actually not configurable on the AB8500,
it is fixed to 4.75 V so drop a comment about that in the code.

Fixes: 2a5f41830aad ("power: supply: ab8500: Standardize voltages")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply_core: Pass pointer to battery info

The function to retrieve battery info (from the device tree) assumes
we have a static info struct that gets populated by calling into
power_supply_get_battery_info().

This is awkward since I want to support tables of static battery
info by just assigning a pointer to all info based on e.g. a
compatible value in the device tree.

We also have a mixture of static and dynamically allocated
variables here.

Bite the bullet and let power_supply_get_battery_info() allocate
also the memory used for the very top level
struct power_supply_battery_info container. Pass pointers
around and lifecycle this with the psy device just like the
stuff we allocate inside it.

Change all current users over.

As part of the change, initializers need to be added to some
previously uninitialized fields in struct
power_supply_battery_info.

Reviewed-By: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize CV voltage

The voltage used in the constant voltage phase of the charging
exist in struct power_supply_battery_info as
constant_charge_voltage_max_uv.

Switch the custom property normal_vol_lvl to this and
consequentially change everything that relates to this value
over to using microvolts rather than millivolts so
we align internal representation of current with the
power core. Prefix every variable we change with *_uv
to indicate the unit everywhere but also to make sure
we do not miss any outlier.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize CC current

The current used in the constant current phase of the charging
exist in struct power_supply_battery_info as
constant_charge_current_max_ua.

Switch the custom property max_out_curr to this and
consequentally change everything that relates to this value
over to using microamperes rather than milliamperes so
we align internal representation of current with the
power core. Prefix every variable we change with *_ua
to indicate the unit everywhere but also to make sure
we do not miss any outlier.

Drop some duplicate unused defines in a header.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Make recharge capacity a constant

The recharge capacity is the hysteresis level for a charger to
restart when a battery does not support maintenance charging.

All products using the AB8500 have batteries supporting
maintenace charging and all code has always set this to 95%.

Turn it into a constant.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize termination current

The AB8500 custom termination current can be replaced by the
corresponding struct power_supply_battery_info field.

Remove the struct member and amend the code to use the
standard property.

Add *_ua suffix for clarity and to make sure we have
changed all code sites using this member.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize voltages

The nominal voltage in this charge driver corresponds to
both the voltage_min_design_uv and voltage_max_design_uv
of struct power_supply_battery_info so assign both if this
is undefined.

The overcharge max voltage (when the charger should cut off)
is migrated at the same time so we move both voltages to
struct power_supply_battery_info.

Adjust the code to deal directly with the microvolt values
instead of converting them to millivolts.

Add *_uv suffixes for clarity and to make sure we have
changed all code sites using this member.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Use only one battery type

The code was going through hoops and loops to detect what
battery is connected and check the resistance for this battery
etc.

Skip this trouble: we will support one battery (currently
"unknown") then we will find the connected battery in the
device tree using a compatible string. The battery resistance
may be used to double-check that the right battery is
connected.

Convert the array of battery types into one battery type so
we can next move over the properties of this one type into
the standard struct power_supply_battery_info.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Standardize operating temperature

Instead of storing the temperature limits in our custom
struct struct ab8500_bm_data, make struct power_supply_battery_info
a member of this and store the min and max temperatures inside
that struct as the temp_min/temp_max and
temp_alert_min/temp_alert_max respectively.

The values can be assigned from the device tree, but if
not present will be set to the same defaults as are currently
in the code.

This way we start to move over to using
struct power_supply_battery_info and make it possible to move
the data over to the device tree and we will move piece by
piece toward using the standard info struct.

Temperature hysteresis is currently not supported by the
standard struct but we move the assignment here as well so
that we have all parameterization in one spot.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: clean up warnings found by checkpatch

Clean up a handful of checkpatch warnings:
- static const char * array should probably be static const char * const
- function arguments should have identifier names
- else should follow close brace '}'
- suspect code indent for conditional statements
- unnecessary parentheses in an if condition
- avoid multiple line dereference
- remove debug showing function execution, ftrace can trace these better
- prefer 'long' over 'long int' as the int is unnecessary

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Rename charging algorithm psy

If we rename the "abx500_chargalg" supply to "ab8500_chargalg"
as it should be named, the existing supplies are supplying that
supply but that was obviously not working since it had the
wrong name.

Now that the dependency kicks in we get a bunch
of NULL references from ab8500_chargalg_external_power_changed()
so check that the workqueue is allocated before we try to
queue work on it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Drop abx500 concept

Drop the entire idea with abx500 being abstract and different from ab8500
in the AB8500 charging drivers. This rids the two identical definitions
of a slew of structs in ab8500-bm.h and makes things less confusion and
easier to understand.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: ab8500: Rename charging algorithm symbols

The "abx500" name on the charging algorithm stems from the ambition
to produce a series of these analog basebands, re-using the same
charging algorithm driver. No ASICs beside AB8500 and AB8505 were
ever produced so this terminology is confusing. Rename the
algorithm file and symbols to reflect the more narrow scope.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>