power: supply: ab8500: Standardize BTI resistance

The Battery Type Indicator (BTI) resistor is a resistor mounted
between a special terminal on the battery and ground. By sending
a fixed current (such as 7mA) through this resistor and measuring
the voltage over it, the resistance can be determined, and this
verifies the battery type.

Typical side view of the battery:

o o o
GND BTI +3.8V

Typical example of the electrical layout:

+3.8 V BTI
| |
| + |
_______ [ ] 7kOhm
___ |
| |
| |
GND GND

By verifying this resistance before attempting to charge the
battery we add an additional level of security.

In some systems this is used for plug-and-play of batteries with
different capacity. In other cases, this is merely used to verify
that the right type of battery is connected, if several batteries
have the same physical shape and can be plugged into the same
slot. Sometimes this is just a surplus security mechanism.

Nokia and Samsung among many other vendors are known to use these
BTI resistors.

Add the BTI properties to struct power_supply_battery_info and
switch the AB8500 charger code over to using it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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: Integrate thermal zone

Instead of providing our own homebrewn thermal measurement
code for an NTC and passing tables, we put the NTC thermistor
into the device tree, create a passive thermal zone, and poll
this thermal zone for the temperature.

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

power: supply: ab8500: Drop BATCTRL thermal mode

The BATCTRL mode reads the temperature of the battery by
enabling a certain probing current (7-20 mA) and then measure
the voltage of the NTC mounted inside the battery.

None of the AB8500 product or the reference designs use this
mode. What we use is the so-called BATTEMP mode which enables
an internal 230 kOhm pull-up to 1.8 V to the external NTC on
pin BatTemp (N16) and then measures the voltage over the NTC
using the ADC:

1.8V (VTVOUT)
|
[ ] 230 kOhm
|
BatTemp +---------------- ADC
Pin N16 | _
|/
[/] NTC
_/|
|
GND

Cut out the BATCTRL code to clear the forest and stop
maintaining code we can never test.

The current inducing method is still used to probe for the
battery type using the internal BTI (battery type indicator)
on the BatCtrl (C3) pin in a separate code path.

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 capacity lookup

The AB8500 charger only has one capacity table with
unspecified temperature, so we assume this capacity is given
for 20 degrees Celsius.

Convert this table to use the OCV (open circuit voltage)
tables in struct power_supply_battery_ocv_table.

In the process, convert the fuel gauge driver to use
microvolts and microamperes so we can use the same internals
as the power supply subsystem without having to multiply
and divide with 1000 in a few places.

Also convert high_curr_threshold and lowbat_threshold to
use microamperes and microvolts as these are closely
related to these changes.

Drop the unused overbat_threshold member in the custom
struct ab8500_fg_parameters.

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

power: supply: ab8500: Standardize temp res lookup

The lookup from battery temperature to internal resistance was
using its own format. Rewrite this to use the table inside
struct power_supply_battery_info:s resist_table.

The supplied resistance table has to be rewritten to express
the resistance in percent of the factory resistance as a
side effect.

We can then rely on the library function
power_supply_temp2resist_simple() to interpolate the internal
resistance percent from the temperature.

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 internal resistance

The nominal internal resistance isn't used by the AB8500
charging code, instead this resistance is measured continuously,
but we anyways migrate this to the standard property in
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 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: Standardize technology

The AB8500 custom battery type 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.

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

power: supply: ab8500: Standardize design capacity

Now that we know that we have only one battery type to
deal with we can proceed to transfer properties to
struct power_supply_battery_info.

The designed capacity for the battery was in a custom field
of the custom battery type in mAh, transfer this to the
standard charge_full_design_uah property in
struct power_supply_battery_info and augment the code
accordingly.

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: Sink current tables into charger code

The two tables for input and output current translation from
register values does not need to be passed around from the
battery manager data. Just push it down into the charger code
where it is used, like other tables in that code.

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

power: supply: ab8500: Use core battery parser

This deploys the core battery DT parser to read the basic properties
of the battery. We only use very little of it as we start out, but
we will improve as we go along.

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>

power: supply: ab8500: Drop unused member

This setting is read directly from the device tree in
the ab8500_charger.c code.

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

power: supply: ab8500: Enable USB and AC

The vendor code tree supplies platform data to enable he
USB charging for AB8500 and AB8500 and disable the AC
charging on the AB8505. This was missed when the driver
was submitted to the mainline kernel.

Fix this by doing what the vendor kernel does: always
register the USB charger, do not register the AC charger
on the AB8505.

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

power: supply: ab8500: Move to componentized binding

The driver has problems with the different components of
the charging code racing with each other to probe().

This results in all four subdrivers populating battery
information to ascertain that it is populated for their
own needs for example.

Fix this by using component probing and thus expressing
to the kernel that these are dependent components.
The probes can happen in any order and will only acquire
resources such as state container, regulators and
interrupts and initialize the data structures, but no
execution happens until the .bind() callback is called.

The charging driver is the main component and binds
first, then bind in order the three subcomponents:
ab8500-fg, ab8500-btemp and ab8500-chargalg.

Do some housekeeping while we are moving the code around.
Like use devm_* for IRQs so as to cut down on some
boilerplate.

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

mfd/power: ab8500: Push data to power supply code

There is a slew of defines, structs and enums and even a
function call only relevant for the charging code that
still lives in <linux/mfd/abx500.h>. Push it down to the
"ab8500-bm.h" header in the power supply subsystem where
it is actually used.

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

mfd/power: ab8500: Push data to power supply code

The global definition of platform data for the battery
management code has no utility after the OF conversion,
move the <linux/mfd/abx500/ab8500-bm.h> to be a local
file in drivers/power/supply and stop defining the
platform data in drivers/power/supply/ab8500_bmdata.c
and broadcast to the kernel only to have it assigned
as platform data to the MFD cells and then picked back
into the same subsystem that defined it in the first
place. This kills off a layer of indirection.

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