power: supply: bq256xx: fix some problem in bq256xx_hw_init

smatch complains that there is a buffer overflow and clang complains
'ret' is never read.

Smatch error:
drivers/power/supply/bq256xx_charger.c:1578 bq256xx_hw_init() error:
buffer overflow 'bq256xx_watchdog_time' 4 <= 4

Clang static checker:
Value stored to 'ret' is never read.

Add check for buffer overflow and error code from regmap_update_bits().

Fixes: 32e4978bb920 ("power: supply: bq256xx: Introduce the BQ256XX charger driver")
Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20231116041822.1378758-1-suhui@nfschina.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: replace deprecated strncpy with strscpy

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect bq->model_name to be NUL-terminated based on its usage with
sysfs_emit and format strings:

val->strval is assigned to bq->model_name in
bq256xx_get_charger_property():
| val->strval = bq->model_name;

... then in power_supply_sysfs.c we use value.strval with a format string:
| ret = sysfs_emit(buf, "%s\n", value.strval);

we assigned value.strval via:
| ret = power_supply_get_property(psy, psp, &value);
... which invokes psy->desc->get_property():
| return psy->desc->get_property(psy, psp, val);

with bq256xx_get_charger_property():
| static const struct power_supply_desc bq256xx_power_supply_desc = {
...
| .get_property = bq256xx_get_charger_property,

Moreover, no NUL-padding is required as bq is zero-allocated in
bq256xx_charger.c:
| bq = devm_kzalloc(dev, sizeof(*bq), GFP_KERNEL);

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Let's also opt to use the more idiomatic strscpy() usage of (dest, src,
sizeof(dest)) as this more closely ties the destination buffer and the
length.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Similar-to: https://lore.kernel.org/all/20231020-strncpy-drivers-power-supply-bq24190_charger-c-v1-1-e896223cb795@google.com/
Similar-to: https://lore.kernel.org/all/20231020-strncpy-drivers-power-supply-bq2515x_charger-c-v1-1-46664c6edf78@google.com/
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231020-strncpy-drivers-power-supply-bq256xx_charger-c-v1-1-2fad856124f9@google.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Some cleanups

Some cleanups:
* Remove trailing comma in the terminator entry for OF/ID/ACPI table.
* Drop a space from terminator entry for OF table.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230902202505.97609-3-biju.das.jz@bp.renesas.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Use i2c_get_match_data()

Use i2c_get_match_data() for OF/ID/ACPI match instead of ID lookup by
replacing OF/ACPI/ID match data from enum bq256xx_id to
struct bq256xx_chip_info.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230902202505.97609-2-biju.das.jz@bp.renesas.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Apply TS_IGNORE from devicetree

TS_IGNORE is default off in bq256xx chip. For some HW which doesn't have
the NTC, we need to set TS_IGNORE to 1 to make the charge work. The new
"ti,no-thermistor" is introduced to toggle it.

Signed-off-by: Hermes Zhang <chenhuiz@axis.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Support to disable charger

To be able to control the charging process flexible, we need to able to
disable the charger. This commit will allow to disable the charger by
"echo 1 > /sys/class/power_supply/bq256xx-charger/charge_type"
(1 = POWER_SUPPLY_CHARGE_TYPE_NONE) and enable the charger by set it to
2/3 (POWER_SUPPLY_CHARGE_TYPE_TRICKLE/POWER_SUPPLY_CHARGE_TYPE_FAST)

Signed-off-by: Hermes Zhang <chenhuiz@axis.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Init ichg/vbat value with chip default value

Init the ichg/vbat reg with chip default value instead of the max value
used now. The max value set in driver will result an unsafe case (e.g.
battery is over charging when in a hot environment) if no user space
update the value later.

Signed-off-by: Hermes Zhang <chenhuiz@axis.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Convert to i2c's .probe_new()

.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in the probe function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Handle OOM correctly

Since we now return a pointer to an allocated object we need
to account for memory allocation failure in a separate
error path.

Fixes: 25fd330370ac ("power: supply_core: Pass pointer to battery info")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
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: bq256xx: add kerneldoc for structure members

Document members of structure to fix W=1 warnings like:

drivers/power/supply/bq256xx_charger.c:240: warning:
Function parameter or member 'charger' not described in 'bq256xx_device'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Fix BQ256XX_NUM_WD_VAL and bq256xx_watchdog_time[] overrun

Corrects BQ256XX_NUM_WD_VAL from value of "8" to "4" and fixes the issue when 'i'
is equal to array size then array index over runs the array

Fixes: 32e4978bb920 ("power: supply: bq256xx: Introduce the BQ256XX charger driver")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ricardo Rivera-Matos <r-rivera-matos@ti.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: bq256xx: Introduce the BQ256XX charger driver

The BQ256XX family of devices are highly integrated buck chargers
for single cell batteries.

Signed-off-by: Ricardo Rivera-Matos <r-rivera-matos@ti.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>