iio: temperature: ltc2983: explicitly set the name in chip_info

Getting the part name with 'spi_get_device_id(spi)->name' is not a very
good pattern. Hence, explicitly add the name in the struct chip_info and
use that instead.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240222-ltc2983-misc-improv-v1-4-cf7d4457e98c@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: rename ltc2983_parse_dt()

Rename ltc2983_parse_dt() to ltc2983_parse_fw() as there's no explicit
dependency on devicetree. No functional change intended...

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240222-ltc2983-misc-improv-v1-2-cf7d4457e98c@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: make use of spi_get_device_match_data()

Use spi_get_device_match_data() as it simplifies the code. No functional
change intended...

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240222-ltc2983-misc-improv-v1-1-cf7d4457e98c@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: support more parts

Add support for the following parts:
* LTC2984
* LTC2986
* LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20221103130041.2153295-14-demonsingur@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: make bulk write buffer DMA-safe

regmap_bulk_write() does not guarantee implicit DMA-safety,
even though the current implementation duplicates the given
buffer. Do not rely on it.

Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20221103130041.2153295-2-demonsingur@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: allocate iio channels once

Currently, every time the device wakes up from sleep, the
iio_chan array is reallocated, leaking the previous one
until the device is removed (basically never).

Move the allocation to the probe function to avoid this.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Fixes: f110f3188e563 ("iio: temperature: Add support for LTC2983")
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221014123724.1401011-2-demonsingur@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: Switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

Using these newer macros allows the compiler to remove the unused
structure and functions when !CONFIG_PM_SLEEP + removes the need to
mark pm functions __maybe_unused.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220621202719.13644-26-jic23@kernel.org

iio: temp: ltc2983: Fix alignment for DMA safety

____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_DMA_MINALIGN definition.

Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-91-jic23@kernel.org

iio: temperature: ltc2983: Make use of device properties

Convert the module to be property provider agnostic and allow
it to be used on non-OF platforms.

The conversion slightly changes the logic behind property reading for
the configuration values. Original code allocates just as much memory
as needed. Then for each separate 32- or 64-bit value it reads it from
the property and converts to a raw one which will be fed to the sensor.
In the new code we allocate the amount of memory needed to retrieve all
values at once from the property and then convert them as required.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Tested-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220307203606.87258-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: Use single error path to put OF node

There are several, possibly copied'n'pasted, places in the functions,
where OF node is put and error returned directly, while the common
exit point exists. Unify all these cases to use a single error path.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220307203606.87258-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: Don't hard code defined constants in messages

In a couple of messages the constants, which have their definitions,
are hard coded into the message text. Unhardcode them.

While at it, add a trailing \n where it's currently missing.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220307203606.87258-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ltc2983: fail probe if no channels are given

If there are no channels defined in the devicetree, there's no point in
probing the device. We were actually requesting a zero sized 'kmalloc'
array but since we were not touching the ZERO_SIZE_PTR afterwards,
nothing bad was actually happening. Hence this is not really a fix but
rather an improvement.

Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210825084149.11587-2-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ltc2983: add support for optional reset gpio

Check if an optional reset gpio is present and if so, make sure to reset
the device.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210825084149.11587-1-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ltc2983: fix device probe

There is no reason to assume that the IRQ rising edge (indicating that
the device start up phase is done) will happen after we request the IRQ.
If the device is already up by the time we request it, the call to
'wait_for_completion_timeout()' will timeout and we will fail the device
probe even though there's nothing wrong.

Fix it by just polling the status register until we get the indication that
the device is up and running. As a side effect of this fix, requesting the
IRQ is also moved to after the setup function.

Fixes: f110f3188e563 ("iio: temperature: Add support for LTC2983")
Reported-and-tested-by: Drew Fustini <drew@pdp7.com>
Reviewed-by: Drew Fustini <drew@pdp7.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210811133220.190264-2-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ltc2983: Fix of_node refcounting

When returning or breaking early from a
`for_each_available_child_of_node()` loop, we need to explicitly call
`of_node_put()` on the child node to possibly release the node.

Fixes: f110f3188e563 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200925091045.302-1-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: remove explicit IIO device parent assignment

This patch applies the semantic patch:
@@
expression I, P, SP;
@@
I = devm_iio_device_alloc(P, SP);
...
- I->dev.parent = P;

It updates 302 files and does 307 deletions.
This semantic patch also removes some comments like
'/* Establish that the iio_dev is a child of the i2c device */'

But this is is only done in case where the block is left empty.

The patch does not seem to cover all cases. It looks like in some cases a
different variable is used in some cases to assign the parent, but it
points to the same reference.
In other cases, the block covered by ... may be just too big to be covered
by the semantic patch.

However, this looks pretty good as well, as it does cover a big bulk of the
drivers that should remove the parent assignment.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: remove redundant comparison to bool

Remove redundant comparison to a boolean variable.

Fixes coccinelle warning:
drivers/iio/temperature//ltc2983.c:393:20-32: WARNING: Comparison to bool
drivers/iio/temperature//ltc2983.c:394:20-32: WARNING: Comparison to bool

Signed-off-by: Rohit Sarkar <rohitsarkar5398@gmail.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: ltc2983: fix u32 read into a unsigned long long

Currently the read of temp using of_property_read_u32_index is reading
a u32 value into a unsigned long long. This relies on machine endianness
to work correctly, so fix this by reading a u32 value and setting temp
to this value.

Addresses-Coverity: ("Reliance on integer endianness")
Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: Add support for LTC2983

The LTC2983 is a Multi-Sensor High Accuracy Digital Temperature
Measurement System. It measures a wide variety of temperature sensors and
digitally outputs the result, in °C or °F, with 0.1°C accuracy and
0.001°C resolution. It can measure the temperature of all standard
thermocouples (type B,E,J,K,N,S,R,T), standard 2-,3-,4-wire RTDs,
thermistors and diodes.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>