The ret variable in tsl2583_suspend() and tsl2583_resume() was
initialized to 0. This is not necessary so this patch removes the
initialization.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The entries in the lux table (als_device_lux) can be updated via sysfs
through the function in_illuminance_lux_table_store(). The last row in
the table must be terminated with values that are zero. The sysfs code
already ensures that the last row is all zeros. The call to memset to
clear out the table is not needed so this patch removes the unnecessary
call.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The comment for tsl2583_probe() does not provide any useful value.
This patch removes the comment.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The comment that describes the code that clears the interrupt bit was
vague and didn't provide much value. This patch adds more detail about
why that bit needs to be cleared.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The header only listed the tsl2580 and tsl2581 devices as supported by
this driver. This patch adds the tsl2583 since it is also supported by
this driver.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver contains a global lux table that can be updated via sysfs.
Change this to a per device lux table so that multiple devices can be
hooked up to the same system with different lux tables.

There are 10 entries, plus 1 for the termination segment, set aside for
the entries in the lux table. When updating the lux table via sysfs,
only 9 entries, plus the terminator, could be added. This changes
the code to allow for the 10 entries, plus the terminator.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

in_illuminance_lux_table_store assumes that an unsigned int is 32 bits.
Replace this with sizeof(value[1]).
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

in_illuminance_lux_table_store() contains some unnecessary parentheses.
This patch removes them since they provide no value.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

tsl2583_als_calibrate() returns the newly computed gain_trim if the
calibration was successful. This function is only called by
in_illuminance_calibrate_store() and the return value inside that
sysfs attribute is only checked to see if an error was returned.
This patch changes tsl2583_als_calibrate() to return 0 on success.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The check for ch1lux > ch0lux inside tsl2583_get_lux is only valid if
the ratio is not equal to zero. Move the code block inside the else
statement. This does away with the need to initialize the variables to
zero.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

If channel 0 does not have any data, then the code sets the lux to zero.
The corresponding comment says that the last value is returned. This
updates the comment to correctly reflect what the code does. It also
clarifies the comment about why 0 is returned.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The definition of the tsl2583_device_lux struct has a series of single
line comments. There are two other cases where the multiline comments
did not have an initial blank line. Change these comments to use the
proper multiline syntax.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

There are two separate files describing the tsl2583 sysfs attributes.
Combine the two files into one. Updated the name of the sysfs attributes
to match the current ABI.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Suggested-by: NPeter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add and remove newlines to improve code readability in preparation for
moving the driver out of staging.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Fixed warning found by make W=2:

warning: comparison between signed and unsigned integer expressions
[-Wsign-compare]
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Most of the values in the #defines have their values aligned on a single
column, but some do not. This changes the remaining defines to use
consistent alignment with the majority to improve code readability.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Some functions and variables were prefixed with either taos, tsl258x,
taos2583, or tsl2583. Change everything to use the tsl2583 prefix since
that is the name of the .c file. The taos_settings member inside the
taos_settings struct was renamed to als_settings.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

There are several places in the code where the function name is
hardcoded in the log message. Use the __func__ constant string to build
the log message. This also clarifies some of the error messages to match
the code and ensures that the correct priority is used since the message
is already being changed.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Address warning from checkpatch:

CHECK: Do not include the paragraph about writing to the Free Software
Foundation's mailing address from the sample GPL notice. The FSF has
changed addresses in the past, and may do so again. Linux already
includes a copy of the GPL.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_probe() calls i2c_smbus_write_byte() to select the control
register, however there are no subsequent calls to
i2c_smbus_read_byte(). The write call is unnecessary and is removed by
this patch.

Verified that the driver still functions correctly using a TSL2581
hooked up to a Raspberry Pi 2.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The current chip state is represented as a tristate (working, suspended,
and unknown). The unknown state was not used. This patch changes the
chip state so that it is now represented as a single boolean value
(suspended).
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The device probing and the suspend/resume code checks a flag internal to
the driver that determines whether or not the chip is in a working
state. These checks are not needed. This patch removes the unnecessary
checks. It will do no harm to the hardware if the chip is
reinitialized if it is already powered on.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_get_lux checks to see if the chip is in a working state. This
check is not necessary since it is only called from tsl2583_read_raw
and in_illuminance_calibrate_store (via taos_als_calibrate). The chip
state is already checked by these functions.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

in_illuminance_calibrate_store() did not check to see if the chip is
in a working state. This patch adds the proper check. The return value
from taos_als_calibrate() was also not checked in this function, so the
proper check was also added while changes are being made here.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The DAC is used to find the peak level of an alternating voltage input
signal by a binary search using the output of a comparator wired to
an interrupt pin. Like so:
                          _
                         | \
    input +------>-------|+ \
                         |   \
           .-------.     |    }---.
           |       |     |   /    |
           |    dac|-->--|- /     |
           |       |     |_/      |
           |       |              |
           |       |              |
           |    irq|------<-------'
           |       |
           '-------'
Signed-off-by: NPeter Rosin <peda@axentia.se>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

It is assumed that the dpot is used as a voltage divider between the
current dpot wiper setting and the maximum resistance of the dpot. The
divided voltage is provided by a vref regulator.

                  .------.
   .-----------.  |      |
   | vref      |--'    .---.
   | regulator |--.    |   |
   '-----------'  |    | d |
                  |    | p |
                  |    | o |  wiper
                  |    | t |<---------+
                  |    |   |
                  |    '---'       dac output voltage
                  |      |
                  '------+------------+
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Example:

$ cat '/sys/bus/iio/devices/iio:device0/out_resistance_raw_available'
[0 1 256]

Meaning: min 0, step 1 and max 256.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Specifically a helper for reading the available maximum raw value of a
channel and a helper for forwarding read_avail requests for raw values
from one iio driver to an iio channel that is consumed.

These rather specific helpers are in turn built with generic helpers
making it easy to build more helpers for available values as needed.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

A large number of attributes can only take a limited range of values.
Currently in IIO this is handled by directly registering additional
*_available attributes thus providing this information to userspace.

It is desirable to provide this information via the core for much the same
reason this was done for the actual channel information attributes in the
first place.  If it isn't there, then it can only really be accessed from
userspace.  Other in kernel IIO consumers have no access to what valid
parameters are.

Two forms are currently supported:
* list of values in one particular IIO_VAL_* format.
	e.g. 1.300000 1.500000 1.730000
* range specification with a step size:
	e.g. [1.000000 0.500000 2.500000]
	equivalent to 1.000000 1.5000000 2.000000 2.500000

An addition set of masks are used to allow different sharing rules for the
*_available attributes generated.

This allows for example:

in_accel_x_offset
in_accel_y_offset
in_accel_offset_available.

We could have gone with having a specification for each and every
info_mask element but that would have meant changing the existing userspace
ABI.  This approach does not.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
[forward ported, added some docs and fixed buffer overflows /peda]
Acked-by: NDaniel Baluta <daniel.baluta@intel.com>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When updating the in_illuminance_calibscale and
in_illuminance_integration_time sysfs attributes, these values were not
actually written to the chip. The chip would continue to use the old
parameters. Extracted out tsl2583_set_als_gain() and
tsl2583_set_als_time() functions that are now called when these sysfs
attributes are updated. The chip initialization also calls these these
new functions.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_chip_on() reads an eight member array called taos_config
that contains the desired state of the chip's registers. Only four
of the registers actually need to be written to. The four that do
not need to be written to are for the {low,high} byte of the lower
interrupt threshold and the {low,high} byte of the upper interrupt
threshold. Interrupts are currently not supported by this driver
so there is no need to write to these registers.

This patch removes the taos_config array and separates out the
i2c calls that write to the CONTROL, TIMING, INTERRUPT and ANALOG
registers. This is part of a larger refactor that was split up to
make the code review easier.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

We have #defines for all the individual sensor registers and
value/mask pairs #defined at the top of the file and used at
exactly one spot.

This is usually good if the #defines give a meaning to the
opaque magic numbers.

However in this case, the semantic meaning is inherent in the
name of the C99-addressable fields, and that means duplication
of information, and only makes the code hard to maintain since
you every time have to add a new #define AND update the site
where it is to be used.

Get rid of the #defines and just open code the values into the
appropriate struct elements. Make sure to explicitly address
the .hz and .value fields in the st_sensor_odr_avl struct
so that the meaning of all values is clear.

This patch is purely syntactic should have no semantic effect.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

We have #defines for all the individual sensor registers and
value/mask pairs #defined at the top of the file and used at
exactly one spot.

This is usually good if the #defines give a meaning to the
opaque magic numbers.

However in this case, the semantic meaning is inherent in the
name of the C99-addressable fields, and that means duplication
of information, and only makes the code hard to maintain since
you every time have to add a new #define AND update the site
where it is to be used.

Get rid of the #defines and just open code the values into the
appropriate struct elements. Make sure to explicitly address
the .hz and .value fields in the st_sensor_odr_avl struct
so that the meaning of all values is clear.

This patch is purely syntactic should have no semantic effect.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

We have #defines for all the individual sensor registers and
value/mask pairs #defined at the top of the file and used at
exactly one spot.

This is usually good if the #defines give a meaning to the
opaque magic numbers.

However in this case, the semantic meaning is inherent in the
name of the C99-addressable fields, and that means duplication
of information, and only makes the code hard to maintain since
you every time have to add a new #define AND update the site
where it is to be used.

Get rid of the #defines and just open code the values into the
appropriate struct elements. Make sure to explicitly address
the .hz and .value fields in the st_sensor_odr_avl struct
so that the meaning of all values is clear.

This patch is purely syntactic should have no semantic effect.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The i2c mux core can then take appropriate action depending on if it is
used for an actual i2c mux, or for an arbitrator or gate. In this case
it is used as a gate.

This will make devicetree bindings simpler when they are eventually
added.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

status is a u8 hence the check if status is less than zero has no effect.
Fix this by replacing status with int ret so the less than zero compare
will correctly detect errors.

Issue found with static analysis with CoverityScan, CID 1375919
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Fixes: 974e6f02 ("iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub")
Reviewed-by: NGuenter Roeck <groeck@chromium.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

We should be testing "ret" here.

Fixes: aa16c6bd ("iio:adc: Add support for AD7766/AD7767")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>