This array is supposed to have 10 elements.  Smatch complains that with
the current code we can have n == max_ints and read beyond the end of
the array.

Fixes: ac4f6eee ("staging: iio: TAOS tsl258x: Device driver")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Move tsl2580, tsl2581, tsl2583 driver out of staging into mainline.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add Brian Masney's copyright to the header and to the MODULE_AUTHOR
for all of the staging cleanups that has been done to this driver.

The original MODULE_AUTHOR() did not have a space between his name and
email address. This patch also adds the missing space.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

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>

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>

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>

Removing a call to the taos_chip_off() makes it unused when CONFIG_PM
is disabled:

drivers/staging/iio/light/tsl2583.c:438:12: error: ‘taos_chip_off’ defined but not used [-Werror=unused-function]

This removes all the #ifdef in this file, and marks the PM functions as
__maybe_unused instead, which is more reliable and gives us better
compile time coverage.

Fixes: 0561155f ("staging: iio: tsl2583: don't shutdown chip when updating the lux table")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_als_calibrate() queries the control register to determine if the
unit is powered on and has the ADC enabled. It then queries the same
register a second time to determine if the ADC reading is valid. This
patch removes the redundant i2c_smbus_read_byte_data() call.

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>

in_illuminance_lux_table_store() shuts down the chip, updates the
contents of the lux table, and then turns the chip back on. The values
in lux table are not used by the chip and are only used internally by
the driver. It is not necessary to change the power state on the chip.
This patch removes the calls to taos_chip_off() and taos_chip_on()
in in_illuminance_lux_table_store().
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_chip_on() explicitly turns the sensor power on and then writes the
8 registers that are stored in taos_config. The first register in
taos_config is the CONTROL register and the configuration is set to
turn the power off. The existing state sequence in taos_chip_on() is:

- Turn device power on
- Turn device power off (via taos_config)
- Configure other 7 registers (via taos_config)
- Turn device power on, enable ADC

This patch changes the code so that the device is not powered off via
taos_config.

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>

in taos_defaults()

The comments in taos_defaults() appear after the line of code
that they apply to. This patch moves the comments so that they appear
before the code. Some of the comments were updated to be more
informative.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

taos_probe() queries the all of the sensor's registers and loads all of
the values into a buffer stored on the stack. Only the chip ID register
was actually used. Change the probe function to just query the chip ID
register on the device.

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>

There were several places where the driver would first call
i2c_smbus_write_byte() to select the register on the device, and then
call i2c_smbus_read_byte() to get the contents of that register. The
code would look roughly like:

/* Select register */
i2c_smbus_write_byte(client, REGISTER);

/* Read the the last register that was written to */
int data = i2c_smbus_read_byte(client);

Rewrite this to use i2c_smbus_read_byte_data() to combine the two
calls into one:

int data = i2c_smbus_read_byte_data(chip->client, REGISTER);

Verified that the driver still functions correctly using a TSL2581
hooked up to a Raspberry Pi 2.

This fixes the following warnings that were found by the
kbuild test robot that were introduced by commit 8ba355cce3c6 ("staging:
iio: tsl2583: check for error code from i2c_smbus_read_byte()").

drivers/staging/iio/light/tsl2583.c:365:5-12: WARNING: Unsigned
expression compared with zero: reg_val < 0

drivers/staging/iio/light/tsl2583.c:388:5-12: WARNING: Unsigned
expression compared with zero: reg_val < 0

This also removes the need for the taos_i2c_read() function since all
callers were only calling the function with a length of 1.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

in_illuminance_input_target_show(), in_illuminance_input_target_store(),
in_illuminance_calibrate_store(), and in_illuminance_lux_table_store()
accesses data from the tsl2583_chip struct. Some of these fields can be
modified by other parts of the driver concurrently. This patch adds the
mutex locking to these sysfs attributes.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

in_illuminance_input_target_store() and in_illuminance_calibrate_store()
validated the data from userspace, however it would not return an
error code to userspace if an invalid value was passed in. This patch
changes these functions so that they return -EINVAL if invalid data is
passed in.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Use the IIO_CONST_ATTR, IIO_DEVICE_ATTR_RW, and IIO_DEVICE_ATTR_WO
macros for creating the in_illuminance_calibscale_available,
in_illuminance_integration_time_available, in_illuminance_input_target,
in_illuminance_calibrate, and in_illuminance_lux_table sysfs entries.
Previously these sysfs entries were prefixed with illuminance0_, however
they are now prefixed with in_illuminance_ to make these sysfs entries
consistent with how the IIO core is creating the other sysfs entries.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The illuminance0_calibscale sysfs attribute is not currently created by
the IIO core. This patch adds the appropriate mask to iio_chan_spec,
along with the appropriate data handling in the read_raw() and
write_raw() functions, so that the sysfs attribute is created by the IIO
core. With this change, this sysfs entry will have its prefix changed
from illuminance0_ to in_illuminance_.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The tsl2583 driver directly creates sysfs attributes that should instead
be created by the IIO core on behalf of the driver. This patch adds the
iio_chan_spec array, the relevant info_mask elements and the read_raw()
and write_raw() functions to take advantage of features provided by the
IIO core. These sysfs attributes were migrated with this patch:
illuminance0_input, illuminance0_calibbias,
illuminance0_integration_time. This also exposes the raw values read
from the two channels on the sensor.

With this change, these four sysfs entries have their prefix changed
from illuminance0_ to in_illuminance_. This is deemed to be acceptable
since none of the IIO light drivers in mainline use the illuminance0_
prefix, however 8 of the IIO light drivers in mainline use the
in_illuminance_ prefix.

Also fix the units of integration_time to meet with the ABI.
Signed-off-by: NBrian Masney <masneyb@onstation.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>