Re: [PATCH v4 2/3] iio: light: Add support for AL3000a illuminance sensor

[Jonathan Cameron]

On Sat, 22 Feb 2025 14:56:41 +0200
Svyatoslav Ryhel <clamor95@xxxxxxxxx> wrote:

> сб, 22 лют. 2025 р. о 14:53 Jonathan Cameron <jic23@xxxxxxxxxx> пише:
> >
> > On Mon, 17 Feb 2025 16:03:35 +0200
> > Svyatoslav Ryhel <clamor95@xxxxxxxxx> wrote:
> >  
> > > AL3000a is a simple I2C-based ambient light sensor, which is
> > > closely related to AL3010 and AL3320a, but has significantly
> > > different way of processing data generated by the sensor.
> > >
> > > Tested-by: Robert Eckelmann <longnoserob@xxxxxxxxx>
> > > Tested-by: Antoni Aloy Torrens <aaloytorrens@xxxxxxxxx>
> > > Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
> > > Reviewed-by: David Heidelberg <david@xxxxxxx>  
> >
> > Whilst I am confused by earlier statements about not
> > having information on the conversion to illuminance values, I'm
> > going to assume the look up table in here is based on some
> > reasonable data from somewhere and hence that this is a sensor
> > with appropriate filtering of the light to be able to do a non linear
> > conversion from the value read and standard light curves.
> >
> > As such the IIO_LIGHT channel type is fine for this device.
> >  
> 
> Thank you, but IIO_INTENSITY may be proper channel as well, after your
> explanations. If you wish, I may upload v5 with swapping LIGHT with
> INTENSITY.

Where does the lux_table set of values come from?
That seems to be key question for this driver.

> 
> > Applied patches 1 and 2 to the togreg branch of iio.git.
> > Note that I'll initially push this out as testing to allow
> > the autobuilders to see if they can find any issues that we missed.
> > Patch 3 will need to go via the appropriate SoC tree as normal.
> >
> > Jonathan
> >  
> > > ---
> > >  drivers/iio/light/Kconfig   |  10 ++
> > >  drivers/iio/light/Makefile  |   1 +
> > >  drivers/iio/light/al3000a.c | 209 ++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 220 insertions(+)
> > >  create mode 100644 drivers/iio/light/al3000a.c
> > >
> > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> > > index 29ffa8491927..37f83e1d8893 100644
> > > --- a/drivers/iio/light/Kconfig
> > > +++ b/drivers/iio/light/Kconfig
> > > @@ -43,6 +43,16 @@ config ADUX1020
> > >        To compile this driver as a module, choose M here: the
> > >        module will be called adux1020.
> > >
> > > +config AL3000A
> > > +     tristate "AL3000a ambient light sensor"
> > > +     depends on I2C
> > > +     help
> > > +       Say Y here if you want to build a driver for the Dyna Image AL3000a
> > > +       ambient light sensor.
> > > +
> > > +       To compile this driver as a module, choose M here: the
> > > +       module will be called al3000a.
> > > +
> > >  config AL3010
> > >       tristate "AL3010 ambient light sensor"
> > >       depends on I2C
> > > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> > > index f14a37442712..03f10786273a 100644
> > > --- a/drivers/iio/light/Makefile
> > > +++ b/drivers/iio/light/Makefile
> > > @@ -7,6 +7,7 @@
> > >  obj-$(CONFIG_ACPI_ALS)               += acpi-als.o
> > >  obj-$(CONFIG_ADJD_S311)              += adjd_s311.o
> > >  obj-$(CONFIG_ADUX1020)               += adux1020.o
> > > +obj-$(CONFIG_AL3000A)                += al3000a.o
> > >  obj-$(CONFIG_AL3010)         += al3010.o
> > >  obj-$(CONFIG_AL3320A)                += al3320a.o
> > >  obj-$(CONFIG_APDS9300)               += apds9300.o
> > > diff --git a/drivers/iio/light/al3000a.c b/drivers/iio/light/al3000a.c
> > > new file mode 100644
> > > index 000000000000..e2fbb1270040
> > > --- /dev/null
> > > +++ b/drivers/iio/light/al3000a.c
> > > @@ -0,0 +1,209 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +#include <linux/array_size.h>
> > > +#include <linux/bitfield.h>
> > > +#include <linux/device.h>
> > > +#include <linux/err.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/mod_devicetable.h>
> > > +#include <linux/module.h>
> > > +#include <linux/pm.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/regulator/consumer.h>
> > > +#include <linux/types.h>
> > > +
> > > +#include <linux/iio/iio.h>
> > > +
> > > +#define AL3000A_REG_SYSTEM           0x00
> > > +#define AL3000A_REG_DATA             0x05
> > > +
> > > +#define AL3000A_CONFIG_ENABLE                0x00
> > > +#define AL3000A_CONFIG_DISABLE               0x0b
> > > +#define AL3000A_CONFIG_RESET         0x0f
> > > +#define AL3000A_GAIN_MASK            GENMASK(5, 0)
> > > +
> > > +/*
> > > + * These are pre-calculated lux values based on possible output of sensor
> > > + * (range 0x00 - 0x3F)
> > > + */
> > > +static const u32 lux_table[] = {
> > > +     1, 1, 1, 2, 2, 2, 3, 4,                                 /* 0 - 7 */
> > > +     4, 5, 6, 7, 9, 11, 13, 16,                              /* 8 - 15 */
> > > +     19, 22, 27, 32, 39, 46, 56, 67,                         /* 16 - 23 */
> > > +     80, 96, 116, 139, 167, 200, 240, 289,                   /* 24 - 31 */
> > > +     347, 416, 499, 600, 720, 864, 1037, 1245,               /* 32 - 39 */
> > > +     1495, 1795, 2155, 2587, 3105, 3728, 4475, 5373,         /* 40 - 47 */
> > > +     6450, 7743, 9296, 11160, 13397, 16084, 19309, 23180,    /* 48 - 55 */
> > > +     27828, 33408, 40107, 48148, 57803, 69393, 83306, 100000 /* 56 - 63 */
> > > +};  
> >