On Sat, 1 Feb 2020 19:00:21 +0100 David Heidelberg <david@xxxxxxx> wrote: > Based on: > - 3320A in-kernel driver > - https://www.spinics.net/lists/linux-iio/msg25145.html > - https://lore.kernel.org/patchwork/patch/684179/ > > I decided to keep it aside of AL3320A due to different approach and much > simpler design of 3010. > > Tested on Nexus 7 2012 (grouper/tilapia). > > Tested-by: David Heidelberg <david@xxxxxxx> > Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx> > Signed-off-by: David Heidelberg <david@xxxxxxx> Hi, A few minor bits inline. Thanks, Jonathan > --- > drivers/iio/light/Kconfig | 10 ++ > drivers/iio/light/Makefile | 1 + > drivers/iio/light/al3010.c | 217 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 228 insertions(+) > create mode 100644 drivers/iio/light/al3010.c > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig > index 9968f982fbc7..43d9b830279d 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 AL3010 > + tristate "AL3010 ambient light sensor" > + depends on I2C > + help > + Say Y here if you want to build a driver for the Dyna Image AL3010 > + ambient light sensor. > + > + To compile this driver as a module, choose M here: the > + module will be called al3010. > + > config AL3320A > tristate "AL3320A ambient light sensor" > depends on I2C > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile > index c98d1cefb861..88bb93550fcc 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_AL3010) += al3010.o > obj-$(CONFIG_AL3320A) += al3320a.o > obj-$(CONFIG_APDS9300) += apds9300.o > obj-$(CONFIG_APDS9960) += apds9960.o > diff --git a/drivers/iio/light/al3010.c b/drivers/iio/light/al3010.c > new file mode 100644 > index 000000000000..4b951c087c83 > --- /dev/null > +++ b/drivers/iio/light/al3010.c > @@ -0,0 +1,217 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * AL3010 - Dyna Image Ambient Light Sensor > + * > + * Copyright (c) 2014, Intel Corporation. > + * Copyright (c) 2016, Dyna-Image Corp. > + * > + * IIO driver for AL3010 (7-bit I2C slave address 0x1C). > + * > + * TODO: interrupt support, thresholds > + */ > + > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/of.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#define AL3010_DRV_NAME "al3010" > + > +#define AL3010_REG_SYSTEM 0x00 > +#define AL3010_REG_DATA_LOW 0x0c > +#define AL3010_REG_CONFIG 0x10 > + > +#define AL3010_CONFIG_DISABLE 0x00 > +#define AL3010_CONFIG_ENABLE 0x01 > + > +#define AL3010_GAIN_SHIFT 4 > +#define AL3010_GAIN_MASK (BIT(6) | BIT(5) | BIT(4)) GENMASK > + > +#define AL3010_GAIN_READ(g) \ > + (((g) & AL3010_GAIN_MASK) >> AL3010_GAIN_SHIFT) > + > +#define AL3010_GAIN_WRITE(g) \ > + (((g) << AL3010_GAIN_SHIFT) & AL3010_GAIN_MASK) > + > +#define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018" > + > +enum al3xxxx_range { > + AL3XXX_RANGE_1, /* 77806 lx */ > + AL3XXX_RANGE_2, /* 19542 lx */ > + AL3XXX_RANGE_3, /* 4863 lx */ > + AL3XXX_RANGE_4 /* 1216 lx */ > +}; > + > +static const int al3010_scales[][2] = { > + {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600} > +}; > + > +struct al3010_data { > + struct i2c_client *client; > +}; > + > +static const struct iio_chan_spec al3010_channels[] = { > + { > + .type = IIO_LIGHT, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + } > +}; > + > +static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE); > + > +static struct attribute *al3010_attributes[] = { > + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, > + NULL, > +}; > + > +static const struct attribute_group al3010_attribute_group = { > + .attrs = al3010_attributes, > +}; > + > +static int al3010_init(struct al3010_data *data) > +{ > + int ret; > + > + /* power on */ Comment is fairly obvious given the code so I wouldn't bother having it. Comments that don't add significant benefit just add stuff that can become wrong in the future ;) > + ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_SYSTEM, > + AL3010_CONFIG_ENABLE); > + if (ret < 0) > + return ret; > + > + ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG, > + AL3010_GAIN_WRITE(AL3XXX_RANGE_3)); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static int al3010_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int *val, > + int *val2, long mask) > +{ > + struct al3010_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + /* > + * ALS ADC value is stored in two adjacent registers: > + * - low byte of output is stored at AL3010_REG_DATA_LOW > + * - high byte of output is stored at AL3010_REG_DATA_LOW + 1 > + */ > + ret = i2c_smbus_read_word_data(data->client, > + AL3010_REG_DATA_LOW); > + if (ret < 0) > + return ret; > + *val = ret; > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + ret = i2c_smbus_read_byte_data(data->client, > + AL3010_REG_CONFIG); > + if (ret < 0) > + return ret; > + > + ret = AL3010_GAIN_READ(ret); > + *val = al3010_scales[ret][0]; > + *val2 = al3010_scales[ret][1]; > + > + return IIO_VAL_INT_PLUS_MICRO; > + } > + return -EINVAL; > +} > + > +static int al3010_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int val, > + int val2, long mask) > +{ > + struct al3010_data *data = iio_priv(indio_dev); > + int i; > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) { > + if (val != al3010_scales[i][0] || > + val2 != al3010_scales[i][1]) > + continue; > + > + return i2c_smbus_write_byte_data(data->client, > + AL3010_REG_CONFIG, > + AL3010_GAIN_WRITE(i)); > + } > + break; > + } > + return -EINVAL; > +} > + > +static const struct iio_info al3010_info = { > + .read_raw = al3010_read_raw, > + .write_raw = al3010_write_raw, > + .attrs = &al3010_attribute_group, > +}; > + > +static int al3010_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct al3010_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); > + data->client = client; > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->info = &al3010_info; > + indio_dev->name = AL3010_DRV_NAME; > + indio_dev->channels = al3010_channels; > + indio_dev->num_channels = ARRAY_SIZE(al3010_channels); > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + ret = al3010_init(data); > + if (ret < 0) { > + dev_err(&client->dev, "al3010 chip init failed\n"); > + return ret; > + } > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static int al3010_remove(struct i2c_client *client) > +{ > + return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, > + AL3010_CONFIG_DISABLE); There is a race here. Until the call to iio_device_unregister is called, the userspace interfaces (and in kernel) interfaces are exposed. When using managed (devm_) interfaces that occurs after remove. So 2 options to avoid this: 1) Don't use devm_ version of iio_device_register then you can explicitly unregister before turning off the device. 2) Use devm_add_action_or_reset to automatically disable the device and allow you to get rid of the remove function entirely. > +} > + > +static const struct i2c_device_id al3010_id[] = { > + {"al3010", 0}, No need to set the data field if not using it. { "als3010" } is fine. > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, al3010_id); > + > +static const struct of_device_id al3010_of_match[] = { > + { .compatible = "dynaimage,al3010", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, al3010_of_match); > + > +static struct i2c_driver al3010_driver = { > + .driver = { > + .name = AL3010_DRV_NAME, > + .of_match_table = al3010_of_match, > + }, > + .probe = al3010_probe, > + .remove = al3010_remove, > + .id_table = al3010_id, > +}; > +module_i2c_driver(al3010_driver); > + > +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxx>"); > +MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver"); > +MODULE_LICENSE("GPL v2");
