> This just adds support for reporting illuminance with default settings. > > All default registers are written on probe because the device otherwise > lacks a reset function.
comments below > Signed-off-by: Crestez Dan Leonard <leonard.cres...@intel.com> > --- > drivers/iio/light/Kconfig | 11 ++ > drivers/iio/light/Makefile | 1 + > drivers/iio/light/max44000.c | 295 > +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 307 insertions(+) > create mode 100644 drivers/iio/light/max44000.c > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig > index cfd3df8..42c15c1 100644 > --- a/drivers/iio/light/Kconfig > +++ b/drivers/iio/light/Kconfig > @@ -320,4 +320,15 @@ config VCNL4000 > To compile this driver as a module, choose M here: the > module will be called vcnl4000. > > +config MAX44000 > + tristate "MAX44000 Ambient and Infrared Proximity Sensor" > + depends on I2C > + select REGMAP_I2C > + help > + Say Y here if you want to build support for Maxim Integrated's > + MAX44000 ambient and infrared proximity sensor device. > + > + To compile this driver as a module, choose M here: > + the module will be called max44000. > + > endmenu > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile > index b2c3105..14b2f36 100644 > --- a/drivers/iio/light/Makefile > +++ b/drivers/iio/light/Makefile > @@ -30,3 +30,4 @@ obj-$(CONFIG_TCS3472) += tcs3472.o > obj-$(CONFIG_TSL4531) += tsl4531.o > obj-$(CONFIG_US5182D) += us5182d.o > obj-$(CONFIG_VCNL4000) += vcnl4000.o > +obj-$(CONFIG_MAX44000) += max44000.o alphabetical order please > diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c > new file mode 100644 > index 0000000..7c12153 > --- /dev/null > +++ b/drivers/iio/light/max44000.c > @@ -0,0 +1,295 @@ > +/* > + * MAX44000 Ambient and Infrared Proximity Sensor > + * > + * Copyright (c) 2016, Intel Corporation. > + * > + * This file is subject to the terms and conditions of version 2 of > + * the GNU General Public License. See the file COPYING in the main > + * directory of this archive for more details. > + * > + * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf > + * > + * 7-bit I2C slave address 0x4a > + */ > + > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/i2c.h> > +#include <linux/regmap.h> > +#include <linux/util_macros.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > +#include <linux/acpi.h> > + > +#define MAX44000_DRV_NAME "max44000" > + > +/* Registers in datasheet order */ > +#define MAX44000_REG_STATUS 0x00 > +#define MAX44000_REG_CFG_MAIN 0x01 > +#define MAX44000_REG_CFG_RX 0x02 > +#define MAX44000_REG_CFG_TX 0x03 > +#define MAX44000_REG_ALS_DATA_HI 0x04 > +#define MAX44000_REG_ALS_DATA_LO 0x05 > +#define MAX44000_REG_PRX_DATA 0x16 > +#define MAX44000_REG_ALS_UPTHR_HI 0x06 > +#define MAX44000_REG_ALS_UPTHR_LO 0x07 > +#define MAX44000_REG_ALS_LOTHR_HI 0x08 > +#define MAX44000_REG_ALS_LOTHR_LO 0x09 > +#define MAX44000_REG_PST 0x0a > +#define MAX44000_REG_PRX_IND 0x0b > +#define MAX44000_REG_PRX_THR 0x0c > +#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f > +#define MAX44000_REG_TRIM_GAIN_IR 0x10 > + > +#define MAX44000_ALSDATA_OVERFLOW 0x4000 > + > +#define MAX44000_REGMASK_READABLE 0x419fff > +#define MAX44000_REGMASK_WRITEABLE 0x019fce > +#define MAX44000_REGMASK_VOLATILE 0x400031 > + > +struct max44000_data { > + struct mutex lock; > + struct i2c_client *client; > + struct regmap *regmap; > +}; > + > +/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */ > +#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5 > + > +static const struct iio_chan_spec max44000_channels[] = { > + { > + .type = IIO_LIGHT, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static inline int max44000_read_alsval(struct max44000_data *data) drop inline, let the compiler figure out if inlining is beneficial > +{ > + u16 regval; > + int ret; > + > + regval = 0; needed? > + ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI, ®val, > 2); sizeof(regval) > + if (ret < 0) > + return ret; > + > + regval = be16_to_cpu(regval); > + > + /* Overflow is explained on datasheet page 17. > + * > + * It's a warning that either the G or IR channel has become saturated > + * and that the value in the register is likely incorrect. > + * > + * The recommendation is to change the scale (ALSPGA). > + * The driver just returns the max representable value. > + */ > + if (regval & MAX44000_ALSDATA_OVERFLOW) > + return 0x3FFF; > + > + return regval; > +} > + > +static int max44000_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct max44000_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + switch (chan->type) { > + case IIO_LIGHT: > + mutex_lock(&data->lock); > + ret = max44000_read_alsval(data); > + mutex_unlock(&data->lock); > + if (ret < 0) > + return ret; > + *val = ret; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > + > + case IIO_CHAN_INFO_SCALE: > + switch (chan->type) { > + case IIO_LIGHT: > + *val = 1; > + *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2; > + return IIO_VAL_FRACTIONAL_LOG2; > + > + default: > + return -EINVAL; > + } > + > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info max44000_info = { > + .driver_module = THIS_MODULE, > + .read_raw = max44000_read_raw, > +}; > + > +static bool max44000_readable_reg(struct device *dev, unsigned int reg) > +{ > + return (1 << reg) & MAX44000_REGMASK_READABLE; > +} > + > +static bool max44000_writeable_reg(struct device *dev, unsigned int reg) > +{ > + return (1 << reg) & MAX44000_REGMASK_WRITEABLE; > +} > + > +static bool max44000_volatile_reg(struct device *dev, unsigned int reg) > +{ > + return (1 << reg) & MAX44000_REGMASK_VOLATILE; > +} > + > +static bool max44000_precious_reg(struct device *dev, unsigned int reg) > +{ > + return reg == MAX44000_REG_STATUS; > +} > + > +/* Datasheet pages 9-10: */ > +static const struct reg_default max44000_reg_defaults[] = { > + { MAX44000_REG_CFG_MAIN, 0x24 }, > + /* Upper 4 bits are not documented but start as 1 on powerup > + * Setting them to 0 causes proximity to misbehave so set them to 1 > + */ > + { MAX44000_REG_CFG_RX, 0xf0 }, > + { MAX44000_REG_CFG_TX, 0x00 }, > + { MAX44000_REG_ALS_UPTHR_HI, 0x00 }, > + { MAX44000_REG_ALS_UPTHR_LO, 0x00 }, > + { MAX44000_REG_ALS_LOTHR_HI, 0x00 }, > + { MAX44000_REG_ALS_LOTHR_LO, 0x00 }, > + { MAX44000_REG_PST, 0x00 }, > + { MAX44000_REG_PRX_IND, 0x00 }, > + { MAX44000_REG_PRX_THR, 0x00 }, > + { MAX44000_REG_TRIM_GAIN_GREEN, 0x80 }, > + { MAX44000_REG_TRIM_GAIN_IR, 0x80 }, > +}; > + > +static const struct regmap_config max44000_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + > + .max_register = MAX44000_REG_PRX_DATA, > + .readable_reg = max44000_readable_reg, > + .writeable_reg = max44000_writeable_reg, > + .volatile_reg = max44000_volatile_reg, > + .precious_reg = max44000_precious_reg, > + > + .use_single_rw = 1, > + .cache_type = REGCACHE_FLAT, > + > + .reg_defaults = max44000_reg_defaults, > + .num_reg_defaults = ARRAY_SIZE(max44000_reg_defaults), > +}; > + > +static int max44000_force_write_defaults(struct max44000_data *data) > +{ > + int i, ret; > + > + for (i = 0; i < ARRAY_SIZE(max44000_reg_defaults); ++i) { > + ret = regmap_write(data->regmap, > + max44000_reg_defaults[i].reg, > + max44000_reg_defaults[i].def); > + if (ret) > + return ret; > + } > + return 0; > +} > + > +static int max44000_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct max44000_data *data; > + struct iio_dev *indio_dev; > + int ret, reg; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + data = iio_priv(indio_dev); > + data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config); > + if (IS_ERR(data->regmap)) { > + dev_err(&client->dev, "regmap_init failed!\n"); > + return PTR_ERR(data->regmap); > + } > + > + i2c_set_clientdata(client, indio_dev); > + data->client = client; > + mutex_init(&data->lock); > + indio_dev->dev.parent = &client->dev; > + indio_dev->info = &max44000_info; > + indio_dev->name = MAX44000_DRV_NAME; > + indio_dev->channels = max44000_channels; > + indio_dev->num_channels = ARRAY_SIZE(max44000_channels); > + > + /* Read status at least once to clear the power-on-reset bit. */ > + ret = regmap_read(data->regmap, MAX44000_REG_STATUS, ®); > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read init status: %d\n", > ret); > + return ret; > + } > + > + /* The device has no reset command, write defaults explicitly. */ > + ret = max44000_force_write_defaults(data); > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to write defaults: %d\n", > ret); > + return ret; > + } > + > + return iio_device_register(indio_dev); devm_ would work here to make _remove obsolete > +} > + > +static int max44000_remove(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + > + iio_device_unregister(indio_dev); > + return 0; > +} > + > +static const struct i2c_device_id max44000_id[] = { > + {"max44000", 0}, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, max44000_id); > + > +#ifdef CONFIG_OF > +static const struct of_device_id max44000_of_match[] = { > + { .compatible = "maxim,max44000" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, max44000_of_match); > +#endif > + > +#ifdef CONFIG_ACPI > +static const struct acpi_device_id max44000_acpi_match[] = { > + {"MAX44000", 0}, > + { } > +}; > +MODULE_DEVICE_TABLE(acpi, max44000_acpi_match); > +#endif > + > +static struct i2c_driver max44000_driver = { > + .driver = { > + .name = MAX44000_DRV_NAME, > + .of_match_table = of_match_ptr(max44000_of_match), > + .acpi_match_table = ACPI_PTR(max44000_acpi_match), > + }, > + .probe = max44000_probe, > + .remove = max44000_remove, > + .id_table = max44000_id, > +}; > + > +module_i2c_driver(max44000_driver); > + > +MODULE_AUTHOR("Crestez Dan Leonard <leonard.cres...@intel.com>"); > +MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald-Stadler +43-664-2444418 (mobile)
