The MAX44009 is a low-power ambient light sensor from Maxim Integrated. It differs from the MAX44000 in that it doesn't have proximity sensing and that it requires far less current (1 micro-amp vs 5 micro-amps). The register mapping and feature set between the two are different enough to require a new driver for the MAX44009. Developed and tested with a BeagleBone Black and UDOO Neo (i.MX6SX) Supported features: * Rising and falling illuminance threshold events * Illuminance triggered buffers * Integration time https://datasheets.maximintegrated.com/en/ds/MAX44009.pdf Signed-off-by: Robert Eshleman <bobbyeshleman@xxxxxxxxx> --- .../bindings/iio/light/max44009.txt | 25 + drivers/iio/light/Kconfig | 13 + drivers/iio/light/Makefile | 1 + drivers/iio/light/max44009.c | 696 ++++++++++++++++++ 4 files changed, 735 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/light/max44009.txt create mode 100644 drivers/iio/light/max44009.c diff --git a/Documentation/devicetree/bindings/iio/light/max44009.txt b/Documentation/devicetree/bindings/iio/light/max44009.txt new file mode 100644 index 000000000000..220c2808dca1 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/light/max44009.txt @@ -0,0 +1,25 @@ +* MAX44009 Ambient Light Sensor + +Required properties: + +- compatible: should be "maxim,max44009" +- reg: the I2C address of the device (default is <0x4a>) + +Optional properties: + +- interrupts : interrupt mapping for GPIO IRQ. Should be configured with + IRQ_TYPE_EDGE_FALLING. + +Refer to interrupt-controller/interrupts.txt for generic interrupt client +node bindings. + +Example: + +max44009: max44009@4a { + compatible = "maxim,max44009"; + reg = <0x4a>; + + interrupt-parent = <&gpio1>; + interrupts = <17 IRQ_TYPE_EDGE_FALLING>; +}; + diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index 36f458433480..cda544f1047d 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -299,6 +299,19 @@ config MAX44000 To compile this driver as a module, choose M here: the module will be called max44000. +config MAX44009 + tristate "MAX44009 Ambient Light Sensor" + depends on I2C + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + select IIO_TRIGGERED_EVENT + help + Say Y here if you want to build support for Maxim Integrated's + MAX44009 ambient light sensor device. + + To compile this driver as a module, choose M here: + the module will be called max44009. + config OPT3001 tristate "Texas Instruments OPT3001 Light Sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index 286bf3975372..e40794fbb435 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o obj-$(CONFIG_LTR501) += ltr501.o obj-$(CONFIG_LV0104CS) += lv0104cs.o obj-$(CONFIG_MAX44000) += max44000.o +obj-$(CONFIG_MAX44009) += max44009.o obj-$(CONFIG_OPT3001) += opt3001.o obj-$(CONFIG_PA12203001) += pa12203001.o obj-$(CONFIG_RPR0521) += rpr0521.o diff --git a/drivers/iio/light/max44009.c b/drivers/iio/light/max44009.c new file mode 100644 index 000000000000..e15aa8eeb2f6 --- /dev/null +++ b/drivers/iio/light/max44009.c @@ -0,0 +1,696 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * max44009.c - Support for MAX44009 Ambient Light Sensor + * + * Copyright (c) 2019 Robert Eshleman <bobbyeshleman@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX44009.pdf + * + * TODO: Support continuous mode and processed event value (IIO_EV_INFO_VALUE) + * + * Default I2C address: 0x4a + * + */ + +#include <linux/bits.h> +#include <linux/i2c.h> +#include <linux/iio/buffer.h> +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/util_macros.h> + +#define MAX44009_DRV_NAME "max44009" +#define MAX44009_IRQ_NAME "max44009_event" + +/* Registers in datasheet order */ +#define MAX44009_REG_STATUS 0x0 +#define MAX44009_REG_ENABLE 0x1 +#define MAX44009_REG_CFG 0x2 +#define MAX44009_REG_LUX_HI 0x3 +#define MAX44009_REG_LUX_LO 0x4 +#define MAX44009_REG_UPPER_THR 0x5 +#define MAX44009_REG_LOWER_THR 0x6 +#define MAX44009_REG_THR_TIMER 0x7 + +#define MAX44009_INT_TIME_MASK (BIT(2) | BIT(1) | BIT(0)) +#define MAX44009_INT_TIME_SHIFT (0) + +#define MAX44009_MANUAL_MODE_MASK BIT(6) + +/* The maxmimum raw rising threshold for the max44009 */ +#define MAX44009_MAXIMUM_THRESHOLD 8355840 + +#define MAX44009_HI_NIBBLE(reg) (((reg) >> 4) & 0xf) +#define MAX44009_LO_NIBBLE(reg) ((reg) & 0xf) + +#define MAX44009_EXP_MASK 0xf00 +#define MAX44009_EXP_RSHIFT 8 +#define MAX44009_LUX_EXP(reg) \ + (1 << (((reg) & MAX44009_EXP_MASK) >> MAX44009_EXP_RSHIFT)) +#define MAX44009_LUX_MANT(reg) ((reg) & 0xff) + +#define MAX44009_LUX(reg) (MAX44009_LUX_EXP(reg) * MAX44009_LUX_MANT(reg)) + +#define MAX44009_THRESH_MANT(reg) ((MAX44009_LO_NIBBLE(reg) << 4) + 15) +#define MAX44009_THRESHOLD(reg) \ + ((1 << MAX44009_HI_NIBBLE(reg)) * MAX44009_THRESH_MANT(reg)) + +static const u32 max44009_int_time_ns_array[] = { + 800000000, + 400000000, + 200000000, + 100000000, + 50000000, /* Manual mode only */ + 25000000, /* Manual mode only */ + 12500000, /* Manual mode only */ + 6250000, /* Manual mode only */ +}; + +static const char max44009_int_time_str[] = + "0.8 " + "0.4 " + "0.2 " + "0.1 " + "0.05 " + "0.025 " + "0.0125 " + "0.00625"; + +static const u8 max44009_scale_avail_ulux_array[] = {45}; +static const char max44009_scale_avail_str[] = "0.045"; + +struct max44009_data { + struct i2c_client *client; + struct iio_trigger *trigger; + struct mutex lock; + int64_t timestamp; +}; + +static const struct iio_event_spec max44009_event_spec[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, +}; + +static const struct iio_chan_spec max44009_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_INT_TIME), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 24, + .storagebits = 32, + }, + .event_spec = max44009_event_spec, + .num_event_specs = ARRAY_SIZE(max44009_event_spec), + }, + IIO_CHAN_SOFT_TIMESTAMP(1), +}; + +static int max44009_read_reg(struct max44009_data *data, char reg) +{ + struct i2c_client *client = data->client; + int ret; + + mutex_lock(&data->lock); + ret = i2c_smbus_read_byte_data(client, reg); + if (ret < 0) { + dev_err(&client->dev, + "failed to read reg 0x%0x, err: %d\n", reg, ret); + goto err; + } + +err: + mutex_unlock(&data->lock); + return ret; +} + +static int max44009_write_reg(struct max44009_data *data, char reg, char buf) +{ + struct i2c_client *client = data->client; + int ret; + + mutex_lock(&data->lock); + ret = i2c_smbus_write_byte_data(client, reg, buf); + if (ret < 0) { + dev_err(&client->dev, + "failed to write reg 0x%0x, err: %d\n", + reg, ret); + goto err; + } + +err: + mutex_unlock(&data->lock); + return ret; +} + +static int max44009_read_int_time(struct max44009_data *data) +{ + int ret = max44009_read_reg(data, MAX44009_REG_CFG); + + if (ret < 0) { + return ret; + } + + return max44009_int_time_ns_array[ret & MAX44009_INT_TIME_MASK]; +} + +static int max44009_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct max44009_data *data = iio_priv(indio_dev); + int ret, int_time; + s64 ns; + + if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) { + ns = val * NSEC_PER_SEC + val2; + int_time = find_closest_descending( + ns, + max44009_int_time_ns_array, + ARRAY_SIZE(max44009_int_time_ns_array)); + + ret = max44009_read_reg(data, MAX44009_REG_CFG); + if (ret < 0) + return ret; + + ret &= ~MAX44009_INT_TIME_MASK; + ret |= (int_time << MAX44009_INT_TIME_SHIFT); + ret |= MAX44009_MANUAL_MODE_MASK; + + return max44009_write_reg(data, MAX44009_REG_CFG, ret); + } + return -EINVAL; +} + +static int max44009_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + long mask) +{ + if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) { + return IIO_VAL_INT_PLUS_NANO; + } else { + return IIO_VAL_INT; + } +} + +#define READ_LUX_XFER_LEN (4) + +static int max44009_read_lux_raw(struct max44009_data *data) +{ + int ret; + struct i2c_msg xfer[READ_LUX_XFER_LEN]; + u8 luxhireg[1] = {MAX44009_REG_LUX_HI}; + u8 luxloreg[1] = {MAX44009_REG_LUX_LO}; + u8 lo = 0; + u8 hi = 0; + u16 reg = 0; + + xfer[0].addr = data->client->addr; + xfer[0].flags = 0; + xfer[0].len = 1; + xfer[0].buf = luxhireg; + + xfer[1].addr = data->client->addr; + xfer[1].flags = I2C_M_RD; + xfer[1].len = 1; + xfer[1].buf = &hi; + + xfer[2].addr = data->client->addr; + xfer[2].flags = 0; + xfer[2].len = 1; + xfer[2].buf = luxloreg; + + xfer[3].addr = data->client->addr; + xfer[3].flags = I2C_M_RD; + xfer[3].len = 1; + xfer[3].buf = &lo; + + /* + * Use i2c_transfer instead of smbus read because i2c_transfer + * does NOT use a stop bit between address write and data read. + * Using a stop bit causes disjoint upper/lower byte reads and + * reduces accuracy + */ + mutex_lock(&data->lock); + ret = i2c_transfer(data->client->adapter, xfer, READ_LUX_XFER_LEN); + mutex_unlock(&data->lock); + if (ret != READ_LUX_XFER_LEN) { + return -EIO; + } + + reg = (((u16)hi) << 4) | (lo & 0xf); + + return MAX44009_LUX(reg); +} + +static int max44009_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct max44009_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: { + switch (chan->type) { + case IIO_LIGHT: { + ret = max44009_read_lux_raw(data); + if (ret < 0) { + return ret; + } + *val = ret; + *val2 = 0; + return IIO_VAL_INT; + } + default: + return -EINVAL; + } + break; + } + + case IIO_CHAN_INFO_INT_TIME: { + ret = max44009_read_int_time(data); + if (ret < 0) { + return ret; + } + + *val2 = ret; + *val = 0; + return IIO_VAL_INT_PLUS_NANO; + } + + default: + return -EINVAL; + } +} + +static IIO_CONST_ATTR(illuminance_scale_available, max44009_scale_avail_str); +static IIO_CONST_ATTR(illuminance_integration_time_available, + max44009_int_time_str); + +static struct attribute *max44009_attributes[] = { + &iio_const_attr_illuminance_integration_time_available.dev_attr.attr, + &iio_const_attr_illuminance_scale_available.dev_attr.attr, NULL +}; + +static const struct attribute_group max44009_attribute_group = { + .attrs = max44009_attributes, +}; + +static int max44009_thresh_byte_from_int(int thresh) +{ + int mantissa, exp; + + if (thresh < 0 || thresh > MAX44009_MAXIMUM_THRESHOLD) { + return -EINVAL; + } + + for (mantissa = thresh, exp = 0; mantissa > 0xff; exp++) { + mantissa >>= 1; + } + + mantissa >>= 4; + mantissa &= 0xf; + exp <<= 4; + + return exp | mantissa; +} + +static int max44009_get_thr_reg(enum iio_event_direction dir) +{ + switch (dir) { + case IIO_EV_DIR_RISING: + return MAX44009_REG_UPPER_THR; + case IIO_EV_DIR_FALLING: + return MAX44009_REG_LOWER_THR; + default: + return -EINVAL; + } +} + +static int max44009_write_thresh(struct iio_dev *indio_dev, + enum iio_event_direction dir, int val) +{ + struct max44009_data *data = iio_priv(indio_dev); + int thresh; + int reg; + + reg = max44009_get_thr_reg(dir); + if (reg < 0) { + return reg; + } + + thresh = max44009_thresh_byte_from_int(val); + if (thresh < 0) { + return thresh; + } + + return max44009_write_reg(data, reg, thresh); +} + +static int max44009_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int val, int val2) +{ + if (info != IIO_EV_INFO_VALUE || chan->type != IIO_LIGHT || val2 != 0) { + return -EINVAL; + } + + return max44009_write_thresh(indio_dev, dir, val); +} + +static int max44009_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int *val, int *val2) +{ + int thresh, reg; + struct max44009_data *data = iio_priv(indio_dev); + + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { + return -EINVAL; + } + + reg = max44009_get_thr_reg(dir); + if (reg < 0) { + return reg; + } + + thresh = max44009_read_reg(data, reg); + if (thresh < 0) { + return thresh; + } + + *val = MAX44009_THRESHOLD(thresh); + + return IIO_VAL_INT; +} + +static int max44009_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + int state) +{ + struct max44009_data *data = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { + return -EINVAL; + } + + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, state); + if (ret < 0) { + return ret; + } + + /* + * Set device to trigger interrupt immediately upon exceeding + * the threshold limit + */ + ret = max44009_write_reg(data, MAX44009_REG_THR_TIMER, 0); + if (ret < 0) { + return ret; + } + + return 0; +} + +static int max44009_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct max44009_data *data = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { + return -EINVAL; + } + + ret = max44009_read_reg(data, MAX44009_REG_ENABLE); + if (ret < 0) { + return ret; + } + + return ret; +} + +static const struct iio_info max44009_info = { + .read_raw = max44009_read_raw, + .write_raw = max44009_write_raw, + .write_raw_get_fmt = max44009_write_raw_get_fmt, + .read_event_value = max44009_read_event_value, + .read_event_config = max44009_read_event_config, + .write_event_value = max44009_write_event_value, + .write_event_config = max44009_write_event_config, + .attrs = &max44009_attribute_group, +}; + +static int max44009_set_trigger_state(struct iio_trigger *trigger, + bool enable) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trigger); + struct max44009_data *data = iio_priv(indio_dev); + int ret; + + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, enable); + if (ret < 0) { + return ret; + } + + ret = max44009_write_reg(data, MAX44009_REG_THR_TIMER, 0); + if (ret < 0) { + return ret; + } + + return ret; +} + +static const struct iio_trigger_ops max44009_trigger_ops = { + .set_trigger_state = max44009_set_trigger_state, +}; + +static irqreturn_t max44009_trigger_handler(int irq, void *p) +{ + struct iio_dev *indio_dev = p; + struct max44009_data *data = iio_priv(indio_dev); + int lux, upper, lower; + int ret; + enum iio_event_direction direction; + + /* 32-bit for lux and 64-bit for timestamp */ + u32 buf[3] = {0}; + + ret = max44009_read_reg(data, MAX44009_REG_STATUS); + if (ret <= 0) { + goto err; + } + + ret = max44009_read_reg(data, MAX44009_REG_ENABLE); + if (ret <= 0) { + goto err; + } + + /* Clear interrupt by disabling interrupt (see datasheet) */ + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, 0); + if (ret < 0) { + goto err; + } + + lux = max44009_read_lux_raw(data); + if (lux < 0) { + goto err; + } + + upper = max44009_read_reg(data, MAX44009_REG_UPPER_THR); + if (upper < 0) { + goto err; + } + upper = MAX44009_THRESHOLD(upper); + + lower = max44009_read_reg(data, MAX44009_REG_LOWER_THR); + if (lower < 0) { + goto err; + } + lower = MAX44009_THRESHOLD(lower); + + /* If lux is NOT out-of-bounds then the interrupt was not triggered + * by this device + */ + if (lux < upper && lux > lower) { + goto err; + } + + /* Get event for correct thresh direction */ + if (lux >= upper) { + direction = IIO_EV_DIR_RISING; + } else if (lux <= lower) { + direction = IIO_EV_DIR_FALLING; + } else { + goto err; + } + + buf[0] = lux; + iio_push_to_buffers_with_timestamp(indio_dev, &buf, data->timestamp); + iio_trigger_notify_done(data->trigger); + + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0, + IIO_EV_TYPE_THRESH, direction), + data->timestamp); + + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, 1); + if (ret < 0) { + goto err; + } + + return IRQ_HANDLED; + +err: + /* Re-enable interrupt */ + max44009_write_reg(data, MAX44009_REG_ENABLE, 1); + return IRQ_NONE; +} + +static irqreturn_t max44009_irq_handler(int irq, void *p) +{ + struct iio_dev *indio_dev = p; + struct max44009_data *data = iio_priv(indio_dev); + + data->timestamp = iio_get_time_ns(indio_dev); + return IRQ_WAKE_THREAD; +} + +static int max44009_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max44009_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 = &max44009_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = MAX44009_DRV_NAME; + indio_dev->channels = max44009_channels; + indio_dev->num_channels = ARRAY_SIZE(max44009_channels); + mutex_init(&data->lock); + + /* Clear stale interrupt bit */ + ret = max44009_read_reg(data, MAX44009_REG_STATUS); + if (ret < 0) { + goto err; + } + + if (client->irq > 0) { + ret = devm_request_threaded_irq(&client->dev, client->irq, + max44009_irq_handler, + max44009_trigger_handler, + IRQF_TRIGGER_FALLING | + IRQF_ONESHOT, + MAX44009_IRQ_NAME, indio_dev); + if (ret < 0) { + goto err; + } + + ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, + max44009_irq_handler, + max44009_trigger_handler, + NULL); + if (ret < 0) { + goto err; + } + + data->trigger = devm_iio_trigger_alloc(indio_dev->dev.parent, + "%s-dev%d", + indio_dev->name, + indio_dev->id); + if (!data->trigger) { + ret = -ENOMEM; + goto err; + } + data->trigger->dev.parent = indio_dev->dev.parent; + data->trigger->ops = &max44009_trigger_ops; + iio_trigger_set_drvdata(data->trigger, indio_dev); + + ret = devm_iio_trigger_register(&client->dev, data->trigger); + if (ret < 0) { + goto err; + } + } + + ret = devm_iio_device_register(&client->dev, indio_dev); + if (ret < 0) { + goto err; + } + + return 0; +err: + mutex_destroy(&data->lock); + return ret; +} + +static const struct i2c_device_id max44009_id[] = { + { "max44009", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max44009_id); + +static struct i2c_driver max44009_driver = { + .driver = { + .name = MAX44009_DRV_NAME, + }, + .probe = max44009_probe, + .id_table = max44009_id, +}; +module_i2c_driver(max44009_driver); + +static const struct of_device_id max44009_of_match[] = { + { .compatible = "maxim,max44009" }, + { } +}; +MODULE_DEVICE_TABLE(of, max44009_of_match); + +MODULE_AUTHOR("Robert Eshleman <bobbyeshleman@xxxxxxxxx>"); +MODULE_LICENSE("GPL v2"); +MODULE_VERSION("1.0.0"); +MODULE_DESCRIPTION("MAX44009 ambient light sensor driver"); -- 2.20.1
