diff options
Diffstat (limited to 'drivers/iio/light/vl6180.c')
| -rw-r--r-- | drivers/iio/light/vl6180.c | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c new file mode 100644 index 000000000..192c77ef3 --- /dev/null +++ b/drivers/iio/light/vl6180.c @@ -0,0 +1,554 @@ +/* + * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity + * sensor + * + * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> + * Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com> + * + * 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. + * + * IIO driver for VL6180 (7-bit I2C slave address 0x29) + * + * Range: 0 to 100mm + * ALS: < 1 Lux up to 100 kLux + * IR: 850nm + * + * TODO: irq, threshold events, continuous mode, hardware buffer + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/mutex.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/delay.h> +#include <linux/util_macros.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define VL6180_DRV_NAME "vl6180" + +/* Device identification register and value */ +#define VL6180_MODEL_ID 0x000 +#define VL6180_MODEL_ID_VAL 0xb4 + +/* Configuration registers */ +#define VL6180_INTR_CONFIG 0x014 +#define VL6180_INTR_CLEAR 0x015 +#define VL6180_OUT_OF_RESET 0x016 +#define VL6180_HOLD 0x017 +#define VL6180_RANGE_START 0x018 +#define VL6180_ALS_START 0x038 +#define VL6180_ALS_GAIN 0x03f +#define VL6180_ALS_IT 0x040 + +/* Status registers */ +#define VL6180_RANGE_STATUS 0x04d +#define VL6180_ALS_STATUS 0x04e +#define VL6180_INTR_STATUS 0x04f + +/* Result value registers */ +#define VL6180_ALS_VALUE 0x050 +#define VL6180_RANGE_VALUE 0x062 +#define VL6180_RANGE_RATE 0x066 + +/* bits of the RANGE_START and ALS_START register */ +#define VL6180_MODE_CONT BIT(1) /* continuous mode */ +#define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */ + +/* bits of the INTR_STATUS and INTR_CONFIG register */ +#define VL6180_ALS_READY BIT(5) +#define VL6180_RANGE_READY BIT(2) + +/* bits of the INTR_CLEAR register */ +#define VL6180_CLEAR_ERROR BIT(2) +#define VL6180_CLEAR_ALS BIT(1) +#define VL6180_CLEAR_RANGE BIT(0) + +/* bits of the HOLD register */ +#define VL6180_HOLD_ON BIT(0) + +/* default value for the ALS_IT register */ +#define VL6180_ALS_IT_100 0x63 /* 100 ms */ + +/* values for the ALS_GAIN register */ +#define VL6180_ALS_GAIN_1 0x46 +#define VL6180_ALS_GAIN_1_25 0x45 +#define VL6180_ALS_GAIN_1_67 0x44 +#define VL6180_ALS_GAIN_2_5 0x43 +#define VL6180_ALS_GAIN_5 0x42 +#define VL6180_ALS_GAIN_10 0x41 +#define VL6180_ALS_GAIN_20 0x40 +#define VL6180_ALS_GAIN_40 0x47 + +struct vl6180_data { + struct i2c_client *client; + struct mutex lock; + unsigned int als_gain_milli; + unsigned int als_it_ms; +}; + +enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX }; + +/** + * struct vl6180_chan_regs - Registers for accessing channels + * @drdy_mask: Data ready bit in status register + * @start_reg: Conversion start register + * @value_reg: Result value register + * @word: Register word length + */ +struct vl6180_chan_regs { + u8 drdy_mask; + u16 start_reg, value_reg; + bool word; +}; + +static const struct vl6180_chan_regs vl6180_chan_regs_table[] = { + [VL6180_ALS] = { + .drdy_mask = VL6180_ALS_READY, + .start_reg = VL6180_ALS_START, + .value_reg = VL6180_ALS_VALUE, + .word = true, + }, + [VL6180_RANGE] = { + .drdy_mask = VL6180_RANGE_READY, + .start_reg = VL6180_RANGE_START, + .value_reg = VL6180_RANGE_VALUE, + .word = false, + }, + [VL6180_PROX] = { + .drdy_mask = VL6180_RANGE_READY, + .start_reg = VL6180_RANGE_START, + .value_reg = VL6180_RANGE_RATE, + .word = true, + }, +}; + +static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf, + u8 len) +{ + __be16 cmdbuf = cpu_to_be16(cmd); + struct i2c_msg msgs[2] = { + { .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf }, + { .addr = client->addr, .len = len, .buf = databuf, + .flags = I2C_M_RD } }; + int ret; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret < 0) + dev_err(&client->dev, "failed reading register 0x%04x\n", cmd); + + return ret; +} + +static int vl6180_read_byte(struct i2c_client *client, u16 cmd) +{ + u8 data; + int ret; + + ret = vl6180_read(client, cmd, &data, sizeof(data)); + if (ret < 0) + return ret; + + return data; +} + +static int vl6180_read_word(struct i2c_client *client, u16 cmd) +{ + __be16 data; + int ret; + + ret = vl6180_read(client, cmd, &data, sizeof(data)); + if (ret < 0) + return ret; + + return be16_to_cpu(data); +} + +static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val) +{ + u8 buf[3]; + struct i2c_msg msgs[1] = { + { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; + int ret; + + buf[0] = cmd >> 8; + buf[1] = cmd & 0xff; + buf[2] = val; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret < 0) { + dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); + return ret; + } + + return 0; +} + +static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val) +{ + __be16 buf[2]; + struct i2c_msg msgs[1] = { + { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; + int ret; + + buf[0] = cpu_to_be16(cmd); + buf[1] = cpu_to_be16(val); + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret < 0) { + dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); + return ret; + } + + return 0; +} + +static int vl6180_measure(struct vl6180_data *data, int addr) +{ + struct i2c_client *client = data->client; + int tries = 20, ret; + u16 value; + + mutex_lock(&data->lock); + /* Start single shot measurement */ + ret = vl6180_write_byte(client, + vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP); + if (ret < 0) + goto fail; + + while (tries--) { + ret = vl6180_read_byte(client, VL6180_INTR_STATUS); + if (ret < 0) + goto fail; + + if (ret & vl6180_chan_regs_table[addr].drdy_mask) + break; + msleep(20); + } + + if (tries < 0) { + ret = -EIO; + goto fail; + } + + /* Read result value from appropriate registers */ + ret = vl6180_chan_regs_table[addr].word ? + vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) : + vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg); + if (ret < 0) + goto fail; + value = ret; + + /* Clear the interrupt flag after data read */ + ret = vl6180_write_byte(client, VL6180_INTR_CLEAR, + VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE); + if (ret < 0) + goto fail; + + ret = value; + +fail: + mutex_unlock(&data->lock); + + return ret; +} + +static const struct iio_chan_spec vl6180_channels[] = { + { + .type = IIO_LIGHT, + .address = VL6180_ALS, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_INT_TIME) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_HARDWAREGAIN), + }, { + .type = IIO_DISTANCE, + .address = VL6180_RANGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, { + .type = IIO_PROXIMITY, + .address = VL6180_PROX, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + } +}; + +/* + * Available Ambient Light Sensor gain settings, 1/1000th, and + * corresponding setting for the VL6180_ALS_GAIN register + */ +static const int vl6180_als_gain_tab[8] = { + 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000 +}; +static const u8 vl6180_als_gain_tab_bits[8] = { + VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25, + VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5, + VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10, + VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40 +}; + +static int vl6180_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct vl6180_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = vl6180_measure(data, chan->address); + if (ret < 0) + return ret; + *val = ret; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_INT_TIME: + *val = data->als_it_ms; + *val2 = 1000; + + return IIO_VAL_FRACTIONAL; + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_LIGHT: + /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */ + *val = 32000; /* 0.32 * 1000 * 100 */ + *val2 = data->als_gain_milli * data->als_it_ms; + + return IIO_VAL_FRACTIONAL; + + case IIO_DISTANCE: + *val = 0; /* sensor reports mm, scale to meter */ + *val2 = 1000; + break; + default: + return -EINVAL; + } + + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_HARDWAREGAIN: + *val = data->als_gain_milli; + *val2 = 1000; + + return IIO_VAL_FRACTIONAL; + + default: + return -EINVAL; + } +} + +static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40"); + +static struct attribute *vl6180_attributes[] = { + &iio_const_attr_als_gain_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group vl6180_attribute_group = { + .attrs = vl6180_attributes, +}; + +/* HOLD is needed before updating any config registers */ +static int vl6180_hold(struct vl6180_data *data, bool hold) +{ + return vl6180_write_byte(data->client, VL6180_HOLD, + hold ? VL6180_HOLD_ON : 0); +} + +static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2) +{ + int i, ret, gain; + + if (val < 1 || val > 40) + return -EINVAL; + + gain = (val * 1000000 + val2) / 1000; + if (gain < 1 || gain > 40000) + return -EINVAL; + + i = find_closest(gain, vl6180_als_gain_tab, + ARRAY_SIZE(vl6180_als_gain_tab)); + + mutex_lock(&data->lock); + ret = vl6180_hold(data, true); + if (ret < 0) + goto fail; + + ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, + vl6180_als_gain_tab_bits[i]); + + if (ret >= 0) + data->als_gain_milli = vl6180_als_gain_tab[i]; + +fail: + vl6180_hold(data, false); + mutex_unlock(&data->lock); + return ret; +} + +static int vl6180_set_it(struct vl6180_data *data, int val, int val2) +{ + int ret, it_ms; + + it_ms = (val2 + 500) / 1000; /* round to ms */ + if (val != 0 || it_ms < 1 || it_ms > 512) + return -EINVAL; + + mutex_lock(&data->lock); + ret = vl6180_hold(data, true); + if (ret < 0) + goto fail; + + ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1); + + if (ret >= 0) + data->als_it_ms = it_ms; + +fail: + vl6180_hold(data, false); + mutex_unlock(&data->lock); + + return ret; +} + +static int vl6180_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct vl6180_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + return vl6180_set_it(data, val, val2); + + case IIO_CHAN_INFO_HARDWAREGAIN: + if (chan->type != IIO_LIGHT) + return -EINVAL; + + return vl6180_set_als_gain(data, val, val2); + default: + return -EINVAL; + } +} + +static const struct iio_info vl6180_info = { + .read_raw = vl6180_read_raw, + .write_raw = vl6180_write_raw, + .attrs = &vl6180_attribute_group, +}; + +static int vl6180_init(struct vl6180_data *data) +{ + struct i2c_client *client = data->client; + int ret; + + ret = vl6180_read_byte(client, VL6180_MODEL_ID); + if (ret < 0) + return ret; + + if (ret != VL6180_MODEL_ID_VAL) { + dev_err(&client->dev, "invalid model ID %02x\n", ret); + return -ENODEV; + } + + ret = vl6180_hold(data, true); + if (ret < 0) + return ret; + + ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET); + if (ret < 0) + return ret; + + /* + * Detect false reset condition here. This bit is always set when the + * system comes out of reset. + */ + if (ret != 0x01) + dev_info(&client->dev, "device is not fresh out of reset\n"); + + /* Enable ALS and Range ready interrupts */ + ret = vl6180_write_byte(client, VL6180_INTR_CONFIG, + VL6180_ALS_READY | VL6180_RANGE_READY); + if (ret < 0) + return ret; + + /* ALS integration time: 100ms */ + data->als_it_ms = 100; + ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100); + if (ret < 0) + return ret; + + /* ALS gain: 1 */ + data->als_gain_milli = 1000; + ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1); + if (ret < 0) + return ret; + + ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00); + if (ret < 0) + return ret; + + return vl6180_hold(data, false); +} + +static int vl6180_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct vl6180_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; + mutex_init(&data->lock); + + indio_dev->dev.parent = &client->dev; + indio_dev->info = &vl6180_info; + indio_dev->channels = vl6180_channels; + indio_dev->num_channels = ARRAY_SIZE(vl6180_channels); + indio_dev->name = VL6180_DRV_NAME; + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = vl6180_init(data); + if (ret < 0) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct of_device_id vl6180_of_match[] = { + { .compatible = "st,vl6180", }, + { }, +}; +MODULE_DEVICE_TABLE(of, vl6180_of_match); + +static const struct i2c_device_id vl6180_id[] = { + { "vl6180", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, vl6180_id); + +static struct i2c_driver vl6180_driver = { + .driver = { + .name = VL6180_DRV_NAME, + .of_match_table = of_match_ptr(vl6180_of_match), + }, + .probe = vl6180_probe, + .id_table = vl6180_id, +}; + +module_i2c_driver(vl6180_driver); + +MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); +MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>"); +MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver"); +MODULE_LICENSE("GPL"); |