/* * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity * sensor * * Copyright 2017 Peter Meerwald-Stadler * Copyright 2017 Manivannan Sadhasivam * * 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 #include #include #include #include #include #include #include #include #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 "); MODULE_AUTHOR("Manivannan Sadhasivam "); MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver"); MODULE_LICENSE("GPL");