diff options
Diffstat (limited to 'drivers/iio/light/lv0104cs.c')
| -rw-r--r-- | drivers/iio/light/lv0104cs.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/iio/light/lv0104cs.c b/drivers/iio/light/lv0104cs.c new file mode 100644 index 000000000..55b8e2855 --- /dev/null +++ b/drivers/iio/light/lv0104cs.c @@ -0,0 +1,531 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * lv0104cs.c: LV0104CS Ambient Light Sensor Driver + * + * Copyright (C) 2018 + * Author: Jeff LaBundy <jeff@labundy.com> + * + * 7-bit I2C slave address: 0x13 + * + * Link to data sheet: http://www.onsemi.com/pub/Collateral/LV0104CS-D.PDF + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define LV0104CS_REGVAL_MEASURE 0xE0 +#define LV0104CS_REGVAL_SLEEP 0x00 + +#define LV0104CS_SCALE_0_25X 0 +#define LV0104CS_SCALE_1X 1 +#define LV0104CS_SCALE_2X 2 +#define LV0104CS_SCALE_8X 3 +#define LV0104CS_SCALE_SHIFT 3 + +#define LV0104CS_INTEG_12_5MS 0 +#define LV0104CS_INTEG_100MS 1 +#define LV0104CS_INTEG_200MS 2 +#define LV0104CS_INTEG_SHIFT 1 + +#define LV0104CS_CALIBSCALE_UNITY 31 + +struct lv0104cs_private { + struct i2c_client *client; + struct mutex lock; + u8 calibscale; + u8 scale; + u8 int_time; +}; + +struct lv0104cs_mapping { + int val; + int val2; + u8 regval; +}; + +static const struct lv0104cs_mapping lv0104cs_calibscales[] = { + { 0, 666666, 0x81 }, + { 0, 800000, 0x82 }, + { 0, 857142, 0x83 }, + { 0, 888888, 0x84 }, + { 0, 909090, 0x85 }, + { 0, 923076, 0x86 }, + { 0, 933333, 0x87 }, + { 0, 941176, 0x88 }, + { 0, 947368, 0x89 }, + { 0, 952380, 0x8A }, + { 0, 956521, 0x8B }, + { 0, 960000, 0x8C }, + { 0, 962962, 0x8D }, + { 0, 965517, 0x8E }, + { 0, 967741, 0x8F }, + { 0, 969696, 0x90 }, + { 0, 971428, 0x91 }, + { 0, 972972, 0x92 }, + { 0, 974358, 0x93 }, + { 0, 975609, 0x94 }, + { 0, 976744, 0x95 }, + { 0, 977777, 0x96 }, + { 0, 978723, 0x97 }, + { 0, 979591, 0x98 }, + { 0, 980392, 0x99 }, + { 0, 981132, 0x9A }, + { 0, 981818, 0x9B }, + { 0, 982456, 0x9C }, + { 0, 983050, 0x9D }, + { 0, 983606, 0x9E }, + { 0, 984126, 0x9F }, + { 1, 0, 0x80 }, + { 1, 16129, 0xBF }, + { 1, 16666, 0xBE }, + { 1, 17241, 0xBD }, + { 1, 17857, 0xBC }, + { 1, 18518, 0xBB }, + { 1, 19230, 0xBA }, + { 1, 20000, 0xB9 }, + { 1, 20833, 0xB8 }, + { 1, 21739, 0xB7 }, + { 1, 22727, 0xB6 }, + { 1, 23809, 0xB5 }, + { 1, 24999, 0xB4 }, + { 1, 26315, 0xB3 }, + { 1, 27777, 0xB2 }, + { 1, 29411, 0xB1 }, + { 1, 31250, 0xB0 }, + { 1, 33333, 0xAF }, + { 1, 35714, 0xAE }, + { 1, 38461, 0xAD }, + { 1, 41666, 0xAC }, + { 1, 45454, 0xAB }, + { 1, 50000, 0xAA }, + { 1, 55555, 0xA9 }, + { 1, 62500, 0xA8 }, + { 1, 71428, 0xA7 }, + { 1, 83333, 0xA6 }, + { 1, 100000, 0xA5 }, + { 1, 125000, 0xA4 }, + { 1, 166666, 0xA3 }, + { 1, 250000, 0xA2 }, + { 1, 500000, 0xA1 }, +}; + +static const struct lv0104cs_mapping lv0104cs_scales[] = { + { 0, 250000, LV0104CS_SCALE_0_25X << LV0104CS_SCALE_SHIFT }, + { 1, 0, LV0104CS_SCALE_1X << LV0104CS_SCALE_SHIFT }, + { 2, 0, LV0104CS_SCALE_2X << LV0104CS_SCALE_SHIFT }, + { 8, 0, LV0104CS_SCALE_8X << LV0104CS_SCALE_SHIFT }, +}; + +static const struct lv0104cs_mapping lv0104cs_int_times[] = { + { 0, 12500, LV0104CS_INTEG_12_5MS << LV0104CS_INTEG_SHIFT }, + { 0, 100000, LV0104CS_INTEG_100MS << LV0104CS_INTEG_SHIFT }, + { 0, 200000, LV0104CS_INTEG_200MS << LV0104CS_INTEG_SHIFT }, +}; + +static int lv0104cs_write_reg(struct i2c_client *client, u8 regval) +{ + int ret; + + ret = i2c_master_send(client, (char *)®val, sizeof(regval)); + if (ret < 0) + return ret; + if (ret != sizeof(regval)) + return -EIO; + + return 0; +} + +static int lv0104cs_read_adc(struct i2c_client *client, u16 *adc_output) +{ + __be16 regval; + int ret; + + ret = i2c_master_recv(client, (char *)®val, sizeof(regval)); + if (ret < 0) + return ret; + if (ret != sizeof(regval)) + return -EIO; + + *adc_output = be16_to_cpu(regval); + + return 0; +} + +static int lv0104cs_get_lux(struct lv0104cs_private *lv0104cs, + int *val, int *val2) +{ + u8 regval = LV0104CS_REGVAL_MEASURE; + u16 adc_output; + int ret; + + regval |= lv0104cs_scales[lv0104cs->scale].regval; + regval |= lv0104cs_int_times[lv0104cs->int_time].regval; + ret = lv0104cs_write_reg(lv0104cs->client, regval); + if (ret) + return ret; + + /* wait for integration time to pass (with margin) */ + switch (lv0104cs->int_time) { + case LV0104CS_INTEG_12_5MS: + msleep(50); + break; + + case LV0104CS_INTEG_100MS: + msleep(150); + break; + + case LV0104CS_INTEG_200MS: + msleep(250); + break; + + default: + return -EINVAL; + } + + ret = lv0104cs_read_adc(lv0104cs->client, &adc_output); + if (ret) + return ret; + + ret = lv0104cs_write_reg(lv0104cs->client, LV0104CS_REGVAL_SLEEP); + if (ret) + return ret; + + /* convert ADC output to lux */ + switch (lv0104cs->scale) { + case LV0104CS_SCALE_0_25X: + *val = adc_output * 4; + *val2 = 0; + return 0; + + case LV0104CS_SCALE_1X: + *val = adc_output; + *val2 = 0; + return 0; + + case LV0104CS_SCALE_2X: + *val = adc_output / 2; + *val2 = (adc_output % 2) * 500000; + return 0; + + case LV0104CS_SCALE_8X: + *val = adc_output / 8; + *val2 = (adc_output % 8) * 125000; + return 0; + + default: + return -EINVAL; + } +} + +static int lv0104cs_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct lv0104cs_private *lv0104cs = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_LIGHT) + return -EINVAL; + + mutex_lock(&lv0104cs->lock); + + switch (mask) { + case IIO_CHAN_INFO_PROCESSED: + ret = lv0104cs_get_lux(lv0104cs, val, val2); + if (ret) + goto err_mutex; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + + case IIO_CHAN_INFO_CALIBSCALE: + *val = lv0104cs_calibscales[lv0104cs->calibscale].val; + *val2 = lv0104cs_calibscales[lv0104cs->calibscale].val2; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + + case IIO_CHAN_INFO_SCALE: + *val = lv0104cs_scales[lv0104cs->scale].val; + *val2 = lv0104cs_scales[lv0104cs->scale].val2; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + + case IIO_CHAN_INFO_INT_TIME: + *val = lv0104cs_int_times[lv0104cs->int_time].val; + *val2 = lv0104cs_int_times[lv0104cs->int_time].val2; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + + default: + ret = -EINVAL; + } + +err_mutex: + mutex_unlock(&lv0104cs->lock); + + return ret; +} + +static int lv0104cs_set_calibscale(struct lv0104cs_private *lv0104cs, + int val, int val2) +{ + int calibscale = val * 1000000 + val2; + int floor, ceil, mid; + int ret, i, index; + + /* round to nearest quantized calibscale (sensitivity) */ + for (i = 0; i < ARRAY_SIZE(lv0104cs_calibscales) - 1; i++) { + floor = lv0104cs_calibscales[i].val * 1000000 + + lv0104cs_calibscales[i].val2; + ceil = lv0104cs_calibscales[i + 1].val * 1000000 + + lv0104cs_calibscales[i + 1].val2; + mid = (floor + ceil) / 2; + + /* round down */ + if (calibscale >= floor && calibscale < mid) { + index = i; + break; + } + + /* round up */ + if (calibscale >= mid && calibscale <= ceil) { + index = i + 1; + break; + } + } + + if (i == ARRAY_SIZE(lv0104cs_calibscales) - 1) + return -EINVAL; + + mutex_lock(&lv0104cs->lock); + + /* set calibscale (sensitivity) */ + ret = lv0104cs_write_reg(lv0104cs->client, + lv0104cs_calibscales[index].regval); + if (ret) + goto err_mutex; + + lv0104cs->calibscale = index; + +err_mutex: + mutex_unlock(&lv0104cs->lock); + + return ret; +} + +static int lv0104cs_set_scale(struct lv0104cs_private *lv0104cs, + int val, int val2) +{ + int i; + + /* hard matching */ + for (i = 0; i < ARRAY_SIZE(lv0104cs_scales); i++) { + if (val != lv0104cs_scales[i].val) + continue; + + if (val2 == lv0104cs_scales[i].val2) + break; + } + + if (i == ARRAY_SIZE(lv0104cs_scales)) + return -EINVAL; + + mutex_lock(&lv0104cs->lock); + lv0104cs->scale = i; + mutex_unlock(&lv0104cs->lock); + + return 0; +} + +static int lv0104cs_set_int_time(struct lv0104cs_private *lv0104cs, + int val, int val2) +{ + int i; + + /* hard matching */ + for (i = 0; i < ARRAY_SIZE(lv0104cs_int_times); i++) { + if (val != lv0104cs_int_times[i].val) + continue; + + if (val2 == lv0104cs_int_times[i].val2) + break; + } + + if (i == ARRAY_SIZE(lv0104cs_int_times)) + return -EINVAL; + + mutex_lock(&lv0104cs->lock); + lv0104cs->int_time = i; + mutex_unlock(&lv0104cs->lock); + + return 0; +} + +static int lv0104cs_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct lv0104cs_private *lv0104cs = iio_priv(indio_dev); + + if (chan->type != IIO_LIGHT) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_CALIBSCALE: + return lv0104cs_set_calibscale(lv0104cs, val, val2); + + case IIO_CHAN_INFO_SCALE: + return lv0104cs_set_scale(lv0104cs, val, val2); + + case IIO_CHAN_INFO_INT_TIME: + return lv0104cs_set_int_time(lv0104cs, val, val2); + + default: + return -EINVAL; + } +} + +static ssize_t lv0104cs_show_calibscale_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(lv0104cs_calibscales); i++) { + len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ", + lv0104cs_calibscales[i].val, + lv0104cs_calibscales[i].val2); + } + + buf[len - 1] = '\n'; + + return len; +} + +static ssize_t lv0104cs_show_scale_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(lv0104cs_scales); i++) { + len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ", + lv0104cs_scales[i].val, + lv0104cs_scales[i].val2); + } + + buf[len - 1] = '\n'; + + return len; +} + +static ssize_t lv0104cs_show_int_time_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(lv0104cs_int_times); i++) { + len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ", + lv0104cs_int_times[i].val, + lv0104cs_int_times[i].val2); + } + + buf[len - 1] = '\n'; + + return len; +} + +static IIO_DEVICE_ATTR(calibscale_available, 0444, + lv0104cs_show_calibscale_avail, NULL, 0); +static IIO_DEVICE_ATTR(scale_available, 0444, + lv0104cs_show_scale_avail, NULL, 0); +static IIO_DEV_ATTR_INT_TIME_AVAIL(lv0104cs_show_int_time_avail); + +static struct attribute *lv0104cs_attributes[] = { + &iio_dev_attr_calibscale_available.dev_attr.attr, + &iio_dev_attr_scale_available.dev_attr.attr, + &iio_dev_attr_integration_time_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group lv0104cs_attribute_group = { + .attrs = lv0104cs_attributes, +}; + +static const struct iio_info lv0104cs_info = { + .attrs = &lv0104cs_attribute_group, + .read_raw = &lv0104cs_read_raw, + .write_raw = &lv0104cs_write_raw, +}; + +static const struct iio_chan_spec lv0104cs_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_CALIBSCALE) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_INT_TIME), + }, +}; + +static int lv0104cs_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct lv0104cs_private *lv0104cs; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*lv0104cs)); + if (!indio_dev) + return -ENOMEM; + + lv0104cs = iio_priv(indio_dev); + + i2c_set_clientdata(client, lv0104cs); + lv0104cs->client = client; + + mutex_init(&lv0104cs->lock); + + lv0104cs->calibscale = LV0104CS_CALIBSCALE_UNITY; + lv0104cs->scale = LV0104CS_SCALE_1X; + lv0104cs->int_time = LV0104CS_INTEG_200MS; + + ret = lv0104cs_write_reg(lv0104cs->client, + lv0104cs_calibscales[LV0104CS_CALIBSCALE_UNITY].regval); + if (ret) + return ret; + + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->dev.parent = &client->dev; + indio_dev->channels = lv0104cs_channels; + indio_dev->num_channels = ARRAY_SIZE(lv0104cs_channels); + indio_dev->name = client->name; + indio_dev->info = &lv0104cs_info; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id lv0104cs_id[] = { + { "lv0104cs", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lv0104cs_id); + +static struct i2c_driver lv0104cs_i2c_driver = { + .driver = { + .name = "lv0104cs", + }, + .id_table = lv0104cs_id, + .probe = lv0104cs_probe, +}; +module_i2c_driver(lv0104cs_i2c_driver); + +MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>"); +MODULE_DESCRIPTION("LV0104CS Ambient Light Sensor Driver"); +MODULE_LICENSE("GPL"); |