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Diffstat (limited to 'drivers/iio/light/veml6075.c')
-rw-r--r--drivers/iio/light/veml6075.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
new file mode 100644
index 0000000000..05d4c0e901
--- /dev/null
+++ b/drivers/iio/light/veml6075.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Vishay VEML6075 UVA and UVB light sensor
+ *
+ * Copyright 2023 Javier Carrasco <javier.carrasco.cruz@gmail.com>
+ *
+ * 7-bit I2C slave, address 0x10
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/units.h>
+
+#include <linux/iio/iio.h>
+
+#define VEML6075_CMD_CONF 0x00 /* configuration register */
+#define VEML6075_CMD_UVA 0x07 /* UVA channel */
+#define VEML6075_CMD_UVB 0x09 /* UVB channel */
+#define VEML6075_CMD_COMP1 0x0A /* visible light compensation */
+#define VEML6075_CMD_COMP2 0x0B /* infrarred light compensation */
+#define VEML6075_CMD_ID 0x0C /* device ID */
+
+#define VEML6075_CONF_IT GENMASK(6, 4) /* intregration time */
+#define VEML6075_CONF_HD BIT(3) /* dynamic setting */
+#define VEML6075_CONF_TRIG BIT(2) /* trigger */
+#define VEML6075_CONF_AF BIT(1) /* active force enable */
+#define VEML6075_CONF_SD BIT(0) /* shutdown */
+
+#define VEML6075_IT_50_MS 0x00
+#define VEML6075_IT_100_MS 0x01
+#define VEML6075_IT_200_MS 0x02
+#define VEML6075_IT_400_MS 0x03
+#define VEML6075_IT_800_MS 0x04
+
+#define VEML6075_AF_DISABLE 0x00
+#define VEML6075_AF_ENABLE 0x01
+
+#define VEML6075_SD_DISABLE 0x00
+#define VEML6075_SD_ENABLE 0x01
+
+/* Open-air coefficients and responsivity */
+#define VEML6075_A_COEF 2220
+#define VEML6075_B_COEF 1330
+#define VEML6075_C_COEF 2950
+#define VEML6075_D_COEF 1740
+#define VEML6075_UVA_RESP 1461
+#define VEML6075_UVB_RESP 2591
+
+static const int veml6075_it_ms[] = { 50, 100, 200, 400, 800 };
+
+struct veml6075_data {
+ struct i2c_client *client;
+ struct regmap *regmap;
+ /*
+ * prevent integration time modification and triggering
+ * measurements while a measurement is underway.
+ */
+ struct mutex lock;
+};
+
+/* channel number */
+enum veml6075_chan {
+ CH_UVA,
+ CH_UVB,
+};
+
+static const struct iio_chan_spec veml6075_channels[] = {
+ {
+ .type = IIO_INTENSITY,
+ .channel = CH_UVA,
+ .modified = 1,
+ .channel2 = IIO_MOD_LIGHT_UVA,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
+ },
+ {
+ .type = IIO_INTENSITY,
+ .channel = CH_UVB,
+ .modified = 1,
+ .channel2 = IIO_MOD_LIGHT_UVB,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
+ },
+ {
+ .type = IIO_UVINDEX,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
+ },
+};
+
+static int veml6075_request_measurement(struct veml6075_data *data)
+{
+ int ret, conf, int_time;
+
+ ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf);
+ if (ret < 0)
+ return ret;
+
+ /* disable shutdown and trigger measurement */
+ ret = regmap_write(data->regmap, VEML6075_CMD_CONF,
+ (conf | VEML6075_CONF_TRIG) & ~VEML6075_CONF_SD);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * A measurement requires between 1.30 and 1.40 times the integration
+ * time for all possible configurations. Using a 1.50 factor simplifies
+ * operations and ensures reliability under all circumstances.
+ */
+ int_time = veml6075_it_ms[FIELD_GET(VEML6075_CONF_IT, conf)];
+ msleep(int_time + (int_time / 2));
+
+ /* shutdown again, data registers are still accessible */
+ return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
+ VEML6075_CONF_SD, VEML6075_CONF_SD);
+}
+
+static int veml6075_uva_comp(int raw_uva, int comp1, int comp2)
+{
+ int comp1a_c, comp2a_c, uva_comp;
+
+ comp1a_c = (comp1 * VEML6075_A_COEF) / 1000U;
+ comp2a_c = (comp2 * VEML6075_B_COEF) / 1000U;
+ uva_comp = raw_uva - comp1a_c - comp2a_c;
+
+ return clamp_val(uva_comp, 0, U16_MAX);
+}
+
+static int veml6075_uvb_comp(int raw_uvb, int comp1, int comp2)
+{
+ int comp1b_c, comp2b_c, uvb_comp;
+
+ comp1b_c = (comp1 * VEML6075_C_COEF) / 1000U;
+ comp2b_c = (comp2 * VEML6075_D_COEF) / 1000U;
+ uvb_comp = raw_uvb - comp1b_c - comp2b_c;
+
+ return clamp_val(uvb_comp, 0, U16_MAX);
+}
+
+static int veml6075_read_comp(struct veml6075_data *data, int *c1, int *c2)
+{
+ int ret;
+
+ ret = regmap_read(data->regmap, VEML6075_CMD_COMP1, c1);
+ if (ret < 0)
+ return ret;
+
+ return regmap_read(data->regmap, VEML6075_CMD_COMP2, c2);
+}
+
+static int veml6075_read_uv_direct(struct veml6075_data *data, int chan,
+ int *val)
+{
+ int c1, c2, ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = veml6075_request_measurement(data);
+ if (ret < 0)
+ return ret;
+
+ ret = veml6075_read_comp(data, &c1, &c2);
+ if (ret < 0)
+ return ret;
+
+ switch (chan) {
+ case CH_UVA:
+ ret = regmap_read(data->regmap, VEML6075_CMD_UVA, val);
+ if (ret < 0)
+ return ret;
+
+ *val = veml6075_uva_comp(*val, c1, c2);
+ return IIO_VAL_INT;
+ case CH_UVB:
+ ret = regmap_read(data->regmap, VEML6075_CMD_UVB, val);
+ if (ret < 0)
+ return ret;
+
+ *val = veml6075_uvb_comp(*val, c1, c2);
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml6075_read_int_time_index(struct veml6075_data *data)
+{
+ int ret, conf;
+
+ ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf);
+ if (ret < 0)
+ return ret;
+
+ return FIELD_GET(VEML6075_CONF_IT, conf);
+}
+
+static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)
+{
+ int int_index;
+
+ guard(mutex)(&data->lock);
+ int_index = veml6075_read_int_time_index(data);
+ if (int_index < 0)
+ return int_index;
+
+ *val = veml6075_it_ms[int_index];
+
+ return IIO_VAL_INT;
+}
+
+static int veml6075_get_uvi_micro(struct veml6075_data *data, int uva_comp,
+ int uvb_comp)
+{
+ int uvia_micro = uva_comp * VEML6075_UVA_RESP;
+ int uvib_micro = uvb_comp * VEML6075_UVB_RESP;
+ int int_index;
+
+ int_index = veml6075_read_int_time_index(data);
+ if (int_index < 0)
+ return int_index;
+
+ switch (int_index) {
+ case VEML6075_IT_50_MS:
+ return uvia_micro + uvib_micro;
+ case VEML6075_IT_100_MS:
+ case VEML6075_IT_200_MS:
+ case VEML6075_IT_400_MS:
+ case VEML6075_IT_800_MS:
+ return (uvia_micro + uvib_micro) / (2 << int_index);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml6075_read_uvi(struct veml6075_data *data, int *val, int *val2)
+{
+ int ret, c1, c2, uva, uvb, uvi_micro;
+
+ guard(mutex)(&data->lock);
+
+ ret = veml6075_request_measurement(data);
+ if (ret < 0)
+ return ret;
+
+ ret = veml6075_read_comp(data, &c1, &c2);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_read(data->regmap, VEML6075_CMD_UVA, &uva);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_read(data->regmap, VEML6075_CMD_UVB, &uvb);
+ if (ret < 0)
+ return ret;
+
+ uvi_micro = veml6075_get_uvi_micro(data, veml6075_uva_comp(uva, c1, c2),
+ veml6075_uvb_comp(uvb, c1, c2));
+ if (uvi_micro < 0)
+ return uvi_micro;
+
+ *val = uvi_micro / MICRO;
+ *val2 = uvi_micro % MICRO;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6075_read_responsivity(int chan, int *val, int *val2)
+{
+ /* scale = 1 / resp */
+ switch (chan) {
+ case CH_UVA:
+ /* resp = 0.93 c/uW/cm2: scale = 1.75268817 */
+ *val = 1;
+ *val2 = 75268817;
+ return IIO_VAL_INT_PLUS_NANO;
+ case CH_UVB:
+ /* resp = 2.1 c/uW/cm2: scale = 0.476190476 */
+ *val = 0;
+ *val2 = 476190476;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml6075_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ *length = ARRAY_SIZE(veml6075_it_ms);
+ *vals = veml6075_it_ms;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml6075_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct veml6075_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return veml6075_read_uv_direct(data, chan->channel, val);
+ case IIO_CHAN_INFO_PROCESSED:
+ return veml6075_read_uvi(data, val, val2);
+ case IIO_CHAN_INFO_INT_TIME:
+ return veml6075_read_int_time_ms(data, val);
+ case IIO_CHAN_INFO_SCALE:
+ return veml6075_read_responsivity(chan->channel, val, val2);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml6075_write_int_time_ms(struct veml6075_data *data, int val)
+{
+ int i = ARRAY_SIZE(veml6075_it_ms);
+
+ guard(mutex)(&data->lock);
+
+ while (i-- > 0) {
+ if (val == veml6075_it_ms[i])
+ break;
+ }
+ if (i < 0)
+ return -EINVAL;
+
+ return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
+ VEML6075_CONF_IT,
+ FIELD_PREP(VEML6075_CONF_IT, i));
+}
+
+static int veml6075_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct veml6075_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ return veml6075_write_int_time_ms(data, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info veml6075_info = {
+ .read_avail = veml6075_read_avail,
+ .read_raw = veml6075_read_raw,
+ .write_raw = veml6075_write_raw,
+};
+
+static bool veml6075_readable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case VEML6075_CMD_CONF:
+ case VEML6075_CMD_UVA:
+ case VEML6075_CMD_UVB:
+ case VEML6075_CMD_COMP1:
+ case VEML6075_CMD_COMP2:
+ case VEML6075_CMD_ID:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool veml6075_writable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case VEML6075_CMD_CONF:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static const struct regmap_config veml6075_regmap_config = {
+ .name = "veml6075",
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = VEML6075_CMD_ID,
+ .readable_reg = veml6075_readable_reg,
+ .writeable_reg = veml6075_writable_reg,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static int veml6075_probe(struct i2c_client *client)
+{
+ struct veml6075_data *data;
+ struct iio_dev *indio_dev;
+ struct regmap *regmap;
+ int config, ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ regmap = devm_regmap_init_i2c(client, &veml6075_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ data->regmap = regmap;
+
+ mutex_init(&data->lock);
+
+ indio_dev->name = "veml6075";
+ indio_dev->info = &veml6075_info;
+ indio_dev->channels = veml6075_channels;
+ indio_dev->num_channels = ARRAY_SIZE(veml6075_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = devm_regulator_get_enable(&client->dev, "vdd");
+ if (ret < 0)
+ return ret;
+
+ /* default: 100ms integration time, active force enable, shutdown */
+ config = FIELD_PREP(VEML6075_CONF_IT, VEML6075_IT_100_MS) |
+ FIELD_PREP(VEML6075_CONF_AF, VEML6075_AF_ENABLE) |
+ FIELD_PREP(VEML6075_CONF_SD, VEML6075_SD_ENABLE);
+ ret = regmap_write(data->regmap, VEML6075_CMD_CONF, config);
+ if (ret < 0)
+ return ret;
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id veml6075_id[] = {
+ { "veml6075" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, veml6075_id);
+
+static const struct of_device_id veml6075_of_match[] = {
+ { .compatible = "vishay,veml6075" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, veml6075_of_match);
+
+static struct i2c_driver veml6075_driver = {
+ .driver = {
+ .name = "veml6075",
+ .of_match_table = veml6075_of_match,
+ },
+ .probe = veml6075_probe,
+ .id_table = veml6075_id,
+};
+
+module_i2c_driver(veml6075_driver);
+
+MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
+MODULE_DESCRIPTION("Vishay VEML6075 UVA and UVB light sensor driver");
+MODULE_LICENSE("GPL");