--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support for Vishay VCNL3020 proximity sensor on i2c bus.
+ * Based on Vishay VCNL4000 driver code.
+ *
+ * TODO: interrupts.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VCNL3020_PROD_ID 0x21
+
+#define VCNL_COMMAND 0x80 /* Command register */
+#define VCNL_PROD_REV 0x81 /* Product ID and Revision ID */
+#define VCNL_PROXIMITY_RATE 0x82 /* Rate of Proximity Measurement */
+#define VCNL_LED_CURRENT 0x83 /* IR LED current for proximity mode */
+#define VCNL_PS_RESULT_HI 0x87 /* Proximity result register, MSB */
+#define VCNL_PS_RESULT_LO 0x88 /* Proximity result register, LSB */
+#define VCNL_PS_ICR 0x89 /* Interrupt Control Register */
+#define VCNL_PS_LO_THR_HI 0x8a /* High byte of low threshold value */
+#define VCNL_PS_LO_THR_LO 0x8b /* Low byte of low threshold value */
+#define VCNL_PS_HI_THR_HI 0x8c /* High byte of high threshold value */
+#define VCNL_PS_HI_THR_LO 0x8d /* Low byte of high threshold value */
+#define VCNL_ISR 0x8e /* Interrupt Status Register */
+#define VCNL_PS_MOD_ADJ 0x8f /* Proximity Modulator Timing Adjustment */
+
+/* Bit masks for COMMAND register */
+#define VCNL_PS_RDY BIT(5) /* proximity data ready? */
+#define VCNL_PS_OD BIT(3) /* start on-demand proximity
+ * measurement
+ */
+
+#define VCNL_ON_DEMAND_TIMEOUT_US 100000
+#define VCNL_POLL_US 20000
+
+/**
+ * struct vcnl3020_data - vcnl3020 specific data.
+ * @regmap: device register map.
+ * @dev: vcnl3020 device.
+ * @rev: revision id.
+ * @lock: lock for protecting access to device hardware registers.
+ */
+struct vcnl3020_data {
+ struct regmap *regmap;
+ struct device *dev;
+ u8 rev;
+ struct mutex lock;
+};
+
+/**
+ * struct vcnl3020_property - vcnl3020 property.
+ * @name: property name.
+ * @reg: i2c register offset.
+ * @conversion_func: conversion function.
+ */
+struct vcnl3020_property {
+ const char *name;
+ u32 reg;
+ u32 (*conversion_func)(u32 *val);
+};
+
+static u32 microamp_to_reg(u32 *val)
+{
+ /*
+ * An example of conversion from uA to reg val:
+ * 200000 uA == 200 mA == 20
+ */
+ return *val /= 10000;
+};
+
+static struct vcnl3020_property vcnl3020_led_current_property = {
+ .name = "vishay,led-current-microamp",
+ .reg = VCNL_LED_CURRENT,
+ .conversion_func = microamp_to_reg,
+};
+
+static int vcnl3020_get_and_apply_property(struct vcnl3020_data *data,
+ struct vcnl3020_property prop)
+{
+ int rc;
+ u32 val;
+
+ rc = device_property_read_u32(data->dev, prop.name, &val);
+ if (rc)
+ return 0;
+
+ if (prop.conversion_func)
+ prop.conversion_func(&val);
+
+ rc = regmap_write(data->regmap, prop.reg, val);
+ if (rc) {
+ dev_err(data->dev, "Error (%d) setting property (%s)\n",
+ rc, prop.name);
+ }
+
+ return rc;
+}
+
+static int vcnl3020_init(struct vcnl3020_data *data)
+{
+ int rc;
+ unsigned int reg;
+
+ rc = regmap_read(data->regmap, VCNL_PROD_REV, ®);
+ if (rc) {
+ dev_err(data->dev,
+ "Error (%d) reading product revision\n", rc);
+ return rc;
+ }
+
+ if (reg != VCNL3020_PROD_ID) {
+ dev_err(data->dev,
+ "Product id (%x) did not match vcnl3020 (%x)\n", reg,
+ VCNL3020_PROD_ID);
+ return -ENODEV;
+ }
+
+ data->rev = reg;
+ mutex_init(&data->lock);
+
+ return vcnl3020_get_and_apply_property(data,
+ vcnl3020_led_current_property);
+};
+
+static int vcnl3020_measure_proximity(struct vcnl3020_data *data, int *val)
+{
+ int rc;
+ unsigned int reg;
+ __be16 res;
+
+ mutex_lock(&data->lock);
+
+ rc = regmap_write(data->regmap, VCNL_COMMAND, VCNL_PS_OD);
+ if (rc)
+ goto err_unlock;
+
+ /* wait for data to become ready */
+ rc = regmap_read_poll_timeout(data->regmap, VCNL_COMMAND, reg,
+ reg & VCNL_PS_RDY, VCNL_POLL_US,
+ VCNL_ON_DEMAND_TIMEOUT_US);
+ if (rc) {
+ dev_err(data->dev,
+ "Error (%d) reading vcnl3020 command register\n", rc);
+ goto err_unlock;
+ }
+
+ /* high & low result bytes read */
+ rc = regmap_bulk_read(data->regmap, VCNL_PS_RESULT_HI, &res,
+ sizeof(res));
+ if (rc)
+ goto err_unlock;
+
+ *val = be16_to_cpu(res);
+
+err_unlock:
+ mutex_unlock(&data->lock);
+
+ return rc;
+}
+
+static const struct iio_chan_spec vcnl3020_channels[] = {
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ },
+};
+
+static int vcnl3020_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ int rc;
+ struct vcnl3020_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ rc = vcnl3020_measure_proximity(data, val);
+ if (rc)
+ return rc;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info vcnl3020_info = {
+ .read_raw = vcnl3020_read_raw,
+};
+
+static const struct regmap_config vcnl3020_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = VCNL_PS_MOD_ADJ,
+};
+
+static int vcnl3020_probe(struct i2c_client *client)
+{
+ struct vcnl3020_data *data;
+ struct iio_dev *indio_dev;
+ struct regmap *regmap;
+ int rc;
+
+ regmap = devm_regmap_init_i2c(client, &vcnl3020_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(&client->dev, "regmap_init failed\n");
+ return PTR_ERR(regmap);
+ }
+
+ 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->regmap = regmap;
+ data->dev = &client->dev;
+
+ rc = vcnl3020_init(data);
+ if (rc)
+ return rc;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &vcnl3020_info;
+ indio_dev->channels = vcnl3020_channels;
+ indio_dev->num_channels = ARRAY_SIZE(vcnl3020_channels);
+ indio_dev->name = "vcnl3020";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct of_device_id vcnl3020_of_match[] = {
+ {
+ .compatible = "vishay,vcnl3020",
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(of, vcnl3020_of_match);
+
+static struct i2c_driver vcnl3020_driver = {
+ .driver = {
+ .name = "vcnl3020",
+ .of_match_table = vcnl3020_of_match,
+ },
+ .probe_new = vcnl3020_probe,
+};
+module_i2c_driver(vcnl3020_driver);
+
+MODULE_AUTHOR("Ivan Mikhaylov <i.mikhaylov@yadro.com>");
+MODULE_DESCRIPTION("Vishay VCNL3020 proximity sensor driver");
+MODULE_LICENSE("GPL");