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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * ltc2497.c - Driver for Analog Devices/Linear Technology LTC2497 ADC
- *
- * Copyright (C) 2017 Analog Devices Inc.
- *
- * Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf
- */
- #include <linux/i2c.h>
- #include <linux/iio/iio.h>
- #include <linux/iio/driver.h>
- #include <linux/module.h>
- #include <linux/mod_devicetable.h>
- #include "ltc2497.h"
- struct ltc2497_driverdata {
- /* this must be the first member */
- struct ltc2497core_driverdata common_ddata;
- struct i2c_client *client;
- /*
- * DMA (thus cache coherency maintenance) requires the
- * transfer buffers to live in their own cache lines.
- */
- __be32 buf ____cacheline_aligned;
- };
- static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,
- u8 address, int *val)
- {
- struct ltc2497_driverdata *st =
- container_of(ddata, struct ltc2497_driverdata, common_ddata);
- int ret;
- if (val) {
- ret = i2c_master_recv(st->client, (char *)&st->buf, 3);
- if (ret < 0) {
- dev_err(&st->client->dev, "i2c_master_recv failed\n");
- return ret;
- }
- *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
- }
- ret = i2c_smbus_write_byte(st->client,
- LTC2497_ENABLE | address);
- if (ret)
- dev_err(&st->client->dev, "i2c transfer failed: %pe\n",
- ERR_PTR(ret));
- return ret;
- }
- static int ltc2497_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
- {
- struct iio_dev *indio_dev;
- struct ltc2497_driverdata *st;
- struct device *dev = &client->dev;
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
- I2C_FUNC_SMBUS_WRITE_BYTE))
- return -EOPNOTSUPP;
- indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
- if (!indio_dev)
- return -ENOMEM;
- st = iio_priv(indio_dev);
- i2c_set_clientdata(client, indio_dev);
- st->client = client;
- st->common_ddata.result_and_measure = ltc2497_result_and_measure;
- return ltc2497core_probe(dev, indio_dev);
- }
- static int ltc2497_remove(struct i2c_client *client)
- {
- struct iio_dev *indio_dev = i2c_get_clientdata(client);
- ltc2497core_remove(indio_dev);
- return 0;
- }
- static const struct i2c_device_id ltc2497_id[] = {
- { "ltc2497", 0 },
- { }
- };
- MODULE_DEVICE_TABLE(i2c, ltc2497_id);
- static const struct of_device_id ltc2497_of_match[] = {
- { .compatible = "lltc,ltc2497", },
- {},
- };
- MODULE_DEVICE_TABLE(of, ltc2497_of_match);
- static struct i2c_driver ltc2497_driver = {
- .driver = {
- .name = "ltc2497",
- .of_match_table = ltc2497_of_match,
- },
- .probe = ltc2497_probe,
- .remove = ltc2497_remove,
- .id_table = ltc2497_id,
- };
- module_i2c_driver(ltc2497_driver);
- MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
- MODULE_DESCRIPTION("Linear Technology LTC2497 ADC driver");
- MODULE_LICENSE("GPL v2");
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