| // 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) may require the |
| * transfer buffers to live in their own cache lines. |
| */ |
| __be32 buf __aligned(IIO_DMA_MINALIGN); |
| }; |
| |
| 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"); |