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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 | // 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"); |