Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Michael Hennerich | 1123 | 90.78% | 1 | 33.33% |
Gaurav Gupta | 112 | 9.05% | 1 | 33.33% |
Thomas Gleixner | 2 | 0.16% | 1 | 33.33% |
Total | 1237 | 3 |
// 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/delay.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/iio/driver.h> #include <linux/iio/sysfs.h> #include <linux/module.h> #include <linux/of.h> #include <linux/regulator/consumer.h> #define LTC2497_ENABLE 0xA0 #define LTC2497_SGL BIT(4) #define LTC2497_DIFF 0 #define LTC2497_SIGN BIT(3) #define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE #define LTC2497_CONVERSION_TIME_MS 150ULL struct ltc2497_st { struct i2c_client *client; struct regulator *ref; ktime_t time_prev; u8 addr_prev; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ __be32 buf ____cacheline_aligned; }; static int ltc2497_wait_conv(struct ltc2497_st *st) { s64 time_elapsed; time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev); if (time_elapsed < LTC2497_CONVERSION_TIME_MS) { /* delay if conversion time not passed * since last read or write */ if (msleep_interruptible( LTC2497_CONVERSION_TIME_MS - time_elapsed)) return -ERESTARTSYS; return 0; } if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) { /* We're in automatic mode - * so the last reading is stil not outdated */ return 0; } return 1; } static int ltc2497_read(struct ltc2497_st *st, u8 address, int *val) { struct i2c_client *client = st->client; int ret; ret = ltc2497_wait_conv(st); if (ret < 0) return ret; if (ret || st->addr_prev != address) { ret = i2c_smbus_write_byte(st->client, LTC2497_ENABLE | address); if (ret < 0) return ret; st->addr_prev = address; if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS)) return -ERESTARTSYS; } ret = i2c_master_recv(client, (char *)&st->buf, 3); if (ret < 0) { dev_err(&client->dev, "i2c_master_recv failed\n"); return ret; } st->time_prev = ktime_get(); /* convert and shift the result, * and finally convert from offset binary to signed integer */ *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17); return ret; } static int ltc2497_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ltc2497_st *st = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&indio_dev->mlock); ret = ltc2497_read(st, chan->address, val); mutex_unlock(&indio_dev->mlock); if (ret < 0) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: ret = regulator_get_voltage(st->ref); if (ret < 0) return ret; *val = ret / 1000; *val2 = 17; return IIO_VAL_FRACTIONAL_LOG2; default: return -EINVAL; } } #define LTC2497_CHAN(_chan, _addr, _ds_name) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (_chan), \ .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .datasheet_name = (_ds_name), \ } #define LTC2497_CHAN_DIFF(_chan, _addr) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \ .channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\ .address = (_addr | _chan), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .differential = 1, \ } static const struct iio_chan_spec ltc2497_channel[] = { LTC2497_CHAN(0, LTC2497_SGL, "CH0"), LTC2497_CHAN(1, LTC2497_SGL, "CH1"), LTC2497_CHAN(2, LTC2497_SGL, "CH2"), LTC2497_CHAN(3, LTC2497_SGL, "CH3"), LTC2497_CHAN(4, LTC2497_SGL, "CH4"), LTC2497_CHAN(5, LTC2497_SGL, "CH5"), LTC2497_CHAN(6, LTC2497_SGL, "CH6"), LTC2497_CHAN(7, LTC2497_SGL, "CH7"), LTC2497_CHAN(8, LTC2497_SGL, "CH8"), LTC2497_CHAN(9, LTC2497_SGL, "CH9"), LTC2497_CHAN(10, LTC2497_SGL, "CH10"), LTC2497_CHAN(11, LTC2497_SGL, "CH11"), LTC2497_CHAN(12, LTC2497_SGL, "CH12"), LTC2497_CHAN(13, LTC2497_SGL, "CH13"), LTC2497_CHAN(14, LTC2497_SGL, "CH14"), LTC2497_CHAN(15, LTC2497_SGL, "CH15"), LTC2497_CHAN_DIFF(0, LTC2497_DIFF), LTC2497_CHAN_DIFF(1, LTC2497_DIFF), LTC2497_CHAN_DIFF(2, LTC2497_DIFF), LTC2497_CHAN_DIFF(3, LTC2497_DIFF), LTC2497_CHAN_DIFF(4, LTC2497_DIFF), LTC2497_CHAN_DIFF(5, LTC2497_DIFF), LTC2497_CHAN_DIFF(6, LTC2497_DIFF), LTC2497_CHAN_DIFF(7, LTC2497_DIFF), LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN), LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN), }; static const struct iio_info ltc2497_info = { .read_raw = ltc2497_read_raw, }; static int ltc2497_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct iio_dev *indio_dev; struct ltc2497_st *st; struct iio_map *plat_data; int ret; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) return -EOPNOTSUPP; indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); i2c_set_clientdata(client, indio_dev); st->client = client; indio_dev->dev.parent = &client->dev; indio_dev->name = id->name; indio_dev->info = <c2497_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = ltc2497_channel; indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel); st->ref = devm_regulator_get(&client->dev, "vref"); if (IS_ERR(st->ref)) return PTR_ERR(st->ref); ret = regulator_enable(st->ref); if (ret < 0) return ret; if (client->dev.platform_data) { plat_data = ((struct iio_map *)client->dev.platform_data); ret = iio_map_array_register(indio_dev, plat_data); if (ret) { dev_err(&indio_dev->dev, "iio map err: %d\n", ret); goto err_regulator_disable; } } ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT); if (ret < 0) goto err_array_unregister; st->addr_prev = LTC2497_CONFIG_DEFAULT; st->time_prev = ktime_get(); ret = iio_device_register(indio_dev); if (ret < 0) goto err_array_unregister; return 0; err_array_unregister: iio_map_array_unregister(indio_dev); err_regulator_disable: regulator_disable(st->ref); return ret; } static int ltc2497_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct ltc2497_st *st = iio_priv(indio_dev); iio_map_array_unregister(indio_dev); iio_device_unregister(indio_dev); regulator_disable(st->ref); 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 = of_match_ptr(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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