247 lines
6.2 KiB
C
247 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ltc2497-core.c - Common code for Analog Devices/Linear Technology
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* LTC2496 and LTC2497 ADCs
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*
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* Copyright (C) 2017 Analog Devices Inc.
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*/
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#include <linux/delay.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/driver.h>
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#include <linux/module.h>
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#include <linux/regulator/consumer.h>
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#include "ltc2497.h"
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#define LTC2497_SGL BIT(4)
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#define LTC2497_DIFF 0
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#define LTC2497_SIGN BIT(3)
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static int ltc2497core_wait_conv(struct ltc2497core_driverdata *ddata)
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{
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s64 time_elapsed;
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time_elapsed = ktime_ms_delta(ktime_get(), ddata->time_prev);
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if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
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/* delay if conversion time not passed
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* since last read or write
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*/
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if (msleep_interruptible(
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LTC2497_CONVERSION_TIME_MS - time_elapsed))
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return -ERESTARTSYS;
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return 0;
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}
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if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
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/* We're in automatic mode -
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* so the last reading is still not outdated
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*/
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return 0;
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}
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return 1;
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}
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static int ltc2497core_read(struct ltc2497core_driverdata *ddata, u8 address, int *val)
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{
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int ret;
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ret = ltc2497core_wait_conv(ddata);
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if (ret < 0)
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return ret;
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if (ret || ddata->addr_prev != address) {
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ret = ddata->result_and_measure(ddata, address, NULL);
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if (ret < 0)
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return ret;
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ddata->addr_prev = address;
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if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
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return -ERESTARTSYS;
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}
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ret = ddata->result_and_measure(ddata, address, val);
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if (ret < 0)
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return ret;
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ddata->time_prev = ktime_get();
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return ret;
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}
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static int ltc2497core_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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mutex_lock(&indio_dev->mlock);
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ret = ltc2497core_read(ddata, chan->address, val);
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mutex_unlock(&indio_dev->mlock);
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if (ret < 0)
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return ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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ret = regulator_get_voltage(ddata->ref);
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if (ret < 0)
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return ret;
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*val = ret / 1000;
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*val2 = ddata->chip_info->resolution + 1;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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}
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#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = (_chan), \
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.address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.datasheet_name = (_ds_name), \
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}
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#define LTC2497_CHAN_DIFF(_chan, _addr) { \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
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.channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
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.address = (_addr | _chan), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.differential = 1, \
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}
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static const struct iio_chan_spec ltc2497core_channel[] = {
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LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
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LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
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LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
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LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
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LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
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LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
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LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
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LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
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LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
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LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
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LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
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LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
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LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
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LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
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LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
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LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
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LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
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LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
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LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
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};
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static const struct iio_info ltc2497core_info = {
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.read_raw = ltc2497core_read_raw,
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};
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int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
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{
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struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
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int ret;
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/*
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* Keep using dev_name() for the iio_dev's name on some of the parts,
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* since updating it would result in a ABI breakage.
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*/
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if (ddata->chip_info->name)
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indio_dev->name = ddata->chip_info->name;
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else
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indio_dev->name = dev_name(dev);
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indio_dev->info = <c2497core_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = ltc2497core_channel;
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indio_dev->num_channels = ARRAY_SIZE(ltc2497core_channel);
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ret = ddata->result_and_measure(ddata, LTC2497_CONFIG_DEFAULT, NULL);
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if (ret < 0)
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return ret;
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ddata->ref = devm_regulator_get(dev, "vref");
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if (IS_ERR(ddata->ref))
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return dev_err_probe(dev, PTR_ERR(ddata->ref),
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"Failed to get vref regulator\n");
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ret = regulator_enable(ddata->ref);
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if (ret < 0) {
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dev_err(dev, "Failed to enable vref regulator: %pe\n",
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ERR_PTR(ret));
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return ret;
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}
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if (dev->platform_data) {
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struct iio_map *plat_data;
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plat_data = (struct iio_map *)dev->platform_data;
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ret = iio_map_array_register(indio_dev, plat_data);
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if (ret) {
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dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
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goto err_regulator_disable;
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}
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}
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ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
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ddata->time_prev = ktime_get();
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ret = iio_device_register(indio_dev);
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if (ret < 0)
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goto err_array_unregister;
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return 0;
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err_array_unregister:
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iio_map_array_unregister(indio_dev);
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err_regulator_disable:
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regulator_disable(ddata->ref);
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return ret;
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}
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EXPORT_SYMBOL_NS(ltc2497core_probe, LTC2497);
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void ltc2497core_remove(struct iio_dev *indio_dev)
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{
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struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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iio_map_array_unregister(indio_dev);
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regulator_disable(ddata->ref);
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}
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EXPORT_SYMBOL_NS(ltc2497core_remove, LTC2497);
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MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers");
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MODULE_LICENSE("GPL v2");
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