// SPDX-License-Identifier: GPL-2.0-only /* * ltc2497-core.c - Common code for Analog Devices/Linear Technology * LTC2496 and LTC2497 ADCs * * Copyright (C) 2017 Analog Devices Inc. */ #include #include #include #include #include #include #include "ltc2497.h" #define LTC2497_SGL BIT(4) #define LTC2497_DIFF 0 #define LTC2497_SIGN BIT(3) static int ltc2497core_wait_conv(struct ltc2497core_driverdata *ddata) { s64 time_elapsed; time_elapsed = ktime_ms_delta(ktime_get(), ddata->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= 0) { /* We're in automatic mode - * so the last reading is still not outdated */ return 0; } return 1; } static int ltc2497core_read(struct ltc2497core_driverdata *ddata, u8 address, int *val) { int ret; ret = ltc2497core_wait_conv(ddata); if (ret < 0) return ret; if (ret || ddata->addr_prev != address) { ret = ddata->result_and_measure(ddata, address, NULL); if (ret < 0) return ret; ddata->addr_prev = address; if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS)) return -ERESTARTSYS; } ret = ddata->result_and_measure(ddata, address, val); if (ret < 0) return ret; ddata->time_prev = ktime_get(); return ret; } static int ltc2497core_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ltc2497core_driverdata *ddata = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&ddata->lock); ret = ltc2497core_read(ddata, chan->address, val); mutex_unlock(&ddata->lock); if (ret < 0) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: ret = regulator_get_voltage(ddata->ref); if (ret < 0) return ret; *val = ret / 1000; *val2 = ddata->chip_info->resolution + 1; 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 ltc2497core_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 ltc2497core_info = { .read_raw = ltc2497core_read_raw, }; int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev) { struct ltc2497core_driverdata *ddata = iio_priv(indio_dev); struct iio_map *plat_data = dev_get_platdata(dev); int ret; /* * Keep using dev_name() for the iio_dev's name on some of the parts, * since updating it would result in a ABI breakage. */ if (ddata->chip_info->name) indio_dev->name = ddata->chip_info->name; else indio_dev->name = dev_name(dev); indio_dev->info = <c2497core_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = ltc2497core_channel; indio_dev->num_channels = ARRAY_SIZE(ltc2497core_channel); ret = ddata->result_and_measure(ddata, LTC2497_CONFIG_DEFAULT, NULL); if (ret < 0) return ret; ddata->ref = devm_regulator_get(dev, "vref"); if (IS_ERR(ddata->ref)) return dev_err_probe(dev, PTR_ERR(ddata->ref), "Failed to get vref regulator\n"); ret = regulator_enable(ddata->ref); if (ret < 0) { dev_err(dev, "Failed to enable vref regulator: %pe\n", ERR_PTR(ret)); return ret; } 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; } ddata->addr_prev = LTC2497_CONFIG_DEFAULT; ddata->time_prev = ktime_get(); mutex_init(&ddata->lock); 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(ddata->ref); return ret; } EXPORT_SYMBOL_NS(ltc2497core_probe, "LTC2497"); void ltc2497core_remove(struct iio_dev *indio_dev) { struct ltc2497core_driverdata *ddata = iio_priv(indio_dev); iio_device_unregister(indio_dev); iio_map_array_unregister(indio_dev); regulator_disable(ddata->ref); } EXPORT_SYMBOL_NS(ltc2497core_remove, "LTC2497"); MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers"); MODULE_LICENSE("GPL v2");