/* * AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter * * Copyright 2016 Qtechnology A/S * 2016 Ricardo Ribalda <ricardo.ribalda@gmail.com> * * Licensed under the GPL-2. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/spi/spi.h> #include <linux/bitops.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/regulator/consumer.h> #include <linux/platform_data/ad5761.h> #define AD5761_ADDR(addr) ((addr & 0xf) << 16) #define AD5761_ADDR_NOOP 0x0 #define AD5761_ADDR_DAC_WRITE 0x3 #define AD5761_ADDR_CTRL_WRITE_REG 0x4 #define AD5761_ADDR_SW_DATA_RESET 0x7 #define AD5761_ADDR_DAC_READ 0xb #define AD5761_ADDR_CTRL_READ_REG 0xc #define AD5761_ADDR_SW_FULL_RESET 0xf #define AD5761_CTRL_USE_INTVREF BIT(5) #define AD5761_CTRL_ETS BIT(6) /** * struct ad5761_chip_info - chip specific information * @int_vref: Value of the internal reference voltage in mV - 0 if external * reference voltage is used * @channel: channel specification */ struct ad5761_chip_info { unsigned long int_vref; const struct iio_chan_spec channel; }; struct ad5761_range_params { int m; int c; }; enum ad5761_supported_device_ids { ID_AD5721, ID_AD5721R, ID_AD5761, ID_AD5761R, }; /** * struct ad5761_state - driver instance specific data * @spi: spi_device * @vref_reg: reference voltage regulator * @use_intref: true when the internal voltage reference is used * @vref: actual voltage reference in mVolts * @range: output range mode used * @data: cache aligned spi buffer */ struct ad5761_state { struct spi_device *spi; struct regulator *vref_reg; bool use_intref; int vref; enum ad5761_voltage_range range; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ union { __be32 d32; u8 d8[4]; } data[3] ____cacheline_aligned; }; static const struct ad5761_range_params ad5761_range_params[] = { [AD5761_VOLTAGE_RANGE_M10V_10V] = { .m = 80, .c = 40, }, [AD5761_VOLTAGE_RANGE_0V_10V] = { .m = 40, .c = 0, }, [AD5761_VOLTAGE_RANGE_M5V_5V] = { .m = 40, .c = 20, }, [AD5761_VOLTAGE_RANGE_0V_5V] = { .m = 20, .c = 0, }, [AD5761_VOLTAGE_RANGE_M2V5_7V5] = { .m = 40, .c = 10, }, [AD5761_VOLTAGE_RANGE_M3V_3V] = { .m = 24, .c = 12, }, [AD5761_VOLTAGE_RANGE_0V_16V] = { .m = 64, .c = 0, }, [AD5761_VOLTAGE_RANGE_0V_20V] = { .m = 80, .c = 0, }, }; static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val) { st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val); return spi_write(st->spi, &st->data[0].d8[1], 3); } static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val) { struct ad5761_state *st = iio_priv(indio_dev); int ret; mutex_lock(&indio_dev->mlock); ret = _ad5761_spi_write(st, addr, val); mutex_unlock(&indio_dev->mlock); return ret; } static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val) { int ret; struct spi_transfer xfers[] = { { .tx_buf = &st->data[0].d8[1], .bits_per_word = 8, .len = 3, .cs_change = true, }, { .tx_buf = &st->data[1].d8[1], .rx_buf = &st->data[2].d8[1], .bits_per_word = 8, .len = 3, }, }; st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr)); st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP)); ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); *val = be32_to_cpu(st->data[2].d32); return ret; } static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val) { struct ad5761_state *st = iio_priv(indio_dev); int ret; mutex_lock(&indio_dev->mlock); ret = _ad5761_spi_read(st, addr, val); mutex_unlock(&indio_dev->mlock); return ret; } static int ad5761_spi_set_range(struct ad5761_state *st, enum ad5761_voltage_range range) { u16 aux; int ret; aux = (range & 0x7) | AD5761_CTRL_ETS; if (st->use_intref) aux |= AD5761_CTRL_USE_INTVREF; ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0); if (ret) return ret; ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux); if (ret) return ret; st->range = range; return 0; } static int ad5761_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ad5761_state *st; int ret; u16 aux; switch (mask) { case IIO_CHAN_INFO_RAW: ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux); if (ret) return ret; *val = aux >> chan->scan_type.shift; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: st = iio_priv(indio_dev); *val = st->vref * ad5761_range_params[st->range].m; *val /= 10; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: st = iio_priv(indio_dev); *val = -(1 << chan->scan_type.realbits); *val *= ad5761_range_params[st->range].c; *val /= ad5761_range_params[st->range].m; return IIO_VAL_INT; default: return -EINVAL; } } static int ad5761_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { u16 aux; if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0) return -EINVAL; aux = val << chan->scan_type.shift; return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux); } static const struct iio_info ad5761_info = { .read_raw = &ad5761_read_raw, .write_raw = &ad5761_write_raw, }; #define AD5761_CHAN(_bits) { \ .type = IIO_VOLTAGE, \ .output = 1, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_OFFSET), \ .scan_type = { \ .sign = 'u', \ .realbits = (_bits), \ .storagebits = 16, \ .shift = 16 - (_bits), \ }, \ } static const struct ad5761_chip_info ad5761_chip_infos[] = { [ID_AD5721] = { .int_vref = 0, .channel = AD5761_CHAN(12), }, [ID_AD5721R] = { .int_vref = 2500, .channel = AD5761_CHAN(12), }, [ID_AD5761] = { .int_vref = 0, .channel = AD5761_CHAN(16), }, [ID_AD5761R] = { .int_vref = 2500, .channel = AD5761_CHAN(16), }, }; static int ad5761_get_vref(struct ad5761_state *st, const struct ad5761_chip_info *chip_info) { int ret; st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref"); if (PTR_ERR(st->vref_reg) == -ENODEV) { /* Use Internal regulator */ if (!chip_info->int_vref) { dev_err(&st->spi->dev, "Voltage reference not found\n"); return -EIO; } st->use_intref = true; st->vref = chip_info->int_vref; return 0; } if (IS_ERR(st->vref_reg)) { dev_err(&st->spi->dev, "Error getting voltage reference regulator\n"); return PTR_ERR(st->vref_reg); } ret = regulator_enable(st->vref_reg); if (ret) { dev_err(&st->spi->dev, "Failed to enable voltage reference\n"); return ret; } ret = regulator_get_voltage(st->vref_reg); if (ret < 0) { dev_err(&st->spi->dev, "Failed to get voltage reference value\n"); goto disable_regulator_vref; } if (ret < 2000000 || ret > 3000000) { dev_warn(&st->spi->dev, "Invalid external voltage ref. value %d uV\n", ret); ret = -EIO; goto disable_regulator_vref; } st->vref = ret / 1000; st->use_intref = false; return 0; disable_regulator_vref: regulator_disable(st->vref_reg); st->vref_reg = NULL; return ret; } static int ad5761_probe(struct spi_device *spi) { struct iio_dev *iio_dev; struct ad5761_state *st; int ret; const struct ad5761_chip_info *chip_info = &ad5761_chip_infos[spi_get_device_id(spi)->driver_data]; enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V; struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev); iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!iio_dev) return -ENOMEM; st = iio_priv(iio_dev); st->spi = spi; spi_set_drvdata(spi, iio_dev); ret = ad5761_get_vref(st, chip_info); if (ret) return ret; if (pdata) voltage_range = pdata->voltage_range; ret = ad5761_spi_set_range(st, voltage_range); if (ret) goto disable_regulator_err; iio_dev->dev.parent = &spi->dev; iio_dev->info = &ad5761_info; iio_dev->modes = INDIO_DIRECT_MODE; iio_dev->channels = &chip_info->channel; iio_dev->num_channels = 1; iio_dev->name = spi_get_device_id(st->spi)->name; ret = iio_device_register(iio_dev); if (ret) goto disable_regulator_err; return 0; disable_regulator_err: if (!IS_ERR_OR_NULL(st->vref_reg)) regulator_disable(st->vref_reg); return ret; } static int ad5761_remove(struct spi_device *spi) { struct iio_dev *iio_dev = spi_get_drvdata(spi); struct ad5761_state *st = iio_priv(iio_dev); iio_device_unregister(iio_dev); if (!IS_ERR_OR_NULL(st->vref_reg)) regulator_disable(st->vref_reg); return 0; } static const struct spi_device_id ad5761_id[] = { {"ad5721", ID_AD5721}, {"ad5721r", ID_AD5721R}, {"ad5761", ID_AD5761}, {"ad5761r", ID_AD5761R}, {} }; MODULE_DEVICE_TABLE(spi, ad5761_id); static struct spi_driver ad5761_driver = { .driver = { .name = "ad5761", }, .probe = ad5761_probe, .remove = ad5761_remove, .id_table = ad5761_id, }; module_spi_driver(ad5761_driver); MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>"); MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver"); MODULE_LICENSE("GPL v2");