/* * Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel * Digital to Analog Converters driver * * Copyright 2011 Analog Devices Inc. * * Licensed under the GPL-2. */ #include <linux/device.h> #include <linux/err.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/spi/spi.h> #include <linux/slab.h> #include <linux/sysfs.h> #include <linux/regulator/consumer.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #define AD5764_REG_SF_NOP 0x0 #define AD5764_REG_SF_CONFIG 0x1 #define AD5764_REG_SF_CLEAR 0x4 #define AD5764_REG_SF_LOAD 0x5 #define AD5764_REG_DATA(x) ((2 << 3) | (x)) #define AD5764_REG_COARSE_GAIN(x) ((3 << 3) | (x)) #define AD5764_REG_FINE_GAIN(x) ((4 << 3) | (x)) #define AD5764_REG_OFFSET(x) ((5 << 3) | (x)) #define AD5764_NUM_CHANNELS 4 /** * struct ad5764_chip_info - chip specific information * @int_vref: Value of the internal reference voltage in uV - 0 if external * reference voltage is used * @channel channel specification */ struct ad5764_chip_info { unsigned long int_vref; const struct iio_chan_spec *channels; }; /** * struct ad5764_state - driver instance specific data * @spi: spi_device * @chip_info: chip info * @vref_reg: vref supply regulators * @data: spi transfer buffers */ struct ad5764_state { struct spi_device *spi; const struct ad5764_chip_info *chip_info; struct regulator_bulk_data vref_reg[2]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ union { __be32 d32; u8 d8[4]; } data[2] ____cacheline_aligned; }; enum ad5764_type { ID_AD5744, ID_AD5744R, ID_AD5764, ID_AD5764R, }; #define AD5764_CHANNEL(_chan, _bits) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .output = 1, \ .channel = (_chan), \ .address = (_chan), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_CALIBSCALE) | \ BIT(IIO_CHAN_INFO_CALIBBIAS), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \ .scan_type = { \ .sign = 'u', \ .realbits = (_bits), \ .storagebits = 16, \ .shift = 16 - (_bits), \ }, \ } #define DECLARE_AD5764_CHANNELS(_name, _bits) \ const struct iio_chan_spec _name##_channels[] = { \ AD5764_CHANNEL(0, (_bits)), \ AD5764_CHANNEL(1, (_bits)), \ AD5764_CHANNEL(2, (_bits)), \ AD5764_CHANNEL(3, (_bits)), \ }; static DECLARE_AD5764_CHANNELS(ad5764, 16); static DECLARE_AD5764_CHANNELS(ad5744, 14); static const struct ad5764_chip_info ad5764_chip_infos[] = { [ID_AD5744] = { .int_vref = 0, .channels = ad5744_channels, }, [ID_AD5744R] = { .int_vref = 5000000, .channels = ad5744_channels, }, [ID_AD5764] = { .int_vref = 0, .channels = ad5764_channels, }, [ID_AD5764R] = { .int_vref = 5000000, .channels = ad5764_channels, }, }; static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg, unsigned int val) { struct ad5764_state *st = iio_priv(indio_dev); int ret; mutex_lock(&indio_dev->mlock); st->data[0].d32 = cpu_to_be32((reg << 16) | val); ret = spi_write(st->spi, &st->data[0].d8[1], 3); mutex_unlock(&indio_dev->mlock); return ret; } static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg, unsigned int *val) { struct ad5764_state *st = iio_priv(indio_dev); int ret; struct spi_transfer t[] = { { .tx_buf = &st->data[0].d8[1], .len = 3, .cs_change = 1, }, { .rx_buf = &st->data[1].d8[1], .len = 3, }, }; mutex_lock(&indio_dev->mlock); st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16)); ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); if (ret >= 0) *val = be32_to_cpu(st->data[1].d32) & 0xffff; mutex_unlock(&indio_dev->mlock); return ret; } static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info) { switch (info) { case 0: return AD5764_REG_DATA(chan->address); case IIO_CHAN_INFO_CALIBBIAS: return AD5764_REG_OFFSET(chan->address); case IIO_CHAN_INFO_CALIBSCALE: return AD5764_REG_FINE_GAIN(chan->address); default: break; } return 0; } static int ad5764_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long info) { const int max_val = (1 << chan->scan_type.realbits); unsigned int reg; switch (info) { case IIO_CHAN_INFO_RAW: if (val >= max_val || val < 0) return -EINVAL; val <<= chan->scan_type.shift; break; case IIO_CHAN_INFO_CALIBBIAS: if (val >= 128 || val < -128) return -EINVAL; break; case IIO_CHAN_INFO_CALIBSCALE: if (val >= 32 || val < -32) return -EINVAL; break; default: return -EINVAL; } reg = ad5764_chan_info_to_reg(chan, info); return ad5764_write(indio_dev, reg, (u16)val); } static int ad5764_get_channel_vref(struct ad5764_state *st, unsigned int channel) { if (st->chip_info->int_vref) return st->chip_info->int_vref; else return regulator_get_voltage(st->vref_reg[channel / 2].consumer); } static int ad5764_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) { struct ad5764_state *st = iio_priv(indio_dev); unsigned int reg; int vref; int ret; switch (info) { case IIO_CHAN_INFO_RAW: reg = AD5764_REG_DATA(chan->address); ret = ad5764_read(indio_dev, reg, val); if (ret < 0) return ret; *val >>= chan->scan_type.shift; return IIO_VAL_INT; case IIO_CHAN_INFO_CALIBBIAS: reg = AD5764_REG_OFFSET(chan->address); ret = ad5764_read(indio_dev, reg, val); if (ret < 0) return ret; *val = sign_extend32(*val, 7); return IIO_VAL_INT; case IIO_CHAN_INFO_CALIBSCALE: reg = AD5764_REG_FINE_GAIN(chan->address); ret = ad5764_read(indio_dev, reg, val); if (ret < 0) return ret; *val = sign_extend32(*val, 5); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: /* vout = 4 * vref + ((dac_code / 65536) - 0.5) */ vref = ad5764_get_channel_vref(st, chan->channel); if (vref < 0) return vref; *val = vref * 4 / 1000; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: *val = -(1 << chan->scan_type.realbits) / 2; return IIO_VAL_INT; } return -EINVAL; } static const struct iio_info ad5764_info = { .read_raw = ad5764_read_raw, .write_raw = ad5764_write_raw, .driver_module = THIS_MODULE, }; static int ad5764_probe(struct spi_device *spi) { enum ad5764_type type = spi_get_device_id(spi)->driver_data; struct iio_dev *indio_dev; struct ad5764_state *st; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (indio_dev == NULL) { dev_err(&spi->dev, "Failed to allocate iio device\n"); return -ENOMEM; } st = iio_priv(indio_dev); spi_set_drvdata(spi, indio_dev); st->spi = spi; st->chip_info = &ad5764_chip_infos[type]; indio_dev->dev.parent = &spi->dev; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->info = &ad5764_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->num_channels = AD5764_NUM_CHANNELS; indio_dev->channels = st->chip_info->channels; if (st->chip_info->int_vref == 0) { st->vref_reg[0].supply = "vrefAB"; st->vref_reg[1].supply = "vrefCD"; ret = devm_regulator_bulk_get(&st->spi->dev, ARRAY_SIZE(st->vref_reg), st->vref_reg); if (ret) { dev_err(&spi->dev, "Failed to request vref regulators: %d\n", ret); return ret; } ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg), st->vref_reg); if (ret) { dev_err(&spi->dev, "Failed to enable vref regulators: %d\n", ret); return ret; } } ret = iio_device_register(indio_dev); if (ret) { dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); goto error_disable_reg; } return 0; error_disable_reg: if (st->chip_info->int_vref == 0) regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); return ret; } static int ad5764_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct ad5764_state *st = iio_priv(indio_dev); iio_device_unregister(indio_dev); if (st->chip_info->int_vref == 0) regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); return 0; } static const struct spi_device_id ad5764_ids[] = { { "ad5744", ID_AD5744 }, { "ad5744r", ID_AD5744R }, { "ad5764", ID_AD5764 }, { "ad5764r", ID_AD5764R }, { } }; MODULE_DEVICE_TABLE(spi, ad5764_ids); static struct spi_driver ad5764_driver = { .driver = { .name = "ad5764", }, .probe = ad5764_probe, .remove = ad5764_remove, .id_table = ad5764_ids, }; module_spi_driver(ad5764_driver); MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC"); MODULE_LICENSE("GPL v2");