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369 lines
8.5 KiB
369 lines
8.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel |
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* Digital to Analog Converters driver |
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* |
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* Copyright 2011 Analog Devices Inc. |
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*/ |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/spi/spi.h> |
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#include <linux/slab.h> |
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#include <linux/sysfs.h> |
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#include <linux/regulator/consumer.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#define AD5764_REG_SF_NOP 0x0 |
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#define AD5764_REG_SF_CONFIG 0x1 |
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#define AD5764_REG_SF_CLEAR 0x4 |
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#define AD5764_REG_SF_LOAD 0x5 |
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#define AD5764_REG_DATA(x) ((2 << 3) | (x)) |
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#define AD5764_REG_COARSE_GAIN(x) ((3 << 3) | (x)) |
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#define AD5764_REG_FINE_GAIN(x) ((4 << 3) | (x)) |
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#define AD5764_REG_OFFSET(x) ((5 << 3) | (x)) |
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#define AD5764_NUM_CHANNELS 4 |
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/** |
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* struct ad5764_chip_info - chip specific information |
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* @int_vref: Value of the internal reference voltage in uV - 0 if external |
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* reference voltage is used |
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* @channels: channel specification |
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*/ |
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struct ad5764_chip_info { |
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unsigned long int_vref; |
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const struct iio_chan_spec *channels; |
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}; |
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/** |
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* struct ad5764_state - driver instance specific data |
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* @spi: spi_device |
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* @chip_info: chip info |
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* @vref_reg: vref supply regulators |
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* @lock: lock to protect the data buffer during SPI ops |
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* @data: spi transfer buffers |
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*/ |
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struct ad5764_state { |
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struct spi_device *spi; |
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const struct ad5764_chip_info *chip_info; |
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struct regulator_bulk_data vref_reg[2]; |
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struct mutex lock; |
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/* |
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* DMA (thus cache coherency maintenance) requires the |
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* transfer buffers to live in their own cache lines. |
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*/ |
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union { |
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__be32 d32; |
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u8 d8[4]; |
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} data[2] ____cacheline_aligned; |
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}; |
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enum ad5764_type { |
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ID_AD5744, |
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ID_AD5744R, |
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ID_AD5764, |
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ID_AD5764R, |
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}; |
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#define AD5764_CHANNEL(_chan, _bits) { \ |
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.type = IIO_VOLTAGE, \ |
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.indexed = 1, \ |
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.output = 1, \ |
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.channel = (_chan), \ |
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.address = (_chan), \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
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BIT(IIO_CHAN_INFO_SCALE) | \ |
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BIT(IIO_CHAN_INFO_CALIBSCALE) | \ |
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BIT(IIO_CHAN_INFO_CALIBBIAS), \ |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \ |
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.scan_type = { \ |
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.sign = 'u', \ |
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.realbits = (_bits), \ |
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.storagebits = 16, \ |
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.shift = 16 - (_bits), \ |
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}, \ |
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} |
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#define DECLARE_AD5764_CHANNELS(_name, _bits) \ |
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const struct iio_chan_spec _name##_channels[] = { \ |
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AD5764_CHANNEL(0, (_bits)), \ |
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AD5764_CHANNEL(1, (_bits)), \ |
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AD5764_CHANNEL(2, (_bits)), \ |
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AD5764_CHANNEL(3, (_bits)), \ |
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}; |
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static DECLARE_AD5764_CHANNELS(ad5764, 16); |
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static DECLARE_AD5764_CHANNELS(ad5744, 14); |
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static const struct ad5764_chip_info ad5764_chip_infos[] = { |
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[ID_AD5744] = { |
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.int_vref = 0, |
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.channels = ad5744_channels, |
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}, |
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[ID_AD5744R] = { |
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.int_vref = 5000000, |
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.channels = ad5744_channels, |
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}, |
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[ID_AD5764] = { |
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.int_vref = 0, |
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.channels = ad5764_channels, |
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}, |
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[ID_AD5764R] = { |
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.int_vref = 5000000, |
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.channels = ad5764_channels, |
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}, |
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}; |
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static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg, |
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unsigned int val) |
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{ |
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struct ad5764_state *st = iio_priv(indio_dev); |
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int ret; |
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mutex_lock(&st->lock); |
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st->data[0].d32 = cpu_to_be32((reg << 16) | val); |
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ret = spi_write(st->spi, &st->data[0].d8[1], 3); |
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mutex_unlock(&st->lock); |
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return ret; |
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} |
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static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg, |
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unsigned int *val) |
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{ |
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struct ad5764_state *st = iio_priv(indio_dev); |
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int ret; |
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struct spi_transfer t[] = { |
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{ |
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.tx_buf = &st->data[0].d8[1], |
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.len = 3, |
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.cs_change = 1, |
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}, { |
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.rx_buf = &st->data[1].d8[1], |
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.len = 3, |
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}, |
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}; |
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mutex_lock(&st->lock); |
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st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16)); |
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ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); |
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if (ret >= 0) |
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*val = be32_to_cpu(st->data[1].d32) & 0xffff; |
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mutex_unlock(&st->lock); |
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return ret; |
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} |
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static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info) |
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{ |
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switch (info) { |
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case IIO_CHAN_INFO_RAW: |
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return AD5764_REG_DATA(chan->address); |
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case IIO_CHAN_INFO_CALIBBIAS: |
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return AD5764_REG_OFFSET(chan->address); |
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case IIO_CHAN_INFO_CALIBSCALE: |
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return AD5764_REG_FINE_GAIN(chan->address); |
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default: |
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break; |
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} |
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return 0; |
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} |
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static int ad5764_write_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int val, int val2, long info) |
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{ |
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const int max_val = (1 << chan->scan_type.realbits); |
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unsigned int reg; |
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switch (info) { |
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case IIO_CHAN_INFO_RAW: |
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if (val >= max_val || val < 0) |
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return -EINVAL; |
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val <<= chan->scan_type.shift; |
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break; |
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case IIO_CHAN_INFO_CALIBBIAS: |
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if (val >= 128 || val < -128) |
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return -EINVAL; |
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break; |
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case IIO_CHAN_INFO_CALIBSCALE: |
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if (val >= 32 || val < -32) |
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return -EINVAL; |
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break; |
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default: |
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return -EINVAL; |
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} |
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reg = ad5764_chan_info_to_reg(chan, info); |
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return ad5764_write(indio_dev, reg, (u16)val); |
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} |
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static int ad5764_get_channel_vref(struct ad5764_state *st, |
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unsigned int channel) |
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{ |
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if (st->chip_info->int_vref) |
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return st->chip_info->int_vref; |
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else |
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return regulator_get_voltage(st->vref_reg[channel / 2].consumer); |
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} |
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static int ad5764_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int *val, int *val2, long info) |
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{ |
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struct ad5764_state *st = iio_priv(indio_dev); |
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unsigned int reg; |
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int vref; |
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int ret; |
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switch (info) { |
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case IIO_CHAN_INFO_RAW: |
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reg = AD5764_REG_DATA(chan->address); |
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ret = ad5764_read(indio_dev, reg, val); |
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if (ret < 0) |
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return ret; |
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*val >>= chan->scan_type.shift; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_CALIBBIAS: |
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reg = AD5764_REG_OFFSET(chan->address); |
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ret = ad5764_read(indio_dev, reg, val); |
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if (ret < 0) |
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return ret; |
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*val = sign_extend32(*val, 7); |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_CALIBSCALE: |
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reg = AD5764_REG_FINE_GAIN(chan->address); |
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ret = ad5764_read(indio_dev, reg, val); |
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if (ret < 0) |
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return ret; |
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*val = sign_extend32(*val, 5); |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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/* vout = 4 * vref + ((dac_code / 65536) - 0.5) */ |
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vref = ad5764_get_channel_vref(st, chan->channel); |
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if (vref < 0) |
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return vref; |
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*val = vref * 4 / 1000; |
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*val2 = chan->scan_type.realbits; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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case IIO_CHAN_INFO_OFFSET: |
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*val = -(1 << chan->scan_type.realbits) / 2; |
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return IIO_VAL_INT; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_info ad5764_info = { |
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.read_raw = ad5764_read_raw, |
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.write_raw = ad5764_write_raw, |
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}; |
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static int ad5764_probe(struct spi_device *spi) |
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{ |
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enum ad5764_type type = spi_get_device_id(spi)->driver_data; |
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struct iio_dev *indio_dev; |
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struct ad5764_state *st; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
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if (indio_dev == NULL) { |
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dev_err(&spi->dev, "Failed to allocate iio device\n"); |
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return -ENOMEM; |
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} |
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st = iio_priv(indio_dev); |
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spi_set_drvdata(spi, indio_dev); |
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st->spi = spi; |
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st->chip_info = &ad5764_chip_infos[type]; |
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indio_dev->name = spi_get_device_id(spi)->name; |
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indio_dev->info = &ad5764_info; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->num_channels = AD5764_NUM_CHANNELS; |
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indio_dev->channels = st->chip_info->channels; |
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mutex_init(&st->lock); |
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if (st->chip_info->int_vref == 0) { |
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st->vref_reg[0].supply = "vrefAB"; |
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st->vref_reg[1].supply = "vrefCD"; |
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ret = devm_regulator_bulk_get(&st->spi->dev, |
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ARRAY_SIZE(st->vref_reg), st->vref_reg); |
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if (ret) { |
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dev_err(&spi->dev, "Failed to request vref regulators: %d\n", |
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ret); |
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return ret; |
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} |
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ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg), |
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st->vref_reg); |
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if (ret) { |
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dev_err(&spi->dev, "Failed to enable vref regulators: %d\n", |
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ret); |
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return ret; |
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} |
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} |
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ret = iio_device_register(indio_dev); |
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if (ret) { |
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dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); |
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goto error_disable_reg; |
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} |
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return 0; |
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error_disable_reg: |
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if (st->chip_info->int_vref == 0) |
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regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); |
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return ret; |
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} |
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static int ad5764_remove(struct spi_device *spi) |
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{ |
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struct iio_dev *indio_dev = spi_get_drvdata(spi); |
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struct ad5764_state *st = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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if (st->chip_info->int_vref == 0) |
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regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); |
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return 0; |
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} |
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static const struct spi_device_id ad5764_ids[] = { |
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{ "ad5744", ID_AD5744 }, |
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{ "ad5744r", ID_AD5744R }, |
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{ "ad5764", ID_AD5764 }, |
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{ "ad5764r", ID_AD5764R }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(spi, ad5764_ids); |
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static struct spi_driver ad5764_driver = { |
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.driver = { |
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.name = "ad5764", |
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}, |
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.probe = ad5764_probe, |
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.remove = ad5764_remove, |
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.id_table = ad5764_ids, |
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}; |
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module_spi_driver(ad5764_driver); |
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MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC"); |
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MODULE_LICENSE("GPL v2");
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