522 lines
13 KiB
C
522 lines
13 KiB
C
/*
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* AD7266/65 SPI ADC driver
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*
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* Copyright 2012 Analog Devices Inc.
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/regulator/consumer.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/platform_data/ad7266.h>
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struct ad7266_state {
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struct spi_device *spi;
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struct regulator *reg;
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unsigned long vref_mv;
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struct spi_transfer single_xfer[3];
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struct spi_message single_msg;
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enum ad7266_range range;
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enum ad7266_mode mode;
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bool fixed_addr;
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struct gpio gpios[3];
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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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* The buffer needs to be large enough to hold two samples (4 bytes) and
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* the naturally aligned timestamp (8 bytes).
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*/
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struct {
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__be16 sample[2];
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s64 timestamp;
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} data ____cacheline_aligned;
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};
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static int ad7266_wakeup(struct ad7266_state *st)
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{
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/* Any read with >= 2 bytes will wake the device */
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return spi_read(st->spi, &st->data.sample[0], 2);
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}
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static int ad7266_powerdown(struct ad7266_state *st)
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{
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/* Any read with < 2 bytes will powerdown the device */
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return spi_read(st->spi, &st->data.sample[0], 1);
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}
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static int ad7266_preenable(struct iio_dev *indio_dev)
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{
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struct ad7266_state *st = iio_priv(indio_dev);
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return ad7266_wakeup(st);
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}
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static int ad7266_postdisable(struct iio_dev *indio_dev)
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{
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struct ad7266_state *st = iio_priv(indio_dev);
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return ad7266_powerdown(st);
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}
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static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
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.preenable = &ad7266_preenable,
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.postenable = &iio_triggered_buffer_postenable,
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.predisable = &iio_triggered_buffer_predisable,
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.postdisable = &ad7266_postdisable,
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};
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static irqreturn_t ad7266_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct ad7266_state *st = iio_priv(indio_dev);
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int ret;
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ret = spi_read(st->spi, st->data.sample, 4);
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if (ret == 0) {
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iio_push_to_buffers_with_timestamp(indio_dev, &st->data,
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pf->timestamp);
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}
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static void ad7266_select_input(struct ad7266_state *st, unsigned int nr)
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{
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unsigned int i;
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if (st->fixed_addr)
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return;
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switch (st->mode) {
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case AD7266_MODE_SINGLE_ENDED:
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nr >>= 1;
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break;
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case AD7266_MODE_PSEUDO_DIFF:
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nr |= 1;
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break;
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case AD7266_MODE_DIFF:
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nr &= ~1;
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break;
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}
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for (i = 0; i < 3; ++i)
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gpio_set_value(st->gpios[i].gpio, (bool)(nr & BIT(i)));
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}
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static int ad7266_update_scan_mode(struct iio_dev *indio_dev,
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const unsigned long *scan_mask)
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{
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struct ad7266_state *st = iio_priv(indio_dev);
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unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength);
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ad7266_select_input(st, nr);
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return 0;
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}
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static int ad7266_read_single(struct ad7266_state *st, int *val,
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unsigned int address)
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{
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int ret;
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ad7266_select_input(st, address);
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ret = spi_sync(st->spi, &st->single_msg);
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*val = be16_to_cpu(st->data.sample[address % 2]);
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return ret;
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}
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static int ad7266_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int *val, int *val2, long m)
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{
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struct ad7266_state *st = iio_priv(indio_dev);
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unsigned long scale_mv;
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int ret;
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switch (m) {
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case IIO_CHAN_INFO_RAW:
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ret = iio_device_claim_direct_mode(indio_dev);
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if (ret)
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return ret;
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ret = ad7266_read_single(st, val, chan->address);
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iio_device_release_direct_mode(indio_dev);
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*val = (*val >> 2) & 0xfff;
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if (chan->scan_type.sign == 's')
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*val = sign_extend32(*val, 11);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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scale_mv = st->vref_mv;
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if (st->mode == AD7266_MODE_DIFF)
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scale_mv *= 2;
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if (st->range == AD7266_RANGE_2VREF)
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scale_mv *= 2;
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*val = scale_mv;
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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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if (st->range == AD7266_RANGE_2VREF &&
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st->mode != AD7266_MODE_DIFF)
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*val = 2048;
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else
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*val = 0;
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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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#define AD7266_CHAN(_chan, _sign) { \
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.type = IIO_VOLTAGE, \
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.indexed = 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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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
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| BIT(IIO_CHAN_INFO_OFFSET), \
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.scan_index = (_chan), \
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.scan_type = { \
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.sign = (_sign), \
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.realbits = 12, \
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.storagebits = 16, \
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.shift = 2, \
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.endianness = IIO_BE, \
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}, \
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}
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#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \
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const struct iio_chan_spec ad7266_channels_##_name[] = { \
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AD7266_CHAN(0, (_sign)), \
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AD7266_CHAN(1, (_sign)), \
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AD7266_CHAN(2, (_sign)), \
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AD7266_CHAN(3, (_sign)), \
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AD7266_CHAN(4, (_sign)), \
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AD7266_CHAN(5, (_sign)), \
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AD7266_CHAN(6, (_sign)), \
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AD7266_CHAN(7, (_sign)), \
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AD7266_CHAN(8, (_sign)), \
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AD7266_CHAN(9, (_sign)), \
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AD7266_CHAN(10, (_sign)), \
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AD7266_CHAN(11, (_sign)), \
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IIO_CHAN_SOFT_TIMESTAMP(13), \
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}
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#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \
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const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \
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AD7266_CHAN(0, (_sign)), \
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AD7266_CHAN(1, (_sign)), \
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IIO_CHAN_SOFT_TIMESTAMP(2), \
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}
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u');
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's');
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u');
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's');
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#define AD7266_CHAN_DIFF(_chan, _sign) { \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = (_chan) * 2, \
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.channel2 = (_chan) * 2 + 1, \
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.address = (_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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| BIT(IIO_CHAN_INFO_OFFSET), \
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.scan_index = (_chan), \
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.scan_type = { \
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.sign = _sign, \
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.realbits = 12, \
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.storagebits = 16, \
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.shift = 2, \
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.endianness = IIO_BE, \
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}, \
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.differential = 1, \
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}
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#define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \
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const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \
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AD7266_CHAN_DIFF(0, (_sign)), \
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AD7266_CHAN_DIFF(1, (_sign)), \
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AD7266_CHAN_DIFF(2, (_sign)), \
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AD7266_CHAN_DIFF(3, (_sign)), \
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AD7266_CHAN_DIFF(4, (_sign)), \
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AD7266_CHAN_DIFF(5, (_sign)), \
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IIO_CHAN_SOFT_TIMESTAMP(6), \
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}
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static AD7266_DECLARE_DIFF_CHANNELS(s, 's');
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static AD7266_DECLARE_DIFF_CHANNELS(u, 'u');
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#define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \
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const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \
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AD7266_CHAN_DIFF(0, (_sign)), \
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AD7266_CHAN_DIFF(1, (_sign)), \
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IIO_CHAN_SOFT_TIMESTAMP(2), \
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}
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static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's');
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static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u');
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static const struct iio_info ad7266_info = {
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.read_raw = &ad7266_read_raw,
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.update_scan_mode = &ad7266_update_scan_mode,
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.driver_module = THIS_MODULE,
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};
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static const unsigned long ad7266_available_scan_masks[] = {
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0x003,
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0x00c,
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0x030,
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0x0c0,
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0x300,
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0xc00,
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0x000,
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};
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static const unsigned long ad7266_available_scan_masks_diff[] = {
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0x003,
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0x00c,
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0x030,
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0x000,
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};
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static const unsigned long ad7266_available_scan_masks_fixed[] = {
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0x003,
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0x000,
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};
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struct ad7266_chan_info {
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const struct iio_chan_spec *channels;
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unsigned int num_channels;
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const unsigned long *scan_masks;
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};
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#define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \
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(((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0))
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static const struct ad7266_chan_info ad7266_chan_infos[] = {
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[AD7266_CHAN_INFO_INDEX(0, 0, 0)] = {
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.channels = ad7266_channels_u,
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.num_channels = ARRAY_SIZE(ad7266_channels_u),
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.scan_masks = ad7266_available_scan_masks,
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},
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[AD7266_CHAN_INFO_INDEX(0, 0, 1)] = {
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.channels = ad7266_channels_u_fixed,
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.num_channels = ARRAY_SIZE(ad7266_channels_u_fixed),
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.scan_masks = ad7266_available_scan_masks_fixed,
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},
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[AD7266_CHAN_INFO_INDEX(0, 1, 0)] = {
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.channels = ad7266_channels_s,
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.num_channels = ARRAY_SIZE(ad7266_channels_s),
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.scan_masks = ad7266_available_scan_masks,
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},
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[AD7266_CHAN_INFO_INDEX(0, 1, 1)] = {
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.channels = ad7266_channels_s_fixed,
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.num_channels = ARRAY_SIZE(ad7266_channels_s_fixed),
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.scan_masks = ad7266_available_scan_masks_fixed,
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},
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[AD7266_CHAN_INFO_INDEX(1, 0, 0)] = {
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.channels = ad7266_channels_diff_u,
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_u),
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.scan_masks = ad7266_available_scan_masks_diff,
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},
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[AD7266_CHAN_INFO_INDEX(1, 0, 1)] = {
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.channels = ad7266_channels_diff_fixed_u,
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u),
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.scan_masks = ad7266_available_scan_masks_fixed,
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},
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[AD7266_CHAN_INFO_INDEX(1, 1, 0)] = {
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.channels = ad7266_channels_diff_s,
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_s),
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.scan_masks = ad7266_available_scan_masks_diff,
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},
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[AD7266_CHAN_INFO_INDEX(1, 1, 1)] = {
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.channels = ad7266_channels_diff_fixed_s,
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s),
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.scan_masks = ad7266_available_scan_masks_fixed,
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},
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};
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static void ad7266_init_channels(struct iio_dev *indio_dev)
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{
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struct ad7266_state *st = iio_priv(indio_dev);
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bool is_differential, is_signed;
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const struct ad7266_chan_info *chan_info;
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int i;
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is_differential = st->mode != AD7266_MODE_SINGLE_ENDED;
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is_signed = (st->range == AD7266_RANGE_2VREF) |
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(st->mode == AD7266_MODE_DIFF);
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i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr);
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chan_info = &ad7266_chan_infos[i];
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indio_dev->channels = chan_info->channels;
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indio_dev->num_channels = chan_info->num_channels;
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indio_dev->available_scan_masks = chan_info->scan_masks;
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indio_dev->masklength = chan_info->num_channels - 1;
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}
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static const char * const ad7266_gpio_labels[] = {
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"AD0", "AD1", "AD2",
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};
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static int ad7266_probe(struct spi_device *spi)
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{
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struct ad7266_platform_data *pdata = spi->dev.platform_data;
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struct iio_dev *indio_dev;
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struct ad7266_state *st;
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unsigned int i;
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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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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->reg = devm_regulator_get(&spi->dev, "vref");
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if (!IS_ERR_OR_NULL(st->reg)) {
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ret = regulator_enable(st->reg);
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if (ret)
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return ret;
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ret = regulator_get_voltage(st->reg);
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if (ret < 0)
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goto error_disable_reg;
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st->vref_mv = ret / 1000;
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} else {
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/* Use internal reference */
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st->vref_mv = 2500;
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}
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if (pdata) {
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st->fixed_addr = pdata->fixed_addr;
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st->mode = pdata->mode;
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st->range = pdata->range;
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if (!st->fixed_addr) {
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for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) {
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st->gpios[i].gpio = pdata->addr_gpios[i];
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st->gpios[i].flags = GPIOF_OUT_INIT_LOW;
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st->gpios[i].label = ad7266_gpio_labels[i];
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}
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ret = gpio_request_array(st->gpios,
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ARRAY_SIZE(st->gpios));
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if (ret)
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goto error_disable_reg;
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}
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} else {
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st->fixed_addr = true;
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st->range = AD7266_RANGE_VREF;
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st->mode = AD7266_MODE_DIFF;
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}
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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indio_dev->dev.parent = &spi->dev;
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indio_dev->dev.of_node = spi->dev.of_node;
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->info = &ad7266_info;
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ad7266_init_channels(indio_dev);
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/* wakeup */
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st->single_xfer[0].rx_buf = &st->data.sample[0];
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st->single_xfer[0].len = 2;
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st->single_xfer[0].cs_change = 1;
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/* conversion */
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st->single_xfer[1].rx_buf = st->data.sample;
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st->single_xfer[1].len = 4;
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st->single_xfer[1].cs_change = 1;
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/* powerdown */
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st->single_xfer[2].tx_buf = &st->data.sample[0];
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st->single_xfer[2].len = 1;
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spi_message_init(&st->single_msg);
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spi_message_add_tail(&st->single_xfer[0], &st->single_msg);
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spi_message_add_tail(&st->single_xfer[1], &st->single_msg);
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spi_message_add_tail(&st->single_xfer[2], &st->single_msg);
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ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
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&ad7266_trigger_handler, &iio_triggered_buffer_setup_ops);
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if (ret)
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goto error_free_gpios;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_buffer_cleanup;
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|
return 0;
|
|
|
|
error_buffer_cleanup:
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
error_free_gpios:
|
|
if (!st->fixed_addr)
|
|
gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios));
|
|
error_disable_reg:
|
|
if (!IS_ERR_OR_NULL(st->reg))
|
|
regulator_disable(st->reg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ad7266_remove(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
if (!st->fixed_addr)
|
|
gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios));
|
|
if (!IS_ERR_OR_NULL(st->reg))
|
|
regulator_disable(st->reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct spi_device_id ad7266_id[] = {
|
|
{"ad7265", 0},
|
|
{"ad7266", 0},
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad7266_id);
|
|
|
|
static struct spi_driver ad7266_driver = {
|
|
.driver = {
|
|
.name = "ad7266",
|
|
},
|
|
.probe = ad7266_probe,
|
|
.remove = ad7266_remove,
|
|
.id_table = ad7266_id,
|
|
};
|
|
module_spi_driver(ad7266_driver);
|
|
|
|
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
|
|
MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC");
|
|
MODULE_LICENSE("GPL v2");
|