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393 lines
9.9 KiB
393 lines
9.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* AD7904/AD7914/AD7923/AD7924/AD7908/AD7918/AD7928 SPI ADC driver |
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* |
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* Copyright 2011 Analog Devices Inc (from AD7923 Driver) |
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* Copyright 2012 CS Systemes d'Information |
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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/sysfs.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/delay.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/sysfs.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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#define AD7923_WRITE_CR BIT(11) /* write control register */ |
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#define AD7923_RANGE BIT(1) /* range to REFin */ |
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#define AD7923_CODING BIT(0) /* coding is straight binary */ |
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#define AD7923_PM_MODE_AS (1) /* auto shutdown */ |
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#define AD7923_PM_MODE_FS (2) /* full shutdown */ |
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#define AD7923_PM_MODE_OPS (3) /* normal operation */ |
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#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */ |
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#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */ |
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#define AD7923_SEQUENCE_ON (3) /* continuous sequence */ |
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#define AD7923_PM_MODE_WRITE(mode) ((mode) << 4) /* write mode */ |
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#define AD7923_CHANNEL_WRITE(channel) ((channel) << 6) /* write channel */ |
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#define AD7923_SEQUENCE_WRITE(sequence) ((((sequence) & 1) << 3) \ |
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+ (((sequence) & 2) << 9)) |
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/* write sequence fonction */ |
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/* left shift for CR : bit 11 transmit in first */ |
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#define AD7923_SHIFT_REGISTER 4 |
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/* val = value, dec = left shift, bits = number of bits of the mask */ |
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#define EXTRACT(val, dec, bits) (((val) >> (dec)) & ((1 << (bits)) - 1)) |
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struct ad7923_state { |
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struct spi_device *spi; |
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struct spi_transfer ring_xfer[5]; |
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struct spi_transfer scan_single_xfer[2]; |
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struct spi_message ring_msg; |
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struct spi_message scan_single_msg; |
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struct regulator *reg; |
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unsigned int settings; |
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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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* Ensure rx_buf can be directly used in iio_push_to_buffers_with_timetamp |
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* Length = 8 channels + 4 extra for 8 byte timestamp |
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*/ |
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__be16 rx_buf[12] ____cacheline_aligned; |
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__be16 tx_buf[4]; |
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}; |
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struct ad7923_chip_info { |
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const struct iio_chan_spec *channels; |
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unsigned int num_channels; |
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}; |
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enum ad7923_id { |
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AD7904, |
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AD7914, |
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AD7924, |
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AD7908, |
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AD7918, |
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AD7928 |
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}; |
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#define AD7923_V_CHAN(index, bits) \ |
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{ \ |
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.type = IIO_VOLTAGE, \ |
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.indexed = 1, \ |
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.channel = index, \ |
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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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.address = index, \ |
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.scan_index = index, \ |
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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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.endianness = IIO_BE, \ |
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}, \ |
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} |
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#define DECLARE_AD7923_CHANNELS(name, bits) \ |
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const struct iio_chan_spec name ## _channels[] = { \ |
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AD7923_V_CHAN(0, bits), \ |
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AD7923_V_CHAN(1, bits), \ |
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AD7923_V_CHAN(2, bits), \ |
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AD7923_V_CHAN(3, bits), \ |
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IIO_CHAN_SOFT_TIMESTAMP(4), \ |
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} |
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#define DECLARE_AD7908_CHANNELS(name, bits) \ |
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const struct iio_chan_spec name ## _channels[] = { \ |
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AD7923_V_CHAN(0, bits), \ |
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AD7923_V_CHAN(1, bits), \ |
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AD7923_V_CHAN(2, bits), \ |
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AD7923_V_CHAN(3, bits), \ |
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AD7923_V_CHAN(4, bits), \ |
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AD7923_V_CHAN(5, bits), \ |
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AD7923_V_CHAN(6, bits), \ |
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AD7923_V_CHAN(7, bits), \ |
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IIO_CHAN_SOFT_TIMESTAMP(8), \ |
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} |
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static DECLARE_AD7923_CHANNELS(ad7904, 8); |
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static DECLARE_AD7923_CHANNELS(ad7914, 10); |
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static DECLARE_AD7923_CHANNELS(ad7924, 12); |
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static DECLARE_AD7908_CHANNELS(ad7908, 8); |
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static DECLARE_AD7908_CHANNELS(ad7918, 10); |
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static DECLARE_AD7908_CHANNELS(ad7928, 12); |
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static const struct ad7923_chip_info ad7923_chip_info[] = { |
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[AD7904] = { |
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.channels = ad7904_channels, |
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.num_channels = ARRAY_SIZE(ad7904_channels), |
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}, |
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[AD7914] = { |
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.channels = ad7914_channels, |
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.num_channels = ARRAY_SIZE(ad7914_channels), |
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}, |
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[AD7924] = { |
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.channels = ad7924_channels, |
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.num_channels = ARRAY_SIZE(ad7924_channels), |
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}, |
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[AD7908] = { |
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.channels = ad7908_channels, |
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.num_channels = ARRAY_SIZE(ad7908_channels), |
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}, |
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[AD7918] = { |
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.channels = ad7918_channels, |
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.num_channels = ARRAY_SIZE(ad7918_channels), |
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}, |
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[AD7928] = { |
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.channels = ad7928_channels, |
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.num_channels = ARRAY_SIZE(ad7928_channels), |
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}, |
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}; |
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/* |
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* ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask |
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*/ |
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static int ad7923_update_scan_mode(struct iio_dev *indio_dev, |
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const unsigned long *active_scan_mask) |
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{ |
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struct ad7923_state *st = iio_priv(indio_dev); |
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int i, cmd, len; |
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len = 0; |
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/* |
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* For this driver the last channel is always the software timestamp so |
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* skip that one. |
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*/ |
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for_each_set_bit(i, active_scan_mask, indio_dev->num_channels - 1) { |
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cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) | |
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AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | |
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st->settings; |
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cmd <<= AD7923_SHIFT_REGISTER; |
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st->tx_buf[len++] = cpu_to_be16(cmd); |
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} |
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/* build spi ring message */ |
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st->ring_xfer[0].tx_buf = &st->tx_buf[0]; |
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st->ring_xfer[0].len = len; |
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st->ring_xfer[0].cs_change = 1; |
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spi_message_init(&st->ring_msg); |
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spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg); |
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for (i = 0; i < len; i++) { |
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st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i]; |
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st->ring_xfer[i + 1].len = 2; |
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st->ring_xfer[i + 1].cs_change = 1; |
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spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg); |
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} |
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/* make sure last transfer cs_change is not set */ |
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st->ring_xfer[i + 1].cs_change = 0; |
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return 0; |
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} |
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static irqreturn_t ad7923_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 ad7923_state *st = iio_priv(indio_dev); |
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int b_sent; |
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b_sent = spi_sync(st->spi, &st->ring_msg); |
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if (b_sent) |
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goto done; |
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iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf, |
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iio_get_time_ns(indio_dev)); |
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done: |
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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 int ad7923_scan_direct(struct ad7923_state *st, unsigned int ch) |
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{ |
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int ret, cmd; |
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cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(ch) | |
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AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | |
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st->settings; |
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cmd <<= AD7923_SHIFT_REGISTER; |
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st->tx_buf[0] = cpu_to_be16(cmd); |
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ret = spi_sync(st->spi, &st->scan_single_msg); |
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if (ret) |
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return ret; |
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return be16_to_cpu(st->rx_buf[0]); |
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} |
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static int ad7923_get_range(struct ad7923_state *st) |
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{ |
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int vref; |
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vref = regulator_get_voltage(st->reg); |
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if (vref < 0) |
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return vref; |
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vref /= 1000; |
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if (!(st->settings & AD7923_RANGE)) |
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vref *= 2; |
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return vref; |
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} |
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static int ad7923_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, |
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int *val2, |
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long m) |
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{ |
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int ret; |
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struct ad7923_state *st = iio_priv(indio_dev); |
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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 = ad7923_scan_direct(st, chan->address); |
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iio_device_release_direct_mode(indio_dev); |
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if (ret < 0) |
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return ret; |
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if (chan->address == EXTRACT(ret, 12, 4)) |
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*val = EXTRACT(ret, 0, 12); |
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else |
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return -EIO; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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ret = ad7923_get_range(st); |
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if (ret < 0) |
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return ret; |
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*val = ret; |
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*val2 = chan->scan_type.realbits; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_info ad7923_info = { |
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.read_raw = &ad7923_read_raw, |
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.update_scan_mode = ad7923_update_scan_mode, |
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}; |
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static void ad7923_regulator_disable(void *data) |
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{ |
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struct ad7923_state *st = data; |
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regulator_disable(st->reg); |
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} |
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static int ad7923_probe(struct spi_device *spi) |
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{ |
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struct ad7923_state *st; |
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struct iio_dev *indio_dev; |
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const struct ad7923_chip_info *info; |
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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) |
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return -ENOMEM; |
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st = iio_priv(indio_dev); |
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st->spi = spi; |
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st->settings = AD7923_CODING | AD7923_RANGE | |
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AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS); |
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info = &ad7923_chip_info[spi_get_device_id(spi)->driver_data]; |
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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->channels = info->channels; |
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indio_dev->num_channels = info->num_channels; |
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indio_dev->info = &ad7923_info; |
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/* Setup default message */ |
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st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; |
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st->scan_single_xfer[0].len = 2; |
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st->scan_single_xfer[0].cs_change = 1; |
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st->scan_single_xfer[1].rx_buf = &st->rx_buf[0]; |
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st->scan_single_xfer[1].len = 2; |
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spi_message_init(&st->scan_single_msg); |
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spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg); |
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spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg); |
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st->reg = devm_regulator_get(&spi->dev, "refin"); |
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if (IS_ERR(st->reg)) |
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return PTR_ERR(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 = devm_add_action_or_reset(&spi->dev, ad7923_regulator_disable, st); |
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if (ret) |
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return ret; |
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ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, |
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&ad7923_trigger_handler, NULL); |
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if (ret) |
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return ret; |
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return devm_iio_device_register(&spi->dev, indio_dev); |
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} |
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static const struct spi_device_id ad7923_id[] = { |
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{"ad7904", AD7904}, |
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{"ad7914", AD7914}, |
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{"ad7923", AD7924}, |
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{"ad7924", AD7924}, |
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{"ad7908", AD7908}, |
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{"ad7918", AD7918}, |
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{"ad7928", AD7928}, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, ad7923_id); |
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static const struct of_device_id ad7923_of_match[] = { |
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{ .compatible = "adi,ad7904", }, |
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{ .compatible = "adi,ad7914", }, |
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{ .compatible = "adi,ad7923", }, |
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{ .compatible = "adi,ad7924", }, |
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{ .compatible = "adi,ad7908", }, |
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{ .compatible = "adi,ad7918", }, |
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{ .compatible = "adi,ad7928", }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, ad7923_of_match); |
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static struct spi_driver ad7923_driver = { |
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.driver = { |
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.name = "ad7923", |
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.of_match_table = ad7923_of_match, |
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}, |
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.probe = ad7923_probe, |
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.id_table = ad7923_id, |
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}; |
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module_spi_driver(ad7923_driver); |
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MODULE_AUTHOR("Michael Hennerich <[email protected]>"); |
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MODULE_AUTHOR("Patrick Vasseur <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD7923 and similar ADC"); |
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MODULE_LICENSE("GPL v2");
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