| /* |
| * AD7904/AD7914/AD7923/AD7924 SPI ADC driver |
| * |
| * Copyright 2011 Analog Devices Inc (from AD7923 Driver) |
| * Copyright 2012 CS Systemes d'Information |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| #include <linux/spi/spi.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/err.h> |
| #include <linux/delay.h> |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/triggered_buffer.h> |
| |
| #define AD7923_WRITE_CR BIT(11) /* write control register */ |
| #define AD7923_RANGE BIT(1) /* range to REFin */ |
| #define AD7923_CODING BIT(0) /* coding is straight binary */ |
| #define AD7923_PM_MODE_AS (1) /* auto shutdown */ |
| #define AD7923_PM_MODE_FS (2) /* full shutdown */ |
| #define AD7923_PM_MODE_OPS (3) /* normal operation */ |
| #define AD7923_CHANNEL_0 (0) /* analog input 0 */ |
| #define AD7923_CHANNEL_1 (1) /* analog input 1 */ |
| #define AD7923_CHANNEL_2 (2) /* analog input 2 */ |
| #define AD7923_CHANNEL_3 (3) /* analog input 3 */ |
| #define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */ |
| #define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */ |
| #define AD7923_SEQUENCE_ON (3) /* continuous sequence */ |
| |
| #define AD7923_MAX_CHAN 4 |
| |
| #define AD7923_PM_MODE_WRITE(mode) ((mode) << 4) /* write mode */ |
| #define AD7923_CHANNEL_WRITE(channel) ((channel) << 6) /* write channel */ |
| #define AD7923_SEQUENCE_WRITE(sequence) ((((sequence) & 1) << 3) \ |
| + (((sequence) & 2) << 9)) |
| /* write sequence fonction */ |
| /* left shift for CR : bit 11 transmit in first */ |
| #define AD7923_SHIFT_REGISTER 4 |
| |
| /* val = value, dec = left shift, bits = number of bits of the mask */ |
| #define EXTRACT(val, dec, bits) (((val) >> (dec)) & ((1 << (bits)) - 1)) |
| |
| struct ad7923_state { |
| struct spi_device *spi; |
| struct spi_transfer ring_xfer[5]; |
| struct spi_transfer scan_single_xfer[2]; |
| struct spi_message ring_msg; |
| struct spi_message scan_single_msg; |
| |
| struct regulator *reg; |
| |
| unsigned int settings; |
| |
| /* |
| * DMA (thus cache coherency maintenance) requires the |
| * transfer buffers to live in their own cache lines. |
| */ |
| __be16 rx_buf[4] ____cacheline_aligned; |
| __be16 tx_buf[4]; |
| }; |
| |
| struct ad7923_chip_info { |
| const struct iio_chan_spec *channels; |
| unsigned int num_channels; |
| }; |
| |
| enum ad7923_id { |
| AD7904, |
| AD7914, |
| AD7924, |
| }; |
| |
| #define AD7923_V_CHAN(index, bits) \ |
| { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = index, \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
| .address = index, \ |
| .scan_index = index, \ |
| .scan_type = { \ |
| .sign = 'u', \ |
| .realbits = (bits), \ |
| .storagebits = 16, \ |
| .endianness = IIO_BE, \ |
| }, \ |
| } |
| |
| #define DECLARE_AD7923_CHANNELS(name, bits) \ |
| const struct iio_chan_spec name ## _channels[] = { \ |
| AD7923_V_CHAN(0, bits), \ |
| AD7923_V_CHAN(1, bits), \ |
| AD7923_V_CHAN(2, bits), \ |
| AD7923_V_CHAN(3, bits), \ |
| IIO_CHAN_SOFT_TIMESTAMP(4), \ |
| } |
| |
| static DECLARE_AD7923_CHANNELS(ad7904, 8); |
| static DECLARE_AD7923_CHANNELS(ad7914, 10); |
| static DECLARE_AD7923_CHANNELS(ad7924, 12); |
| |
| static const struct ad7923_chip_info ad7923_chip_info[] = { |
| [AD7904] = { |
| .channels = ad7904_channels, |
| .num_channels = ARRAY_SIZE(ad7904_channels), |
| }, |
| [AD7914] = { |
| .channels = ad7914_channels, |
| .num_channels = ARRAY_SIZE(ad7914_channels), |
| }, |
| [AD7924] = { |
| .channels = ad7924_channels, |
| .num_channels = ARRAY_SIZE(ad7924_channels), |
| }, |
| }; |
| |
| /** |
| * ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask |
| **/ |
| static int ad7923_update_scan_mode(struct iio_dev *indio_dev, |
| const unsigned long *active_scan_mask) |
| { |
| struct ad7923_state *st = iio_priv(indio_dev); |
| int i, cmd, len; |
| |
| len = 0; |
| for_each_set_bit(i, active_scan_mask, AD7923_MAX_CHAN) { |
| cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) | |
| AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | |
| st->settings; |
| cmd <<= AD7923_SHIFT_REGISTER; |
| st->tx_buf[len++] = cpu_to_be16(cmd); |
| } |
| /* build spi ring message */ |
| st->ring_xfer[0].tx_buf = &st->tx_buf[0]; |
| st->ring_xfer[0].len = len; |
| st->ring_xfer[0].cs_change = 1; |
| |
| spi_message_init(&st->ring_msg); |
| spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg); |
| |
| for (i = 0; i < len; i++) { |
| st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i]; |
| st->ring_xfer[i + 1].len = 2; |
| st->ring_xfer[i + 1].cs_change = 1; |
| spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg); |
| } |
| /* make sure last transfer cs_change is not set */ |
| st->ring_xfer[i + 1].cs_change = 0; |
| |
| return 0; |
| } |
| |
| /** |
| * ad7923_trigger_handler() bh of trigger launched polling to ring buffer |
| * |
| * Currently there is no option in this driver to disable the saving of |
| * timestamps within the ring. |
| **/ |
| static irqreturn_t ad7923_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad7923_state *st = iio_priv(indio_dev); |
| int b_sent; |
| |
| b_sent = spi_sync(st->spi, &st->ring_msg); |
| if (b_sent) |
| goto done; |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf, |
| iio_get_time_ns(indio_dev)); |
| |
| done: |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch) |
| { |
| int ret, cmd; |
| |
| cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(ch) | |
| AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | |
| st->settings; |
| cmd <<= AD7923_SHIFT_REGISTER; |
| st->tx_buf[0] = cpu_to_be16(cmd); |
| |
| ret = spi_sync(st->spi, &st->scan_single_msg); |
| if (ret) |
| return ret; |
| |
| return be16_to_cpu(st->rx_buf[0]); |
| } |
| |
| static int ad7923_get_range(struct ad7923_state *st) |
| { |
| int vref; |
| |
| vref = regulator_get_voltage(st->reg); |
| if (vref < 0) |
| return vref; |
| |
| vref /= 1000; |
| |
| if (!(st->settings & AD7923_RANGE)) |
| vref *= 2; |
| |
| return vref; |
| } |
| |
| static int ad7923_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, |
| int *val2, |
| long m) |
| { |
| int ret; |
| struct ad7923_state *st = iio_priv(indio_dev); |
| |
| switch (m) { |
| case IIO_CHAN_INFO_RAW: |
| ret = iio_device_claim_direct_mode(indio_dev); |
| if (ret) |
| return ret; |
| ret = ad7923_scan_direct(st, chan->address); |
| iio_device_release_direct_mode(indio_dev); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (chan->address == EXTRACT(ret, 12, 4)) |
| *val = EXTRACT(ret, 0, 12); |
| else |
| return -EIO; |
| |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| ret = ad7923_get_range(st); |
| if (ret < 0) |
| return ret; |
| *val = ret; |
| *val2 = chan->scan_type.realbits; |
| return IIO_VAL_FRACTIONAL_LOG2; |
| } |
| return -EINVAL; |
| } |
| |
| static const struct iio_info ad7923_info = { |
| .read_raw = &ad7923_read_raw, |
| .update_scan_mode = ad7923_update_scan_mode, |
| }; |
| |
| static int ad7923_probe(struct spi_device *spi) |
| { |
| struct ad7923_state *st; |
| struct iio_dev *indio_dev; |
| const struct ad7923_chip_info *info; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| st = iio_priv(indio_dev); |
| |
| spi_set_drvdata(spi, indio_dev); |
| |
| st->spi = spi; |
| st->settings = AD7923_CODING | AD7923_RANGE | |
| AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS); |
| |
| info = &ad7923_chip_info[spi_get_device_id(spi)->driver_data]; |
| |
| indio_dev->name = spi_get_device_id(spi)->name; |
| indio_dev->dev.parent = &spi->dev; |
| indio_dev->dev.of_node = spi->dev.of_node; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = info->channels; |
| indio_dev->num_channels = info->num_channels; |
| indio_dev->info = &ad7923_info; |
| |
| /* Setup default message */ |
| |
| st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; |
| st->scan_single_xfer[0].len = 2; |
| st->scan_single_xfer[0].cs_change = 1; |
| st->scan_single_xfer[1].rx_buf = &st->rx_buf[0]; |
| st->scan_single_xfer[1].len = 2; |
| |
| spi_message_init(&st->scan_single_msg); |
| spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg); |
| spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg); |
| |
| st->reg = devm_regulator_get(&spi->dev, "refin"); |
| if (IS_ERR(st->reg)) |
| return PTR_ERR(st->reg); |
| |
| ret = regulator_enable(st->reg); |
| if (ret) |
| return ret; |
| |
| ret = iio_triggered_buffer_setup(indio_dev, NULL, |
| &ad7923_trigger_handler, NULL); |
| if (ret) |
| goto error_disable_reg; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto error_cleanup_ring; |
| |
| return 0; |
| |
| error_cleanup_ring: |
| iio_triggered_buffer_cleanup(indio_dev); |
| error_disable_reg: |
| regulator_disable(st->reg); |
| |
| return ret; |
| } |
| |
| static int ad7923_remove(struct spi_device *spi) |
| { |
| struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| struct ad7923_state *st = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| iio_triggered_buffer_cleanup(indio_dev); |
| regulator_disable(st->reg); |
| |
| return 0; |
| } |
| |
| static const struct spi_device_id ad7923_id[] = { |
| {"ad7904", AD7904}, |
| {"ad7914", AD7914}, |
| {"ad7923", AD7924}, |
| {"ad7924", AD7924}, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(spi, ad7923_id); |
| |
| static struct spi_driver ad7923_driver = { |
| .driver = { |
| .name = "ad7923", |
| }, |
| .probe = ad7923_probe, |
| .remove = ad7923_remove, |
| .id_table = ad7923_id, |
| }; |
| module_spi_driver(ad7923_driver); |
| |
| MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); |
| MODULE_AUTHOR("Patrick Vasseur <patrick.vasseur@c-s.fr>"); |
| MODULE_DESCRIPTION("Analog Devices AD7904/AD7914/AD7923/AD7924 ADC"); |
| MODULE_LICENSE("GPL v2"); |