/* * AD7266/65 SPI ADC driver * * Copyright 2012 Analog Devices Inc. * * Licensed under the GPL-2. */ #include <linux/device.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/spi/spi.h> #include <linux/regulator/consumer.h> #include <linux/err.h> #include <linux/gpio.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/iio/iio.h> #include <linux/iio/buffer.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #include <linux/platform_data/ad7266.h> struct ad7266_state { struct spi_device *spi; struct regulator *reg; unsigned long vref_mv; struct spi_transfer single_xfer[3]; struct spi_message single_msg; enum ad7266_range range; enum ad7266_mode mode; bool fixed_addr; struct gpio gpios[3]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. * The buffer needs to be large enough to hold two samples (4 bytes) and * the naturally aligned timestamp (8 bytes). */ struct { __be16 sample[2]; s64 timestamp; } data ____cacheline_aligned; }; static int ad7266_wakeup(struct ad7266_state *st) { /* Any read with >= 2 bytes will wake the device */ return spi_read(st->spi, &st->data.sample[0], 2); } static int ad7266_powerdown(struct ad7266_state *st) { /* Any read with < 2 bytes will powerdown the device */ return spi_read(st->spi, &st->data.sample[0], 1); } static int ad7266_preenable(struct iio_dev *indio_dev) { struct ad7266_state *st = iio_priv(indio_dev); return ad7266_wakeup(st); } static int ad7266_postdisable(struct iio_dev *indio_dev) { struct ad7266_state *st = iio_priv(indio_dev); return ad7266_powerdown(st); } static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { .preenable = &ad7266_preenable, .postenable = &iio_triggered_buffer_postenable, .predisable = &iio_triggered_buffer_predisable, .postdisable = &ad7266_postdisable, }; static irqreturn_t ad7266_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ad7266_state *st = iio_priv(indio_dev); int ret; ret = spi_read(st->spi, st->data.sample, 4); if (ret == 0) { iio_push_to_buffers_with_timestamp(indio_dev, &st->data, pf->timestamp); } iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static void ad7266_select_input(struct ad7266_state *st, unsigned int nr) { unsigned int i; if (st->fixed_addr) return; switch (st->mode) { case AD7266_MODE_SINGLE_ENDED: nr >>= 1; break; case AD7266_MODE_PSEUDO_DIFF: nr |= 1; break; case AD7266_MODE_DIFF: nr &= ~1; break; } for (i = 0; i < 3; ++i) gpio_set_value(st->gpios[i].gpio, (bool)(nr & BIT(i))); } static int ad7266_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask) { struct ad7266_state *st = iio_priv(indio_dev); unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength); ad7266_select_input(st, nr); return 0; } static int ad7266_read_single(struct ad7266_state *st, int *val, unsigned int address) { int ret; ad7266_select_input(st, address); ret = spi_sync(st->spi, &st->single_msg); *val = be16_to_cpu(st->data.sample[address % 2]); return ret; } static int ad7266_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { struct ad7266_state *st = iio_priv(indio_dev); unsigned long scale_mv; int ret; switch (m) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; ret = ad7266_read_single(st, val, chan->address); iio_device_release_direct_mode(indio_dev); *val = (*val >> 2) & 0xfff; if (chan->scan_type.sign == 's') *val = sign_extend32(*val, 11); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: scale_mv = st->vref_mv; if (st->mode == AD7266_MODE_DIFF) scale_mv *= 2; if (st->range == AD7266_RANGE_2VREF) scale_mv *= 2; *val = scale_mv; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: if (st->range == AD7266_RANGE_2VREF && st->mode != AD7266_MODE_DIFF) *val = 2048; else *val = 0; return IIO_VAL_INT; } return -EINVAL; } #define AD7266_CHAN(_chan, _sign) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (_chan), \ .address = (_chan), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ | BIT(IIO_CHAN_INFO_OFFSET), \ .scan_index = (_chan), \ .scan_type = { \ .sign = (_sign), \ .realbits = 12, \ .storagebits = 16, \ .shift = 2, \ .endianness = IIO_BE, \ }, \ } #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \ const struct iio_chan_spec ad7266_channels_##_name[] = { \ AD7266_CHAN(0, (_sign)), \ AD7266_CHAN(1, (_sign)), \ AD7266_CHAN(2, (_sign)), \ AD7266_CHAN(3, (_sign)), \ AD7266_CHAN(4, (_sign)), \ AD7266_CHAN(5, (_sign)), \ AD7266_CHAN(6, (_sign)), \ AD7266_CHAN(7, (_sign)), \ AD7266_CHAN(8, (_sign)), \ AD7266_CHAN(9, (_sign)), \ AD7266_CHAN(10, (_sign)), \ AD7266_CHAN(11, (_sign)), \ IIO_CHAN_SOFT_TIMESTAMP(13), \ } #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \ const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \ AD7266_CHAN(0, (_sign)), \ AD7266_CHAN(1, (_sign)), \ IIO_CHAN_SOFT_TIMESTAMP(2), \ } static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u'); static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's'); static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u'); static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's'); #define AD7266_CHAN_DIFF(_chan, _sign) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (_chan) * 2, \ .channel2 = (_chan) * 2 + 1, \ .address = (_chan), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ | BIT(IIO_CHAN_INFO_OFFSET), \ .scan_index = (_chan), \ .scan_type = { \ .sign = _sign, \ .realbits = 12, \ .storagebits = 16, \ .shift = 2, \ .endianness = IIO_BE, \ }, \ .differential = 1, \ } #define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \ const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \ AD7266_CHAN_DIFF(0, (_sign)), \ AD7266_CHAN_DIFF(1, (_sign)), \ AD7266_CHAN_DIFF(2, (_sign)), \ AD7266_CHAN_DIFF(3, (_sign)), \ AD7266_CHAN_DIFF(4, (_sign)), \ AD7266_CHAN_DIFF(5, (_sign)), \ IIO_CHAN_SOFT_TIMESTAMP(6), \ } static AD7266_DECLARE_DIFF_CHANNELS(s, 's'); static AD7266_DECLARE_DIFF_CHANNELS(u, 'u'); #define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \ const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \ AD7266_CHAN_DIFF(0, (_sign)), \ AD7266_CHAN_DIFF(1, (_sign)), \ IIO_CHAN_SOFT_TIMESTAMP(2), \ } static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's'); static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u'); static const struct iio_info ad7266_info = { .read_raw = &ad7266_read_raw, .update_scan_mode = &ad7266_update_scan_mode, }; static const unsigned long ad7266_available_scan_masks[] = { 0x003, 0x00c, 0x030, 0x0c0, 0x300, 0xc00, 0x000, }; static const unsigned long ad7266_available_scan_masks_diff[] = { 0x003, 0x00c, 0x030, 0x000, }; static const unsigned long ad7266_available_scan_masks_fixed[] = { 0x003, 0x000, }; struct ad7266_chan_info { const struct iio_chan_spec *channels; unsigned int num_channels; const unsigned long *scan_masks; }; #define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \ (((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0)) static const struct ad7266_chan_info ad7266_chan_infos[] = { [AD7266_CHAN_INFO_INDEX(0, 0, 0)] = { .channels = ad7266_channels_u, .num_channels = ARRAY_SIZE(ad7266_channels_u), .scan_masks = ad7266_available_scan_masks, }, [AD7266_CHAN_INFO_INDEX(0, 0, 1)] = { .channels = ad7266_channels_u_fixed, .num_channels = ARRAY_SIZE(ad7266_channels_u_fixed), .scan_masks = ad7266_available_scan_masks_fixed, }, [AD7266_CHAN_INFO_INDEX(0, 1, 0)] = { .channels = ad7266_channels_s, .num_channels = ARRAY_SIZE(ad7266_channels_s), .scan_masks = ad7266_available_scan_masks, }, [AD7266_CHAN_INFO_INDEX(0, 1, 1)] = { .channels = ad7266_channels_s_fixed, .num_channels = ARRAY_SIZE(ad7266_channels_s_fixed), .scan_masks = ad7266_available_scan_masks_fixed, }, [AD7266_CHAN_INFO_INDEX(1, 0, 0)] = { .channels = ad7266_channels_diff_u, .num_channels = ARRAY_SIZE(ad7266_channels_diff_u), .scan_masks = ad7266_available_scan_masks_diff, }, [AD7266_CHAN_INFO_INDEX(1, 0, 1)] = { .channels = ad7266_channels_diff_fixed_u, .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u), .scan_masks = ad7266_available_scan_masks_fixed, }, [AD7266_CHAN_INFO_INDEX(1, 1, 0)] = { .channels = ad7266_channels_diff_s, .num_channels = ARRAY_SIZE(ad7266_channels_diff_s), .scan_masks = ad7266_available_scan_masks_diff, }, [AD7266_CHAN_INFO_INDEX(1, 1, 1)] = { .channels = ad7266_channels_diff_fixed_s, .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s), .scan_masks = ad7266_available_scan_masks_fixed, }, }; static void ad7266_init_channels(struct iio_dev *indio_dev) { struct ad7266_state *st = iio_priv(indio_dev); bool is_differential, is_signed; const struct ad7266_chan_info *chan_info; int i; is_differential = st->mode != AD7266_MODE_SINGLE_ENDED; is_signed = (st->range == AD7266_RANGE_2VREF) | (st->mode == AD7266_MODE_DIFF); i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr); chan_info = &ad7266_chan_infos[i]; indio_dev->channels = chan_info->channels; indio_dev->num_channels = chan_info->num_channels; indio_dev->available_scan_masks = chan_info->scan_masks; indio_dev->masklength = chan_info->num_channels - 1; } static const char * const ad7266_gpio_labels[] = { "AD0", "AD1", "AD2", }; static int ad7266_probe(struct spi_device *spi) { struct ad7266_platform_data *pdata = spi->dev.platform_data; struct iio_dev *indio_dev; struct ad7266_state *st; unsigned int i; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (indio_dev == NULL) return -ENOMEM; st = iio_priv(indio_dev); st->reg = devm_regulator_get_optional(&spi->dev, "vref"); if (!IS_ERR(st->reg)) { ret = regulator_enable(st->reg); if (ret) return ret; ret = regulator_get_voltage(st->reg); if (ret < 0) goto error_disable_reg; st->vref_mv = ret / 1000; } else { /* Any other error indicates that the regulator does exist */ if (PTR_ERR(st->reg) != -ENODEV) return PTR_ERR(st->reg); /* Use internal reference */ st->vref_mv = 2500; } if (pdata) { st->fixed_addr = pdata->fixed_addr; st->mode = pdata->mode; st->range = pdata->range; if (!st->fixed_addr) { for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) { st->gpios[i].gpio = pdata->addr_gpios[i]; st->gpios[i].flags = GPIOF_OUT_INIT_LOW; st->gpios[i].label = ad7266_gpio_labels[i]; } ret = gpio_request_array(st->gpios, ARRAY_SIZE(st->gpios)); if (ret) goto error_disable_reg; } } else { st->fixed_addr = true; st->range = AD7266_RANGE_VREF; st->mode = AD7266_MODE_DIFF; } spi_set_drvdata(spi, indio_dev); st->spi = spi; indio_dev->dev.parent = &spi->dev; indio_dev->dev.of_node = spi->dev.of_node; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &ad7266_info; ad7266_init_channels(indio_dev); /* wakeup */ st->single_xfer[0].rx_buf = &st->data.sample[0]; st->single_xfer[0].len = 2; st->single_xfer[0].cs_change = 1; /* conversion */ st->single_xfer[1].rx_buf = st->data.sample; st->single_xfer[1].len = 4; st->single_xfer[1].cs_change = 1; /* powerdown */ st->single_xfer[2].tx_buf = &st->data.sample[0]; st->single_xfer[2].len = 1; spi_message_init(&st->single_msg); spi_message_add_tail(&st->single_xfer[0], &st->single_msg); spi_message_add_tail(&st->single_xfer[1], &st->single_msg); spi_message_add_tail(&st->single_xfer[2], &st->single_msg); ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, &ad7266_trigger_handler, &iio_triggered_buffer_setup_ops); if (ret) goto error_free_gpios; ret = iio_device_register(indio_dev); if (ret) goto error_buffer_cleanup; 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(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(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");