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Diffstat (limited to 'drivers/iio/adc/ad7266.c')
-rw-r--r--drivers/iio/adc/ad7266.c496
1 files changed, 496 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7266.c b/drivers/iio/adc/ad7266.c
new file mode 100644
index 000000000..468c2656d
--- /dev/null
+++ b/drivers/iio/adc/ad7266.c
@@ -0,0 +1,496 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AD7266/65 SPI ADC driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ */
+
+#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/consumer.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_desc *gpios[3];
+
+ /*
+ * DMA (thus cache coherency maintenance) may require 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 __aligned(IIO_DMA_MINALIGN);
+};
+
+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,
+ .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)
+ gpiod_set_value(st->gpios[i], (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,
+ chan->scan_type.realbits - 1);
+
+ 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 void ad7266_reg_disable(void *reg)
+{
+ regulator_disable(reg);
+}
+
+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 = devm_add_action_or_reset(&spi->dev, ad7266_reg_disable, st->reg);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_voltage(st->reg);
+ if (ret < 0)
+ return ret;
+
+ 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] = devm_gpiod_get(&spi->dev,
+ ad7266_gpio_labels[i],
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->gpios[i])) {
+ ret = PTR_ERR(st->gpios[i]);
+ return ret;
+ }
+ }
+ }
+ } else {
+ st->fixed_addr = true;
+ st->range = AD7266_RANGE_VREF;
+ st->mode = AD7266_MODE_DIFF;
+ }
+
+ st->spi = spi;
+
+ 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 = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, &iio_pollfunc_store_time,
+ &ad7266_trigger_handler, &iio_triggered_buffer_setup_ops);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+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,
+ .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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 21:22:26 +0000