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path: root/drivers/iio/adc/ti-ads131e08.c
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Diffstat (limited to 'drivers/iio/adc/ti-ads131e08.c')
-rw-r--r--drivers/iio/adc/ti-ads131e08.c948
1 files changed, 948 insertions, 0 deletions
diff --git a/drivers/iio/adc/ti-ads131e08.c b/drivers/iio/adc/ti-ads131e08.c
new file mode 100644
index 000000000000..0060d5f0abb0
--- /dev/null
+++ b/drivers/iio/adc/ti-ads131e08.c
@@ -0,0 +1,948 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Texas Instruments ADS131E0x 4-, 6- and 8-Channel ADCs
+ *
+ * Copyright (c) 2020 AVL DiTEST GmbH
+ * Tomislav Denis <tomislav.denis@avl.com>
+ *
+ * Datasheet: https://www.ti.com/lit/ds/symlink/ads131e08.pdf
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <asm/unaligned.h>
+
+/* Commands */
+#define ADS131E08_CMD_RESET 0x06
+#define ADS131E08_CMD_START 0x08
+#define ADS131E08_CMD_STOP 0x0A
+#define ADS131E08_CMD_OFFSETCAL 0x1A
+#define ADS131E08_CMD_SDATAC 0x11
+#define ADS131E08_CMD_RDATA 0x12
+#define ADS131E08_CMD_RREG(r) (BIT(5) | (r & GENMASK(4, 0)))
+#define ADS131E08_CMD_WREG(r) (BIT(6) | (r & GENMASK(4, 0)))
+
+/* Registers */
+#define ADS131E08_ADR_CFG1R 0x01
+#define ADS131E08_ADR_CFG3R 0x03
+#define ADS131E08_ADR_CH0R 0x05
+
+/* Configuration register 1 */
+#define ADS131E08_CFG1R_DR_MASK GENMASK(2, 0)
+
+/* Configuration register 3 */
+#define ADS131E08_CFG3R_PDB_REFBUF_MASK BIT(7)
+#define ADS131E08_CFG3R_VREF_4V_MASK BIT(5)
+
+/* Channel settings register */
+#define ADS131E08_CHR_GAIN_MASK GENMASK(6, 4)
+#define ADS131E08_CHR_MUX_MASK GENMASK(2, 0)
+#define ADS131E08_CHR_PWD_MASK BIT(7)
+
+/* ADC misc */
+#define ADS131E08_DEFAULT_DATA_RATE 1
+#define ADS131E08_DEFAULT_PGA_GAIN 1
+#define ADS131E08_DEFAULT_MUX 0
+
+#define ADS131E08_VREF_2V4_mV 2400
+#define ADS131E08_VREF_4V_mV 4000
+
+#define ADS131E08_WAIT_RESET_CYCLES 18
+#define ADS131E08_WAIT_SDECODE_CYCLES 4
+#define ADS131E08_WAIT_OFFSETCAL_MS 153
+#define ADS131E08_MAX_SETTLING_TIME_MS 6
+
+#define ADS131E08_NUM_STATUS_BYTES 3
+#define ADS131E08_NUM_DATA_BYTES_MAX 24
+#define ADS131E08_NUM_DATA_BYTES(dr) (((dr) >= 32) ? 2 : 3)
+#define ADS131E08_NUM_DATA_BITS(dr) (ADS131E08_NUM_DATA_BYTES(dr) * 8)
+#define ADS131E08_NUM_STORAGE_BYTES 4
+
+enum ads131e08_ids {
+ ads131e04,
+ ads131e06,
+ ads131e08,
+};
+
+struct ads131e08_info {
+ unsigned int max_channels;
+ const char *name;
+};
+
+struct ads131e08_channel_config {
+ unsigned int pga_gain;
+ unsigned int mux;
+};
+
+struct ads131e08_state {
+ const struct ads131e08_info *info;
+ struct spi_device *spi;
+ struct iio_trigger *trig;
+ struct clk *adc_clk;
+ struct regulator *vref_reg;
+ struct ads131e08_channel_config *channel_config;
+ unsigned int data_rate;
+ unsigned int vref_mv;
+ unsigned int sdecode_delay_us;
+ unsigned int reset_delay_us;
+ unsigned int readback_len;
+ struct completion completion;
+ struct {
+ u8 data[ADS131E08_NUM_DATA_BYTES_MAX];
+ s64 ts __aligned(8);
+ } tmp_buf;
+
+ u8 tx_buf[3] ____cacheline_aligned;
+ /*
+ * Add extra one padding byte to be able to access the last channel
+ * value using u32 pointer
+ */
+ u8 rx_buf[ADS131E08_NUM_STATUS_BYTES +
+ ADS131E08_NUM_DATA_BYTES_MAX + 1];
+};
+
+static const struct ads131e08_info ads131e08_info_tbl[] = {
+ [ads131e04] = {
+ .max_channels = 4,
+ .name = "ads131e04",
+ },
+ [ads131e06] = {
+ .max_channels = 6,
+ .name = "ads131e06",
+ },
+ [ads131e08] = {
+ .max_channels = 8,
+ .name = "ads131e08",
+ },
+};
+
+struct ads131e08_data_rate_desc {
+ unsigned int rate; /* data rate in kSPS */
+ u8 reg; /* reg value */
+};
+
+static const struct ads131e08_data_rate_desc ads131e08_data_rate_tbl[] = {
+ { .rate = 64, .reg = 0x00 },
+ { .rate = 32, .reg = 0x01 },
+ { .rate = 16, .reg = 0x02 },
+ { .rate = 8, .reg = 0x03 },
+ { .rate = 4, .reg = 0x04 },
+ { .rate = 2, .reg = 0x05 },
+ { .rate = 1, .reg = 0x06 },
+};
+
+struct ads131e08_pga_gain_desc {
+ unsigned int gain; /* PGA gain value */
+ u8 reg; /* field value */
+};
+
+static const struct ads131e08_pga_gain_desc ads131e08_pga_gain_tbl[] = {
+ { .gain = 1, .reg = 0x01 },
+ { .gain = 2, .reg = 0x02 },
+ { .gain = 4, .reg = 0x04 },
+ { .gain = 8, .reg = 0x05 },
+ { .gain = 12, .reg = 0x06 },
+};
+
+static const u8 ads131e08_valid_channel_mux_values[] = { 0, 1, 3, 4 };
+
+static int ads131e08_exec_cmd(struct ads131e08_state *st, u8 cmd)
+{
+ int ret;
+
+ ret = spi_write_then_read(st->spi, &cmd, 1, NULL, 0);
+ if (ret)
+ dev_err(&st->spi->dev, "Exec cmd(%02x) failed\n", cmd);
+
+ return ret;
+}
+
+static int ads131e08_read_reg(struct ads131e08_state *st, u8 reg)
+{
+ int ret;
+ struct spi_transfer transfer[] = {
+ {
+ .tx_buf = &st->tx_buf,
+ .len = 2,
+ .delay_usecs = st->sdecode_delay_us,
+ }, {
+ .rx_buf = &st->rx_buf,
+ .len = 1,
+ },
+ };
+
+ st->tx_buf[0] = ADS131E08_CMD_RREG(reg);
+ st->tx_buf[1] = 0;
+
+ ret = spi_sync_transfer(st->spi, transfer, ARRAY_SIZE(transfer));
+ if (ret) {
+ dev_err(&st->spi->dev, "Read register failed\n");
+ return ret;
+ }
+
+ return st->rx_buf[0];
+}
+
+static int ads131e08_write_reg(struct ads131e08_state *st, u8 reg, u8 value)
+{
+ int ret;
+ struct spi_transfer transfer[] = {
+ {
+ .tx_buf = &st->tx_buf,
+ .len = 3,
+ .delay_usecs = st->sdecode_delay_us,
+ }
+ };
+
+ st->tx_buf[0] = ADS131E08_CMD_WREG(reg);
+ st->tx_buf[1] = 0;
+ st->tx_buf[2] = value;
+
+ ret = spi_sync_transfer(st->spi, transfer, ARRAY_SIZE(transfer));
+ if (ret)
+ dev_err(&st->spi->dev, "Write register failed\n");
+
+ return ret;
+}
+
+static int ads131e08_read_data(struct ads131e08_state *st, int rx_len)
+{
+ int ret;
+ struct spi_transfer transfer[] = {
+ {
+ .tx_buf = &st->tx_buf,
+ .len = 1,
+ }, {
+ .rx_buf = &st->rx_buf,
+ .len = rx_len,
+ },
+ };
+
+ st->tx_buf[0] = ADS131E08_CMD_RDATA;
+
+ ret = spi_sync_transfer(st->spi, transfer, ARRAY_SIZE(transfer));
+ if (ret)
+ dev_err(&st->spi->dev, "Read data failed\n");
+
+ return ret;
+}
+
+static int ads131e08_set_data_rate(struct ads131e08_state *st, int data_rate)
+{
+ int i, reg, ret;
+
+ for (i = 0; i < ARRAY_SIZE(ads131e08_data_rate_tbl); i++) {
+ if (ads131e08_data_rate_tbl[i].rate == data_rate)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(ads131e08_data_rate_tbl)) {
+ dev_err(&st->spi->dev, "invalid data rate value\n");
+ return -EINVAL;
+ }
+
+ reg = ads131e08_read_reg(st, ADS131E08_ADR_CFG1R);
+ if (reg < 0)
+ return reg;
+
+ reg &= ~ADS131E08_CFG1R_DR_MASK;
+ reg |= FIELD_PREP(ADS131E08_CFG1R_DR_MASK,
+ ads131e08_data_rate_tbl[i].reg);
+
+ ret = ads131e08_write_reg(st, ADS131E08_ADR_CFG1R, reg);
+ if (ret)
+ return ret;
+
+ st->data_rate = data_rate;
+ st->readback_len = ADS131E08_NUM_STATUS_BYTES +
+ ADS131E08_NUM_DATA_BYTES(st->data_rate) *
+ st->info->max_channels;
+
+ return 0;
+}
+
+static int ads131e08_pga_gain_to_field_value(struct ads131e08_state *st,
+ unsigned int pga_gain)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ads131e08_pga_gain_tbl); i++) {
+ if (ads131e08_pga_gain_tbl[i].gain == pga_gain)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(ads131e08_pga_gain_tbl)) {
+ dev_err(&st->spi->dev, "invalid PGA gain value\n");
+ return -EINVAL;
+ }
+
+ return ads131e08_pga_gain_tbl[i].reg;
+}
+
+static int ads131e08_set_pga_gain(struct ads131e08_state *st,
+ unsigned int channel, unsigned int pga_gain)
+{
+ int field_value, reg;
+
+ field_value = ads131e08_pga_gain_to_field_value(st, pga_gain);
+ if (field_value < 0)
+ return field_value;
+
+ reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
+ if (reg < 0)
+ return reg;
+
+ reg &= ~ADS131E08_CHR_GAIN_MASK;
+ reg |= FIELD_PREP(ADS131E08_CHR_GAIN_MASK, field_value);
+
+ return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, reg);
+}
+
+static int ads131e08_validate_channel_mux(struct ads131e08_state *st,
+ unsigned int mux)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ads131e08_valid_channel_mux_values); i++) {
+ if (ads131e08_valid_channel_mux_values[i] == mux)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(ads131e08_valid_channel_mux_values)) {
+ dev_err(&st->spi->dev, "invalid channel mux value\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int ads131e08_set_channel_mux(struct ads131e08_state *st,
+ unsigned int channel, unsigned int mux)
+{
+ int reg;
+
+ reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
+ if (reg < 0)
+ return reg;
+
+ reg &= ~ADS131E08_CHR_MUX_MASK;
+ reg |= FIELD_PREP(ADS131E08_CHR_MUX_MASK, mux);
+
+ return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, reg);
+}
+
+static int ads131e08_power_down_channel(struct ads131e08_state *st,
+ unsigned int channel, bool value)
+{
+ int reg;
+
+ reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
+ if (reg < 0)
+ return reg;
+
+ reg &= ~ADS131E08_CHR_PWD_MASK;
+ reg |= FIELD_PREP(ADS131E08_CHR_PWD_MASK, value);
+
+ return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, reg);
+}
+
+static int ads131e08_config_reference_voltage(struct ads131e08_state *st)
+{
+ int reg;
+
+ reg = ads131e08_read_reg(st, ADS131E08_ADR_CFG3R);
+ if (reg < 0)
+ return reg;
+
+ reg &= ~ADS131E08_CFG3R_PDB_REFBUF_MASK;
+ if (!st->vref_reg) {
+ reg |= FIELD_PREP(ADS131E08_CFG3R_PDB_REFBUF_MASK, 1);
+ reg &= ~ADS131E08_CFG3R_VREF_4V_MASK;
+ reg |= FIELD_PREP(ADS131E08_CFG3R_VREF_4V_MASK,
+ st->vref_mv == ADS131E08_VREF_4V_mV);
+ }
+
+ return ads131e08_write_reg(st, ADS131E08_ADR_CFG3R, reg);
+}
+
+static int ads131e08_initial_config(struct iio_dev *indio_dev)
+{
+ const struct iio_chan_spec *channel = indio_dev->channels;
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ unsigned long active_channels = 0;
+ int ret, i;
+
+ ret = ads131e08_exec_cmd(st, ADS131E08_CMD_RESET);
+ if (ret)
+ return ret;
+
+ udelay(st->reset_delay_us);
+
+ /* Disable read data in continuous mode (enabled by default) */
+ ret = ads131e08_exec_cmd(st, ADS131E08_CMD_SDATAC);
+ if (ret)
+ return ret;
+
+ ret = ads131e08_set_data_rate(st, ADS131E08_DEFAULT_DATA_RATE);
+ if (ret)
+ return ret;
+
+ ret = ads131e08_config_reference_voltage(st);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ ret = ads131e08_set_pga_gain(st, channel->channel,
+ st->channel_config[i].pga_gain);
+ if (ret)
+ return ret;
+
+ ret = ads131e08_set_channel_mux(st, channel->channel,
+ st->channel_config[i].mux);
+ if (ret)
+ return ret;
+
+ active_channels |= BIT(channel->channel);
+ channel++;
+ }
+
+ /* Power down unused channels */
+ for_each_clear_bit(i, &active_channels, st->info->max_channels) {
+ ret = ads131e08_power_down_channel(st, i, true);
+ if (ret)
+ return ret;
+ }
+
+ /* Request channel offset calibration */
+ ret = ads131e08_exec_cmd(st, ADS131E08_CMD_OFFSETCAL);
+ if (ret)
+ return ret;
+
+ /*
+ * Channel offset calibration is triggered with the first START
+ * command. Since calibration takes more time than settling operation,
+ * this causes timeout error when command START is sent first
+ * time (e.g. first call of the ads131e08_read_direct method).
+ * To avoid this problem offset calibration is triggered here.
+ */
+ ret = ads131e08_exec_cmd(st, ADS131E08_CMD_START);
+ if (ret)
+ return ret;
+
+ msleep(ADS131E08_WAIT_OFFSETCAL_MS);
+
+ return ads131e08_exec_cmd(st, ADS131E08_CMD_STOP);
+}
+
+static int ads131e08_pool_data(struct ads131e08_state *st)
+{
+ unsigned long timeout;
+ int ret;
+
+ reinit_completion(&st->completion);
+
+ ret = ads131e08_exec_cmd(st, ADS131E08_CMD_START);
+ if (ret)
+ return ret;
+
+ timeout = msecs_to_jiffies(ADS131E08_MAX_SETTLING_TIME_MS);
+ ret = wait_for_completion_timeout(&st->completion, timeout);
+ if (!ret)
+ return -ETIMEDOUT;
+
+ ret = ads131e08_read_data(st, st->readback_len);
+ if (ret)
+ return ret;
+
+ return ads131e08_exec_cmd(st, ADS131E08_CMD_STOP);
+}
+
+static int ads131e08_read_direct(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *value)
+{
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ u8 num_bits, *src;
+ int ret;
+
+ ret = ads131e08_pool_data(st);
+ if (ret)
+ return ret;
+
+ src = st->rx_buf + ADS131E08_NUM_STATUS_BYTES +
+ channel->channel * ADS131E08_NUM_DATA_BYTES(st->data_rate);
+
+ num_bits = ADS131E08_NUM_DATA_BITS(st->data_rate);
+ *value = sign_extend32(get_unaligned_be32(src) >> (32 - num_bits), num_bits - 1);
+
+ return 0;
+}
+
+static int ads131e08_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *value,
+ int *value2, long mask)
+{
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ads131e08_read_direct(indio_dev, channel, value);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ if (st->vref_reg) {
+ ret = regulator_get_voltage(st->vref_reg);
+ if (ret < 0)
+ return ret;
+
+ *value = ret / 1000;
+ } else {
+ *value = st->vref_mv;
+ }
+
+ *value /= st->channel_config[channel->address].pga_gain;
+ *value2 = ADS131E08_NUM_DATA_BITS(st->data_rate) - 1;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *value = st->data_rate;
+
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ads131e08_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int value,
+ int value2, long mask)
+{
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ads131e08_set_data_rate(st, value);
+ iio_device_release_direct_mode(indio_dev);
+ return ret;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 2 4 8 16 32 64");
+
+static struct attribute *ads131e08_attributes[] = {
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group ads131e08_attribute_group = {
+ .attrs = ads131e08_attributes,
+};
+
+static int ads131e08_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int writeval, unsigned int *readval)
+{
+ struct ads131e08_state *st = iio_priv(indio_dev);
+
+ if (readval) {
+ int ret = ads131e08_read_reg(st, reg);
+ *readval = ret;
+ return ret;
+ }
+
+ return ads131e08_write_reg(st, reg, writeval);
+}
+
+static const struct iio_info ads131e08_iio_info = {
+ .read_raw = ads131e08_read_raw,
+ .write_raw = ads131e08_write_raw,
+ .attrs = &ads131e08_attribute_group,
+ .debugfs_reg_access = &ads131e08_debugfs_reg_access,
+};
+
+static int ads131e08_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ u8 cmd = state ? ADS131E08_CMD_START : ADS131E08_CMD_STOP;
+
+ return ads131e08_exec_cmd(st, cmd);
+}
+
+static const struct iio_trigger_ops ads131e08_trigger_ops = {
+ .set_trigger_state = &ads131e08_set_trigger_state,
+ .validate_device = &iio_trigger_validate_own_device,
+};
+
+static irqreturn_t ads131e08_trigger_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = private;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ unsigned int chn, i = 0;
+ u8 *src, *dest;
+ int ret;
+
+ /*
+ * The number of data bits per channel depends on the data rate.
+ * For 32 and 64 ksps data rates, number of data bits per channel
+ * is 16. This case is not compliant with used (fixed) scan element
+ * type (be:s24/32>>8). So we use a little tweak to pack properly
+ * 16 bits of data into the buffer.
+ */
+ unsigned int num_bytes = ADS131E08_NUM_DATA_BYTES(st->data_rate);
+ u8 tweek_offset = num_bytes == 2 ? 1 : 0;
+
+ if (iio_trigger_using_own(indio_dev))
+ ret = ads131e08_read_data(st, st->readback_len);
+ else
+ ret = ads131e08_pool_data(st);
+
+ if (ret)
+ goto out;
+
+ for_each_set_bit(chn, indio_dev->active_scan_mask, indio_dev->masklength) {
+ src = st->rx_buf + ADS131E08_NUM_STATUS_BYTES + chn * num_bytes;
+ dest = st->tmp_buf.data + i * ADS131E08_NUM_STORAGE_BYTES;
+
+ /*
+ * Tweek offset is 0:
+ * +---+---+---+---+
+ * |D0 |D1 |D2 | X | (3 data bytes)
+ * +---+---+---+---+
+ * a+0 a+1 a+2 a+3
+ *
+ * Tweek offset is 1:
+ * +---+---+---+---+
+ * |P0 |D0 |D1 | X | (one padding byte and 2 data bytes)
+ * +---+---+---+---+
+ * a+0 a+1 a+2 a+3
+ */
+ memcpy(dest + tweek_offset, src, num_bytes);
+
+ /*
+ * Data conversion from 16 bits of data to 24 bits of data
+ * is done by sign extension (properly filling padding byte).
+ */
+ if (tweek_offset)
+ *dest = *src & BIT(7) ? 0xff : 0x00;
+
+ i++;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, st->tmp_buf.data,
+ iio_get_time_ns(indio_dev));
+
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ads131e08_interrupt(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct ads131e08_state *st = iio_priv(indio_dev);
+
+ if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev))
+ iio_trigger_poll(st->trig);
+ else
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+}
+
+static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
+{
+ struct ads131e08_state *st = iio_priv(indio_dev);
+ struct ads131e08_channel_config *channel_config;
+ struct device *dev = &st->spi->dev;
+ struct iio_chan_spec *channels;
+ struct fwnode_handle *node;
+ unsigned int channel, tmp;
+ int num_channels, i, ret;
+
+ ret = device_property_read_u32(dev, "ti,vref-internal", &tmp);
+ if (ret)
+ tmp = 0;
+
+ switch (tmp) {
+ case 0:
+ st->vref_mv = ADS131E08_VREF_2V4_mV;
+ break;
+ case 1:
+ st->vref_mv = ADS131E08_VREF_4V_mV;
+ break;
+ default:
+ dev_err(&st->spi->dev, "invalid internal voltage reference\n");
+ return -EINVAL;
+ }
+
+ num_channels = device_get_child_node_count(dev);
+ if (num_channels == 0) {
+ dev_err(&st->spi->dev, "no channel children\n");
+ return -ENODEV;
+ }
+
+ if (num_channels > st->info->max_channels) {
+ dev_err(&st->spi->dev, "num of channel children out of range\n");
+ return -EINVAL;
+ }
+
+ channels = devm_kcalloc(&st->spi->dev, num_channels,
+ sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ channel_config = devm_kcalloc(&st->spi->dev, num_channels,
+ sizeof(*channel_config), GFP_KERNEL);
+ if (!channel_config)
+ return -ENOMEM;
+
+ i = 0;
+ device_for_each_child_node(dev, node) {
+ ret = fwnode_property_read_u32(node, "reg", &channel);
+ if (ret)
+ return ret;
+
+ ret = fwnode_property_read_u32(node, "ti,gain", &tmp);
+ if (ret) {
+ channel_config[i].pga_gain = ADS131E08_DEFAULT_PGA_GAIN;
+ } else {
+ ret = ads131e08_pga_gain_to_field_value(st, tmp);
+ if (ret < 0)
+ return ret;
+
+ channel_config[i].pga_gain = tmp;
+ }
+
+ ret = fwnode_property_read_u32(node, "ti,mux", &tmp);
+ if (ret) {
+ channel_config[i].mux = ADS131E08_DEFAULT_MUX;
+ } else {
+ ret = ads131e08_validate_channel_mux(st, tmp);
+ if (ret)
+ return ret;
+
+ channel_config[i].mux = tmp;
+ }
+
+ channels[i].type = IIO_VOLTAGE;
+ channels[i].indexed = 1;
+ channels[i].channel = channel;
+ channels[i].address = i;
+ channels[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE);
+ channels[i].info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+ channels[i].scan_index = channel;
+ channels[i].scan_type.sign = 's';
+ channels[i].scan_type.realbits = 24;
+ channels[i].scan_type.storagebits = 32;
+ channels[i].scan_type.shift = 8;
+ channels[i].scan_type.endianness = IIO_BE;
+ i++;
+ }
+
+ indio_dev->channels = channels;
+ indio_dev->num_channels = num_channels;
+ st->channel_config = channel_config;
+
+ return 0;
+}
+
+static void ads131e08_regulator_disable(void *data)
+{
+ struct ads131e08_state *st = data;
+
+ regulator_disable(st->vref_reg);
+}
+
+static void ads131e08_clk_disable(void *data)
+{
+ struct ads131e08_state *st = data;
+
+ clk_disable_unprepare(st->adc_clk);
+}
+
+static int ads131e08_probe(struct spi_device *spi)
+{
+ const struct ads131e08_info *info;
+ struct ads131e08_state *st;
+ struct iio_dev *indio_dev;
+ unsigned long adc_clk_hz;
+ unsigned long adc_clk_ns;
+ int ret;
+
+ info = device_get_match_data(&spi->dev);
+ if (!info) {
+ dev_err(&spi->dev, "failed to get match data\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev) {
+ dev_err(&spi->dev, "failed to allocate IIO device\n");
+ return -ENOMEM;
+ }
+
+ st = iio_priv(indio_dev);
+ st->info = info;
+ st->spi = spi;
+
+ ret = ads131e08_alloc_channels(indio_dev);
+ if (ret)
+ return ret;
+
+ indio_dev->name = st->info->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &ads131e08_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ init_completion(&st->completion);
+
+ if (spi->irq) {
+ ret = devm_request_irq(&spi->dev, spi->irq,
+ ads131e08_interrupt,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ spi->dev.driver->name, indio_dev);
+ if (ret)
+ return dev_err_probe(&spi->dev, ret,
+ "request irq failed\n");
+ } else {
+ dev_err(&spi->dev, "data ready IRQ missing\n");
+ return -ENODEV;
+ }
+
+ st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+ indio_dev->name, indio_dev->id);
+ if (!st->trig) {
+ dev_err(&spi->dev, "failed to allocate IIO trigger\n");
+ return -ENOMEM;
+ }
+
+ st->trig->ops = &ads131e08_trigger_ops;
+ st->trig->dev.parent = &spi->dev;
+ iio_trigger_set_drvdata(st->trig, indio_dev);
+ ret = devm_iio_trigger_register(&spi->dev, st->trig);
+ if (ret) {
+ dev_err(&spi->dev, "failed to register IIO trigger\n");
+ return -ENOMEM;
+ }
+
+ indio_dev->trig = iio_trigger_get(st->trig);
+
+ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+ NULL, &ads131e08_trigger_handler, NULL);
+ if (ret) {
+ dev_err(&spi->dev, "failed to setup IIO buffer\n");
+ return ret;
+ }
+
+ st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
+ if (!IS_ERR(st->vref_reg)) {
+ ret = regulator_enable(st->vref_reg);
+ if (ret) {
+ dev_err(&spi->dev,
+ "failed to enable external vref supply\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(&spi->dev, ads131e08_regulator_disable, st);
+ if (ret)
+ return ret;
+ } else {
+ if (PTR_ERR(st->vref_reg) != -ENODEV)
+ return PTR_ERR(st->vref_reg);
+
+ st->vref_reg = NULL;
+ }
+
+ st->adc_clk = devm_clk_get(&spi->dev, "adc-clk");
+ if (IS_ERR(st->adc_clk))
+ return dev_err_probe(&spi->dev, PTR_ERR(st->adc_clk),
+ "failed to get the ADC clock\n");
+
+ ret = clk_prepare_enable(st->adc_clk);
+ if (ret) {
+ dev_err(&spi->dev, "failed to prepare/enable the ADC clock\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(&spi->dev, ads131e08_clk_disable, st);
+ if (ret)
+ return ret;
+
+ adc_clk_hz = clk_get_rate(st->adc_clk);
+ if (!adc_clk_hz) {
+ dev_err(&spi->dev, "failed to get the ADC clock rate\n");
+ return -EINVAL;
+ }
+
+ adc_clk_ns = NSEC_PER_SEC / adc_clk_hz;
+ st->sdecode_delay_us = DIV_ROUND_UP(
+ ADS131E08_WAIT_SDECODE_CYCLES * adc_clk_ns, NSEC_PER_USEC);
+ st->reset_delay_us = DIV_ROUND_UP(
+ ADS131E08_WAIT_RESET_CYCLES * adc_clk_ns, NSEC_PER_USEC);
+
+ ret = ads131e08_initial_config(indio_dev);
+ if (ret) {
+ dev_err(&spi->dev, "initial configuration failed\n");
+ return ret;
+ }
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ads131e08_of_match[] = {
+ { .compatible = "ti,ads131e04",
+ .data = &ads131e08_info_tbl[ads131e04], },
+ { .compatible = "ti,ads131e06",
+ .data = &ads131e08_info_tbl[ads131e06], },
+ { .compatible = "ti,ads131e08",
+ .data = &ads131e08_info_tbl[ads131e08], },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ads131e08_of_match);
+
+static struct spi_driver ads131e08_driver = {
+ .driver = {
+ .name = "ads131e08",
+ .of_match_table = ads131e08_of_match,
+ },
+ .probe = ads131e08_probe,
+};
+module_spi_driver(ads131e08_driver);
+
+MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
+MODULE_DESCRIPTION("Driver for ADS131E0x ADC family");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 05:51:23 +0300