From: Tomislav Denis <tomislav.denis@xxxxxxx> The ADS131E0x are a family of multichannel, simultaneous sampling, 24-bit, delta-sigma, analog-to-digital converters (ADCs) with a built-in programmable gain amplifier (PGA), internal reference and an onboard oscillator. Signed-off-by: Tomislav Denis <tomislav.denis@xxxxxxx> --- MAINTAINERS | 6 + drivers/iio/adc/Kconfig | 12 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ti-ads131e08.c | 921 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 940 insertions(+) create mode 100644 drivers/iio/adc/ti-ads131e08.c diff --git a/MAINTAINERS b/MAINTAINERS index 2ac5688..167aabf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17367,6 +17367,12 @@ M: Robert Richter <rric@xxxxxxxxxx> S: Odd Fixes F: drivers/gpio/gpio-thunderx.c +TI ADS131E0X ADC SERIES DRIVER +M: Tomislav Denis <tomislav.denis@xxxxxxx> +L: linux-iio@xxxxxxxxxxxxxxx +S: Maintained +F: drivers/iio/adc/ti-ads131e08.c + TI AM437X VPFE DRIVER M: "Lad, Prabhakar" <prabhakar.csengg@xxxxxxxxx> L: linux-media@xxxxxxxxxxxxxxx diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 15587a1..ef5471a 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1151,6 +1151,18 @@ config TI_ADS124S08 This driver can also be built as a module. If so, the module will be called ti-ads124s08. +config TI_ADS131E08 + tristate "Texas Instruments ADS131E08" + depends on SPI && OF + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here you get support for Texas Instruments ADS131E08 and + ADS131E04 chips. + + This driver can also be built as a module. If so, the module will be + called ti-ads131e08. + config TI_AM335X_ADC tristate "TI's AM335X ADC driver" depends on MFD_TI_AM335X_TSCADC && HAS_DMA diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 5fca90a..a226657 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -103,6 +103,7 @@ obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o +obj-$(CONFIG_TI_ADS131E08) += ti-ads131e08.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o diff --git a/drivers/iio/adc/ti-ads131e08.c b/drivers/iio/adc/ti-ads131e08.c new file mode 100644 index 0000000..cf9d047 --- /dev/null +++ b/drivers/iio/adc/ti-ads131e08.c @@ -0,0 +1,921 @@ +// 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@xxxxxxx> + * + * Datasheet: https://www.ti.com/lit/ds/symlink/ads131e08.pdf + */ + +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/bitfield.h> +#include <linux/spi/spi.h> +#include <linux/regulator/consumer.h> +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/sysfs.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) (0x20 | (r & GENMASK(4, 0))) +#define ADS131E08_CMD_WREG(r) (0x40 | (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; +}; + +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, + }, + [ads131e06] = { + .max_channels = 6, + }, + [ads131e08] = { + .max_channels = 8, + }, +}; + +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; /* reg 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, + "%s: SPI write failed for cmd: %02x\n", __func__, cmd); + return ret; + } + + return 0; +} + +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, "%s: SPI transfer failed\n", __func__); + 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, "%s: SPI transfer failed\n", __func__); + return ret; + } + + return 0; +} + +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, "%s: SPI transfer failed\n", __func__); + return ret; + } + + return 0; +} + +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_set_pga_gain(struct ads131e08_state *st, + unsigned int channel, unsigned int pga_gain) +{ + int i, reg; + + 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; + } + + 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, ads131e08_pga_gain_tbl[i].reg); + + return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, reg); +} + +static int ads131e08_set_channel_mux(struct ads131e08_state *st, + unsigned int channel, unsigned int mux) +{ + int i, reg; + + 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; + } + + 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 | + ~ADS131E08_CFG3R_VREF_4V_MASK; + reg |= FIELD_PREP(ADS131E08_CFG3R_PDB_REFBUF_MASK, + IS_ERR(st->vref_reg)); + 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) +{ + struct ads131e08_state *st = iio_priv(indio_dev); + const struct iio_chan_spec *channel = indio_dev->channels; + int ret, i; + u8 active_channels = 0; + + 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 (i = 0; i < st->info->max_channels; ++i) { + if (!(active_channels & BIT(i))) { + 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 first START command. + * Since calibration take 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); + + ret = ads131e08_exec_cmd(st, ADS131E08_CMD_STOP); + if (ret) + return ret; + + return 0; +} + +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); + int ret; + u8 num_bits, *src; + + reinit_completion(&st->completion); + + ret = ads131e08_exec_cmd(st, ADS131E08_CMD_START); + if (ret) + return ret; + + ret = wait_for_completion_timeout(&st->completion, + msecs_to_jiffies(ADS131E08_MAX_SETTLING_TIME_MS)); + if (!ret) + return -ETIMEDOUT; + + ret = ads131e08_read_data(st, st->readback_len); + if (ret) + return ret; + + ret = ads131e08_exec_cmd(st, ADS131E08_CMD_STOP); + 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 ret; +} + +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: + *value = st->vref_mv / + 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; + } + + 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; + } + + 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, (u8)reg); + *readval = ret; + return ret; + } + + return ads131e08_write_reg(st, (u8)reg, (u8)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, +}; + +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); + int ret; + unsigned int chn, i = 0; + u8 *src, *dest; + /* + * 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 litle tweek 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; + + ret = ads131e08_read_data(st, st->readback_len); + 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 etension (properly filling padding byte). + */ + if (tweek_offset) + memset(dest, *src & BIT(7) ? 0xff : 0x00, 1); + + 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_poll(st->trig); + else + complete(&st->completion); + + return IRQ_HANDLED; +} + +static int ads131e08_parse_dt(struct iio_dev *indio_dev, + struct device_node *node) +{ + struct ads131e08_state *st = iio_priv(indio_dev); + struct iio_chan_spec *channels; + struct ads131e08_channel_config *channel_config; + struct device_node *child; + unsigned int channel, tmp; + int num_channels, i, ret; + + ret = of_property_read_u32(node, "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 = of_get_available_child_count(node); + 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(struct iio_chan_spec), GFP_KERNEL); + if (!channels) + return -ENOMEM; + + channel_config = devm_kcalloc(&st->spi->dev, num_channels, + sizeof(struct ads131e08_channel_config), GFP_KERNEL); + if (!channel_config) + return -ENOMEM; + + i = 0; + for_each_available_child_of_node(node, child) { + ret = of_property_read_u32(child, "reg", &channel); + if (ret) + return ret; + + ret = of_property_read_u32(child, "ti,gain", &tmp); + if (ret) + channel_config[i].pga_gain = ADS131E08_DEFAULT_PGA_GAIN; + else + channel_config[i].pga_gain = tmp; + + ret = of_property_read_u32(child, "ti,mux", &tmp); + if (ret) + channel_config[i].mux = ADS131E08_DEFAULT_MUX; + else + 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) +{ + struct iio_dev *indio_dev; + struct ads131e08_state *st; + int ret; + unsigned long adc_clk_hz, adc_clk_ns; + + 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; + } + + spi_set_drvdata(spi, indio_dev); + + st = iio_priv(indio_dev); + st->info = &ads131e08_info_tbl[spi_get_device_id(spi)->driver_data]; + st->spi = spi; + + ret = ads131e08_parse_dt(indio_dev, spi->dev.of_node); + if (ret) + return ret; + + 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->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) { + dev_err(&spi->dev, "failed to allocate IRQ\n"); + return ret; + } + } 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) { + regulator_disable(st->vref_reg); + return ret; + } + + ret = regulator_get_voltage(st->vref_reg); + if (ret < 0) { + dev_err(&spi->dev, "failed to get vref voltage\n"); + return ret; + } + + st->vref_mv = ret / 1000; + } + + st->adc_clk = devm_clk_get(&spi->dev, "adc-clk"); + if (IS_ERR(st->adc_clk)) { + dev_err(&spi->dev, "failed to get the ADC clock\n"); + return PTR_ERR(st->adc_clk); + } + + 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) { + clk_disable_unprepare(st->adc_clk); + 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, 1000); + st->reset_delay_us = DIV_ROUND_UP( + ADS131E08_WAIT_RESET_CYCLES * adc_clk_ns, 1000); + + ret = ads131e08_initial_config(indio_dev); + if (ret) { + dev_err(&spi->dev, "initial configuration failed\n"); + return ret; + } + + ret = devm_iio_device_register(&spi->dev, indio_dev); + if (ret) { + dev_err(&spi->dev, "failed to register IIO device\n"); + return ret; + } + + return 0; +} + +static const struct of_device_id ads131e08_of_match[] = { + { .compatible = "ti,ads131e04", }, + { .compatible = "ti,ads131e06", }, + { .compatible = "ti,ads131e08", }, + {} +}; +MODULE_DEVICE_TABLE(of, ads131e08_of_match); + +static const struct spi_device_id ads131e08_id[] = { + { "ads131e04", ads131e04}, + { "ads131e06", ads131e06}, + { "ads131e08", ads131e08}, + {} +}; +MODULE_DEVICE_TABLE(spi, ads131e08_id); + +static struct spi_driver ads131e08_driver = { + .driver = { + .name = "ads131e08", + .of_match_table = ads131e08_of_match, + }, + .probe = ads131e08_probe, + .id_table = ads131e08_id, +}; +module_spi_driver(ads131e08_driver); + +MODULE_AUTHOR("Tomislav Denis <tomislav.denis@xxxxxxx>"); +MODULE_DESCRIPTION("Driver for ADS131E0x ADC family"); +MODULE_LICENSE("GPL v2"); -- 2.7.4
