Skeleton driver for the TI ADS1298 medical ADC. This device is typically used for ECG and similar measurements. Supports data acquisition at configurable scale and sampling frequency. Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx> --- drivers/iio/adc/Kconfig | 12 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ti-ads1298.c | 740 +++++++++++++++++++++++++++++++++++ 3 files changed, 753 insertions(+) create mode 100644 drivers/iio/adc/ti-ads1298.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 35f9867da12c..57ccbf347828 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1318,6 +1318,18 @@ config TI_ADS8688 This driver can also be built as a module. If so, the module will be called ti-ads8688. +config TI_ADS1298 + tristate "Texas Instruments ADS1298" + depends on SPI + select IIO_BUFFER + default y + help + If you say yes here you get support for Texas Instruments ADS1298 + medical ADC chips + + This driver can also be built as a module. If so, the module will be + called ti-ads1298. + config TI_ADS124S08 tristate "Texas Instruments ADS124S08" depends on SPI diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index bee11d442af4..ff0e3633eded 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -117,6 +117,7 @@ obj-$(CONFIG_TI_ADS7924) += ti-ads7924.o obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o +obj-$(CONFIG_TI_ADS1298) += ti-ads1298.o obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o obj-$(CONFIG_TI_ADS131E08) += ti-ads131e08.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.c new file mode 100644 index 000000000000..54466285063f --- /dev/null +++ b/drivers/iio/adc/ti-ads1298.c @@ -0,0 +1,740 @@ +// SPDX-License-Identifier: GPL-2.0 +/* TI ADS1298 chip family driver + * Copyright (C) 2023 Topic Embedded Products + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include <linux/gpio/consumer.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> +#include <linux/iio/sysfs.h> + +#include <asm/unaligned.h> + +#define ADS1298_WAKEUP 0x02 +#define ADS1298_STANDBY 0x04 +#define ADS1298_RESET 0x06 +#define ADS1298_START 0x08 +#define ADS1298_STOP 0x0A +#define ADS1298_RDATAC 0x10 +#define ADS1298_SDATAC 0x11 +#define ADS1298_RDATA 0x12 + +/* Commands */ +#define ADS1298_CMD_WAKEUP 0x02 +#define ADS1298_CMD_STANDBY 0x04 +#define ADS1298_CMD_RESET 0x06 +#define ADS1298_CMD_START 0x08 +#define ADS1298_CMD_STOP 0x0a +#define ADS1298_CMD_RDATAC 0x10 +#define ADS1298_CMD_SDATAC 0x11 +#define ADS1298_CMD_RDATA 0x12 +#define ADS1298_CMD_RREG 0x20 +#define ADS1298_CMD_WREG 0x40 + +/* Registers */ +#define ADS1298_REG_ID 0x00 +#define ADS1298_REG_CONFIG1 0x01 +#define ADS1298_MASK_CONFIG1_HR BIT(7) +#define ADS1298_MASK_CONFIG1_DR 0x07 +#define ADS1298_REG_CONFIG2 0x02 +#define ADS1298_MASK_CONFIG2_RESERVED BIT(6) +#define ADS1298_MASK_CONFIG2_WCT_CHOP BIT(5) +#define ADS1298_MASK_CONFIG2_INT_TEST BIT(4) +#define ADS1298_MASK_CONFIG2_TEST_AMP BIT(2) +#define ADS1298_MASK_CONFIG2_TEST_FREQ_DC GENMASK(1, 0) +#define ADS1298_MASK_CONFIG2_TEST_FREQ_SLOW 0 +#define ADS1298_MASK_CONFIG2_TEST_FREQ_FAST BIT(0) +#define ADS1298_REG_CONFIG3 0x03 +#define ADS1298_MASK_CONFIG3_PWR_REFBUF BIT(7) +#define ADS1298_MASK_CONFIG3_RESERVED BIT(6) +#define ADS1298_MASK_CONFIG3_VREF_4V BIT(5) +#define ADS1298_REG_LOFF 0x04 +#define ADS1298_REG_CHnSET(n) (0x05 + n) +#define ADS1298_MASK_CH_PD BIT(7) +#define ADS1298_MASK_CH_PGA GENMASK(6, 4) +#define ADS1298_MASK_CH_MUX GENMASK(2, 0) +#define ADS1298_REG_LOFF_STATP 0x12 +#define ADS1298_REG_LOFF_STATN 0x13 + +#define ADS1298_REG_CONFIG4 0x17 +#define ADS1298_MASK_CONFIG4_SINGLE_SHOT BIT(3) +#define ADS1298_REG_WCT1 0x18 +#define ADS1298_REG_WCT2 0x19 + +#define ADS1298_MAX_CHANNELS 8 +#define ADS1298_CLK_RATE 2048000 +/* + * Read/write register commands require 4 clocks to decode, for speeds above + * 2x the clock rate, this would require extra time between the command byte and + * the data. Much simpler is to just limit the SPI transfer speed while doing + * register access. + */ +#define ADS1298_SPI_BUS_SPEED_SLOW ADS1298_CLK_RATE +/* For reading and writing registers, we need a 3-byte buffer */ +#define ADS1298_SPI_CMD_BUFFER_SIZE 3 +/* Outputs status word and 8 samples of 24 bits each, plus the command byte */ +#define ADS1298_SPI_RDATA_BUFFER_SIZE ((ADS1298_MAX_CHANNELS + 1) * 3 + 1) + +struct ads1298_private { + const struct ads1298_chip_info *chip_info; + struct spi_device *spi; + struct regulator *reg_avdd; + struct regulator *reg_vref; + struct clk *clk; + struct regmap *regmap; + struct completion completion; + struct iio_trigger *trig; + struct spi_transfer rdata_xfer; + struct spi_message rdata_msg; + spinlock_t irq_busy_lock; /* Handshake between SPI and DRDY irqs */ + bool rdata_xfer_busy; + + /* Temporary storage for demuxing data after SPI transfer */ + u8 bounce_buffer[ADS1298_MAX_CHANNELS * 4]; + + /* For synchronous SPI exchanges (read/write registers) */ + u8 cmd_buffer[ADS1298_SPI_CMD_BUFFER_SIZE] ____cacheline_aligned; + + /* Buffer used for incoming SPI data */ + u8 rx_buffer[ADS1298_SPI_RDATA_BUFFER_SIZE] ____cacheline_aligned; + /* Contains the RDATA command and zeroes to clock out */ + u8 tx_buffer[ADS1298_SPI_RDATA_BUFFER_SIZE] ____cacheline_aligned; +}; + +#define ADS1298_CHAN(index) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .address = 3 * index + 4, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 24, \ + .storagebits = 32, \ + .endianness = IIO_BE, \ + }, \ +} + +static const struct iio_chan_spec ads1298_channels[] = { + ADS1298_CHAN(0), + ADS1298_CHAN(1), + ADS1298_CHAN(2), + ADS1298_CHAN(3), + ADS1298_CHAN(4), + ADS1298_CHAN(5), + ADS1298_CHAN(6), + ADS1298_CHAN(7), +}; + +static int ads1298_write_cmd(struct ads1298_private *priv, u8 command) +{ + struct spi_transfer cmd_xfer = { + .tx_buf = priv->cmd_buffer, + .rx_buf = priv->cmd_buffer, + .len = 1, + .speed_hz = ADS1298_SPI_BUS_SPEED_SLOW, + .delay.value = 2, + .delay.unit = SPI_DELAY_UNIT_USECS, + }; + + priv->cmd_buffer[0] = command; + + return spi_sync_transfer(priv->spi, &cmd_xfer, 1); +} + +static int ads1298_read_one(struct ads1298_private *priv, int chan_index) +{ + int ret; + + /* Enable the channel */ + ret = regmap_update_bits(priv->regmap, ADS1298_REG_CHnSET(chan_index), + ADS1298_MASK_CH_PD, 0); + if (ret) + return ret; + + /* Enable single-shot mode, so we don't need to send a STOP */ + ret = regmap_update_bits(priv->regmap, ADS1298_REG_CONFIG4, + ADS1298_MASK_CONFIG4_SINGLE_SHOT, + ADS1298_MASK_CONFIG4_SINGLE_SHOT); + if (ret) + return ret; + + reinit_completion(&priv->completion); + + ret = ads1298_write_cmd(priv, ADS1298_CMD_START); + if (ret < 0) { + dev_err(&priv->spi->dev, "CMD_START error: %d\n", ret); + return ret; + } + + /* Cannot take longer than 40ms (250Hz) */ + ret = wait_for_completion_timeout(&priv->completion, + msecs_to_jiffies(50)); + if (!ret) + return -ETIMEDOUT; + + return 0; +} + +static int ads1298_get_samp_freq(struct ads1298_private *priv, int *val) +{ + unsigned long rate; + int ret; + unsigned int cfg; + + ret = regmap_read(priv->regmap, ADS1298_REG_CONFIG1, &cfg); + if (ret) + return ret; + + if (priv->clk) + rate = clk_get_rate(priv->clk); + else + rate = ADS1298_CLK_RATE; + if (!rate) + return -EINVAL; + + if (cfg & ADS1298_MASK_CONFIG1_HR) + rate >>= 6; /* HR mode */ + else + rate >>= 7; /* LP mode */ + + *val = rate >> (cfg & ADS1298_MASK_CONFIG1_DR); + + return IIO_VAL_INT; +} + +static int ads1298_set_samp_freq(struct ads1298_private *priv, int val) +{ + unsigned long rate; + unsigned int factor; + unsigned int cfg; + + if (priv->clk) + rate = clk_get_rate(priv->clk); + else + rate = ADS1298_CLK_RATE; + if (!rate) + return -EINVAL; + + factor = (rate >> 6) / val; + if (factor >= 128) { + cfg = 0x06; /* Lowest frequency possible, must use LR mode */ + } else if (factor <= 1) { + cfg = ADS1298_MASK_CONFIG1_HR; /* Fastest possible */ + } else { + cfg = fls(factor) - 1; + cfg |= ADS1298_MASK_CONFIG1_HR; /* Use HR mode */ + } + + return regmap_update_bits(priv->regmap, ADS1298_REG_CONFIG1, + ADS1298_MASK_CONFIG1_HR | ADS1298_MASK_CONFIG1_DR, + cfg); +} + +static const u8 ads1298_pga_settings[] = { 6, 1, 2, 3, 4, 8, 12 }; + +static int ads1298_get_scale(struct ads1298_private *priv, + int channel, int *val, int *val2) +{ + int ret; + unsigned int regval; + u8 gain; + + if (priv->reg_vref) { + ret = regulator_get_voltage(priv->reg_vref); + if (ret < 0) + return ret; + + *val = ret / 1000; /* Convert to millivolts */ + } else { + ret = regmap_read(priv->regmap, ADS1298_REG_CONFIG3, ®val); + if (ret) + return ret; + + /* Refererence in millivolts */ + *val = regval & ADS1298_MASK_CONFIG3_VREF_4V ? 4000 : 2400; + } + + ret = regmap_read(priv->regmap, ADS1298_REG_CHnSET(channel), ®val); + if (ret) + return ret; + + gain = ads1298_pga_settings[FIELD_GET(ADS1298_MASK_CH_PGA, regval)]; + *val /= gain; /* Full scale is VREF / gain */ + + *val2 = 23; /* Signed 24-bit, max amplitude is 2^23 */ + + return IIO_VAL_FRACTIONAL_LOG2; +} + + +static int ads1298_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + /* When busy, just peek in the buffer */ + if (!iio_buffer_enabled(indio_dev)) { + ret = ads1298_read_one(priv, chan->scan_index); + if (ret) + return ret; + } + *val = sign_extend32(get_unaligned_be24( + priv->rx_buffer + chan->address), 23); + ret = IIO_VAL_INT; + break; + case IIO_CHAN_INFO_SCALE: + ret = ads1298_get_scale(priv, chan->channel, val, val2); + break; + case IIO_CHAN_INFO_SAMP_FREQ: + ret = ads1298_get_samp_freq(priv, val); + break; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + ret = regmap_read(priv->regmap, ADS1298_REG_CONFIG1, val); + if (!ret) { + ret = IIO_VAL_INT; + *val = (16 << (*val & ADS1298_MASK_CONFIG1_DR)); + } + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int ads1298_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + ret = ads1298_set_samp_freq(priv, val); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int ads1298_reg_write(void *context, unsigned int reg, unsigned int val) +{ + struct ads1298_private *priv = context; + struct spi_transfer reg_write_xfer = { + .tx_buf = priv->cmd_buffer, + .rx_buf = priv->cmd_buffer, + .len = 3, + .speed_hz = ADS1298_SPI_BUS_SPEED_SLOW, + .delay.value = 2, + .delay.unit = SPI_DELAY_UNIT_USECS, + }; + + priv->cmd_buffer[0] = ADS1298_CMD_WREG | reg; + priv->cmd_buffer[1] = 0x0; + priv->cmd_buffer[2] = val; + + return spi_sync_transfer(priv->spi, ®_write_xfer, 1); +} + +static int ads1298_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + struct ads1298_private *priv = context; + struct spi_transfer reg_read_xfer = { + .tx_buf = priv->cmd_buffer, + .rx_buf = priv->cmd_buffer, + .len = 3, + .speed_hz = ADS1298_SPI_BUS_SPEED_SLOW, + .delay.value = 2, + .delay.unit = SPI_DELAY_UNIT_USECS, + }; + int ret; + + priv->cmd_buffer[0] = ADS1298_CMD_RREG | reg; + priv->cmd_buffer[1] = 0x0; + priv->cmd_buffer[2] = 0; + + ret = spi_sync_transfer(priv->spi, ®_read_xfer, 1); + if (ret) + return ret; + + *val = priv->cmd_buffer[2]; + + return 0; +} + +static int ads1298_reg_access(struct iio_dev *indio_dev, unsigned int reg, + unsigned int writeval, unsigned int *readval) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + + if (!readval) + return regmap_write(priv->regmap, reg, writeval); + + return regmap_read(priv->regmap, reg, readval); +} + +static int ads1298_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + int i; + + /* Power down channels that aren't in use */ + for (i = 0; i < ADS1298_MAX_CHANNELS; i++) { + regmap_update_bits(priv->regmap, ADS1298_REG_CHnSET(i), + ADS1298_MASK_CH_PD, + test_bit(i, scan_mask) ? + 0 : ADS1298_MASK_CH_PD); + } + + return 0; +} + +static const struct iio_info ads1298_info = { + .read_raw = &ads1298_read_raw, + .write_raw = &ads1298_write_raw, + .update_scan_mode = &ads1298_update_scan_mode, + .debugfs_reg_access = &ads1298_reg_access, +}; + +static void ads1298_rdata_unmark_busy(struct ads1298_private *priv) +{ + unsigned long flags; + + /* Notify we're no longer waiting for the SPI transfer to complete */ + spin_lock_irqsave(&priv->irq_busy_lock, flags); + priv->rdata_xfer_busy = false; + spin_unlock_irqrestore(&priv->irq_busy_lock, flags); +} + +static void ads1298_rdata_complete(void *context) +{ + struct iio_dev *indio_dev = context; + struct ads1298_private *priv = iio_priv(indio_dev); + int scan_index; + u8 *bounce = priv->bounce_buffer; + + if (!iio_buffer_enabled(indio_dev)) { + /* Happens when running in single transfer mode */ + ads1298_rdata_unmark_busy(priv); + complete(&priv->completion); + return; + } + + /* Demux the channel data into our bounce buffer */ + for_each_set_bit(scan_index, indio_dev->active_scan_mask, + indio_dev->masklength) { + const struct iio_chan_spec *scan_chan = + &indio_dev->channels[scan_index]; + const u8 *data = priv->rx_buffer + scan_chan->address; + + /* Transfer 24-bit value into 32-bit array */ + memcpy(bounce + 1, data, 3); + bounce += 4; + } + + /* rx_buffer can be overwritten from this point on */ + ads1298_rdata_unmark_busy(priv); + + iio_push_to_buffers(indio_dev, priv->bounce_buffer); +} + +static irqreturn_t ads1298_interrupt(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct ads1298_private *priv = iio_priv(indio_dev); + unsigned long flags; + bool wasbusy; + + /* Prevent that we submit a message that was still in progress */ + spin_lock_irqsave(&priv->irq_busy_lock, flags); + wasbusy = priv->rdata_xfer_busy; + priv->rdata_xfer_busy = true; + spin_unlock_irqrestore(&priv->irq_busy_lock, flags); + + if (!wasbusy) + spi_async(priv->spi, &priv->rdata_msg); + + return IRQ_HANDLED; +}; + +static int ads1298_buffer_postenable(struct iio_dev *indio_dev) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + int ret; + + /* Disable single-shot mode */ + ret = regmap_update_bits(priv->regmap, ADS1298_REG_CONFIG4, + ADS1298_MASK_CONFIG4_SINGLE_SHOT, 0); + if (ret) + return ret; + + return ads1298_write_cmd(priv, ADS1298_CMD_START); +} + +static int ads1298_buffer_predisable(struct iio_dev *indio_dev) +{ + struct ads1298_private *priv = iio_priv(indio_dev); + + return ads1298_write_cmd(priv, ADS1298_CMD_STOP); +} + +static const struct iio_buffer_setup_ops ads1298_setup_ops = { + .postenable = &ads1298_buffer_postenable, + .predisable = &ads1298_buffer_predisable, +}; + +static void ads1298_reg_disable(void *reg) +{ + regulator_disable(reg); +} + +static const struct regmap_range ads1298_regmap_volatile_range[] = { + regmap_reg_range(ADS1298_REG_LOFF_STATP, ADS1298_REG_LOFF_STATN), +}; + +static const struct regmap_access_table ads1298_regmap_volatile = { + .yes_ranges = ads1298_regmap_volatile_range, + .n_yes_ranges = ARRAY_SIZE(ads1298_regmap_volatile_range), +}; + +static const struct regmap_config ads1298_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .reg_read = ads1298_reg_read, + .reg_write = ads1298_reg_write, + .max_register = ADS1298_REG_WCT2, + .volatile_table = &ads1298_regmap_volatile, + .cache_type = REGCACHE_RBTREE, +}; + +static const char *ads1298_family_name(unsigned int id) +{ + switch (id & 0xe0) { + case 0x80: + return "ADS129x"; + case 0xc0: + return "ADS129xR"; + default: + return "(unknown)"; + } +} + +static int ads1298_init(struct ads1298_private *priv) +{ + struct device *dev = &priv->spi->dev; + int ret; + unsigned int val; + + /* Device initializes into RDATAC mode, which we don't want. */ + ret = ads1298_write_cmd(priv, ADS1298_CMD_SDATAC); + if (ret) + return ret; + + ret = regmap_read(priv->regmap, ADS1298_REG_ID, &val); + if (ret) + return ret; + + if ((val & 0x18) == 0x10) { + dev_info(dev, "Found %s, %d channels\n", + ads1298_family_name(val), + 4 + 2 * (val & 0x07)); + } else { + dev_err(dev, "Unknown ID: 0x%x\n", val); + return -ENODEV; + } + + /* Enable internal test signal, double amplitude, double frequency */ + regmap_write(priv->regmap, ADS1298_REG_CONFIG2, + ADS1298_MASK_CONFIG2_RESERVED | + ADS1298_MASK_CONFIG2_INT_TEST | + ADS1298_MASK_CONFIG2_TEST_AMP | + ADS1298_MASK_CONFIG2_TEST_FREQ_FAST); + + val = ADS1298_MASK_CONFIG3_RESERVED; /* Must write 1 always */ + if (!priv->reg_vref) { + /* Enable internal reference */ + val |= ADS1298_MASK_CONFIG3_PWR_REFBUF; + /* Use 4V VREF when power supply is at least 4.4V */ + if (regulator_get_voltage(priv->reg_avdd) >= 4400000) + val |= ADS1298_MASK_CONFIG3_VREF_4V; + } + regmap_write(priv->regmap, ADS1298_REG_CONFIG3, val); + + for (val = 0; val < ADS1298_MAX_CHANNELS; val++) { + /* Set mux to analog input, PGA = 6x */ + regmap_write(priv->regmap, ADS1298_REG_CHnSET(val), 0x00); + } + + return 0; +} + +static int ads1298_probe(struct spi_device *spi) +{ + struct ads1298_private *priv; + struct iio_dev *indio_dev; + struct device *dev = &spi->dev; + struct gpio_desc *reset_gpio; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (indio_dev == NULL) + return -ENOMEM; + + priv = iio_priv(indio_dev); + + reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(reset_gpio)) + return dev_err_probe(dev, ret, "Cannot get reset GPIO\n"); + + priv->reg_avdd = devm_regulator_get(dev, "avdd"); + if (IS_ERR(priv->reg_avdd)) + return dev_err_probe(dev, PTR_ERR(priv->reg_avdd), + "Failed to get avdd regulator\n"); + + /* VREF can be supplied externally. Otherwise use internal reference */ + priv->reg_vref = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(priv->reg_vref)) { + if (PTR_ERR(priv->reg_vref) == -ENODEV) + priv->reg_vref = NULL; + else + return dev_err_probe(dev, PTR_ERR(priv->reg_avdd), + "Failed to get vref regulator\n"); + } else { + ret = regulator_enable(priv->reg_vref); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, ads1298_reg_disable, + priv->reg_vref); + if (ret) + return ret; + } + + priv->clk = devm_clk_get_enabled(dev, "clk"); + if (IS_ERR(priv->clk)) + return dev_err_probe(dev, PTR_ERR(priv->clk), + "Failed to get clk\n"); + + ret = regulator_enable(priv->reg_avdd); + if (ret) + return dev_err_probe(dev, ret, + "Failed to enable avdd regulator\n"); + + ret = devm_add_action_or_reset(dev, ads1298_reg_disable, + priv->reg_avdd); + if (ret) + return ret; + + priv->spi = spi; + init_completion(&priv->completion); + spin_lock_init(&priv->irq_busy_lock); + priv->regmap = devm_regmap_init(dev, NULL, priv, + &ads1298_regmap_config); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + priv->tx_buffer[0] = ADS1298_CMD_RDATA; + priv->rdata_xfer.tx_buf = priv->tx_buffer; + priv->rdata_xfer.rx_buf = priv->rx_buffer; + priv->rdata_xfer.len = ADS1298_SPI_RDATA_BUFFER_SIZE; + /* Must keep CS low for 4 clocks */ + priv->rdata_xfer.delay.value = 2; + priv->rdata_xfer.delay.unit = SPI_DELAY_UNIT_USECS; + spi_message_init_with_transfers(&priv->rdata_msg, &priv->rdata_xfer, 1); + priv->rdata_msg.complete = &ads1298_rdata_complete; + priv->rdata_msg.context = indio_dev; + + /* Avoid giving all the same name, iio scope doesn't handle that well */ + indio_dev->name = devm_kasprintf(dev, GFP_KERNEL, "%s@%s", + spi_get_device_id(spi)->name, + dev_name(dev)); + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + indio_dev->channels = ads1298_channels; + indio_dev->num_channels = ADS1298_MAX_CHANNELS; + indio_dev->info = &ads1298_info; + + if (reset_gpio) { + udelay(1); /* Minimum pulse width is 2 clocks at 2MHz */ + gpiod_set_value(reset_gpio, 0); + } else { + ret = ads1298_write_cmd(priv, ADS1298_CMD_RESET); + if (ret) + return dev_err_probe(dev, ret, "RESET failed\n"); + } + /* Wait 18 clock cycles for reset command to complete */ + udelay(9); + + ret = ads1298_init(priv); + if (ret) + return dev_err_probe(dev, ret, "Init failed\n"); + + ret = devm_request_irq(&spi->dev, spi->irq, &ads1298_interrupt, + IRQF_TRIGGER_FALLING, indio_dev->name, + indio_dev); + if (ret) + return ret; + + ret = devm_iio_kfifo_buffer_setup(&spi->dev, indio_dev, + &ads1298_setup_ops); + if (ret) + return ret; + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id ads1298_id[] = { + { "ads1298", }, + { } +}; +MODULE_DEVICE_TABLE(spi, ads1298_id); + +static const struct of_device_id ads1298_of_table[] = { + { .compatible = "ti,ads1298" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ads1298_of_table); + +static struct spi_driver ads1298_driver = { + .driver = { + .name = "ads1298", + .of_match_table = ads1298_of_table, + }, + .probe = ads1298_probe, + .id_table = ads1298_id, +}; +module_spi_driver(ads1298_driver); + +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@xxxxxxxx>"); +MODULE_DESCRIPTION("TI ADS1298 ADC"); +MODULE_LICENSE("GPL"); -- 2.34.1 Met vriendelijke groet / kind regards, Mike Looijmans System Expert TOPIC Embedded Products B.V. Materiaalweg 4, 5681 RJ Best The Netherlands T: +31 (0) 499 33 69 69 E: mike.looijmans@xxxxxxxx W: www.topic.nl Please consider the environment before printing this e-mail