| // SPDX-License-Identifier: GPL-2.0 |
| /* TI ADS124S0X chip family driver |
| * Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/ |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/delay.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| |
| #include <linux/gpio/consumer.h> |
| #include <linux/spi/spi.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/iio/sysfs.h> |
| |
| #include <linux/unaligned.h> |
| |
| /* Commands */ |
| #define ADS124S08_CMD_NOP 0x00 |
| #define ADS124S08_CMD_WAKEUP 0x02 |
| #define ADS124S08_CMD_PWRDWN 0x04 |
| #define ADS124S08_CMD_RESET 0x06 |
| #define ADS124S08_CMD_START 0x08 |
| #define ADS124S08_CMD_STOP 0x0a |
| #define ADS124S08_CMD_SYOCAL 0x16 |
| #define ADS124S08_CMD_SYGCAL 0x17 |
| #define ADS124S08_CMD_SFOCAL 0x19 |
| #define ADS124S08_CMD_RDATA 0x12 |
| #define ADS124S08_CMD_RREG 0x20 |
| #define ADS124S08_CMD_WREG 0x40 |
| |
| /* Registers */ |
| #define ADS124S08_ID_REG 0x00 |
| #define ADS124S08_STATUS 0x01 |
| #define ADS124S08_INPUT_MUX 0x02 |
| #define ADS124S08_PGA 0x03 |
| #define ADS124S08_DATA_RATE 0x04 |
| #define ADS124S08_REF 0x05 |
| #define ADS124S08_IDACMAG 0x06 |
| #define ADS124S08_IDACMUX 0x07 |
| #define ADS124S08_VBIAS 0x08 |
| #define ADS124S08_SYS 0x09 |
| #define ADS124S08_OFCAL0 0x0a |
| #define ADS124S08_OFCAL1 0x0b |
| #define ADS124S08_OFCAL2 0x0c |
| #define ADS124S08_FSCAL0 0x0d |
| #define ADS124S08_FSCAL1 0x0e |
| #define ADS124S08_FSCAL2 0x0f |
| #define ADS124S08_GPIODAT 0x10 |
| #define ADS124S08_GPIOCON 0x11 |
| |
| /* ADS124S0x common channels */ |
| #define ADS124S08_AIN0 0x00 |
| #define ADS124S08_AIN1 0x01 |
| #define ADS124S08_AIN2 0x02 |
| #define ADS124S08_AIN3 0x03 |
| #define ADS124S08_AIN4 0x04 |
| #define ADS124S08_AIN5 0x05 |
| #define ADS124S08_AINCOM 0x0c |
| /* ADS124S08 only channels */ |
| #define ADS124S08_AIN6 0x06 |
| #define ADS124S08_AIN7 0x07 |
| #define ADS124S08_AIN8 0x08 |
| #define ADS124S08_AIN9 0x09 |
| #define ADS124S08_AIN10 0x0a |
| #define ADS124S08_AIN11 0x0b |
| #define ADS124S08_MAX_CHANNELS 12 |
| |
| #define ADS124S08_POS_MUX_SHIFT 0x04 |
| #define ADS124S08_INT_REF 0x09 |
| |
| #define ADS124S08_START_REG_MASK 0x1f |
| #define ADS124S08_NUM_BYTES_MASK 0x1f |
| |
| #define ADS124S08_START_CONV 0x01 |
| #define ADS124S08_STOP_CONV 0x00 |
| |
| enum ads124s_id { |
| ADS124S08_ID, |
| ADS124S06_ID, |
| }; |
| |
| struct ads124s_chip_info { |
| const struct iio_chan_spec *channels; |
| unsigned int num_channels; |
| }; |
| |
| struct ads124s_private { |
| const struct ads124s_chip_info *chip_info; |
| struct gpio_desc *reset_gpio; |
| struct spi_device *spi; |
| struct mutex lock; |
| /* |
| * Used to correctly align data. |
| * Ensure timestamp is naturally aligned. |
| * Note that the full buffer length may not be needed if not |
| * all channels are enabled, as long as the alignment of the |
| * timestamp is maintained. |
| */ |
| u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u32)] __aligned(8); |
| u8 data[5] __aligned(IIO_DMA_MINALIGN); |
| }; |
| |
| #define ADS124S08_CHAN(index) \ |
| { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = index, \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .scan_index = index, \ |
| .scan_type = { \ |
| .sign = 'u', \ |
| .realbits = 32, \ |
| .storagebits = 32, \ |
| }, \ |
| } |
| |
| static const struct iio_chan_spec ads124s06_channels[] = { |
| ADS124S08_CHAN(0), |
| ADS124S08_CHAN(1), |
| ADS124S08_CHAN(2), |
| ADS124S08_CHAN(3), |
| ADS124S08_CHAN(4), |
| ADS124S08_CHAN(5), |
| }; |
| |
| static const struct iio_chan_spec ads124s08_channels[] = { |
| ADS124S08_CHAN(0), |
| ADS124S08_CHAN(1), |
| ADS124S08_CHAN(2), |
| ADS124S08_CHAN(3), |
| ADS124S08_CHAN(4), |
| ADS124S08_CHAN(5), |
| ADS124S08_CHAN(6), |
| ADS124S08_CHAN(7), |
| ADS124S08_CHAN(8), |
| ADS124S08_CHAN(9), |
| ADS124S08_CHAN(10), |
| ADS124S08_CHAN(11), |
| }; |
| |
| static const struct ads124s_chip_info ads124s_chip_info_tbl[] = { |
| [ADS124S08_ID] = { |
| .channels = ads124s08_channels, |
| .num_channels = ARRAY_SIZE(ads124s08_channels), |
| }, |
| [ADS124S06_ID] = { |
| .channels = ads124s06_channels, |
| .num_channels = ARRAY_SIZE(ads124s06_channels), |
| }, |
| }; |
| |
| static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command) |
| { |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| |
| priv->data[0] = command; |
| |
| return spi_write(priv->spi, &priv->data[0], 1); |
| } |
| |
| static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data) |
| { |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| |
| priv->data[0] = ADS124S08_CMD_WREG | reg; |
| priv->data[1] = 0x0; |
| priv->data[2] = data; |
| |
| return spi_write(priv->spi, &priv->data[0], 3); |
| } |
| |
| static int ads124s_reset(struct iio_dev *indio_dev) |
| { |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| |
| if (priv->reset_gpio) { |
| gpiod_set_value(priv->reset_gpio, 0); |
| udelay(200); |
| gpiod_set_value(priv->reset_gpio, 1); |
| } else { |
| return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET); |
| } |
| |
| return 0; |
| }; |
| |
| static int ads124s_read(struct iio_dev *indio_dev) |
| { |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| int ret; |
| struct spi_transfer t[] = { |
| { |
| .tx_buf = &priv->data[0], |
| .len = 4, |
| .cs_change = 1, |
| }, { |
| .tx_buf = &priv->data[1], |
| .rx_buf = &priv->data[1], |
| .len = 4, |
| }, |
| }; |
| |
| priv->data[0] = ADS124S08_CMD_RDATA; |
| memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data) - 1); |
| |
| ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t)); |
| if (ret < 0) |
| return ret; |
| |
| return get_unaligned_be24(&priv->data[2]); |
| } |
| |
| static int ads124s_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long m) |
| { |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| int ret; |
| |
| mutex_lock(&priv->lock); |
| switch (m) { |
| case IIO_CHAN_INFO_RAW: |
| ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX, |
| chan->channel); |
| if (ret) { |
| dev_err(&priv->spi->dev, "Set ADC CH failed\n"); |
| goto out; |
| } |
| |
| ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV); |
| if (ret) { |
| dev_err(&priv->spi->dev, "Start conversions failed\n"); |
| goto out; |
| } |
| |
| ret = ads124s_read(indio_dev); |
| if (ret < 0) { |
| dev_err(&priv->spi->dev, "Read ADC failed\n"); |
| goto out; |
| } |
| |
| *val = ret; |
| |
| ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV); |
| if (ret) { |
| dev_err(&priv->spi->dev, "Stop conversions failed\n"); |
| goto out; |
| } |
| |
| ret = IIO_VAL_INT; |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| out: |
| mutex_unlock(&priv->lock); |
| return ret; |
| } |
| |
| static const struct iio_info ads124s_info = { |
| .read_raw = &ads124s_read_raw, |
| }; |
| |
| static irqreturn_t ads124s_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ads124s_private *priv = iio_priv(indio_dev); |
| int scan_index, j = 0; |
| int ret; |
| |
| iio_for_each_active_channel(indio_dev, scan_index) { |
| ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX, |
| scan_index); |
| if (ret) |
| dev_err(&priv->spi->dev, "Set ADC CH failed\n"); |
| |
| ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV); |
| if (ret) |
| dev_err(&priv->spi->dev, "Start ADC conversions failed\n"); |
| |
| priv->buffer[j] = ads124s_read(indio_dev); |
| ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV); |
| if (ret) |
| dev_err(&priv->spi->dev, "Stop ADC conversions failed\n"); |
| |
| j++; |
| } |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, priv->buffer, |
| pf->timestamp); |
| |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int ads124s_probe(struct spi_device *spi) |
| { |
| struct ads124s_private *ads124s_priv; |
| struct iio_dev *indio_dev; |
| const struct spi_device_id *spi_id = spi_get_device_id(spi); |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv)); |
| if (indio_dev == NULL) |
| return -ENOMEM; |
| |
| ads124s_priv = iio_priv(indio_dev); |
| |
| ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev, |
| "reset", GPIOD_OUT_LOW); |
| if (IS_ERR(ads124s_priv->reset_gpio)) |
| dev_info(&spi->dev, "Reset GPIO not defined\n"); |
| |
| ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data]; |
| |
| ads124s_priv->spi = spi; |
| |
| indio_dev->name = spi_id->name; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = ads124s_priv->chip_info->channels; |
| indio_dev->num_channels = ads124s_priv->chip_info->num_channels; |
| indio_dev->info = &ads124s_info; |
| |
| mutex_init(&ads124s_priv->lock); |
| |
| ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, |
| ads124s_trigger_handler, NULL); |
| if (ret) { |
| dev_err(&spi->dev, "iio triggered buffer setup failed\n"); |
| return ret; |
| } |
| |
| ads124s_reset(indio_dev); |
| |
| return devm_iio_device_register(&spi->dev, indio_dev); |
| } |
| |
| static const struct spi_device_id ads124s_id[] = { |
| { "ads124s06", ADS124S06_ID }, |
| { "ads124s08", ADS124S08_ID }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(spi, ads124s_id); |
| |
| static const struct of_device_id ads124s_of_table[] = { |
| { .compatible = "ti,ads124s06" }, |
| { .compatible = "ti,ads124s08" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, ads124s_of_table); |
| |
| static struct spi_driver ads124s_driver = { |
| .driver = { |
| .name = "ads124s08", |
| .of_match_table = ads124s_of_table, |
| }, |
| .probe = ads124s_probe, |
| .id_table = ads124s_id, |
| }; |
| module_spi_driver(ads124s_driver); |
| |
| MODULE_AUTHOR("Dan Murphy <dmuprhy@ti.com>"); |
| MODULE_DESCRIPTION("TI TI_ADS12S0X ADC"); |
| MODULE_LICENSE("GPL v2"); |