diff options
Diffstat (limited to 'drivers/iio/adc/ti-ads124s08.c')
| -rw-r--r-- | drivers/iio/adc/ti-ads124s08.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/iio/adc/ti-ads124s08.c b/drivers/iio/adc/ti-ads124s08.c new file mode 100644 index 000000000..b4a128b19 --- /dev/null +++ b/drivers/iio/adc/ti-ads124s08.c @@ -0,0 +1,380 @@ +// 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/of.h> +#include <linux/of_gpio.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 <asm/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] ____cacheline_aligned; +}; + +#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, unsigned int chan) +{ + 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, chan->channel); + 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; + + for_each_set_bit(scan_index, indio_dev->active_scan_mask, + indio_dev->masklength) { + 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, scan_index); + 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]; + + spi_set_drvdata(spi, indio_dev); + + 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"); |