378 lines
9.0 KiB
C
378 lines
9.0 KiB
C
// 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 <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] __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;
|
|
|
|
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);
|
|
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");
|