#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dev_printk.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/units.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#define ADS1119_CMD_RESET 0x06
#define ADS1119_CMD_POWERDOWN 0x02
#define ADS1119_CMD_START_SYNC 0x08
#define ADS1119_CMD_RDATA 0x10
#define ADS1119_CMD_RREG_CONFIG 0x20
#define ADS1119_CMD_RREG_STATUS 0x24
#define ADS1119_CMD_WREG 0x40
#define ADS1119_CMD_RREG(reg) (0x20 | (reg) << 2)
#define ADS1119_REG_CONFIG 0x00
#define ADS1119_CONFIG_VREF_FIELD BIT(0)
#define ADS1119_CONFIG_CM_FIELD BIT(1)
#define ADS1119_CONFIG_DR_FIELD GENMASK(3, 2)
#define ADS1119_CONFIG_GAIN_FIELD BIT(4)
#define ADS1119_CONFIG_MUX_FIELD GENMASK(7, 5)
#define ADS1119_VREF_INTERNAL 0
#define ADS1119_VREF_EXTERNAL 1
#define ADS1119_VREF_INTERNAL_VAL 2048000
#define ADS1119_CM_SINGLE 0
#define ADS1119_CM_CONTINUOUS 1
#define ADS1119_DR_20_SPS 0
#define ADS1119_DR_90_SPS 1
#define ADS1119_DR_330_SPS 2
#define ADS1119_DR_1000_SPS 3
#define ADS1119_GAIN_1 0
#define ADS1119_GAIN_4 1
#define ADS1119_MUX_AIN0_AIN1 0
#define ADS1119_MUX_AIN2_AIN3 1
#define ADS1119_MUX_AIN1_AIN2 2
#define ADS1119_MUX_AIN0 3
#define ADS1119_MUX_AIN1 4
#define ADS1119_MUX_AIN2 5
#define ADS1119_MUX_AIN3 6
#define ADS1119_MUX_SHORTED 7
#define ADS1119_REG_STATUS 0x01
#define ADS1119_STATUS_DRDY_FIELD BIT(7)
#define ADS1119_DEFAULT_GAIN 1
#define ADS1119_DEFAULT_DATARATE 20
#define ADS1119_SUSPEND_DELAY 2000
#define ADS1119_MAX_DRDY_TIMEOUT 85000
#define ADS1119_MAX_CHANNELS 7
#define ADS1119_MAX_SINGLE_CHANNELS 4
struct ads1119_channel_config {
int gain;
int datarate;
int mux;
};
struct ads1119_state {
struct completion completion;
struct i2c_client *client;
struct gpio_desc *reset_gpio;
struct iio_trigger *trig;
struct ads1119_channel_config *channels_cfg;
unsigned int num_channels_cfg;
unsigned int cached_config;
int vref_uV;
};
static const char * const ads1119_power_supplies[] = {
"avdd", "dvdd"
};
static const int ads1119_available_datarates[] = {
20, 90, 330, 1000,
};
static const int ads1119_available_gains[] = {
1, 1,
1, 4,
};
static int ads1119_upd_cfg_reg(struct ads1119_state *st, unsigned int fields,
unsigned int val)
{
unsigned int config = st->cached_config;
int ret;
config &= ~fields;
config |= val;
ret = i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG, config);
if (ret)
return ret;
st->cached_config = config;
return 0;
}
static bool ads1119_data_ready(struct ads1119_state *st)
{
int status;
status = i2c_smbus_read_byte_data(st->client, ADS1119_CMD_RREG_STATUS);
if (status < 0)
return false;
return FIELD_GET(ADS1119_STATUS_DRDY_FIELD, status);
}
static int ads1119_reset(struct ads1119_state *st)
{
st->cached_config = 0;
if (!st->reset_gpio)
return i2c_smbus_write_byte(st->client, ADS1119_CMD_RESET);
gpiod_set_value_cansleep(st->reset_gpio, 1);
udelay(1);
gpiod_set_value_cansleep(st->reset_gpio, 0);
udelay(1);
return 0;
}
static int ads1119_set_conv_mode(struct ads1119_state *st, bool continuous)
{
unsigned int mode;
if (continuous)
mode = ADS1119_CM_CONTINUOUS;
else
mode = ADS1119_CM_SINGLE;
return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_CM_FIELD,
FIELD_PREP(ADS1119_CONFIG_CM_FIELD, mode));
}
static int ads1119_get_hw_gain(int gain)
{
if (gain == 4)
return ADS1119_GAIN_4;
else
return ADS1119_GAIN_1;
}
static int ads1119_get_hw_datarate(int datarate)
{
switch (datarate) {
case 90:
return ADS1119_DR_90_SPS;
case 330:
return ADS1119_DR_330_SPS;
case 1000:
return ADS1119_DR_1000_SPS;
case 20:
default:
return ADS1119_DR_20_SPS;
}
}
static int ads1119_configure_channel(struct ads1119_state *st, int mux,
int gain, int datarate)
{
int ret;
ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_MUX_FIELD,
FIELD_PREP(ADS1119_CONFIG_MUX_FIELD, mux));
if (ret)
return ret;
ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_GAIN_FIELD,
FIELD_PREP(ADS1119_CONFIG_GAIN_FIELD,
ads1119_get_hw_gain(gain)));
if (ret)
return ret;
return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_DR_FIELD,
FIELD_PREP(ADS1119_CONFIG_DR_FIELD,
ads1119_get_hw_datarate(datarate)));
}
static int ads1119_poll_data_ready(struct ads1119_state *st,
struct iio_chan_spec const *chan)
{
unsigned int datarate = st->channels_cfg[chan->address].datarate;
unsigned long wait_time;
bool data_ready;
wait_time = DIV_ROUND_CLOSEST(MICRO, 5 * datarate);
return read_poll_timeout(ads1119_data_ready, data_ready,
data_ready, wait_time,
ADS1119_MAX_DRDY_TIMEOUT, false, st);
}
static int ads1119_read_data(struct ads1119_state *st,
struct iio_chan_spec const *chan,
unsigned int *val)
{
unsigned int timeout;
int ret = 0;
timeout = msecs_to_jiffies(ADS1119_MAX_DRDY_TIMEOUT);
if (!st->client->irq) {
ret = ads1119_poll_data_ready(st, chan);
if (ret)
return ret;
} else if (!wait_for_completion_timeout(&st->completion, timeout)) {
return -ETIMEDOUT;
}
ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA);
if (ret < 0)
return ret;
*val = ret;
return 0;
}
static int ads1119_single_conversion(struct ads1119_state *st,
struct iio_chan_spec const *chan,
int *val,
bool calib_offset)
{
struct device *dev = &st->client->dev;
int mux = st->channels_cfg[chan->address].mux;
int gain = st->channels_cfg[chan->address].gain;
int datarate = st->channels_cfg[chan->address].datarate;
unsigned int sample;
int ret;
if (calib_offset)
mux = ADS1119_MUX_SHORTED;
ret = pm_runtime_resume_and_get(dev);
if (ret)
return ret;
ret = ads1119_configure_channel(st, mux, gain, datarate);
if (ret)
goto pdown;
if (st->client->irq)
reinit_completion(&st->completion);
ret = i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
if (ret)
goto pdown;
ret = ads1119_read_data(st, chan, &sample);
if (ret)
goto pdown;
*val = sign_extend32(sample, chan->scan_type.realbits - 1);
ret = IIO_VAL_INT;
pdown:
pm_runtime_put_autosuspend(dev);
return ret;
}
static int ads1119_validate_datarate(struct ads1119_state *st, int datarate)
{
switch (datarate) {
case 20:
case 90:
case 330:
case 1000:
return datarate;
default:
return -EINVAL;
}
}
static int ads1119_read_avail(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type, int *length,
long mask)
{
switch (mask) {
case IIO_CHAN_INFO_SCALE:
*type = IIO_VAL_FRACTIONAL;
*vals = ads1119_available_gains;
*length = ARRAY_SIZE(ads1119_available_gains);
return IIO_AVAIL_LIST;
case IIO_CHAN_INFO_SAMP_FREQ:
*type = IIO_VAL_INT;
*vals = ads1119_available_datarates;
*length = ARRAY_SIZE(ads1119_available_datarates);
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
}
static int ads1119_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct ads1119_state *st = iio_priv(indio_dev);
unsigned int index = chan->address;
int ret;
if (index >= st->num_channels_cfg)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = ads1119_single_conversion(st, chan, val, false);
iio_device_release_direct(indio_dev);
return ret;
case IIO_CHAN_INFO_OFFSET:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = ads1119_single_conversion(st, chan, val, true);
iio_device_release_direct(indio_dev);
return ret;
case IIO_CHAN_INFO_SCALE:
*val = st->vref_uV / 1000;
*val /= st->channels_cfg[index].gain;
*val2 = chan->scan_type.realbits - 1;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = st->channels_cfg[index].datarate;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ads1119_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long mask)
{
struct ads1119_state *st = iio_priv(indio_dev);
unsigned int index = chan->address;
int ret;
if (index >= st->num_channels_cfg)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
ret = MICRO / ((val * MICRO) + val2);
if (ret != 1 && ret != 4)
return -EINVAL;
st->channels_cfg[index].gain = ret;
return 0;
case IIO_CHAN_INFO_SAMP_FREQ:
ret = ads1119_validate_datarate(st, val);
if (ret < 0)
return ret;
st->channels_cfg[index].datarate = ret;
return 0;
default:
return -EINVAL;
}
}
static int ads1119_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned int reg, unsigned int writeval,
unsigned int *readval)
{
struct ads1119_state *st = iio_priv(indio_dev);
int ret;
if (reg > ADS1119_REG_STATUS)
return -EINVAL;
if (readval) {
ret = i2c_smbus_read_byte_data(st->client,
ADS1119_CMD_RREG(reg));
if (ret < 0)
return ret;
*readval = ret;
return 0;
}
if (reg > ADS1119_REG_CONFIG)
return -EINVAL;
return i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG,
writeval);
}
static const struct iio_info ads1119_info = {
.read_avail = ads1119_read_avail,
.read_raw = ads1119_read_raw,
.write_raw = ads1119_write_raw,
.debugfs_reg_access = ads1119_debugfs_reg_access,
};
static int ads1119_triggered_buffer_preenable(struct iio_dev *indio_dev)
{
struct ads1119_state *st = iio_priv(indio_dev);
struct device *dev = &st->client->dev;
unsigned int index;
int ret;
index = find_first_bit(indio_dev->active_scan_mask,
iio_get_masklength(indio_dev));
ret = ads1119_set_conv_mode(st, true);
if (ret)
return ret;
ret = ads1119_configure_channel(st,
st->channels_cfg[index].mux,
st->channels_cfg[index].gain,
st->channels_cfg[index].datarate);
if (ret)
return ret;
ret = pm_runtime_resume_and_get(dev);
if (ret)
return ret;
return i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
}
static int ads1119_triggered_buffer_postdisable(struct iio_dev *indio_dev)
{
struct ads1119_state *st = iio_priv(indio_dev);
struct device *dev = &st->client->dev;
int ret;
ret = ads1119_set_conv_mode(st, false);
if (ret)
return ret;
pm_runtime_put_autosuspend(dev);
return 0;
}
static const struct iio_buffer_setup_ops ads1119_buffer_setup_ops = {
.preenable = ads1119_triggered_buffer_preenable,
.postdisable = ads1119_triggered_buffer_postdisable,
.validate_scan_mask = &iio_validate_scan_mask_onehot,
};
static const struct iio_trigger_ops ads1119_trigger_ops = {
.validate_device = &iio_trigger_validate_own_device,
};
static irqreturn_t ads1119_irq_handler(int irq, void *dev_id)
{
struct iio_dev *indio_dev = dev_id;
struct ads1119_state *st = iio_priv(indio_dev);
if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev))
iio_trigger_poll(indio_dev->trig);
else
complete(&st->completion);
return IRQ_HANDLED;
}
static irqreturn_t ads1119_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
struct iio_dev *indio_dev = pf->indio_dev;
struct ads1119_state *st = iio_priv(indio_dev);
struct {
s16 sample;
aligned_s64 timestamp;
} scan = { };
unsigned int index;
int ret;
if (!iio_trigger_using_own(indio_dev)) {
index = find_first_bit(indio_dev->active_scan_mask,
iio_get_masklength(indio_dev));
ret = ads1119_poll_data_ready(st, &indio_dev->channels[index]);
if (ret) {
dev_err(&st->client->dev,
"Failed to poll data on trigger (%d)\n", ret);
goto done;
}
}
ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA);
if (ret < 0) {
dev_err(&st->client->dev,
"Failed to read data on trigger (%d)\n", ret);
goto done;
}
scan.sample = ret;
iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
iio_get_time_ns(indio_dev));
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ads1119_init(struct ads1119_state *st, bool vref_external)
{
int ret;
ret = ads1119_reset(st);
if (ret)
return ret;
if (vref_external)
return ads1119_upd_cfg_reg(st,
ADS1119_CONFIG_VREF_FIELD,
FIELD_PREP(ADS1119_CONFIG_VREF_FIELD,
ADS1119_VREF_EXTERNAL));
return 0;
}
static int ads1119_map_analog_inputs_mux(int ain_pos, int ain_neg,
bool differential)
{
if (ain_pos >= ADS1119_MAX_SINGLE_CHANNELS)
return -EINVAL;
if (!differential)
return ADS1119_MUX_AIN0 + ain_pos;
if (ain_pos == 0 && ain_neg == 1)
return ADS1119_MUX_AIN0_AIN1;
else if (ain_pos == 1 && ain_neg == 2)
return ADS1119_MUX_AIN1_AIN2;
else if (ain_pos == 2 && ain_neg == 3)
return ADS1119_MUX_AIN2_AIN3;
return -EINVAL;
}
static int ads1119_alloc_and_config_channels(struct iio_dev *indio_dev)
{
const struct iio_chan_spec ads1119_channel =
(const struct iio_chan_spec) {
.type = IIO_VOLTAGE,
.indexed = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SAMP_FREQ),
.info_mask_shared_by_all_available =
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_SAMP_FREQ),
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
};
const struct iio_chan_spec ads1119_ts = IIO_CHAN_SOFT_TIMESTAMP(0);
struct ads1119_state *st = iio_priv(indio_dev);
struct iio_chan_spec *iio_channels, *chan;
struct device *dev = &st->client->dev;
unsigned int num_channels, i;
bool differential;
u32 ain[2];
int ret;
st->num_channels_cfg = device_get_child_node_count(dev);
if (st->num_channels_cfg > ADS1119_MAX_CHANNELS)
return dev_err_probe(dev, -EINVAL,
"Too many channels %d, max is %d\n",
st->num_channels_cfg,
ADS1119_MAX_CHANNELS);
st->channels_cfg = devm_kcalloc(dev, st->num_channels_cfg,
sizeof(*st->channels_cfg), GFP_KERNEL);
if (!st->channels_cfg)
return -ENOMEM;
num_channels = st->num_channels_cfg + 1;
iio_channels = devm_kcalloc(dev, num_channels, sizeof(*iio_channels),
GFP_KERNEL);
if (!iio_channels)
return -ENOMEM;
i = 0;
device_for_each_child_node_scoped(dev, child) {
chan = &iio_channels[i];
differential = fwnode_property_present(child, "diff-channels");
if (differential)
ret = fwnode_property_read_u32_array(child,
"diff-channels",
ain, 2);
else
ret = fwnode_property_read_u32(child, "single-channel",
&ain[0]);
if (ret)
return dev_err_probe(dev, ret,
"Failed to get channel property\n");
ret = ads1119_map_analog_inputs_mux(ain[0], ain[1],
differential);
if (ret < 0)
return dev_err_probe(dev, ret,
"Invalid channel value\n");
st->channels_cfg[i].mux = ret;
st->channels_cfg[i].gain = ADS1119_DEFAULT_GAIN;
st->channels_cfg[i].datarate = ADS1119_DEFAULT_DATARATE;
*chan = ads1119_channel;
chan->channel = ain[0];
chan->address = i;
chan->scan_index = i;
if (differential) {
chan->channel2 = ain[1];
chan->differential = 1;
}
dev_dbg(dev, "channel: index %d, mux %d\n", i,
st->channels_cfg[i].mux);
i++;
}
iio_channels[i] = ads1119_ts;
iio_channels[i].address = i;
iio_channels[i].scan_index = i;
indio_dev->channels = iio_channels;
indio_dev->num_channels = num_channels;
return 0;
}
static void ads1119_powerdown(void *data)
{
struct ads1119_state *st = data;
i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN);
}
static int ads1119_probe(struct i2c_client *client)
{
struct iio_dev *indio_dev;
struct ads1119_state *st;
struct device *dev = &client->dev;
bool vref_external = true;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->client = client;
indio_dev->name = "ads1119";
indio_dev->info = &ads1119_info;
indio_dev->modes = INDIO_DIRECT_MODE;
i2c_set_clientdata(client, indio_dev);
ret = devm_regulator_bulk_get_enable(dev,
ARRAY_SIZE(ads1119_power_supplies),
ads1119_power_supplies);
if (ret)
return dev_err_probe(dev, ret,
"Failed to get and enable supplies\n");
st->vref_uV = devm_regulator_get_enable_read_voltage(dev, "vref");
if (st->vref_uV == -ENODEV) {
vref_external = false;
st->vref_uV = ADS1119_VREF_INTERNAL_VAL;
} else if (st->vref_uV < 0) {
return dev_err_probe(dev, st->vref_uV, "Failed to get vref\n");
}
st->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(st->reset_gpio))
return dev_err_probe(dev, PTR_ERR(st->reset_gpio),
"Failed to get reset gpio\n");
ret = ads1119_alloc_and_config_channels(indio_dev);
if (ret)
return ret;
init_completion(&st->completion);
ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
ads1119_trigger_handler,
&ads1119_buffer_setup_ops);
if (ret)
return dev_err_probe(dev, ret, "Failed to setup IIO buffer\n");
if (client->irq > 0) {
ret = devm_request_irq(dev, client->irq, ads1119_irq_handler,
IRQF_NO_THREAD, "ads1119", indio_dev);
if (ret)
return dev_err_probe(dev, ret,
"Failed to allocate irq\n");
st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
indio_dev->name,
iio_device_id(indio_dev));
if (!st->trig)
return -ENOMEM;
st->trig->ops = &ads1119_trigger_ops;
iio_trigger_set_drvdata(st->trig, indio_dev);
ret = devm_iio_trigger_register(dev, st->trig);
if (ret)
return dev_err_probe(dev, ret,
"Failed to register IIO trigger\n");
}
ret = ads1119_init(st, vref_external);
if (ret)
return dev_err_probe(dev, ret,
"Failed to initialize device\n");
pm_runtime_set_autosuspend_delay(dev, ADS1119_SUSPEND_DELAY);
pm_runtime_use_autosuspend(dev);
pm_runtime_mark_last_busy(dev);
pm_runtime_set_active(dev);
ret = devm_pm_runtime_enable(dev);
if (ret)
return dev_err_probe(dev, ret, "Failed to enable pm runtime\n");
ret = devm_add_action_or_reset(dev, ads1119_powerdown, st);
if (ret)
return ret;
return devm_iio_device_register(dev, indio_dev);
}
static int ads1119_runtime_suspend(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct ads1119_state *st = iio_priv(indio_dev);
return i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN);
}
static DEFINE_RUNTIME_DEV_PM_OPS(ads1119_pm_ops, ads1119_runtime_suspend,
NULL, NULL);
static const struct of_device_id __maybe_unused ads1119_of_match[] = {
{ .compatible = "ti,ads1119" },
{ }
};
MODULE_DEVICE_TABLE(of, ads1119_of_match);
static const struct i2c_device_id ads1119_id[] = {
{ "ads1119" },
{ }
};
MODULE_DEVICE_TABLE(i2c, ads1119_id);
static struct i2c_driver ads1119_driver = {
.driver = {
.name = "ads1119",
.of_match_table = ads1119_of_match,
.pm = pm_ptr(&ads1119_pm_ops),
},
.probe = ads1119_probe,
.id_table = ads1119_id,
};
module_i2c_driver(ads1119_driver);
MODULE_AUTHOR("João Paulo Gonçalves <joao.goncalves@toradex.com>");
MODULE_DESCRIPTION("Texas Instruments ADS1119 ADC Driver");
MODULE_LICENSE("GPL");
