mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 09:50:04 +00:00
![Uwe Kleine-König](/assets/img/avatar_default.png)
After commitb8a1a4cd5a
("i2c: Provide a temporary .probe_new() call-back type"), all drivers being converted to .probe_new() and then03c835f498
("i2c: Switch .probe() to not take an id parameter") convert back to (the new) .probe() to be able to eventually drop .probe_new() from struct i2c_driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230515205048.19561-1-u.kleine-koenig@pengutronix.de Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
445 lines
11 KiB
C
445 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* ADS1100 - Texas Instruments Analog-to-Digital Converter
|
|
*
|
|
* Copyright (c) 2023, Topic Embedded Products
|
|
*
|
|
* Datasheet: https://www.ti.com/lit/gpn/ads1100
|
|
* IIO driver for ADS1100 and ADS1000 ADC 16-bit I2C
|
|
*/
|
|
|
|
#include <linux/bitfield.h>
|
|
#include <linux/bits.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/property.h>
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/regulator/consumer.h>
|
|
#include <linux/units.h>
|
|
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/iio/types.h>
|
|
|
|
/* The ADS1100 has a single byte config register */
|
|
|
|
/* Conversion in progress bit */
|
|
#define ADS1100_CFG_ST_BSY BIT(7)
|
|
/* Single conversion bit */
|
|
#define ADS1100_CFG_SC BIT(4)
|
|
/* Data rate */
|
|
#define ADS1100_DR_MASK GENMASK(3, 2)
|
|
/* Gain */
|
|
#define ADS1100_PGA_MASK GENMASK(1, 0)
|
|
|
|
#define ADS1100_CONTINUOUS 0
|
|
#define ADS1100_SINGLESHOT ADS1100_CFG_SC
|
|
|
|
#define ADS1100_SLEEP_DELAY_MS 2000
|
|
|
|
static const int ads1100_data_rate[] = { 128, 32, 16, 8 };
|
|
static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 };
|
|
|
|
struct ads1100_data {
|
|
struct i2c_client *client;
|
|
struct regulator *reg_vdd;
|
|
struct mutex lock;
|
|
int scale_avail[2 * 4]; /* 4 gain settings */
|
|
u8 config;
|
|
bool supports_data_rate; /* Only the ADS1100 can select the rate */
|
|
};
|
|
|
|
static const struct iio_chan_spec ads1100_channel = {
|
|
.type = IIO_VOLTAGE,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
|
.info_mask_shared_by_all =
|
|
BIT(IIO_CHAN_INFO_SCALE) | 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,
|
|
},
|
|
.datasheet_name = "AIN",
|
|
};
|
|
|
|
static int ads1100_set_config_bits(struct ads1100_data *data, u8 mask, u8 value)
|
|
{
|
|
int ret;
|
|
u8 config = (data->config & ~mask) | (value & mask);
|
|
|
|
if (data->config == config)
|
|
return 0; /* Already done */
|
|
|
|
ret = i2c_master_send(data->client, &config, 1);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
data->config = config;
|
|
|
|
return 0;
|
|
};
|
|
|
|
static int ads1100_data_bits(struct ads1100_data *data)
|
|
{
|
|
return ads1100_data_rate_bits[FIELD_GET(ADS1100_DR_MASK, data->config)];
|
|
}
|
|
|
|
static int ads1100_get_adc_result(struct ads1100_data *data, int chan, int *val)
|
|
{
|
|
int ret;
|
|
__be16 buffer;
|
|
s16 value;
|
|
|
|
if (chan != 0)
|
|
return -EINVAL;
|
|
|
|
ret = pm_runtime_resume_and_get(&data->client->dev);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));
|
|
|
|
pm_runtime_mark_last_busy(&data->client->dev);
|
|
pm_runtime_put_autosuspend(&data->client->dev);
|
|
|
|
if (ret < 0) {
|
|
dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Value is always 16-bit 2's complement */
|
|
value = be16_to_cpu(buffer);
|
|
|
|
/* Shift result to compensate for bit resolution vs. sample rate */
|
|
value <<= 16 - ads1100_data_bits(data);
|
|
|
|
*val = sign_extend32(value, 15);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
|
|
{
|
|
int microvolts;
|
|
int gain;
|
|
|
|
/* With Vdd between 2.7 and 5V, the scale is always below 1 */
|
|
if (val)
|
|
return -EINVAL;
|
|
|
|
if (!val2)
|
|
return -EINVAL;
|
|
|
|
microvolts = regulator_get_voltage(data->reg_vdd);
|
|
/*
|
|
* val2 is in 'micro' units, n = val2 / 1000000
|
|
* result must be millivolts, d = microvolts / 1000
|
|
* the full-scale value is d/n, corresponds to 2^15,
|
|
* hence the gain = (d / n) >> 15, factoring out the 1000 and moving the
|
|
* bitshift so everything fits in 32-bits yields this formula.
|
|
*/
|
|
gain = DIV_ROUND_CLOSEST(microvolts, BIT(15)) * MILLI / val2;
|
|
if (gain < BIT(0) || gain > BIT(3))
|
|
return -EINVAL;
|
|
|
|
ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate)
|
|
{
|
|
unsigned int i;
|
|
unsigned int size;
|
|
|
|
size = data->supports_data_rate ? ARRAY_SIZE(ads1100_data_rate) : 1;
|
|
for (i = 0; i < size; i++) {
|
|
if (ads1100_data_rate[i] == rate)
|
|
return ads1100_set_config_bits(data, ADS1100_DR_MASK,
|
|
FIELD_PREP(ADS1100_DR_MASK, i));
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int ads1100_get_vdd_millivolts(struct ads1100_data *data)
|
|
{
|
|
return regulator_get_voltage(data->reg_vdd) / (MICRO / MILLI);
|
|
}
|
|
|
|
static void ads1100_calc_scale_avail(struct ads1100_data *data)
|
|
{
|
|
int millivolts = ads1100_get_vdd_millivolts(data);
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(data->scale_avail) / 2; i++) {
|
|
data->scale_avail[i * 2 + 0] = millivolts;
|
|
data->scale_avail[i * 2 + 1] = 15 + i;
|
|
}
|
|
}
|
|
|
|
static int ads1100_read_avail(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
const int **vals, int *type, int *length,
|
|
long mask)
|
|
{
|
|
struct ads1100_data *data = iio_priv(indio_dev);
|
|
|
|
if (chan->type != IIO_VOLTAGE)
|
|
return -EINVAL;
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_SAMP_FREQ:
|
|
*type = IIO_VAL_INT;
|
|
*vals = ads1100_data_rate;
|
|
if (data->supports_data_rate)
|
|
*length = ARRAY_SIZE(ads1100_data_rate);
|
|
else
|
|
*length = 1;
|
|
return IIO_AVAIL_LIST;
|
|
case IIO_CHAN_INFO_SCALE:
|
|
*type = IIO_VAL_FRACTIONAL_LOG2;
|
|
*vals = data->scale_avail;
|
|
*length = ARRAY_SIZE(data->scale_avail);
|
|
return IIO_AVAIL_LIST;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int ads1100_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan, int *val,
|
|
int *val2, long mask)
|
|
{
|
|
int ret;
|
|
struct ads1100_data *data = iio_priv(indio_dev);
|
|
|
|
mutex_lock(&data->lock);
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
ret = iio_device_claim_direct_mode(indio_dev);
|
|
if (ret)
|
|
break;
|
|
|
|
ret = ads1100_get_adc_result(data, chan->address, val);
|
|
if (ret >= 0)
|
|
ret = IIO_VAL_INT;
|
|
iio_device_release_direct_mode(indio_dev);
|
|
break;
|
|
case IIO_CHAN_INFO_SCALE:
|
|
/* full-scale is the supply voltage in millivolts */
|
|
*val = ads1100_get_vdd_millivolts(data);
|
|
*val2 = 15 + FIELD_GET(ADS1100_PGA_MASK, data->config);
|
|
ret = IIO_VAL_FRACTIONAL_LOG2;
|
|
break;
|
|
case IIO_CHAN_INFO_SAMP_FREQ:
|
|
*val = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK,
|
|
data->config)];
|
|
ret = IIO_VAL_INT;
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
mutex_unlock(&data->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ads1100_write_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan, int val,
|
|
int val2, long mask)
|
|
{
|
|
struct ads1100_data *data = iio_priv(indio_dev);
|
|
int ret;
|
|
|
|
mutex_lock(&data->lock);
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_SCALE:
|
|
ret = ads1100_set_scale(data, val, val2);
|
|
break;
|
|
case IIO_CHAN_INFO_SAMP_FREQ:
|
|
ret = ads1100_set_data_rate(data, chan->address, val);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
mutex_unlock(&data->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct iio_info ads1100_info = {
|
|
.read_avail = ads1100_read_avail,
|
|
.read_raw = ads1100_read_raw,
|
|
.write_raw = ads1100_write_raw,
|
|
};
|
|
|
|
static int ads1100_setup(struct ads1100_data *data)
|
|
{
|
|
int ret;
|
|
u8 buffer[3];
|
|
|
|
/* Setup continuous sampling mode at 8sps */
|
|
buffer[0] = ADS1100_DR_MASK | ADS1100_CONTINUOUS;
|
|
ret = i2c_master_send(data->client, buffer, 1);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = i2c_master_recv(data->client, buffer, sizeof(buffer));
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* Config register returned in third byte, strip away the busy status */
|
|
data->config = buffer[2] & ~ADS1100_CFG_ST_BSY;
|
|
|
|
/* Detect the sample rate capability by checking the DR bits */
|
|
data->supports_data_rate = FIELD_GET(ADS1100_DR_MASK, buffer[2]) != 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ads1100_reg_disable(void *reg)
|
|
{
|
|
regulator_disable(reg);
|
|
}
|
|
|
|
static void ads1100_disable_continuous(void *data)
|
|
{
|
|
ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
|
|
}
|
|
|
|
static int ads1100_probe(struct i2c_client *client)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct ads1100_data *data;
|
|
struct device *dev = &client->dev;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
data = iio_priv(indio_dev);
|
|
dev_set_drvdata(dev, data);
|
|
data->client = client;
|
|
mutex_init(&data->lock);
|
|
|
|
indio_dev->name = "ads1100";
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->channels = &ads1100_channel;
|
|
indio_dev->num_channels = 1;
|
|
indio_dev->info = &ads1100_info;
|
|
|
|
data->reg_vdd = devm_regulator_get(dev, "vdd");
|
|
if (IS_ERR(data->reg_vdd))
|
|
return dev_err_probe(dev, PTR_ERR(data->reg_vdd),
|
|
"Failed to get vdd regulator\n");
|
|
|
|
ret = regulator_enable(data->reg_vdd);
|
|
if (ret < 0)
|
|
return dev_err_probe(dev, ret,
|
|
"Failed to enable vdd regulator\n");
|
|
|
|
ret = devm_add_action_or_reset(dev, ads1100_reg_disable, data->reg_vdd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = ads1100_setup(data);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret,
|
|
"Failed to communicate with device\n");
|
|
|
|
ret = devm_add_action_or_reset(dev, ads1100_disable_continuous, data);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ads1100_calc_scale_avail(data);
|
|
|
|
pm_runtime_set_autosuspend_delay(dev, ADS1100_SLEEP_DELAY_MS);
|
|
pm_runtime_use_autosuspend(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_iio_device_register(dev, indio_dev);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret,
|
|
"Failed to register IIO device\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ads1100_runtime_suspend(struct device *dev)
|
|
{
|
|
struct ads1100_data *data = dev_get_drvdata(dev);
|
|
|
|
ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
|
|
regulator_disable(data->reg_vdd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ads1100_runtime_resume(struct device *dev)
|
|
{
|
|
struct ads1100_data *data = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
ret = regulator_enable(data->reg_vdd);
|
|
if (ret) {
|
|
dev_err(&data->client->dev, "Failed to enable Vdd\n");
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We'll always change the mode bit in the config register, so there is
|
|
* no need here to "force" a write to the config register. If the device
|
|
* has been power-cycled, we'll re-write its config register now.
|
|
*/
|
|
return ads1100_set_config_bits(data, ADS1100_CFG_SC,
|
|
ADS1100_CONTINUOUS);
|
|
}
|
|
|
|
static DEFINE_RUNTIME_DEV_PM_OPS(ads1100_pm_ops,
|
|
ads1100_runtime_suspend,
|
|
ads1100_runtime_resume,
|
|
NULL);
|
|
|
|
static const struct i2c_device_id ads1100_id[] = {
|
|
{ "ads1100" },
|
|
{ "ads1000" },
|
|
{ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, ads1100_id);
|
|
|
|
static const struct of_device_id ads1100_of_match[] = {
|
|
{.compatible = "ti,ads1100" },
|
|
{.compatible = "ti,ads1000" },
|
|
{ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(of, ads1100_of_match);
|
|
|
|
static struct i2c_driver ads1100_driver = {
|
|
.driver = {
|
|
.name = "ads1100",
|
|
.of_match_table = ads1100_of_match,
|
|
.pm = pm_ptr(&ads1100_pm_ops),
|
|
},
|
|
.probe = ads1100_probe,
|
|
.id_table = ads1100_id,
|
|
};
|
|
|
|
module_i2c_driver(ads1100_driver);
|
|
|
|
MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
|
|
MODULE_DESCRIPTION("Texas Instruments ADS1100 ADC driver");
|
|
MODULE_LICENSE("GPL");
|