[PATCH 3/3] iio: adc: Add ti-ads1110 support to ti-ads1100 driver
From: Jakub Szczudlo
Date: Sun Jun 07 2026 - 14:41:20 EST
From: jszczudlo <jakubszczudlo40@xxxxxxxxx>
add ADS1100 support
make changing gain and datarate wait for new reading
fix unbalanced regulator disable when removing in singleshot mode
Signed-off-by: jszczudlo <jakubszczudlo40@xxxxxxxxx>
---
drivers/iio/adc/ti-ads1100.c | 165 ++++++++++++++++++++++++++---------
1 file changed, 126 insertions(+), 39 deletions(-)
diff --git a/drivers/iio/adc/ti-ads1100.c b/drivers/iio/adc/ti-ads1100.c
index aa8946063c7d..11d6fe1e8abc 100644
--- a/drivers/iio/adc/ti-ads1100.c
+++ b/drivers/iio/adc/ti-ads1100.c
@@ -5,18 +5,15 @@
* Copyright (c) 2023, Topic Embedded Products
*
* Datasheet: https://www.ti.com/lit/gpn/ads1100
- * IIO driver for ADS1100 and ADS1000 ADC 16-bit I2C
+ * IIO driver for ADS1100, ADS1000 and ADS1110 ADC 16-bit I2C
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
-#include <linux/cleanup.h>
-#include <linux/delay.h>
-#include <linux/module.h>
-#include <linux/init.h>
#include <linux/i2c.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
#include <linux/mutex.h>
-#include <linux/property.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/units.h>
@@ -39,17 +36,39 @@
#define ADS1100_SINGLESHOT ADS1100_CFG_SC
#define ADS1100_SLEEP_DELAY_MS 2000
+#define ADS1110_REFERENCE_VOLTAGE_MICROVOLT 2048000
+
+/* Timeout based on the minimum sample rate of 8 SPS (7500000us) */
+#define ADS11x0_MAX_DRDY_TIMEOUT 7500000
static const int ads1100_data_rate[] = { 128, 32, 16, 8 };
+static const int ads1110_data_rate[] = { 240, 60, 30, 15 };
static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 };
+struct ads11x0_config {
+ const int *data_rate;
+ bool has_reference_voltage;
+};
+
+static const struct ads11x0_config ads1100_config = {
+ .data_rate = ads1100_data_rate,
+ .has_reference_voltage = false,
+};
+
+static const struct ads11x0_config ads1110_config = {
+ .data_rate = ads1110_data_rate,
+ .has_reference_voltage = true,
+};
+
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 */
+ bool supports_data_rate; /* Only the ADS1100/ADS1110 can select the rate */
+ bool has_reference_voltage; /* The ADS1110 has an internal reference, so fixed scale */
+ const int *data_rate;
};
static const struct iio_chan_spec ads1100_channel = {
@@ -59,12 +78,6 @@ static const struct iio_chan_spec ads1100_channel = {
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",
};
@@ -85,6 +98,50 @@ static int ads1100_set_config_bits(struct ads1100_data *data, u8 mask, u8 value)
return 0;
};
+static int ads11x0_get_voltage_microvolts(struct ads1100_data *data)
+{
+ if (data->has_reference_voltage)
+ return ADS1110_REFERENCE_VOLTAGE_MICROVOLT;
+ else
+ return regulator_get_voltage(data->reg_vdd);
+}
+
+static int ads11x0_get_voltage_milivolts(struct ads1100_data *data)
+{
+ return ads11x0_get_voltage_microvolts(data) / (MICRO / MILLI);
+}
+
+static bool ads11x0_new_data_ready(struct ads1100_data *data)
+{
+ int ret;
+ u8 buffer[3];
+
+ ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));
+ if (ret < sizeof(buffer)) {
+ dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
+ return 0;
+ }
+
+ int return_val = FIELD_GET(ADS1100_CFG_ST_BSY, buffer[2]);
+
+ return return_val;
+}
+
+static int ads11x0_poll_data_ready(struct ads1100_data *data)
+{
+ bool data_ready;
+ u8 buffer[3];
+ int datarate = data->data_rate[FIELD_GET(ADS1100_DR_MASK, data->config)];
+ unsigned long wait_time = DIV_ROUND_CLOSEST(MICRO, 5 * datarate);
+
+ /* To be sure that polled value will have value after config change */
+ i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));
+
+ return read_poll_timeout(ads11x0_new_data_ready, data_ready,
+ !data_ready, wait_time,
+ ADS11x0_MAX_DRDY_TIMEOUT, false, data);
+}
+
static int ads1100_data_bits(struct ads1100_data *data)
{
return ads1100_data_rate_bits[FIELD_GET(ADS1100_DR_MASK, data->config)];
@@ -105,9 +162,10 @@ static int ads1100_get_adc_result(struct ads1100_data *data, int chan, int *val)
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) {
+ if (ret < sizeof(buffer)) {
dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
return ret;
}
@@ -127,7 +185,7 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
{
int microvolts;
int gain;
-
+ int ret;
/* With Vdd between 2.7 and 5V, the scale is always below 1 */
if (val)
return -EINVAL;
@@ -135,7 +193,7 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
if (!val2)
return -EINVAL;
- microvolts = regulator_get_voltage(data->reg_vdd);
+ microvolts = ads11x0_get_voltage_microvolts(data);
/*
* val2 is in 'micro' units, n = val2 / 1000000
* result must be millivolts, d = microvolts / 1000
@@ -147,34 +205,49 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
if (gain < BIT(0) || gain > BIT(3))
return -EINVAL;
+ ret = pm_runtime_resume_and_get(&data->client->dev);
+ if (ret < 0)
+ return ret;
+
ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1);
- return 0;
+ ret = ads11x0_poll_data_ready(data);
+
+ pm_runtime_mark_last_busy(&data->client->dev);
+ pm_runtime_put_autosuspend(&data->client->dev);
+
+ return ret;
}
static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate)
{
unsigned int i;
unsigned int size;
+ int ret;
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));
+ if (data->data_rate[i] == rate) {
+ ret = pm_runtime_resume_and_get(&data->client->dev);
+ if (ret < 0)
+ return ret;
+
+ ads1100_set_config_bits(data, ADS1100_DR_MASK,
+ FIELD_PREP(ADS1100_DR_MASK, i));
+ ret = ads11x0_poll_data_ready(data);
+
+ pm_runtime_mark_last_busy(&data->client->dev);
+ pm_runtime_put_autosuspend(&data->client->dev);
+ return ret;
+ }
}
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);
+ int millivolts = ads11x0_get_voltage_milivolts(data);
unsigned int i;
for (i = 0; i < ARRAY_SIZE(data->scale_avail) / 2; i++) {
@@ -196,7 +269,7 @@ static int ads1100_read_avail(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
*type = IIO_VAL_INT;
- *vals = ads1100_data_rate;
+ *vals = data->data_rate;
if (data->supports_data_rate)
*length = ARRAY_SIZE(ads1100_data_rate);
else
@@ -233,12 +306,11 @@ static int ads1100_read_raw(struct iio_dev *indio_dev,
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
/* full-scale is the supply voltage in millivolts */
- *val = ads1100_get_vdd_millivolts(data);
+ *val = ads11x0_get_voltage_milivolts(data);
*val2 = 15 + FIELD_GET(ADS1100_PGA_MASK, data->config);
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_SAMP_FREQ:
- *val = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK,
- data->config)];
+ *val = data->data_rate[FIELD_GET(ADS1100_DR_MASK, data->config)];
return IIO_VAL_INT;
default:
return -EINVAL;
@@ -280,8 +352,8 @@ static int ads1100_setup(struct ads1100_data *data)
return ret;
ret = i2c_master_recv(data->client, buffer, sizeof(buffer));
- if (ret < 0)
- return ret;
+ if (ret < sizeof(buffer))
+ return -1;
/* Config register returned in third byte, strip away the busy status */
data->config = buffer[2] & ~ADS1100_CFG_ST_BSY;
@@ -292,9 +364,13 @@ static int ads1100_setup(struct ads1100_data *data)
return 0;
}
-static void ads1100_reg_disable(void *reg)
+static void ads1100_reg_disable(void *data)
{
- regulator_disable(reg);
+ struct ads1100_data *ads1100_data = data;
+
+ /* Disable when not already disabled by the driver */
+ if (!(ads1100_data->config & ADS1100_CFG_SC))
+ regulator_disable(ads1100_data->reg_vdd);
}
static void ads1100_disable_continuous(void *data)
@@ -307,6 +383,7 @@ static int ads1100_probe(struct i2c_client *client)
struct iio_dev *indio_dev;
struct ads1100_data *data;
struct device *dev = &client->dev;
+ const struct ads11x0_config *model;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
@@ -334,10 +411,18 @@ static int ads1100_probe(struct i2c_client *client)
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);
+ ret = devm_add_action_or_reset(dev, ads1100_reg_disable, data);
if (ret)
return ret;
+ model = device_get_match_data(dev);
+ if (!model)
+ return dev_err_probe(dev, ret,
+ "Can't set device data\n");
+
+ data->data_rate = model->data_rate;
+ data->has_reference_voltage = model->has_reference_voltage;
+
ret = ads1100_setup(data);
if (ret)
return dev_err_probe(dev, ret,
@@ -400,16 +485,18 @@ static DEFINE_RUNTIME_DEV_PM_OPS(ads1100_pm_ops,
NULL);
static const struct i2c_device_id ads1100_id[] = {
- { "ads1100" },
- { "ads1000" },
+ { .name = "ads1100", .driver_data = (kernel_ulong_t)&ads1100_config },
+ { .name = "ads1000", .driver_data = (kernel_ulong_t)&ads1100_config },
+ { .name = "ads1110", .driver_data = (kernel_ulong_t)&ads1110_config },
{ }
};
MODULE_DEVICE_TABLE(i2c, ads1100_id);
static const struct of_device_id ads1100_of_match[] = {
- {.compatible = "ti,ads1100" },
- {.compatible = "ti,ads1000" },
+ { .compatible = "ti,ads1100", .data = &ads1100_config },
+ { .compatible = "ti,ads1000", .data = &ads1100_config },
+ { .compatible = "ti,ads1110", .data = &ads1110_config },
{ }
};
--
2.47.3