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path: root/drivers/iio/adc/ti-ads1015.c
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Diffstat (limited to 'drivers/iio/adc/ti-ads1015.c')
-rw-r--r--drivers/iio/adc/ti-ads1015.c123
1 files changed, 72 insertions, 51 deletions
diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index cde6f130a99a..472641fc890c 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -80,18 +80,12 @@ static const unsigned int ads1115_data_rate[] = {
8, 16, 32, 64, 128, 250, 475, 860
};
-static const struct {
- int scale;
- int uscale;
-} ads1015_scale[] = {
- {3, 0},
- {2, 0},
- {1, 0},
- {0, 500000},
- {0, 250000},
- {0, 125000},
- {0, 125000},
- {0, 125000},
+/*
+ * Translation from PGA bits to full-scale positive and negative input voltage
+ * range in mV
+ */
+static int ads1015_fullscale_range[] = {
+ 6144, 4096, 2048, 1024, 512, 256, 256, 256
};
#define ADS1015_V_CHAN(_chan, _addr) { \
@@ -182,6 +176,12 @@ struct ads1015_data {
struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
unsigned int *data_rate;
+ /*
+ * Set to true when the ADC is switched to the continuous-conversion
+ * mode and exits from a power-down state. This flag is used to avoid
+ * getting the stale result from the conversion register.
+ */
+ bool conv_invalid;
};
static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
@@ -234,33 +234,43 @@ static int ads1015_set_power_state(struct ads1015_data *data, bool on)
ret = pm_runtime_put_autosuspend(dev);
}
- return ret;
+ return ret < 0 ? ret : 0;
}
static
int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
{
int ret, pga, dr, conv_time;
- bool change;
+ unsigned int old, mask, cfg;
if (chan < 0 || chan >= ADS1015_CHANNELS)
return -EINVAL;
+ ret = regmap_read(data->regmap, ADS1015_CFG_REG, &old);
+ if (ret)
+ return ret;
+
pga = data->channel_data[chan].pga;
dr = data->channel_data[chan].data_rate;
+ mask = ADS1015_CFG_MUX_MASK | ADS1015_CFG_PGA_MASK |
+ ADS1015_CFG_DR_MASK;
+ cfg = chan << ADS1015_CFG_MUX_SHIFT | pga << ADS1015_CFG_PGA_SHIFT |
+ dr << ADS1015_CFG_DR_SHIFT;
- ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG,
- ADS1015_CFG_MUX_MASK |
- ADS1015_CFG_PGA_MASK,
- chan << ADS1015_CFG_MUX_SHIFT |
- pga << ADS1015_CFG_PGA_SHIFT,
- &change);
- if (ret < 0)
+ cfg = (old & ~mask) | (cfg & mask);
+
+ ret = regmap_write(data->regmap, ADS1015_CFG_REG, cfg);
+ if (ret)
return ret;
- if (change) {
- conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
+ if (old != cfg || data->conv_invalid) {
+ int dr_old = (old & ADS1015_CFG_DR_MASK) >>
+ ADS1015_CFG_DR_SHIFT;
+
+ conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]);
+ conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
usleep_range(conv_time, conv_time + 1);
+ data->conv_invalid = false;
}
return regmap_read(data->regmap, ADS1015_CONV_REG, val);
@@ -297,17 +307,20 @@ err:
return IRQ_HANDLED;
}
-static int ads1015_set_scale(struct ads1015_data *data, int chan,
+static int ads1015_set_scale(struct ads1015_data *data,
+ struct iio_chan_spec const *chan,
int scale, int uscale)
{
int i, ret, rindex = -1;
+ int fullscale = div_s64((scale * 1000000LL + uscale) <<
+ (chan->scan_type.realbits - 1), 1000000);
- for (i = 0; i < ARRAY_SIZE(ads1015_scale); i++)
- if (ads1015_scale[i].scale == scale &&
- ads1015_scale[i].uscale == uscale) {
+ for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) {
+ if (ads1015_fullscale_range[i] == fullscale) {
rindex = i;
break;
}
+ }
if (rindex < 0)
return -EINVAL;
@@ -317,32 +330,23 @@ static int ads1015_set_scale(struct ads1015_data *data, int chan,
if (ret < 0)
return ret;
- data->channel_data[chan].pga = rindex;
+ data->channel_data[chan->address].pga = rindex;
return 0;
}
static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
{
- int i, ret, rindex = -1;
+ int i;
- for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++)
+ for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
if (data->data_rate[i] == rate) {
- rindex = i;
- break;
+ data->channel_data[chan].data_rate = i;
+ return 0;
}
- if (rindex < 0)
- return -EINVAL;
-
- ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
- ADS1015_CFG_DR_MASK,
- rindex << ADS1015_CFG_DR_SHIFT);
- if (ret < 0)
- return ret;
-
- data->channel_data[chan].data_rate = rindex;
+ }
- return 0;
+ return -EINVAL;
}
static int ads1015_read_raw(struct iio_dev *indio_dev,
@@ -384,9 +388,9 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
}
case IIO_CHAN_INFO_SCALE:
idx = data->channel_data[chan->address].pga;
- *val = ads1015_scale[idx].scale;
- *val2 = ads1015_scale[idx].uscale;
- ret = IIO_VAL_INT_PLUS_MICRO;
+ *val = ads1015_fullscale_range[idx];
+ *val2 = chan->scan_type.realbits - 1;
+ ret = IIO_VAL_FRACTIONAL_LOG2;
break;
case IIO_CHAN_INFO_SAMP_FREQ:
idx = data->channel_data[chan->address].data_rate;
@@ -413,7 +417,7 @@ static int ads1015_write_raw(struct iio_dev *indio_dev,
mutex_lock(&data->lock);
switch (mask) {
case IIO_CHAN_INFO_SCALE:
- ret = ads1015_set_scale(data, chan->address, val, val2);
+ ret = ads1015_set_scale(data, chan, val, val2);
break;
case IIO_CHAN_INFO_SAMP_FREQ:
ret = ads1015_set_data_rate(data, chan->address, val);
@@ -445,7 +449,10 @@ static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
.validate_scan_mask = &iio_validate_scan_mask_onehot,
};
-static IIO_CONST_ATTR(scale_available, "3 2 1 0.5 0.25 0.125");
+static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available,
+ "3 2 1 0.5 0.25 0.125");
+static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available,
+ "0.1875 0.125 0.0625 0.03125 0.015625 0.007813");
static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available,
sampling_frequency_available, "128 250 490 920 1600 2400 3300");
@@ -453,7 +460,7 @@ static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available,
sampling_frequency_available, "8 16 32 64 128 250 475 860");
static struct attribute *ads1015_attributes[] = {
- &iio_const_attr_scale_available.dev_attr.attr,
+ &iio_const_attr_ads1015_scale_available.dev_attr.attr,
&iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr,
NULL,
};
@@ -463,7 +470,7 @@ static const struct attribute_group ads1015_attribute_group = {
};
static struct attribute *ads1115_attributes[] = {
- &iio_const_attr_scale_available.dev_attr.attr,
+ &iio_const_attr_ads1115_scale_available.dev_attr.attr,
&iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr,
NULL,
};
@@ -624,6 +631,15 @@ static int ads1015_probe(struct i2c_client *client,
dev_err(&client->dev, "iio triggered buffer setup failed\n");
return ret;
}
+
+ ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
+ ADS1015_CFG_MOD_MASK,
+ ADS1015_CONTINUOUS << ADS1015_CFG_MOD_SHIFT);
+ if (ret)
+ return ret;
+
+ data->conv_invalid = true;
+
ret = pm_runtime_set_active(&client->dev);
if (ret)
goto err_buffer_cleanup;
@@ -679,10 +695,15 @@ static int ads1015_runtime_resume(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct ads1015_data *data = iio_priv(indio_dev);
+ int ret;
- return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
+ ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
ADS1015_CFG_MOD_MASK,
ADS1015_CONTINUOUS << ADS1015_CFG_MOD_SHIFT);
+ if (!ret)
+ data->conv_invalid = true;
+
+ return ret;
}
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-23 16:15:06 +0000