iio: adc: ti-ads1015: fix scale information for ADS1115

[mirror_ubuntu-artful-kernel.git] / drivers / iio / adc / ti-ads1015.c

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 884b8e461b1755ddbcbfbb3611deaa3b4a4c8fb9..f32d0467a195828095f7299ef67f9cf23320df0a 100644 (file)
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -81,18 +81,12 @@ 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) {                         \
@@ -252,9 +246,11 @@ int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
 
        ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG,
                                       ADS1015_CFG_MUX_MASK |
-                                      ADS1015_CFG_PGA_MASK,
+                                      ADS1015_CFG_PGA_MASK |
+                                      ADS1015_CFG_DR_MASK,
                                       chan << ADS1015_CFG_MUX_SHIFT |
-                                      pga << ADS1015_CFG_PGA_SHIFT,
+                                      pga << ADS1015_CFG_PGA_SHIFT |
+                                      dr << ADS1015_CFG_DR_SHIFT,
                                       &change);
        if (ret < 0)
                return ret;
@@ -298,17 +294,20 @@ 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;
 
@@ -318,32 +317,23 @@ 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,
@@ -385,9 +375,9 @@ 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;
@@ -414,7 +404,7 @@ 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);
@@ -446,7 +436,10 @@ 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");
@@ -454,7 +447,7 @@ 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,
 };
@@ -464,7 +457,7 @@ 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,
 };