iio:bma180: Expose temperature channel

8-bit signed; 0 LSB @ 24 °C, 0.5 °C per LSB

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 59 insertions, 21 deletions

diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
index aa7566fc031f..91260a071fe9 100644
--- a/drivers/iio/accel/bma180.c
+++ b/drivers/iio/accel/bma180.c
@@ -29,6 +29,7 @@
 /* Register set */
 #define BMA180_CHIP_ID          0x00 /* Need to distinguish BMA180 from other */
 #define BMA180_ACC_X_LSB        0x02 /* First of 6 registers of accel data */
+#define BMA180_TEMP             0x08
 #define BMA180_CTRL_REG0        0x0d
 #define BMA180_RESET            0x10
 #define BMA180_BW_TCS           0x20
@@ -84,27 +85,37 @@ struct bma180_data {
         char *buff;
 };
 
-enum bma180_axis {
+enum bma180_chan {
         AXIS_X,
         AXIS_Y,
         AXIS_Z,
+        TEMP
 };
 
 static int bma180_bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
 static int bma180_scale_table[] = { 1275, 1863, 2452, 3727, 4903, 9709, 19417 };
 
-static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
+static int bma180_get_data_reg(struct bma180_data *data, enum bma180_chan chan)
 {
-        u8 reg = BMA180_ACC_X_LSB + axis * 2;
         int ret;
 
         if (data->sleep_state)
                 return -EBUSY;
 
-        ret = i2c_smbus_read_word_data(data->client, reg);
-        if (ret < 0)
-                dev_err(&data->client->dev,
-                        "failed to read accel_%c register\n", 'x' + axis);
+        switch (chan) {
+        case TEMP:
+                ret = i2c_smbus_read_byte_data(data->client, BMA180_TEMP);
+                if (ret < 0)
+                        dev_err(&data->client->dev, "failed to read temp register\n");
+                break;
+        default:
+                ret = i2c_smbus_read_word_data(data->client,
+                        BMA180_ACC_X_LSB + chan * 2);
+                if (ret < 0)
+                        dev_err(&data->client->dev,
+                                "failed to read accel_%c register\n",
+                                'x' + chan);
+        }
 
         return ret;
 }
@@ -337,22 +348,35 @@ static int bma180_read_raw(struct iio_dev *indio_dev,
         switch (mask) {
         case IIO_CHAN_INFO_RAW:
                 mutex_lock(&data->mutex);
-                if (iio_buffer_enabled(indio_dev))
-                        ret = -EBUSY;
-                else
-                        ret = bma180_get_acc_reg(data, chan->scan_index);
+                if (iio_buffer_enabled(indio_dev)) {
+                        mutex_unlock(&data->mutex);
+                        return -EBUSY;
+                }
+                ret = bma180_get_data_reg(data, chan->scan_index);
                 mutex_unlock(&data->mutex);
                 if (ret < 0)
                         return ret;
-                *val = (s16)ret >> chan->scan_type.shift;
+                *val = sign_extend32(ret >> chan->scan_type.shift,
+                        chan->scan_type.realbits - 1);
                 return IIO_VAL_INT;
         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                 *val = data->bw;
                 return IIO_VAL_INT;
         case IIO_CHAN_INFO_SCALE:
-                *val = 0;
-                *val2 = data->scale;
-                return IIO_VAL_INT_PLUS_MICRO;
+                switch (chan->type) {
+                case IIO_ACCEL:
+                        *val = 0;
+                        *val2 = data->scale;
+                        return IIO_VAL_INT_PLUS_MICRO;
+                case IIO_TEMP:
+                        *val = 500;
+                        return IIO_VAL_INT;
+                default:
+                        return -EINVAL;
+                }
+        case IIO_CHAN_INFO_OFFSET:
+                *val = 48; /* 0 LSB @ 24 degree C */
+                return IIO_VAL_INT;
         default:
                 return -EINVAL;
         }
@@ -443,7 +467,7 @@ static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
         { },
 };
 
-#define BMA180_CHANNEL(_axis) {                                 \
+#define BMA180_ACC_CHANNEL(_axis) {                                     \
         .type = IIO_ACCEL,                                              \
         .modified = 1,                                                  \
         .channel2 = IIO_MOD_##_axis,                                    \
@@ -460,11 +484,24 @@ static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
         .ext_info = bma180_ext_info,                                    \
 }
 
+#define BMA180_TEMP_CHANNEL {                                           \
+        .type = IIO_TEMP,                                               \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
+                BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),   \
+        .scan_index = TEMP,                                             \
+        .scan_type = {                                                  \
+                .sign = 's',                                            \
+                .realbits = 8,                                          \
+                .storagebits = 16,                                      \
+        },                                                              \
+}
+
 static const struct iio_chan_spec bma180_channels[] = {
-        BMA180_CHANNEL(X),
-        BMA180_CHANNEL(Y),
-        BMA180_CHANNEL(Z),
-        IIO_CHAN_SOFT_TIMESTAMP(3),
+        BMA180_ACC_CHANNEL(X),
+        BMA180_ACC_CHANNEL(Y),
+        BMA180_ACC_CHANNEL(Z),
+        BMA180_TEMP_CHANNEL,
+        IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
 static irqreturn_t bma180_trigger_handler(int irq, void *p)
@@ -479,13 +516,14 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p)
 
         for_each_set_bit(bit, indio_dev->buffer->scan_mask,
                          indio_dev->masklength) {
-                ret = bma180_get_acc_reg(data, bit);
+                ret = bma180_get_data_reg(data, bit);
                 if (ret < 0) {
                         mutex_unlock(&data->mutex);
                         goto err;
                 }
                 ((s16 *)data->buff)[i++] = ret;
         }
+
         mutex_unlock(&data->mutex);
 
         iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns);