[PATCH v2 2/5] max44000: Initial support for proximity reading

From: Crestez Dan Leonard
Date: Mon Apr 11 2016 - 14:53:04 EST


The proximity sensor relies on sending pulses to an external IR led and
it is disabled by default on powerup. The driver will enable it with a
default power setting.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
---
drivers/iio/light/max44000.c | 46 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index 707cc24..39853ff 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -59,6 +59,11 @@
*/
#define MAX44000_REG_CFG_RX_DEFAULT 0xf0

+/* REG_TX bits */
+#define MAX44000_LED_CURRENT_MASK 0xf
+#define MAX44000_LED_CURRENT_MAX 11
+#define MAX44000_LED_CURRENT_DEFAULT 6
+
#define MAX44000_ALSDATA_OVERFLOW 0x4000

#define MAX44000_REGMASK_READABLE ( \
@@ -111,6 +116,12 @@ static const struct iio_chan_spec max44000_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME),
+ },
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
},
};
@@ -142,11 +153,23 @@ static int max44000_read_alsval(struct max44000_data *data)
return regval;
}

+static int max44000_write_led_current_raw(struct max44000_data *data, int val)
+{
+ /* Maybe we should clamp the value instead? */
+ if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
+ return -ERANGE;
+ if (val >= 8)
+ val += 4;
+ return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
+ MAX44000_LED_CURRENT_MASK, val);
+}
+
static int max44000_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct max44000_data *data = iio_priv(indio_dev);
+ unsigned int regval;
int ret;

switch (mask) {
@@ -161,6 +184,15 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
*val = ret;
return IIO_VAL_INT;

+ case IIO_PROXIMITY:
+ mutex_lock(&data->lock);
+ ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+ *val = regval;
+ return IIO_VAL_INT;
+
default:
return -EINVAL;
}
@@ -279,8 +311,18 @@ static int max44000_probe(struct i2c_client *client,
return ret;
}

- /* Reset CFG bits to ALS-only mode and no interrupts */
- reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
+ /*
+ * By default the LED pulse used for the proximity sensor is disabled.
+ * Set a middle value so that we get some sort of valid data by default.
+ */
+ ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to write init config: %d\n", ret);
+ return ret;
+ }
+
+ /* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
+ reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
if (ret < 0) {
dev_err(&client->dev, "failed to write init config: %d\n", ret);
--
2.5.5