iio: light: vcnl4000: Set ps high definition for 4040/4200

The vcnl4040/vcnl4200 proximity sensor defaults to 12 bit data
resolution, but the chip also supports 16 bit data resolution, which is
called proximity high definition (PS_HD).

Make the vcnl4040/vcnl4200 proximity sensor use the high definition for
all data readings. Please note that in order to preserve the 12 bit
integer part of the in_proximity_raw output, the format is changed from
integer to fixed point.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Link: https://lore.kernel.org/r/20231221-vcnl4000-ps-hd-v3-1-6dcc889372be@axis.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index fdf763a04b0bfac2fef3eb50a1f1d85df995122e..4e3641ff2ed446262c12380e520d3d220865c00c 100644 (file)
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -90,6 +90,7 @@
 #define VCNL4040_PS_CONF1_PS_SHUTDOWN  BIT(0)
 #define VCNL4040_PS_CONF2_PS_IT        GENMASK(3, 1) /* Proximity integration time */
 #define VCNL4040_CONF1_PS_PERS GENMASK(5, 4) /* Proximity interrupt persistence setting */
+#define VCNL4040_PS_CONF2_PS_HD                BIT(11) /* Proximity high definition */
 #define VCNL4040_PS_CONF2_PS_INT       GENMASK(9, 8) /* Proximity interrupt mode */
 #define VCNL4040_PS_CONF3_MPS          GENMASK(6, 5) /* Proximity multi pulse number */
 #define VCNL4040_PS_MS_LED_I           GENMASK(10, 8) /* Proximity current */
@@ -114,6 +115,13 @@
 #define VCNL4010_INT_DRDY \
        (BIT(VCNL4010_INT_PROXIMITY) | BIT(VCNL4010_INT_ALS))
 
+#define VCNL4040_CONF3_PS_MPS_16BITS   3       /* 8 multi pulses */
+#define VCNL4040_CONF3_PS_LED_I_16BITS 3       /* 120 mA */
+
+#define VCNL4040_CONF3_PS_SAMPLE_16BITS \
+       (FIELD_PREP(VCNL4040_PS_CONF3_MPS, VCNL4040_CONF3_PS_MPS_16BITS) | \
+        FIELD_PREP(VCNL4040_PS_MS_LED_I, VCNL4040_CONF3_PS_LED_I_16BITS))
+
 static const int vcnl4010_prox_sampling_frequency[][2] = {
        {1, 950000},
        {3, 906250},
@@ -195,6 +203,7 @@ struct vcnl4000_data {
        enum vcnl4000_device_ids id;
        int rev;
        int al_scale;
+       int ps_scale;
        u8 ps_int;              /* proximity interrupt mode */
        u8 als_int;             /* ambient light interrupt mode*/
        const struct vcnl4000_chip_spec *chip_spec;
@@ -345,6 +354,7 @@ static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool on)
 static int vcnl4200_init(struct vcnl4000_data *data)
 {
        int ret, id;
+       u16 regval;
 
        ret = i2c_smbus_read_word_data(data->client, VCNL4200_DEV_ID);
        if (ret < 0)
@@ -386,9 +396,32 @@ static int vcnl4200_init(struct vcnl4000_data *data)
                break;
        }
        data->al_scale = data->chip_spec->ulux_step;
+       data->ps_scale = 16;
        mutex_init(&data->vcnl4200_al.lock);
        mutex_init(&data->vcnl4200_ps.lock);
 
+       /* Use 16 bits proximity sensor readings */
+       ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
+       if (ret < 0)
+               return ret;
+
+       regval = ret | VCNL4040_PS_CONF2_PS_HD;
+       ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1,
+                                       regval);
+       if (ret < 0)
+               return ret;
+
+       /* Align proximity sensor sample rate to 16 bits data width */
+       ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF3);
+       if (ret < 0)
+               return ret;
+
+       regval = ret | VCNL4040_CONF3_PS_SAMPLE_16BITS;
+       ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF3,
+                                       regval);
+       if (ret < 0)
+               return ret;
+
        ret = data->chip_spec->set_power_state(data, true);
        if (ret < 0)
                return ret;
@@ -901,8 +934,9 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
                        break;
                case IIO_PROXIMITY:
                        ret = data->chip_spec->measure_proximity(data, val);
+                       *val2 = data->ps_scale;
                        if (!ret)
-                               ret = IIO_VAL_INT;
+                               ret = IIO_VAL_FRACTIONAL;
                        break;
                default:
                        ret = -EINVAL;