On Wed, 10 Jan 2024 13:58:07 +0100
Mårten Lindahl <marten.lindahl@xxxxxxxx> wrote:
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@xxxxxxxx>
Hi Mårten,
I don't understand why we'd try to carry on with using the device if
the additional register accesses fail. Just fail the probe, the hardware
is broken.
Jonathan
---
Changes in v2:
- Update registers for sample rate to align it with 16 bit sensor readings.
- Change sysfs output from IIO_VAL_INT to IIO_VAL_FRACTIONAL and scale by 16.
- Link to v1: https://lore.kernel.org/r/20231221-vcnl4000-ps-hd-v1-1-a024bfb28896@xxxxxxxx
---
drivers/iio/light/vcnl4000.c | 40 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index fdf763a04b0b..a078c573131e 100644
--- 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 +396,36 @@ 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) {
+ regval = (ret | VCNL4040_PS_CONF2_PS_HD);
Trivial but those brackets are unnecessary.
+ ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1,
+ regval);
+ }
+
+ if (ret < 0) {
+ dev_info(&data->client->dev, "Default to 12 bits sensor data");
Silly question - how can we get here? If it's a case of a read or a write failing
then that's a critical failure and we have very little idea what the state is.
If that happens I'd just fail to probe the driver rather than carrying on with
12 bit assumed.
+ data->ps_scale = 1;
+ goto out;
+ }
+
+ /* Align proximity sensor sample rate to 16 bits data width */
+ ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF3);
+ if (ret >= 0) {
If the read fails, something is very wrong. Fail the probe.
+ regval = (ret | VCNL4040_CONF3_PS_SAMPLE_16BITS);
+ ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF3,
+ regval);
+ }
+
+ if (ret < 0)
+ dev_warn(&data->client->dev, "Sample rate may not be accurate");
If this fails, fail the probe. Don't try to carry on anyway.
+
+out:
ret = data->chip_spec->set_power_state(data, true);
if (ret < 0)
return ret;
@@ -901,8 +938,9 @@ 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;
---
base-commit: a39b6ac3781d46ba18193c9dbb2110f31e9bffe9
change-id: 20231221-vcnl4000-ps-hd-863f4f8fcea7
Best regards,
