On Thu, 28 Jun 2018 16:31:26 +0200
Mathieu Othacehe <m.othacehe@xxxxxxxxx> wrote:
> This patch adds support for the ISL29501 Time of Flight sensor.
>
> Signed-off-by: Mathieu Othacehe <m.othacehe@xxxxxxxxx>
A few minors + some missing docs / possible changes in the use
of extended_name which is in the category of 'only use this in unusual
circumstances' as it breaks being able to use generic userspace code.
Are we stalled on the floating point support question, or is the
driver just 'limited' but still useful before we have that resolved?
Thanks,
Jonathan
> ---
> Documentation/ABI/testing/sysfs-bus-iio-isl29501 | 47 +
> .../devicetree/bindings/iio/light/isl29501.txt | 13 +
> drivers/iio/light/Kconfig | 13 +
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/isl29501.c | 1140 ++++++++++++++++++++
> 5 files changed, 1214 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-isl29501
> create mode 100644 Documentation/devicetree/bindings/iio/light/isl29501.txt
> create mode 100644 drivers/iio/light/isl29501.c
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-isl29501 b/Documentation/ABI/testing/sysfs-bus-iio-isl29501
> new file mode 100644
> index 0000000..39f004b3
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-isl29501
> @@ -0,0 +1,47 @@
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_agc_gain
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_agc_gain_bias
> +KernelVersion: 4.18
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + This sensor has an automatic gain control (agc) loop
> + which sets the analog signal levels at an optimum
> + level by controlling programmable gain amplifiers. The
> + criteria for optimal gain is determined by the sensor.
> +
> + Return the actual gain value as an integer in [0; 65536]
> + range when read from.
> +
> + The agc gain read when measuring crosstalk shall be
> + written into in_proximity0_agc_gain_bias.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_temp_a
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_temp_b
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_light_a
> +What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_light_b
> +KernelVersion: 4.18
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + The sensor is able to perform correction of distance
> + measurements due to changing temperature and ambient
> + light conditions. It can be programmed to correct for
> + a second order error polynomial.
> +
> + Phase data has to be collected when temperature and
> + ambient light are modulated independently.
> +
> + Then a least squares curve fit to a second order
> + polynomial has to be generated from the data. The
> + resultant curves have the form ax^2 + bx + c.
> +
> + From those two curves, a and b coefficients shall be
> + stored in in_proximity0_calib_phase_temp_a and
> + in_proximity0_calib_phase_temp_b for temperature and
> + in in_proximity0_calib_phase_light_a and
> + in_proximity0_calib_phase_light_b for ambient light.
> +
> + Those values must be integer in [0; 8355840] range.
> +
> + Finally, the c constant is set by the sensor
> + internally.
> +
> + The value stored in sensor is displayed when read from.
> \ No newline at end of file
Add one as it makes this go away.
The extended_name channels add more custom ABI that needs documenting here as well.
> diff --git a/Documentation/devicetree/bindings/iio/light/isl29501.txt b/Documentation/devicetree/bindings/iio/light/isl29501.txt
> new file mode 100644
> index 0000000..4695799
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/light/isl29501.txt
> @@ -0,0 +1,13 @@
> +* ISL29501 Time-of-flight sensor.
> +
> +Required properties:
> +
> + - compatible : should be "renesas,isl29501"
> + - reg : the I2C address of the sensor
> +
> +Example:
> +
> +isl29501@57 {
> + compatible = "renesas,isl29501";
> + reg = <0x57>;
> +};
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index c7ef8d1..3882bdc 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -194,6 +194,19 @@ config ISL29125
> To compile this driver as a module, choose M here: the module will be
> called isl29125.
>
> +config ISL29501
> + tristate "Intersil ISL29501 Time Of Flight sensor"
> + depends on I2C
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + select IIO_KFIFO_BUF
> + help
> + Say Y here if you want to build a driver for the Intersil ISL29501
> + Time of Flight sensor.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called isl29501.
> +
> config HID_SENSOR_ALS
> depends on HID_SENSOR_HUB
> select IIO_BUFFER
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 80943af..81c0631 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_HID_SENSOR_PROX) += hid-sensor-prox.o
> obj-$(CONFIG_SENSORS_ISL29018) += isl29018.o
> obj-$(CONFIG_SENSORS_ISL29028) += isl29028.o
> obj-$(CONFIG_ISL29125) += isl29125.o
> +obj-$(CONFIG_ISL29501) += isl29501.o
> obj-$(CONFIG_JSA1212) += jsa1212.o
> obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
> obj-$(CONFIG_LTR501) += ltr501.o
> diff --git a/drivers/iio/light/isl29501.c b/drivers/iio/light/isl29501.c
> new file mode 100644
> index 0000000..dc2149c
> --- /dev/null
> +++ b/drivers/iio/light/isl29501.c
> @@ -0,0 +1,1140 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * isl29501.c: ISL29501 Time of Flight sensor driver.
> + *
> + * Copyright (C) 2018
> + * Author: Mathieu Othacehe <m.othacehe@xxxxxxxxx>
> + *
> + * 7-bit I2C slave address: 0x57
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/of_device.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +/* Control, setting and status registers */
> +#define ISL29501_DEVICE_ID 0x00
> +#define ISL29501_ID 0x0A
> +
> +/* Sampling control registers */
> +#define ISL29501_INTEGRATION_PERIOD 0x10
> +#define ISL29501_SAMPLE_PERIOD 0x11
> +
> +/* Closed loop calibration registers */
> +#define ISL29501_CROSSTALK_I_MSB 0x24
> +#define ISL29501_CROSSTALK_I_LSB 0x25
> +#define ISL29501_CROSSTALK_I_EXPONENT 0x26
> +#define ISL29501_CROSSTALK_Q_MSB 0x27
> +#define ISL29501_CROSSTALK_Q_LSB 0x28
> +#define ISL29501_CROSSTALK_Q_EXPONENT 0x29
> +#define ISL29501_CROSSTALK_GAIN_MSB 0x2A
> +#define ISL29501_CROSSTALK_GAIN_LSB 0x2B
> +#define ISL29501_MAGNITUDE_REF_EXP 0x2C
> +#define ISL29501_MAGNITUDE_REF_MSB 0x2D
> +#define ISL29501_MAGNITUDE_REF_LSB 0x2E
> +#define ISL29501_PHASE_OFFSET_MSB 0x2F
> +#define ISL29501_PHASE_OFFSET_LSB 0x30
> +
> +/* Analog control registers */
> +#define ISL29501_DRIVER_RANGE 0x90
> +#define ISL29501_EMITTER_DAC 0x91
> +
> +#define ISL29501_COMMAND_REGISTER 0xB0
> +
> +/* Commands */
> +#define ISL29501_EMUL_SAMPLE_START_PIN 0x49
> +#define ISL29501_RESET_ALL_REGISTERS 0xD7
> +#define ISL29501_RESET_INT_SM 0xD1
> +
> +/* Ambiant light and temperature corrections */
> +#define ISL29501_TEMP_REFERENCE 0x31
> +#define ISL29501_PHASE_EXPONENT 0x33
> +#define ISL29501_TEMP_COEFF_A 0x34
> +#define ISL29501_TEMP_COEFF_B 0x39
> +#define ISL29501_AMBIANT_COEFF_A 0x36
> +#define ISL29501_AMBIANT_COEFF_B 0x3B
> +
> +/* Data output registers */
> +#define ISL29501_DISTANCE_MSB_DATA 0xD1
> +#define ISL29501_DISTANCE_LSB_DATA 0xD2
> +#define ISL29501_PRECISION_MSB 0xD3
> +#define ISL29501_PRECISION_LSB 0xD4
> +#define ISL29501_MAGNITUDE_EXPONENT 0xD5
> +#define ISL29501_MAGNITUDE_MSB 0xD6
> +#define ISL29501_MAGNITUDE_LSB 0xD7
> +#define ISL29501_PHASE_MSB 0xD8
> +#define ISL29501_PHASE_LSB 0xD9
> +#define ISL29501_I_RAW_EXPONENT 0xDA
> +#define ISL29501_I_RAW_MSB 0xDB
> +#define ISL29501_I_RAW_LSB 0xDC
> +#define ISL29501_Q_RAW_EXPONENT 0xDD
> +#define ISL29501_Q_RAW_MSB 0xDE
> +#define ISL29501_Q_RAW_LSB 0xDF
> +#define ISL29501_DIE_TEMPERATURE 0xE2
> +#define ISL29501_AMBIENT_LIGHT 0xE3
> +#define ISL29501_GAIN_MSB 0xE6
> +#define ISL29501_GAIN_LSB 0xE7
> +
> +#define ISL29501_MAX_EXP_VAL 15
> +
> +#define ISL29501_INT_TIME_AVAILABLE \
> + "0.00007 0.00014 0.00028 0.00057 0.00114 " \
> + "0.00228 0.00455 0.00910 0.01820 0.03640 " \
> + "0.07281 0.14561"
> +
> +#define ISL29501_CURRENT_SCALE_AVAILABLE \
> + "0.0039 0.0078 0.0118 0.0157 0.0196 " \
> + "0.0235 0.0275 0.0314 0.0352 0.0392 " \
> + "0.0431 0.0471 0.0510 0.0549 0.0588"
> +
> +enum isl29501_correction_coeff {
> + COEFF_TEMP_A,
> + COEFF_TEMP_B,
> + COEFF_LIGHT_A,
> + COEFF_LIGHT_B,
> + COEFF_MAX,
> +};
> +
> +struct isl29501_private {
> + struct i2c_client *client;
> + struct mutex lock;
> + /* Exact representation of correction coefficients. */
> + unsigned int shadow_coeffs[COEFF_MAX];
> +};
> +
> +enum isl29501_register_name {
> + REG_DISTANCE,
> + REG_AMPLITUDE,
> + REG_PHASE,
> + REG_I_RAW,
> + REG_Q_RAW,
> + REG_TEMPERATURE,
> + REG_AMBIENT_LIGHT,
> + REG_GAIN,
> + REG_I_BIAS,
> + REG_Q_BIAS,
> + REG_GAIN_BIAS,
> + REG_AMPL_BIAS,
> + REG_PHASE_EXP,
> + REG_CALIB_PHASE_TEMP_A,
> + REG_CALIB_PHASE_TEMP_B,
> + REG_CALIB_PHASE_LIGHT_A,
> + REG_CALIB_PHASE_LIGHT_B,
> + REG_DISTANCE_BIAS,
> + REG_TEMPERATURE_BIAS,
> + REG_INT_TIME,
> + REG_SAMPLE_TIME,
> + REG_DRIVER_RANGE,
> + REG_EMITTER_DAC,
> +};
> +
> +struct isl29501_register_desc {
> + u8 msb;
> + u8 lsb;
> + u8 exp;
> +};
> +
> +static const struct isl29501_register_desc isl29501_registers[] = {
> + [REG_DISTANCE] = {
> + .msb = ISL29501_DISTANCE_MSB_DATA,
> + .lsb = ISL29501_DISTANCE_LSB_DATA,
> + },
> + [REG_AMPLITUDE] = {
> + .msb = ISL29501_MAGNITUDE_MSB,
> + .lsb = ISL29501_MAGNITUDE_LSB,
> + .exp = ISL29501_MAGNITUDE_EXPONENT,
> + },
> + [REG_PHASE] = {
> + .msb = ISL29501_PHASE_MSB,
> + .lsb = ISL29501_PHASE_LSB,
> + },
> + [REG_I_RAW] = {
> + .msb = ISL29501_I_RAW_MSB,
> + .lsb = ISL29501_I_RAW_LSB,
> + .exp = ISL29501_I_RAW_EXPONENT,
> + },
> + [REG_Q_RAW] = {
> + .msb = ISL29501_Q_RAW_MSB,
> + .lsb = ISL29501_Q_RAW_LSB,
> + .exp = ISL29501_Q_RAW_EXPONENT,
> + },
> + [REG_TEMPERATURE] = {
> + .lsb = ISL29501_DIE_TEMPERATURE,
> + },
> + [REG_AMBIENT_LIGHT] = {
> + .lsb = ISL29501_AMBIENT_LIGHT,
> + },
> + [REG_GAIN] = {
> + .msb = ISL29501_GAIN_MSB,
> + .lsb = ISL29501_GAIN_LSB,
> + },
> + [REG_I_BIAS] = {
> + .msb = ISL29501_CROSSTALK_I_MSB,
> + .lsb = ISL29501_CROSSTALK_I_LSB,
> + .exp = ISL29501_CROSSTALK_I_EXPONENT,
> + },
> + [REG_Q_BIAS] = {
> + .msb = ISL29501_CROSSTALK_Q_MSB,
> + .lsb = ISL29501_CROSSTALK_Q_LSB,
> + .exp = ISL29501_CROSSTALK_Q_EXPONENT,
> + },
> + [REG_GAIN_BIAS] = {
> + .msb = ISL29501_CROSSTALK_GAIN_MSB,
> + .lsb = ISL29501_CROSSTALK_GAIN_LSB,
> + },
> + [REG_AMPL_BIAS] = {
> + .msb = ISL29501_MAGNITUDE_REF_MSB,
> + .lsb = ISL29501_MAGNITUDE_REF_LSB,
> + .exp = ISL29501_MAGNITUDE_REF_EXP,
> + },
> + [REG_PHASE_EXP] = {
> + .lsb = ISL29501_PHASE_EXPONENT,
> + },
> + [REG_CALIB_PHASE_TEMP_A] = {
> + .lsb = ISL29501_TEMP_COEFF_A,
> + },
> + [REG_CALIB_PHASE_TEMP_B] = {
> + .lsb = ISL29501_TEMP_COEFF_B,
> + },
> + [REG_CALIB_PHASE_LIGHT_A] = {
> + .lsb = ISL29501_AMBIANT_COEFF_A,
> + },
> + [REG_CALIB_PHASE_LIGHT_B] = {
> + .lsb = ISL29501_AMBIANT_COEFF_B,
> + },
> + [REG_DISTANCE_BIAS] = {
> + .msb = ISL29501_PHASE_OFFSET_MSB,
> + .lsb = ISL29501_PHASE_OFFSET_LSB,
> + },
> + [REG_TEMPERATURE_BIAS] = {
> + .lsb = ISL29501_TEMP_REFERENCE,
> + },
> + [REG_INT_TIME] = {
> + .lsb = ISL29501_INTEGRATION_PERIOD,
> + },
> + [REG_SAMPLE_TIME] = {
> + .lsb = ISL29501_SAMPLE_PERIOD,
> + },
> + [REG_DRIVER_RANGE] = {
> + .lsb = ISL29501_DRIVER_RANGE,
> + },
> + [REG_EMITTER_DAC] = {
> + .lsb = ISL29501_EMITTER_DAC,
> + },
> +};
> +
> +static int isl29501_register_read(struct isl29501_private *isl29501,
> + enum isl29501_register_name name,
> + u32 *val)
> +{
> + const struct isl29501_register_desc *reg = &isl29501_registers[name];
> + u8 msb = 0, lsb = 0, exp = 0;
> + s32 ret;
> +
> + mutex_lock(&isl29501->lock);
> + if (reg->msb) {
> + ret = i2c_smbus_read_byte_data(isl29501->client, reg->msb);
> + if (ret < 0)
> + goto err;
> + msb = ret;
> + }
> +
> + if (reg->lsb) {
> + ret = i2c_smbus_read_byte_data(isl29501->client, reg->lsb);
> + if (ret < 0)
> + goto err;
> + lsb = ret;
> + }
> +
> + if (reg->exp) {
> + ret = i2c_smbus_read_byte_data(isl29501->client, reg->exp);
> + if (ret < 0)
> + goto err;
> + exp = ret;
> + }
> + mutex_unlock(&isl29501->lock);
> +
> + *val = ((msb << 8) + lsb) << exp;
> +
> + return 0;
> +err:
> + mutex_unlock(&isl29501->lock);
> + return ret;
> +}
> +
> +static u32 isl29501_register_write(struct isl29501_private *isl29501,
> + enum isl29501_register_name name,
> + u32 value)
> +{
> + const struct isl29501_register_desc *reg = &isl29501_registers[name];
> + u8 msb, lsb;
> + int ret;
> +
> + if (!reg->msb && value > U8_MAX)
> + return -ERANGE;
> +
> + if (!reg->exp && value > U16_MAX)
> + return -ERANGE;
> +
> + if (reg->exp) {
> + /* TODO: Implement float write */
> + return -EINVAL;
> + }
> +
> + if (!reg->msb) {
> + lsb = value & 0xFF;
> + } else {
> + msb = (value >> 8) & 0xFF;
> + lsb = value & 0xFF;
> + }
> +
> + mutex_lock(&isl29501->lock);
> + if (reg->msb) {
> + ret = i2c_smbus_write_byte_data(isl29501->client,
> + reg->msb, msb);
> + if (ret < 0)
> + goto err;
> + }
> +
> + ret = i2c_smbus_write_byte_data(isl29501->client, reg->lsb, lsb);
> + if (ret < 0)
> + goto err;
> + mutex_unlock(&isl29501->lock);
> +
> + return 0;
> +err:
> + mutex_unlock(&isl29501->lock);
> + return ret;
ret = i2c_smbus_write_byte_data(...)
err:
mutex_unlock(&isl29501->lock);
return err;
}
> +}
> +
> +static ssize_t isl29501_read_ext(struct iio_dev *indio_dev,
> + uintptr_t private,
> + const struct iio_chan_spec *chan,
> + char *buf)
> +{
> + struct isl29501_private *isl29501 = iio_priv(indio_dev);
> + enum isl29501_register_name reg = private;
> + int ret;
> + u32 value, gain, coeff, exp;
> +
> + switch (reg) {
> + case REG_GAIN:
> + case REG_GAIN_BIAS:
> + ret = isl29501_register_read(isl29501, reg, &gain);
> + if (ret < 0)
> + return ret;
> +
> + value = gain;
> + break;
> + case REG_CALIB_PHASE_TEMP_A:
> + case REG_CALIB_PHASE_TEMP_B:
> + case REG_CALIB_PHASE_LIGHT_A:
> + case REG_CALIB_PHASE_LIGHT_B:
> + ret = isl29501_register_read(isl29501, REG_PHASE_EXP, &exp);
> + if (ret < 0)
> + return ret;
> +
> + ret = isl29501_register_read(isl29501, reg, &coeff);
> + if (ret < 0)
> + return ret;
> +
> + value = coeff << exp;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return sprintf(buf, "%u\n", value);
> +}
> +
> +static int isl29501_set_shadow_coeff(struct isl29501_private *isl29501,
> + enum isl29501_register_name reg,
> + unsigned int val)
> +{
> + enum isl29501_correction_coeff coeff;
> +
> + switch (reg) {
> + case REG_CALIB_PHASE_TEMP_A:
> + coeff = COEFF_TEMP_A;
> + break;
> + case REG_CALIB_PHASE_TEMP_B:
> + coeff = COEFF_TEMP_B;
> + break;
> + case REG_CALIB_PHASE_LIGHT_A:
> + coeff = COEFF_LIGHT_A;
> + break;
> + case REG_CALIB_PHASE_LIGHT_B:
> + coeff = COEFF_LIGHT_B;
> + break;
> + default:
> + return -EINVAL;
> + }
> + isl29501->shadow_coeffs[coeff] = val;
> +
> + return 0;
> +}
> +
> +static int isl29501_write_coeff(struct isl29501_private *isl29501,
> + enum isl29501_correction_coeff coeff,
> + int val)
> +{
> + enum isl29501_register_name reg;
> +
> + switch (coeff) {
> + case COEFF_TEMP_A:
> + reg = REG_CALIB_PHASE_TEMP_A;
> + break;
> + case COEFF_TEMP_B:
> + reg = REG_CALIB_PHASE_TEMP_B;
> + break;
> + case COEFF_LIGHT_A:
> + reg = REG_CALIB_PHASE_LIGHT_A;
> + break;
> + case COEFF_LIGHT_B:
> + reg = REG_CALIB_PHASE_LIGHT_B;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return isl29501_register_write(isl29501, reg, val);
> +}
> +
> +static unsigned int isl29501_find_corr_exp(unsigned int val,
> + unsigned int max_exp,
> + unsigned int max_mantissa)
> +{
> + unsigned int exp = 1;
> +
> + /*
> + * Correction coefficients are represented under
> + * mantissa * 2^exponent form, where mantissa and exponent
> + * are stored in two separate registers of the sensor.
> + *
> + * Compute and return the lowest exponent such as:
> + * mantissa = value / 2^exponent
> + *
> + * where mantissa < max_mantissa.
> + */
> + if (val <= max_mantissa)
> + return 0;
> +
> + while ((val >> exp) > max_mantissa) {
> + exp++;
> +
> + if (exp > max_exp)
> + return max_exp;
> + }
> +
> + return exp;
> +}
> +
> +static ssize_t isl29501_write_ext(struct iio_dev *indio_dev,
> + uintptr_t private,
> + const struct iio_chan_spec *chan,
> + const char *buf, size_t len)
> +{
> + struct isl29501_private *isl29501 = iio_priv(indio_dev);
> + enum isl29501_register_name reg = private;
> + unsigned int val;
> + int max_exp = 0;
> + int ret;
> + int i;
> +
> + ret = kstrtouint(buf, 10, &val);
> + if (ret)
> + return ret;
> +
> + switch (reg) {
> + case REG_GAIN_BIAS:
> + if (val > U16_MAX)
> + return -ERANGE;
> +
> + ret = isl29501_register_write(isl29501, reg, val);
> + if (ret < 0)
> + return ret;
> +
> + break;
> + case REG_CALIB_PHASE_TEMP_A:
> + case REG_CALIB_PHASE_TEMP_B:
> + case REG_CALIB_PHASE_LIGHT_A:
> + case REG_CALIB_PHASE_LIGHT_B:
> +
> + if (val > (U8_MAX << ISL29501_MAX_EXP_VAL))
> + return -ERANGE;
> +
> + /* Store the correction coefficient under its exact form. */
> + ret = isl29501_set_shadow_coeff(isl29501, reg, val);
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * Find the highest exponent needed to represent
> + * correction coefficients.
> + */
> + for (i = 0; i < COEFF_MAX; i++) {
> + int corr;
> + int corr_exp;
> +
> + corr = isl29501->shadow_coeffs[i];
> + corr_exp = isl29501_find_corr_exp(corr,
> + ISL29501_MAX_EXP_VAL,
> + U8_MAX / 2);
> + dev_dbg(&isl29501->client->dev,
> + "found exp of corr(%d) = %d\n", corr, corr_exp);
> +
> + max_exp = max(max_exp, corr_exp);
> + }
> +
> + /*
> + * Represent every correction coefficient under
> + * mantissa * 2^max_exponent form and force the
> + * writing of those coefficients on the sensor.
> + */
> + for (i = 0; i < COEFF_MAX; i++) {
> + int corr;
> + int mantissa;
> +
> + corr = isl29501->shadow_coeffs[i];
> + if (!corr)
> + continue;
> +
> + mantissa = corr >> max_exp;
> +
> + ret = isl29501_write_coeff(isl29501, i, mantissa);
> + if (ret < 0)
> + return ret;
> + }
> +
> + ret = isl29501_register_write(isl29501, REG_PHASE_EXP, max_exp);
> + if (ret < 0)
> + return ret;
> +
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return len;
> +}
> +
> +#define _ISL29501_EXT_INFO(_name, _ident) { \
> + .name = _name, \
> + .read = isl29501_read_ext, \
> + .write = isl29501_write_ext, \
> + .private = _ident, \
> + .shared = IIO_SEPARATE, \
> +}
> +
> +static const struct iio_chan_spec_ext_info isl29501_ext_info[] = {
> + _ISL29501_EXT_INFO("agc_gain", REG_GAIN),
> + _ISL29501_EXT_INFO("agc_gain_bias", REG_GAIN_BIAS),
> + _ISL29501_EXT_INFO("calib_phase_temp_a", REG_CALIB_PHASE_TEMP_A),
> + _ISL29501_EXT_INFO("calib_phase_temp_b", REG_CALIB_PHASE_TEMP_B),
> + _ISL29501_EXT_INFO("calib_phase_light_a", REG_CALIB_PHASE_LIGHT_A),
> + _ISL29501_EXT_INFO("calib_phase_light_b", REG_CALIB_PHASE_LIGHT_B),
> + { },
> +};
> +
> +#define ISL29501_DISTANCE_SCAN_INDEX 0
> +#define ISL29501_TIMESTAMP_SCAN_INDEX 1
> +
> +#define ISL29501_MAGNITUDE_CHANNEL 0
> +#define ISL29501_AMBIENT_LIGHT_CHANNEL 1
> +
> +static const struct iio_chan_spec isl29501_channels[] = {
> + {
> + .type = IIO_PROXIMITY,
> + .scan_index = ISL29501_DISTANCE_SCAN_INDEX,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) |
> + BIT(IIO_CHAN_INFO_CALIBBIAS),
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 16,
> + .storagebits = 16,
> + .endianness = IIO_CPU,
> + },
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) |
> + BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .ext_info = isl29501_ext_info,
> + },
> + {
> + .type = IIO_PHASE,
> + .scan_index = -1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + },
> + {
> + .type = IIO_INTENSITY,
> + .channel = ISL29501_MAGNITUDE_CHANNEL,
> + .extend_name = "magnitude",
Of what? As with the one below, we need to figure out how userspace
might use this. Honestly I suspect in this case it won't try to
so we may be fine with this even though I don't like it.
It's a bit like the hardwaregain which we added to allow tweaking
of 'related' signals like this one, but we don't have an equivalent
to get the value. hardwareamp would be to confusing.
> + .scan_index = -1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBBIAS),
> + },
> + {
> + .type = IIO_INTENSITY,
> + .channel = ISL29501_MAGNITUDE_CHANNEL,
> + .scan_index = -1,
> + .modified = 1,
> + .channel2 = IIO_MOD_I,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBBIAS),
> + },
> + {
> + .type = IIO_INTENSITY,
> + .channel = ISL29501_MAGNITUDE_CHANNEL,
> + .scan_index = -1,
> + .modified = 1,
> + .channel2 = IIO_MOD_Q,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBBIAS),
> + },
> + {
> + .type = IIO_CURRENT,
> + .scan_index = -1,
> + .output = 1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + },
> + {
> + .type = IIO_TEMP,
> + .scan_index = -1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) |
> + BIT(IIO_CHAN_INFO_CALIBBIAS),
> + },
> + {
> + .type = IIO_INTENSITY,
> + .channel = ISL29501_AMBIENT_LIGHT_CHANNEL,
> + .extend_name = "ambient_light",
Hmm. The issue is that extend_name creates abi that userspace
tools will have no idea how to do anything with this.
If this is actually ambient light and hence measured in lux
this should simply be an IIO_LIGHT channel. It seems from
a quick glance that it is very poorly defined as there is no
intent that it should be used for anything other than
rejection from the distance measurements.
So I would use the modifier IIO_MOD_LIGHT_CLEAR as I think that
is the nearest we have given we don't know if it measures IR or
not. That can be applied to an intensity channel to give you
an ABI compliant value.
> + .scan_index = -1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(ISL29501_TIMESTAMP_SCAN_INDEX),
> +};
> +
> +static int isl29501_reset_registers(struct isl29501_private *isl29501)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(isl29501->client,
> + ISL29501_COMMAND_REGISTER,
> + ISL29501_RESET_ALL_REGISTERS);
Check error on this one..
> + ret = i2c_smbus_write_byte_data(isl29501->client,
> + ISL29501_COMMAND_REGISTER,
> + ISL29501_RESET_INT_SM);
> + if (ret < 0) {
> + dev_err(&isl29501->client->dev,
> + "cannot reset registers %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int isl29501_begin_acquisition(struct isl29501_private *isl29501)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(isl29501->client,
> + ISL29501_COMMAND_REGISTER,
> + ISL29501_EMUL_SAMPLE_START_PIN);
> + if (ret < 0) {
> + dev_err(&isl29501->client->dev,
> + "cannot begin acquisition %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static IIO_CONST_ATTR_INT_TIME_AVAIL(ISL29501_INT_TIME_AVAILABLE);
> +static IIO_CONST_ATTR(out_current_scale_available,
> + ISL29501_CURRENT_SCALE_AVAILABLE);
> +
> +static struct attribute *isl29501_attributes[] = {
> + &iio_const_attr_integration_time_available.dev_attr.attr,
> + &iio_const_attr_out_current_scale_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group isl29501_attribute_group = {
> + .attrs = isl29501_attributes,
> +};
> +
> +static const int isl29501_current_scale_table[][2] = {
> + {0, 3900}, {0, 7800}, {0, 11800}, {0, 15700},
> + {0, 19600}, {0, 23500}, {0, 27500}, {0, 31400},
> + {0, 35200}, {0, 39200}, {0, 43100}, {0, 47100},
> + {0, 51000}, {0, 54900}, {0, 58800},
> +};
> +
> +static const int isl29501_int_time[][2] = {
> + {0, 70}, /* 0.07 ms */
> + {0, 140}, /* 0.14 ms */
> + {0, 280}, /* 0.28 ms */
> + {0, 570}, /* 0.57 ms */
> + {0, 1140}, /* 1.14 ms */
> + {0, 2280}, /* 2.28 ms */
> + {0, 4550}, /* 4.55 ms */
> + {0, 9100}, /* 9.11 ms */
> + {0, 18200}, /* 18.2 ms */
> + {0, 36400}, /* 36.4 ms */
> + {0, 72810}, /* 72.81 ms */
> + {0, 145610} /* 145.28 ms */
> +};
> +
> +static int isl29501_get_raw(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int *raw)
> +{
> + int ret;
> +
> + switch (chan->type) {
> + case IIO_PROXIMITY:
> + ret = isl29501_register_read(isl29501, REG_DISTANCE, raw);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_INTENSITY:
> + if (chan->channel == ISL29501_MAGNITUDE_CHANNEL) {
> + switch (chan->channel2) {
> + case IIO_NO_MOD:
> + case IIO_MOD_I:
> + case IIO_MOD_Q:
> + /* TODO: implement float read */
> + return -EINVAL;
> + default:
> + return -EINVAL;
> + }
> + } else if (chan->channel == ISL29501_AMBIENT_LIGHT_CHANNEL) {
> + ret = isl29501_register_read(isl29501,
> + REG_AMBIENT_LIGHT,
> + raw);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + } else {
> + return IIO_VAL_INT;
> + }
> + case IIO_PHASE:
> + ret = isl29501_register_read(isl29501, REG_PHASE, raw);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CURRENT:
> + ret = isl29501_register_read(isl29501, REG_EMITTER_DAC, raw);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_TEMP:
> + ret = isl29501_register_read(isl29501, REG_TEMPERATURE, raw);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_get_scale(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int *val, int *val2)
> +{
> + int ret;
> + u32 current_scale;
> +
> + switch (chan->type) {
> + case IIO_PROXIMITY:
> + /* distance = raw_distance * 33.31 / 65536 (m) */
> + *val = 3331;
> + *val2 = 6553600;
> +
> + return IIO_VAL_FRACTIONAL;
> + case IIO_PHASE:
> + /* phase = raw_phase * 2pi / 65536 (rad) */
> + *val = 0;
> + *val2 = 95874;
> +
> + return IIO_VAL_INT_PLUS_NANO;
> + case IIO_INTENSITY:
> + if (chan->channel != ISL29501_AMBIENT_LIGHT_CHANNEL)
> + return -EINVAL;
> + /* light = raw_light * 35 / 10000 (mA) */
> + *val = 35;
> + *val2 = 10000;
> +
> + return IIO_VAL_FRACTIONAL;
> + case IIO_CURRENT:
> + ret = isl29501_register_read(isl29501,
> + REG_DRIVER_RANGE,
> + ¤t_scale);
> + if (ret < 0)
> + return ret;
> +
> + if (current_scale > ARRAY_SIZE(isl29501_current_scale_table))
> + return -EINVAL;
> +
> + if (!current_scale) {
> + *val = 0;
> + *val2 = 0;
> + return IIO_VAL_INT;
> + }
> +
> + *val = isl29501_current_scale_table[current_scale - 1][0];
> + *val2 = isl29501_current_scale_table[current_scale - 1][1];
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> + case IIO_TEMP:
> + /* temperature = raw_temperature * 125 / 100000 (milli °C) */
> + *val = 125;
> + *val2 = 100000;
> +
> + return IIO_VAL_FRACTIONAL;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_get_calibbias(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int *bias)
> +{
> + switch (chan->type) {
> + case IIO_PROXIMITY:
> + return isl29501_register_read(isl29501,
> + REG_DISTANCE_BIAS,
> + bias);
> + case IIO_INTENSITY:
> + if (chan->channel != ISL29501_MAGNITUDE_CHANNEL)
> + return -EINVAL;
> +
> + switch (chan->channel2) {
> + case IIO_NO_MOD:
> + case IIO_MOD_I:
> + case IIO_MOD_Q:
> + /* TODO: Implement float read */
> + return -EINVAL;
> + default:
> + return -EINVAL;
> + }
> + case IIO_TEMP:
> + return isl29501_register_read(isl29501,
> + REG_TEMPERATURE_BIAS,
> + bias);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_get_inttime(struct isl29501_private *isl29501,
> + int *val, int *val2)
> +{
> + int ret;
> + u32 inttime;
> +
> + ret = isl29501_register_read(isl29501, REG_INT_TIME, &inttime);
> + if (ret < 0)
> + return ret;
> +
> + if (inttime >= ARRAY_SIZE(isl29501_int_time))
> + return -EINVAL;
> +
> + *val = isl29501_int_time[inttime][0];
> + *val2 = isl29501_int_time[inttime][1];
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int isl29501_get_freq(struct isl29501_private *isl29501,
> + int *val, int *val2)
> +{
> + int ret;
> + int sample_time;
> + unsigned long long freq;
> +
> + ret = isl29501_register_read(isl29501, REG_SAMPLE_TIME, &sample_time);
> + if (ret < 0)
> + return ret;
> +
> + /* freq = 1 / (0.000450 * (sample_time + 1) * 10^-6) */
> + freq = 1000000ULL * 1000000ULL / (450ULL * (sample_time + 1ULL));
> +
> + *val = freq / 1000000;
> + *val2 = freq % 1000000;
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int isl29501_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + struct isl29501_private *isl29501 = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + return isl29501_get_raw(isl29501, chan, val);
> + case IIO_CHAN_INFO_SCALE:
> + return isl29501_get_scale(isl29501, chan, val, val2);
> + case IIO_CHAN_INFO_INT_TIME:
> + return isl29501_get_inttime(isl29501, val, val2);
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + return isl29501_get_freq(isl29501, val, val2);
> + case IIO_CHAN_INFO_CALIBBIAS:
> + return isl29501_get_calibbias(isl29501, chan, val);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_set_raw(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int raw)
> +{
> + switch (chan->type) {
> + case IIO_CURRENT:
> + return isl29501_register_write(isl29501, REG_EMITTER_DAC, raw);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_set_inttime(struct isl29501_private *isl29501,
> + int val, int val2)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(isl29501_int_time); i++) {
> + if (isl29501_int_time[i][0] == val &&
> + isl29501_int_time[i][1] == val2) {
> + return isl29501_register_write(isl29501,
> + REG_INT_TIME,
> + i);
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int isl29501_set_scale(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int val, int val2)
> +{
> + int i;
> +
> + if (chan->type != IIO_CURRENT)
> + return -EINVAL;
> +
> + for (i = 0; i < ARRAY_SIZE(isl29501_current_scale_table); i++) {
> + if (isl29501_current_scale_table[i][0] == val &&
> + isl29501_current_scale_table[i][1] == val2) {
> + return isl29501_register_write(isl29501,
> + REG_DRIVER_RANGE,
> + i + 1);
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int isl29501_set_calibbias(struct isl29501_private *isl29501,
> + const struct iio_chan_spec *chan,
> + int bias)
> +{
> + switch (chan->type) {
> + case IIO_PROXIMITY:
> + return isl29501_register_write(isl29501,
> + REG_DISTANCE_BIAS,
> + bias);
> + case IIO_INTENSITY:
> + if (chan->channel != ISL29501_MAGNITUDE_CHANNEL)
> + return -EINVAL;
> +
> + switch (chan->channel2) {
> + case IIO_NO_MOD:
> + case IIO_MOD_I:
> + case IIO_MOD_Q:
> + /* TODO: Implement float read */
> + return -EINVAL;
> + default:
> + return -EINVAL;
> + }
> + case IIO_TEMP:
> + return isl29501_register_write(isl29501,
> + REG_TEMPERATURE_BIAS,
> + bias);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int isl29501_set_freq(struct isl29501_private *isl29501,
> + int val, int val2)
> +{
> + int freq;
> + unsigned long long sample_time;
> +
> + /* sample_freq = 1 / (0.000450 * (sample_time + 1) * 10^-6) */
> + freq = val * 1000000 + val2 % 1000000;
> + sample_time = (2222ULL * 1000000ULL / freq) - 1ULL;
> +
> + if (sample_time > 255)
> + return -ERANGE;
> +
> + return isl29501_register_write(isl29501, REG_SAMPLE_TIME, sample_time);
> +}
> +
> +static int isl29501_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct isl29501_private *isl29501 = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + return isl29501_set_raw(isl29501, chan, val);
> + case IIO_CHAN_INFO_INT_TIME:
> + return isl29501_set_inttime(isl29501, val, val2);
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + return isl29501_set_freq(isl29501, val, val2);
> + case IIO_CHAN_INFO_SCALE:
> + return isl29501_set_scale(isl29501, chan, val, val2);
> + case IIO_CHAN_INFO_CALIBBIAS:
> + return isl29501_set_calibbias(isl29501, chan, val);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct iio_info isl29501_info = {
> + .read_raw = &isl29501_read_raw,
> + .write_raw = &isl29501_write_raw,
> + .attrs = &isl29501_attribute_group,
> +};
> +
> +static int isl29501_init_chip(struct isl29501_private *isl29501)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(isl29501->client, ISL29501_DEVICE_ID);
> + if (ret < 0) {
> + dev_err(&isl29501->client->dev, "Error reading device id\n");
> + return ret;
> + }
> +
> + if (ret != ISL29501_ID) {
> + dev_err(&isl29501->client->dev,
> + "Wrong chip id, got %x expected %x\n",
> + ret, ISL29501_DEVICE_ID);
> + return -ENODEV;
> + }
> +
> + ret = isl29501_reset_registers(isl29501);
> + if (ret < 0)
> + return ret;
> +
> + return isl29501_begin_acquisition(isl29501);
> +}
> +
> +static irqreturn_t isl29501_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct isl29501_private *isl29501 = iio_priv(indio_dev);
> + const unsigned long *active_mask = indio_dev->active_scan_mask;
> + u32 buffer[4]; /* 1x16-bit + ts */
Just notice this is not zeroed and we only write to some of it.
Hence there is potential information leakage here. Please just
set it to 0 to be safe.
u32 buffer[4] = {}; will do that.
> +
> + if (test_bit(ISL29501_DISTANCE_SCAN_INDEX, active_mask))
> + isl29501_register_read(isl29501, REG_DISTANCE, buffer);
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int isl29501_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct iio_dev *indio_dev;
> + struct isl29501_private *isl29501;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*isl29501));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + isl29501 = iio_priv(indio_dev);
> +
> + i2c_set_clientdata(client, indio_dev);
> + isl29501->client = client;
> +
> + mutex_init(&isl29501->lock);
> +
> + ret = isl29501_init_chip(isl29501);
> + if (ret < 0)
> + return ret;
> +
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->channels = isl29501_channels;
> + indio_dev->num_channels = ARRAY_SIZE(isl29501_channels);
> + indio_dev->name = client->name;
> + indio_dev->info = &isl29501_info;
> +
> + ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
> + iio_pollfunc_store_time,
> + isl29501_trigger_handler,
> + NULL);
> + if (ret < 0) {
> + dev_err(&client->dev, "unable to setup iio triggered buffer\n");
> + return ret;
> + }
> + return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static const struct i2c_device_id isl29501_id[] = {
> + {"isl29501", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, isl29501_id);
> +
> +#if defined(CONFIG_OF)
> +static const struct of_device_id isl29501_i2c_matches[] = {
> + { .compatible = "renesas,isl29501" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, isl29501_i2c_matches);
> +#endif
> +
> +static struct i2c_driver isl29501_driver = {
> + .driver = {
> + .name = "isl29501",
> + },
> + .id_table = isl29501_id,
> + .probe = isl29501_probe,
> +};
> +module_i2c_driver(isl29501_driver);
> +
> +MODULE_AUTHOR("Mathieu Othacehe <m.othacehe@xxxxxxxxx>");
> +MODULE_DESCRIPTION("ISL29501 Time of Flight sensor driver");
> +MODULE_LICENSE("GPL v2");
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