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charset="utf-8" The AD4170 design has features to aid interfacing with weigh scale and RTD sensors that are expected to be setup with external circuitry for proper sensor operation. A key characteristic of those sensors is that the circuit they are in must be excited with a pair of signals. The external circuit can be excited either by voltage supply or by AD4170 excitation signals. The sensor can then be read through a different pair of lines that are connected to AD4170 ADC. Configure AD4170 to handle external circuit sensors. Signed-off-by: Marcelo Schmitt --- No changes in v6. drivers/iio/adc/ad4170.c | 494 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 490 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c index 3ee66ac651f1..2a2d4a05e9af 100644 --- a/drivers/iio/adc/ad4170.c +++ b/drivers/iio/adc/ad4170.c @@ -67,6 +67,8 @@ #define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x)) #define AD4170_OFFSET_REG(x) (0xCA + 14 * (x)) #define AD4170_GAIN_REG(x) (0xCD + 14 * (x)) +#define AD4170_V_BIAS_REG 0x135 +#define AD4170_CURRENT_SRC_REG(x) (0x139 + 2 * (x)) #define AD4170_GPIO_MODE_REG 0x191 #define AD4170_GPIO_OUTPUT_REG 0x193 #define AD4170_GPIO_INPUT_REG 0x195 @@ -98,6 +100,10 @@ #define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8) #define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0) =20 +/* AD4170_MISC_REG */ +#define AD4170_MISC_CHOP_IEXC_MSK GENMASK(15, 14) +#define AD4170_MISC_CHOP_ADC_MSK GENMASK(9, 8) + /* AD4170_AFE_REG */ #define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10) #define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8) @@ -108,12 +114,19 @@ /* AD4170_FILTER_REG */ #define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0) =20 +/* AD4170_CURRENT_SRC_REG */ +#define AD4170_CURRENT_SRC_I_OUT_PIN_MSK GENMASK(12, 8) +#define AD4170_CURRENT_SRC_I_OUT_VAL_MSK GENMASK(2, 0) + /* AD4170_GPIO_MODE_REG */ #define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0) #define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2) #define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4) #define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6) =20 +/* AD4170_GPIO_OUTPUT_REG */ +#define AD4170_GPIO_OUTPUT_GPIO_MSK(x) BIT(x) + /* AD4170 register constants */ =20 /* AD4170_CLOCK_CTRL_REG constants */ @@ -137,6 +150,11 @@ #define AD4170_CHAN_MAP_REFIN2_N 28 #define AD4170_CHAN_MAP_REFOUT 29 =20 +/* AD4170_MISC_REG constants */ +#define AD4170_MISC_CHOP_IEXC_PAIR1 0x1 +#define AD4170_MISC_CHOP_IEXC_PAIR2 0x2 +#define AD4170_MISC_CHOP_IEXC_BOTH 0x3 + /* AD4170_PIN_MUXING_REG constants */ #define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0 #define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1 @@ -154,6 +172,10 @@ #define AD4170_FILTER_FILTER_TYPE_SINC5 0x4 #define AD4170_FILTER_FILTER_TYPE_SINC3 0x6 =20 +/* AD4170_CURRENT_SRC_REG constants */ +#define AD4170_CURRENT_SRC_I_OUT_PIN_AIN(x) (x) +#define AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(x) ((x) + 17) + /* AD4170_GPIO_MODE_REG constants */ #define AD4170_GPIO_MODE_GPIO_INPUT 1 #define AD4170_GPIO_MODE_GPIO_OUTPUT 2 @@ -168,6 +190,7 @@ #define AD4170_INVALID_SETUP 9 #define AD4170_SPI_INST_PHASE_LEN 2 #define AD4170_SPI_MAX_XFER_LEN 6 +#define AD4170_NUM_CURRENT_SRC 4 #define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ) =20 #define AD4170_INT_REF_2_5V 2500000 @@ -189,8 +212,19 @@ =20 #define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5 =20 +/* Analog pin functions */ +#define AD4170_PIN_UNASSIGNED 0x00 +#define AD4170_PIN_ANALOG_IN 0x01 +#define AD4170_PIN_CURRENT_OUT 0x02 +#define AD4170_PIN_VBIAS 0x04 + /* GPIO pin functions */ #define AD4170_GPIO_UNASSIGNED 0x00 +#define AD4170_GPIO_AC_EXCITATION 0x02 +#define AD4170_GPIO_OUTPUT 0x04 + +/* Current source */ +#define AD4170_CURRENT_SRC_DISABLED 0xFF =20 static const unsigned int ad4170_reg_size[] =3D { [AD4170_CONFIG_A_REG] =3D 1, @@ -229,6 +263,8 @@ static const unsigned int ad4170_reg_size[] =3D { [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] =3D 3, [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] =3D 3, [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] =3D 3, + [AD4170_V_BIAS_REG] =3D 2, + [AD4170_CURRENT_SRC_REG(0) ... AD4170_CURRENT_SRC_REG(3)] =3D 2, [AD4170_GPIO_MODE_REG] =3D 2, [AD4170_GPIO_OUTPUT_REG] =3D 2, [AD4170_GPIO_INPUT_REG] =3D 2, @@ -298,6 +334,41 @@ static const unsigned int ad4170_sinc5_filt_fs_tbl[] = =3D { 1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256, }; =20 +static const unsigned int ad4170_iout_pin_tbl[] =3D { + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(1), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(2), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(3), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(4), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(5), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(6), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(7), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(8), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(1), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(2), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(3), +}; + +static const unsigned int ad4170_iout_current_ua_tbl[] =3D { + 0, 10, 50, 100, 250, 500, 1000, 1500, +}; + +enum ad4170_sensor_enum { + AD4170_ADC_SENSOR =3D 0, + AD4170_WEIGH_SCALE_SENSOR =3D 1, + AD4170_RTD_SENSOR =3D 2, + AD4170_THERMOCOUPLE_SENSOR =3D 3, +}; + +/* maps adi,sensor-type property value to enum */ +static const char * const ad4170_sensor_type[] =3D { + [AD4170_ADC_SENSOR] =3D "adc", + [AD4170_WEIGH_SCALE_SENSOR] =3D "weighscale", + [AD4170_RTD_SENSOR] =3D "rtd", + [AD4170_THERMOCOUPLE_SENSOR] =3D "thermocouple", +}; + struct ad4170_chip_info { const char *name; }; @@ -382,6 +453,7 @@ struct ad4170_state { struct gpio_chip gpiochip; unsigned int clock_ctrl; int gpio_fn[AD4170_NUM_GPIO_PINS]; + unsigned int cur_src_pins[AD4170_NUM_CURRENT_SRC]; /* * DMA (thus cache coherency maintenance) requires the transfer buffers * to live in their own cache lines. @@ -910,6 +982,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_sta= te *st, int ain_n, int v_diff; =20 *ain_voltage =3D 0; + /* + * The voltage bias (vbias) sets the common-mode voltage of the channel + * to (AVDD + AVSS)/2. If provided, AVSS supply provides the magnitude + * (absolute value) of the negative voltage supplied to the AVSS pin. + * So, we do AVDD - AVSS to compute the DC voltage generated by the bias + * voltage generator. + */ + if (st->pins_fn[ain_n] & AD4170_PIN_VBIAS) { + int v_diff =3D st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_= SUP]; + *ain_voltage =3D v_diff / 2; + return 0; + } + if (ain_n <=3D AD4170_CHAN_MAP_TEMP_SENSOR) return 0; =20 @@ -964,6 +1049,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_st= ate *st, int ain_n, } } =20 +static int ad4170_validate_analog_input(struct ad4170_state *st, int pin) +{ + if (pin <=3D AD4170_MAX_ANALOG_PINS) { + if (st->pins_fn[pin] & AD4170_PIN_CURRENT_OUT) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Pin %d already used with fn %u.\n", + pin, st->pins_fn[pin]); + + st->pins_fn[pin] |=3D AD4170_PIN_ANALOG_IN; + } + return 0; +} + static int ad4170_validate_channel_input(struct ad4170_state *st, int pin,= bool com) { /* Check common-mode input pin is mapped to a special input. */ @@ -978,7 +1076,7 @@ static int ad4170_validate_channel_input(struct ad4170= _state *st, int pin, bool "Invalid analog input pin number. %d\n", pin); =20 - return 0; + return ad4170_validate_analog_input(st, pin); } =20 /* @@ -1718,6 +1816,371 @@ static int ad4170_gpio_init(struct iio_dev *indio_d= ev) return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev); } =20 +static int ad4170_validate_excitation_pin(struct ad4170_state *st, u32 pin) +{ + struct device *dev =3D &st->spi->dev; + unsigned int i; + + /* Check the pin number is valid */ + for (i =3D 0; i < ARRAY_SIZE(ad4170_iout_pin_tbl); i++) + if (ad4170_iout_pin_tbl[i] =3D=3D pin) + break; + + if (i =3D=3D ARRAY_SIZE(ad4170_iout_pin_tbl)) + return dev_err_probe(dev, -EINVAL, + "Invalid excitation pin: %u\n", + pin); + + /* Check the pin is available */ + if (pin <=3D AD4170_MAX_ANALOG_PINS) { + if (st->pins_fn[pin] !=3D AD4170_PIN_UNASSIGNED) + return dev_err_probe(dev, -EINVAL, + "Pin %u already used with fn %u\n", + pin, st->pins_fn[pin]); + + st->pins_fn[pin] |=3D AD4170_PIN_CURRENT_OUT; + } else { + unsigned int gpio =3D pin - AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0); + + if (st->gpio_fn[gpio] !=3D AD4170_GPIO_UNASSIGNED) + return dev_err_probe(dev, -EINVAL, + "GPIO %u already used with fn %u\n", + gpio, st->gpio_fn[gpio]); + + st->gpio_fn[gpio] |=3D AD4170_GPIO_AC_EXCITATION; + } + + return 0; +} + +static int ad4170_validate_excitation_pins(struct ad4170_state *st, + u32 *exc_pins, int num_exc_pins) +{ + unsigned int i; + int ret; + + for (i =3D 0; i < num_exc_pins; i++) { + ret =3D ad4170_validate_excitation_pin(st, exc_pins[i]); + if (ret) + return ret; + } + return 0; +} + +static const char *const ad4170_i_out_pin_dt_props[] =3D { + "adi,excitation-pin-0", + "adi,excitation-pin-1", + "adi,excitation-pin-2", + "adi,excitation-pin-3", +}; + +static const char *const ad4170_i_out_val_dt_props[] =3D { + "adi,excitation-current-0-microamp", + "adi,excitation-current-1-microamp", + "adi,excitation-current-2-microamp", + "adi,excitation-current-3-microamp", +}; + +/* + * Parses firmware data describing output current source setup. There are 4 + * excitation currents (IOUT0 to IOUT3) that can be configured independent= ly. + * Excitation currents are added if they are output on the same pin. + */ +static int ad4170_parse_exc_current(struct ad4170_state *st, + struct fwnode_handle *child, + unsigned int *exc_pins, + unsigned int *exc_curs, + unsigned int *num_exc_pins) +{ + struct device *dev =3D &st->spi->dev; + unsigned int num_pins, i, j; + u32 pin, val; + int ret; + + num_pins =3D 0; + for (i =3D 0; i < AD4170_NUM_CURRENT_SRC; i++) { + /* Parse excitation current output pin properties. */ + pin =3D AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0); + ret =3D fwnode_property_read_u32(child, ad4170_i_out_pin_dt_props[i], + &pin); + if (ret) + continue; + + exc_pins[num_pins] =3D pin; + + /* Parse excitation current value properties. */ + val =3D ad4170_iout_current_ua_tbl[0]; + fwnode_property_read_u32(child, + ad4170_i_out_val_dt_props[i], &val); + + for (j =3D 0; j < ARRAY_SIZE(ad4170_iout_current_ua_tbl); j++) + if (ad4170_iout_current_ua_tbl[j] =3D=3D val) + break; + + if (j =3D=3D ARRAY_SIZE(ad4170_iout_current_ua_tbl)) + return dev_err_probe(dev, -EINVAL, "Invalid %s: %uuA\n", + ad4170_i_out_val_dt_props[i], val); + + exc_curs[num_pins] =3D j; + num_pins++; + } + *num_exc_pins =3D num_pins; + + return 0; +} + +static int ad4170_setup_current_src(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, + bool ac_excited) +{ + unsigned int exc_cur_pair, i, j; + int ret; + + for (i =3D 0; i < num_exc_pins; i++) { + unsigned int exc_cur =3D exc_curs[i]; + unsigned int pin =3D exc_pins[i]; + unsigned int current_src =3D 0; + + for (j =3D 0; j < AD4170_NUM_CURRENT_SRC; j++) + if (st->cur_src_pins[j] =3D=3D AD4170_CURRENT_SRC_DISABLED) + break; + + if (j =3D=3D AD4170_NUM_CURRENT_SRC) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Too many excitation current sources\n"); + + current_src |=3D FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_PIN_MSK, pin); + current_src |=3D FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_VAL_MSK, exc_cur); + st->cur_src_pins[j] =3D pin; + ret =3D regmap_write(st->regmap, AD4170_CURRENT_SRC_REG(j), + current_src); + if (ret) + return ret; + } + + if (!ac_excited) + return 0; + + if (num_exc_pins < 2) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Current chopping requested but only one pin provided: %u\n", + exc_pins[0]); + + /* + * Two use cases to handle here: + * - 2 pairs of excitation currents; + * - 1 pair of excitation currents. + */ + if (num_exc_pins =3D=3D 4) { + for (i =3D 0; i < AD4170_NUM_CURRENT_SRC; i++) + if (st->cur_src_pins[i] !=3D exc_pins[i]) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Unable to use 4 exc pins\n"); + } else { + /* + * Excitation current chopping is configured in pairs. Current + * sources IOUT0 and IOUT1 form pair 1, IOUT2 and IOUT3 make up + * pair 2. So, if current chopping was requested, check if the + * first end of the first pair of excitation currents is + * available. Try the next pair if IOUT0 has already been + * configured for another channel. + */ + i =3D st->cur_src_pins[0] =3D=3D exc_pins[0] ? 0 : 2; + + if (st->cur_src_pins[i] !=3D exc_pins[0] || + st->cur_src_pins[i + 1] !=3D exc_pins[1]) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Failed to setup current chopping\n"); + + st->cur_src_pins[i] =3D exc_pins[0]; + st->cur_src_pins[i + 1] =3D exc_pins[1]; + + if (i =3D=3D 0) + exc_cur_pair =3D AD4170_MISC_CHOP_IEXC_PAIR1; + else + exc_cur_pair =3D AD4170_MISC_CHOP_IEXC_PAIR2; + } + + /* + * Configure excitation current chopping. + * Chop both pairs if using four excitation pins. + */ + setup->misc |=3D FIELD_PREP(AD4170_MISC_CHOP_IEXC_MSK, + num_exc_pins =3D=3D 2 ? + exc_cur_pair : + AD4170_MISC_CHOP_IEXC_BOTH); + + return 0; +} + +static int ad4170_setup_bridge(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, + bool ac_excited) +{ + unsigned long gpio_mask; + unsigned int i; + int ret; + + /* + * If a specific current is provided through + * adi,excitation-current-n-microamp, set excitation pins provided + * through adi,excitation-pin-n to excite the bridge circuit. + */ + for (i =3D 0; i < num_exc_pins; i++) + if (exc_curs[i] > 0) + return ad4170_setup_current_src(st, child, setup, exc_pins, + exc_curs, num_exc_pins, + ac_excited); + + /* + * Else, use predefined ACX1, ACX1 negated, ACX2, ACX2 negated signals + * to AC excite the bridge. Those signals are output on GPIO2, GPIO0, + * GPIO3, and GPIO1, respectively. If only two pins are specified for AC + * excitation, use ACX1 and ACX2 (GPIO2 and GPIO3). + * + * Also, to avoid any short-circuit condition when more than one channel + * is enabled, set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to + * DC excite the bridge whenever a channel without AC excitation is + * selected. That is needed because GPIO pins are controlled by the next + * highest priority GPIO function when a channel doesn't enable AC + * excitation. See datasheet Figure 113 Weigh Scale (AC Excitation) for + * the reference circuit diagram. + */ + if (num_exc_pins =3D=3D 2) { + setup->misc |=3D FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x3); + + gpio_mask =3D AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK; + ret =3D regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT)); + if (ret) + return ret; + + /* + * Set GPIO2 high and GPIO3 low to DC excite the bridge when + * a different channel is selected. + */ + gpio_mask =3D AD4170_GPIO_OUTPUT_GPIO_MSK(3) | + AD4170_GPIO_OUTPUT_GPIO_MSK(2); + ret =3D regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1)); + if (ret) + return ret; + + st->gpio_fn[3] |=3D AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |=3D AD4170_GPIO_OUTPUT; + } else { + setup->misc |=3D FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x2); + + gpio_mask =3D AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK | + AD4170_GPIO_MODE_GPIO1_MSK | AD4170_GPIO_MODE_GPIO0_MSK; + ret =3D regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO1_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO0_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT)); + if (ret) + return ret; + + /* + * Set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to DC + * excite the bridge when a different channel is selected. + */ + gpio_mask =3D AD4170_GPIO_OUTPUT_GPIO_MSK(3) | + AD4170_GPIO_OUTPUT_GPIO_MSK(2) | + AD4170_GPIO_OUTPUT_GPIO_MSK(1) | + AD4170_GPIO_OUTPUT_GPIO_MSK(0); + ret =3D regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(1), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(0), 1)); + if (ret) + return ret; + + st->gpio_fn[3] |=3D AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |=3D AD4170_GPIO_OUTPUT; + st->gpio_fn[1] |=3D AD4170_GPIO_OUTPUT; + st->gpio_fn[0] |=3D AD4170_GPIO_OUTPUT; + } + + return 0; +} + +static int ad4170_setup_rtd(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, bool ac_excited) +{ + return ad4170_setup_current_src(st, child, setup, exc_pins, + exc_curs, num_exc_pins, ac_excited); +} + +static int ad4170_parse_external_sensor(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, + struct iio_chan_spec *chan, u8 s_type) +{ + unsigned int num_exc_pins, reg_val; + struct device *dev =3D &st->spi->dev; + u32 pins[2], exc_pins[4], exc_curs[4]; + bool ac_excited, vbias; + int ret; + + ret =3D fwnode_property_read_u32_array(child, "diff-channels", pins, + ARRAY_SIZE(pins)); + if (ret) + return dev_err_probe(dev, ret, + "Failed to read sensor diff-channels\n"); + + chan->differential =3D true; + chan->channel =3D pins[0]; + chan->channel2 =3D pins[1]; + + ret =3D ad4170_parse_exc_current(st, child, exc_pins, exc_curs, &num_exc_= pins); + if (ret) + return ret; + + /* The external sensor may not need excitation from the ADC chip. */ + if (num_exc_pins =3D=3D 0) + return 0; + + ret =3D ad4170_validate_excitation_pins(st, exc_pins, num_exc_pins); + if (ret) + return ret; + + ac_excited =3D fwnode_property_read_bool(child, "adi,excitation-ac"); + + if (s_type =3D=3D AD4170_THERMOCOUPLE_SENSOR) { + vbias =3D fwnode_property_read_bool(child, "adi,vbias"); + if (vbias) { + st->pins_fn[chan->channel2] |=3D AD4170_PIN_VBIAS; + reg_val =3D BIT(chan->channel2); + return regmap_write(st->regmap, AD4170_V_BIAS_REG, + reg_val); + } + } + if (s_type =3D=3D AD4170_WEIGH_SCALE_SENSOR) + ret =3D ad4170_setup_bridge(st, child, setup, exc_pins, exc_curs, + num_exc_pins, ac_excited); + else + ret =3D ad4170_setup_rtd(st, child, setup, exc_pins, exc_curs, + num_exc_pins, ac_excited); + + return ret; +} + static int ad4170_parse_reference(struct ad4170_state *st, struct fwnode_handle *child, struct ad4170_setup *setup) @@ -1810,6 +2273,7 @@ static int ad4170_parse_channel_node(struct iio_dev *= indio_dev, struct ad4170_setup *setup; struct iio_chan_spec *chan; unsigned int ref_select; + unsigned int s_type; unsigned int ch_reg; bool bipolar; int ret; @@ -1837,10 +2301,28 @@ static int ad4170_parse_channel_node(struct iio_dev= *indio_dev, if (ret) return ret; =20 - ret =3D ad4170_parse_adc_channel_type(dev, child, chan); - if (ret) - return ret; + ret =3D fwnode_property_match_property_string(child, "adi,sensor-type", + ad4170_sensor_type, + ARRAY_SIZE(ad4170_sensor_type)); =20 + /* Default to conventional ADC channel if sensor type not present */ + s_type =3D ret < 0 ? AD4170_ADC_SENSOR : ret; + switch (s_type) { + case AD4170_ADC_SENSOR: + ret =3D ad4170_parse_adc_channel_type(dev, child, chan); + if (ret) + return ret; + + break; + case AD4170_WEIGH_SCALE_SENSOR: + case AD4170_THERMOCOUPLE_SENSOR: + case AD4170_RTD_SENSOR: + ret =3D ad4170_parse_external_sensor(st, child, setup, chan, s_type); + if (ret) + return ret; + + break; + } bipolar =3D fwnode_property_read_bool(child, "bipolar"); setup->afe |=3D FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar); if (bipolar) @@ -2037,6 +2519,7 @@ static int ad4170_parse_firmware(struct iio_dev *indi= o_dev) struct ad4170_state *st =3D iio_priv(indio_dev); struct device *dev =3D &st->spi->dev; int reg_data, ret; + unsigned int i; =20 ret =3D ad4170_clock_select(indio_dev); if (ret) @@ -2046,6 +2529,9 @@ static int ad4170_parse_firmware(struct iio_dev *indi= o_dev) if (ret) return ret; =20 + for (i =3D 0; i < AD4170_NUM_CURRENT_SRC; i++) + st->cur_src_pins[i] =3D AD4170_CURRENT_SRC_DISABLED; + /* On power on, device defaults to using SDO pin for data ready signal */ st->int_pin_sel =3D AD4170_INT_PIN_SDO; ret =3D device_property_match_property_string(dev, "interrupt-names", --=20 2.47.2