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Mon, 2 Jun 2025 07:40:19 -0400 Received: from ASHBCASHYB5.ad.analog.com (10.64.17.133) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.10; Mon, 2 Jun 2025 07:40:19 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBCASHYB5.ad.analog.com (10.64.17.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.10; Mon, 2 Jun 2025 07:40:19 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.1748.10 via Frontend Transport; Mon, 2 Jun 2025 07:40:19 -0400 Received: from work.ad.analog.com (HYB-hERzalRezfV.ad.analog.com [10.65.205.9]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 552Be3g0025000; Mon, 2 Jun 2025 07:40:06 -0400 From: Marcelo Schmitt To: , , , CC: , , , , , , , , , , , Subject: [PATCH v4 10/11] iio: adc: ad4170: Add support for weigh scale and RTD sensors Date: Mon, 2 Jun 2025 08:40:01 -0300 Message-ID: <0633d4c716e12c92b7b49a06efdbbd8cd1ef19c0.1748829860.git.marcelo.schmitt@analog.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: CZ_nVOWVDYYChABD25PWZrX1BpWtcBGC X-Proofpoint-ORIG-GUID: CZ_nVOWVDYYChABD25PWZrX1BpWtcBGC X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNjAyMDEwMCBTYWx0ZWRfXwCwJX3u6kclt 67frKdFBgZCv6JV4PwEbvZl8KUIhghO2TzaqP3Rb1JiTQAVcIxk5Gakz/Fggf/54SpAbxB0OOPD FVMc//Nnu4Nb97bKIucicZ1uMcxyrvcwuLjVJgnjV05goXR5GoQnvVaiLG/QtCcp+V7fOaBbKwr Y+pteityIROUOk1vCVxr4e/ssnLLvnD7K6GtNYuN/osKqfFcDrdiNCvvJqbSMO+LC/XE11fCChN LkiREYF6gXPAF6GI5Teq3xRtgWmzTi3vP34MdnY6xh+yjUppPHmazEGB+qvSHiXoEy4rdfDJTo1 0mXiaoCgQgrOV3fB5NPLw5pAIC/qO2CZ3a1+zxMFfDUNO+ygmXzWbYHGMr/uXRz/zZu0b+fscz/ XvkemzbBsBsQIO04y6i1msrghbNuQ6dTOoEbBFtJg36QEm7vdMqIDeFIRb28PGWMA8TWrcaB X-Authority-Analysis: v=2.4 cv=DY4XqutW c=1 sm=1 tr=0 ts=683d8da5 cx=c_pps a=PpDZqlmH/M8setHirZLBMw==:117 a=PpDZqlmH/M8setHirZLBMw==:17 a=6IFa9wvqVegA:10 a=gAnH3GRIAAAA:8 a=b54mGPezs8RaO1Bbk_YA:9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-06-02_05,2025-05-30_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 suspectscore=0 spamscore=0 clxscore=1015 malwarescore=0 adultscore=0 bulkscore=0 impostorscore=0 phishscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505160000 definitions=main-2506020100 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 --- Change log v3 -> v4 - Update to string adi,sensor-type dt property. - Adapted external sensor dt prop parsing to work with the updated version of those props. drivers/iio/adc/ad4170.c | 500 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 494 insertions(+), 6 deletions(-) diff --git a/drivers/iio/adc/ad4170.c b/drivers/iio/adc/ad4170.c index 6e17f47a78bf..23b634d324a7 100644 --- a/drivers/iio/adc/ad4170.c +++ b/drivers/iio/adc/ad4170.c @@ -64,6 +64,8 @@ #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 @@ -95,6 +97,10 @@ #define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8) #define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0) +/* 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) @@ -105,12 +111,19 @@ /* AD4170_FILTER_REG */ #define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0) +/* 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) +/* AD4170_GPIO_OUTPUT_REG */ +#define AD4170_GPIO_OUTPUT_GPIO_MSK(x) BIT(x) + /* AD4170 register constants */ /* AD4170_CLOCK_CTRL_REG constants */ @@ -134,6 +147,11 @@ #define AD4170_CHAN_MAP_REFIN2_N 28 #define AD4170_CHAN_MAP_REFOUT 29 +/* 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 @@ -151,6 +169,10 @@ #define AD4170_FILTER_FILTER_TYPE_SINC5 0x4 #define AD4170_FILTER_FILTER_TYPE_SINC3 0x6 +/* 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 @@ -164,6 +186,7 @@ #define AD4170_MAX_SETUPS 8 #define AD4170_INVALID_SETUP 9 #define AD4170_SPI_MAX_XFER_LEN 6 +#define AD4170_NUM_CURRENT_SRC 4 #define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ) #define AD4170_INT_REF_2_5V 2500000 @@ -185,8 +208,19 @@ #define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5 +/* 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 static const unsigned int ad4170_reg_size[] = { [AD4170_CONFIG_A_REG] = 1, @@ -225,6 +259,8 @@ static const unsigned int ad4170_reg_size[] = { [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3, [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3, [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3, + [AD4170_V_BIAS_REG] = 2, + [AD4170_CURRENT_SRC_REG(0) ... AD4170_CURRENT_SRC_REG(3)] = 2, [AD4170_GPIO_MODE_REG] = 2, [AD4170_GPIO_OUTPUT_REG] = 2, [AD4170_GPIO_INPUT_REG] = 2, @@ -287,6 +323,41 @@ static const unsigned int ad4170_sinc5_filt_fs_tbl[] = { 1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256, }; +static const unsigned int ad4170_iout_pin_tbl[] = { + 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[] = { + 0, 10, 50, 100, 250, 500, 1000, 1500, +}; + +enum ad4170_sensor_enum { + AD4170_ADC_SENSOR = 0, + AD4170_WEIGH_SCALE_SENSOR = 1, + AD4170_RTD_SENSOR = 2, + AD4170_THERMOCOUPLE_SENSOR = 3, +}; + +/* maps adi,sensor-type property value to enum */ +static const char * const ad4170_sensor_type[] = { + [AD4170_ADC_SENSOR] = "adc", + [AD4170_WEIGH_SCALE_SENSOR] = "weighscale", + [AD4170_RTD_SENSOR] = "rtd", + [AD4170_THERMOCOUPLE_SENSOR] = "thermocouple", +}; + struct ad4170_chip_info { const char *name; }; @@ -371,6 +442,7 @@ 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. @@ -913,6 +985,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n, int v_diff; *ain_voltage = 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 = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP]; + *ain_voltage = v_diff / 2; + return 0; + } + if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR) return 0; @@ -967,6 +1052,19 @@ static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n, } } +static int ad4170_validate_analog_input(struct ad4170_state *st, int pin) +{ + if (pin <= 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] |= 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. */ @@ -981,7 +1079,7 @@ static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool "Invalid analog input pin number. %d\n", pin); - return 0; + return ad4170_validate_analog_input(st, pin); } /* @@ -1718,6 +1816,373 @@ static int ad4170_gpio_init(struct iio_dev *indio_dev) return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev); } +static int ad4170_validate_excitation_pin(struct ad4170_state *st, u32 pin) +{ + struct device *dev = &st->spi->dev; + unsigned int i; + + /* Check the pin number is valid */ + for (i = 0; i < ARRAY_SIZE(ad4170_iout_pin_tbl); i++) + if (ad4170_iout_pin_tbl[i] == pin) + break; + + if (i == 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 <= AD4170_MAX_ANALOG_PINS) { + if (st->pins_fn[pin] != 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] |= AD4170_PIN_CURRENT_OUT; + } else { + unsigned int gpio = pin - AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0); + + if (st->gpio_fn[gpio] != 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] |= 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 = 0; i < num_exc_pins; i++) { + unsigned int pin = exc_pins[i]; + + ret = ad4170_validate_excitation_pin(st, pin); + if (ret) + return ret; + } + return 0; +} + +static const char *const ad4170_i_out_pin_dt_props[] = { + "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[] = { + "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 independently. + * 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 = &st->spi->dev; + unsigned int num_pins, i, j; + u32 pin, val; + int ret; + + num_pins = 0; + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) { + /* Parse excitation current output pin properties. */ + pin = AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0); + ret = fwnode_property_read_u32(child, ad4170_i_out_pin_dt_props[i], + &pin); + if (ret) + continue; + + exc_pins[num_pins] = pin; + + /* Parse excitation current value properties. */ + val = ad4170_iout_current_ua_tbl[0]; + fwnode_property_read_u32(child, + ad4170_i_out_val_dt_props[i], &val); + + for (j = 0; j < ARRAY_SIZE(ad4170_iout_current_ua_tbl); j++) + if (ad4170_iout_current_ua_tbl[j] == val) + break; + + if (j == 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] = j; + num_pins++; + } + *num_exc_pins = 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 = 0; i < num_exc_pins; i++) { + unsigned int exc_cur = exc_curs[i]; + unsigned int pin = exc_pins[i]; + unsigned int current_src = 0; + + for (j = 0; j < AD4170_NUM_CURRENT_SRC; j++) + if (st->cur_src_pins[j] == AD4170_CURRENT_SRC_DISABLED) + break; + + if (j == AD4170_NUM_CURRENT_SRC) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Too many excitation current sources\n"); + + current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_PIN_MSK, pin); + current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_VAL_MSK, exc_cur); + st->cur_src_pins[j] = pin; + ret = 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 == 4) { + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) + if (st->cur_src_pins[i] != 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 = st->cur_src_pins[0] == exc_pins[0] ? 0 : 2; + + if (st->cur_src_pins[i] != exc_pins[0] || + st->cur_src_pins[i + 1] != exc_pins[1]) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Failed to setup current chopping\n"); + + st->cur_src_pins[i] = exc_pins[0]; + st->cur_src_pins[i + 1] = exc_pins[1]; + + if (i == 0) + exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR1; + else + exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR2; + } + + /* + * Configure excitation current chopping. + * Chop both pairs if using four excitation pins. + */ + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_IEXC_MSK, + num_exc_pins == 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 = 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 == 2) { + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x3); + + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK; + ret = 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 = AD4170_GPIO_OUTPUT_GPIO_MSK(3) | + AD4170_GPIO_OUTPUT_GPIO_MSK(2); + ret = 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] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |= AD4170_GPIO_OUTPUT; + } else { + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x2); + + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK | + AD4170_GPIO_MODE_GPIO1_MSK | AD4170_GPIO_MODE_GPIO0_MSK; + ret = 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 = 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 = 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] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[1] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[0] |= 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 = &st->spi->dev; + u32 pins[2], exc_pins[4], exc_curs[4]; + bool ac_excited, vbias; + int ret; + + ret = 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 = true; + chan->channel = pins[0]; + chan->channel2 = pins[1]; + + ret = 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 == 0) + return 0; + + ret = ad4170_validate_excitation_pins(st, exc_pins, num_exc_pins); + if (ret) + return ret; + + ac_excited = fwnode_property_read_bool(child, "adi,excitation-ac"); + + if (s_type == AD4170_THERMOCOUPLE_SENSOR) { + vbias = fwnode_property_read_bool(child, "adi,vbias"); + if (vbias) { + st->pins_fn[chan->channel2] |= AD4170_PIN_VBIAS; + reg_val = BIT(chan->channel2); + return regmap_write(st->regmap, AD4170_V_BIAS_REG, + reg_val); + } + } + if (s_type == AD4170_WEIGH_SCALE_SENSOR) + ret = ad4170_setup_bridge(st, child, setup, exc_pins, exc_curs, + num_exc_pins, ac_excited); + else + ret = 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) @@ -1803,8 +2268,9 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev, struct ad4170_chan_info *chan_info; struct ad4170_setup *setup; struct iio_chan_spec *chan; + unsigned int ref_select; + unsigned int s_type; unsigned int ch_reg; - u8 ref_select; bool bipolar; int ret; @@ -1832,10 +2298,28 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev, if (ret) return ret; - ret = ad4170_parse_adc_channel_type(dev, child, chan); - if (ret < 0) - return ret; + ret = fwnode_property_match_property_string(child, "adi,sensor-type", + ad4170_sensor_type, + ARRAY_SIZE(ad4170_sensor_type)); + /* Default to conventional ADC channel if sensor type not present */ + s_type = ret < 0 ? AD4170_ADC_SENSOR : ret; + switch (s_type) { + case AD4170_ADC_SENSOR: + ret = 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 = ad4170_parse_external_sensor(st, child, setup, chan, s_type); + if (ret) + return ret; + + break; + } bipolar = fwnode_property_read_bool(child, "bipolar"); setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar); if (bipolar) @@ -1843,11 +2327,11 @@ static int ad4170_parse_channel_node(struct iio_dev *indio_dev, else chan->scan_type.sign = 'u'; - ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe); ret = ad4170_validate_channel(st, chan); if (ret < 0) return ret; + ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe); ret = ad4170_get_input_range(st, chan, ch_reg, ref_select); if (ret < 0) return dev_err_probe(dev, ret, "Invalid input config\n"); @@ -2031,6 +2515,7 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev) struct ad4170_state *st = iio_priv(indio_dev); struct device *dev = &st->spi->dev; int reg_data, ret; + unsigned int i; ret = ad4170_clock_select(indio_dev); if (ret) @@ -2040,6 +2525,9 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev) if (ret) return ret; + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) + st->cur_src_pins[i] = AD4170_CURRENT_SRC_DISABLED; + /* On power on, device defaults to using SDO pin for data ready signal */ st->int_pin_sel = AD4170_INT_PIN_SDO; ret = device_property_match_property_string(dev, "interrupt-names",