--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
+ * driver
+ *
+ * Copyright 2019 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+/* register map */
+#define LTC2983_STATUS_REG 0x0000
+#define LTC2983_TEMP_RES_START_REG 0x0010
+#define LTC2983_TEMP_RES_END_REG 0x005F
+#define LTC2983_GLOBAL_CONFIG_REG 0x00F0
+#define LTC2983_MULT_CHANNEL_START_REG 0x00F4
+#define LTC2983_MULT_CHANNEL_END_REG 0x00F7
+#define LTC2983_MUX_CONFIG_REG 0x00FF
+#define LTC2983_CHAN_ASSIGN_START_REG 0x0200
+#define LTC2983_CHAN_ASSIGN_END_REG 0x024F
+#define LTC2983_CUST_SENS_TBL_START_REG 0x0250
+#define LTC2983_CUST_SENS_TBL_END_REG 0x03CF
+
+#define LTC2983_DIFFERENTIAL_CHAN_MIN 2
+#define LTC2983_MAX_CHANNELS_NR 20
+#define LTC2983_MIN_CHANNELS_NR 1
+#define LTC2983_SLEEP 0x97
+#define LTC2983_CUSTOM_STEINHART_SIZE 24
+#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ 6
+#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ 4
+
+#define LTC2983_CHAN_START_ADDR(chan) \
+ (((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
+#define LTC2983_CHAN_RES_ADDR(chan) \
+ (((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG)
+#define LTC2983_THERMOCOUPLE_DIFF_MASK BIT(3)
+#define LTC2983_THERMOCOUPLE_SGL(x) \
+ FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x)
+#define LTC2983_THERMOCOUPLE_OC_CURR_MASK GENMASK(1, 0)
+#define LTC2983_THERMOCOUPLE_OC_CURR(x) \
+ FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x)
+#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK BIT(2)
+#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \
+ FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x)
+
+#define LTC2983_THERMISTOR_DIFF_MASK BIT(2)
+#define LTC2983_THERMISTOR_SGL(x) \
+ FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x)
+#define LTC2983_THERMISTOR_R_SHARE_MASK BIT(1)
+#define LTC2983_THERMISTOR_R_SHARE(x) \
+ FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x)
+#define LTC2983_THERMISTOR_C_ROTATE_MASK BIT(0)
+#define LTC2983_THERMISTOR_C_ROTATE(x) \
+ FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x)
+
+#define LTC2983_DIODE_DIFF_MASK BIT(2)
+#define LTC2983_DIODE_SGL(x) \
+ FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x)
+#define LTC2983_DIODE_3_CONV_CYCLE_MASK BIT(1)
+#define LTC2983_DIODE_3_CONV_CYCLE(x) \
+ FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x)
+#define LTC2983_DIODE_AVERAGE_ON_MASK BIT(0)
+#define LTC2983_DIODE_AVERAGE_ON(x) \
+ FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x)
+
+#define LTC2983_RTD_4_WIRE_MASK BIT(3)
+#define LTC2983_RTD_ROTATION_MASK BIT(1)
+#define LTC2983_RTD_C_ROTATE(x) \
+ FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x)
+#define LTC2983_RTD_KELVIN_R_SENSE_MASK GENMASK(3, 2)
+#define LTC2983_RTD_N_WIRES_MASK GENMASK(3, 2)
+#define LTC2983_RTD_N_WIRES(x) \
+ FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x)
+#define LTC2983_RTD_R_SHARE_MASK BIT(0)
+#define LTC2983_RTD_R_SHARE(x) \
+ FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1)
+
+#define LTC2983_COMMON_HARD_FAULT_MASK GENMASK(31, 30)
+#define LTC2983_COMMON_SOFT_FAULT_MASK GENMASK(27, 25)
+
+#define LTC2983_STATUS_START_MASK BIT(7)
+#define LTC2983_STATUS_START(x) FIELD_PREP(LTC2983_STATUS_START_MASK, x)
+
+#define LTC2983_STATUS_CHAN_SEL_MASK GENMASK(4, 0)
+#define LTC2983_STATUS_CHAN_SEL(x) \
+ FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x)
+
+#define LTC2983_TEMP_UNITS_MASK BIT(2)
+#define LTC2983_TEMP_UNITS(x) FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x)
+
+#define LTC2983_NOTCH_FREQ_MASK GENMASK(1, 0)
+#define LTC2983_NOTCH_FREQ(x) FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x)
+
+#define LTC2983_RES_VALID_MASK BIT(24)
+#define LTC2983_DATA_MASK GENMASK(23, 0)
+#define LTC2983_DATA_SIGN_BIT 23
+
+#define LTC2983_CHAN_TYPE_MASK GENMASK(31, 27)
+#define LTC2983_CHAN_TYPE(x) FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x)
+
+/* cold junction for thermocouples and rsense for rtd's and thermistor's */
+#define LTC2983_CHAN_ASSIGN_MASK GENMASK(26, 22)
+#define LTC2983_CHAN_ASSIGN(x) FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x)
+
+#define LTC2983_CUSTOM_LEN_MASK GENMASK(5, 0)
+#define LTC2983_CUSTOM_LEN(x) FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x)
+
+#define LTC2983_CUSTOM_ADDR_MASK GENMASK(11, 6)
+#define LTC2983_CUSTOM_ADDR(x) FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x)
+
+#define LTC2983_THERMOCOUPLE_CFG_MASK GENMASK(21, 18)
+#define LTC2983_THERMOCOUPLE_CFG(x) \
+ FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x)
+#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK GENMASK(31, 29)
+#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK GENMASK(28, 25)
+
+#define LTC2983_RTD_CFG_MASK GENMASK(21, 18)
+#define LTC2983_RTD_CFG(x) FIELD_PREP(LTC2983_RTD_CFG_MASK, x)
+#define LTC2983_RTD_EXC_CURRENT_MASK GENMASK(17, 14)
+#define LTC2983_RTD_EXC_CURRENT(x) \
+ FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x)
+#define LTC2983_RTD_CURVE_MASK GENMASK(13, 12)
+#define LTC2983_RTD_CURVE(x) FIELD_PREP(LTC2983_RTD_CURVE_MASK, x)
+
+#define LTC2983_THERMISTOR_CFG_MASK GENMASK(21, 19)
+#define LTC2983_THERMISTOR_CFG(x) \
+ FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x)
+#define LTC2983_THERMISTOR_EXC_CURRENT_MASK GENMASK(18, 15)
+#define LTC2983_THERMISTOR_EXC_CURRENT(x) \
+ FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x)
+
+#define LTC2983_DIODE_CFG_MASK GENMASK(26, 24)
+#define LTC2983_DIODE_CFG(x) FIELD_PREP(LTC2983_DIODE_CFG_MASK, x)
+#define LTC2983_DIODE_EXC_CURRENT_MASK GENMASK(23, 22)
+#define LTC2983_DIODE_EXC_CURRENT(x) \
+ FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x)
+#define LTC2983_DIODE_IDEAL_FACTOR_MASK GENMASK(21, 0)
+#define LTC2983_DIODE_IDEAL_FACTOR(x) \
+ FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x)
+
+#define LTC2983_R_SENSE_VAL_MASK GENMASK(26, 0)
+#define LTC2983_R_SENSE_VAL(x) FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x)
+
+#define LTC2983_ADC_SINGLE_ENDED_MASK BIT(26)
+#define LTC2983_ADC_SINGLE_ENDED(x) \
+ FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x)
+
+enum {
+ LTC2983_SENSOR_THERMOCOUPLE = 1,
+ LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9,
+ LTC2983_SENSOR_RTD = 10,
+ LTC2983_SENSOR_RTD_CUSTOM = 18,
+ LTC2983_SENSOR_THERMISTOR = 19,
+ LTC2983_SENSOR_THERMISTOR_STEINHART = 26,
+ LTC2983_SENSOR_THERMISTOR_CUSTOM = 27,
+ LTC2983_SENSOR_DIODE = 28,
+ LTC2983_SENSOR_SENSE_RESISTOR = 29,
+ LTC2983_SENSOR_DIRECT_ADC = 30,
+};
+
+#define to_thermocouple(_sensor) \
+ container_of(_sensor, struct ltc2983_thermocouple, sensor)
+
+#define to_rtd(_sensor) \
+ container_of(_sensor, struct ltc2983_rtd, sensor)
+
+#define to_thermistor(_sensor) \
+ container_of(_sensor, struct ltc2983_thermistor, sensor)
+
+#define to_diode(_sensor) \
+ container_of(_sensor, struct ltc2983_diode, sensor)
+
+#define to_rsense(_sensor) \
+ container_of(_sensor, struct ltc2983_rsense, sensor)
+
+#define to_adc(_sensor) \
+ container_of(_sensor, struct ltc2983_adc, sensor)
+
+struct ltc2983_data {
+ struct regmap *regmap;
+ struct spi_device *spi;
+ struct mutex lock;
+ struct completion completion;
+ struct iio_chan_spec *iio_chan;
+ struct ltc2983_sensor **sensors;
+ u32 mux_delay_config;
+ u32 filter_notch_freq;
+ u16 custom_table_size;
+ u8 num_channels;
+ u8 iio_channels;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ * Holds the converted temperature
+ */
+ __be32 temp ____cacheline_aligned;
+};
+
+struct ltc2983_sensor {
+ int (*fault_handler)(const struct ltc2983_data *st, const u32 result);
+ int (*assign_chan)(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor);
+ /* specifies the sensor channel */
+ u32 chan;
+ /* sensor type */
+ u32 type;
+};
+
+struct ltc2983_custom_sensor {
+ /* raw table sensor data */
+ u8 *table;
+ size_t size;
+ /* address offset */
+ s8 offset;
+ bool is_steinhart;
+};
+
+struct ltc2983_thermocouple {
+ struct ltc2983_sensor sensor;
+ struct ltc2983_custom_sensor *custom;
+ u32 sensor_config;
+ u32 cold_junction_chan;
+};
+
+struct ltc2983_rtd {
+ struct ltc2983_sensor sensor;
+ struct ltc2983_custom_sensor *custom;
+ u32 sensor_config;
+ u32 r_sense_chan;
+ u32 excitation_current;
+ u32 rtd_curve;
+};
+
+struct ltc2983_thermistor {
+ struct ltc2983_sensor sensor;
+ struct ltc2983_custom_sensor *custom;
+ u32 sensor_config;
+ u32 r_sense_chan;
+ u32 excitation_current;
+};
+
+struct ltc2983_diode {
+ struct ltc2983_sensor sensor;
+ u32 sensor_config;
+ u32 excitation_current;
+ u32 ideal_factor_value;
+};
+
+struct ltc2983_rsense {
+ struct ltc2983_sensor sensor;
+ u32 r_sense_val;
+};
+
+struct ltc2983_adc {
+ struct ltc2983_sensor sensor;
+ bool single_ended;
+};
+
+/*
+ * Convert to Q format numbers. These number's are integers where
+ * the number of integer and fractional bits are specified. The resolution
+ * is given by 1/@resolution and tell us the number of fractional bits. For
+ * instance a resolution of 2^-10 means we have 10 fractional bits.
+ */
+static u32 __convert_to_raw(const u64 val, const u32 resolution)
+{
+ u64 __res = val * resolution;
+
+ /* all values are multiplied by 1000000 to remove the fraction */
+ do_div(__res, 1000000);
+
+ return __res;
+}
+
+static u32 __convert_to_raw_sign(const u64 val, const u32 resolution)
+{
+ s64 __res = -(s32)val;
+
+ __res = __convert_to_raw(__res, resolution);
+
+ return (u32)-__res;
+}
+
+static int __ltc2983_fault_handler(const struct ltc2983_data *st,
+ const u32 result, const u32 hard_mask,
+ const u32 soft_mask)
+{
+ const struct device *dev = &st->spi->dev;
+
+ if (result & hard_mask) {
+ dev_err(dev, "Invalid conversion: Sensor HARD fault\n");
+ return -EIO;
+ } else if (result & soft_mask) {
+ /* just print a warning */
+ dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n");
+ }
+
+ return 0;
+}
+
+static int __ltc2983_chan_assign_common(const struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor,
+ u32 chan_val)
+{
+ u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
+ __be32 __chan_val;
+
+ chan_val |= LTC2983_CHAN_TYPE(sensor->type);
+ dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
+ chan_val);
+ __chan_val = cpu_to_be32(chan_val);
+ return regmap_bulk_write(st->regmap, reg, &__chan_val,
+ sizeof(__chan_val));
+}
+
+static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
+ struct ltc2983_custom_sensor *custom,
+ u32 *chan_val)
+{
+ u32 reg;
+ u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ :
+ LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
+ const struct device *dev = &st->spi->dev;
+ /*
+ * custom->size holds the raw size of the table. However, when
+ * configuring the sensor channel, we must write the number of
+ * entries of the table minus 1. For steinhart sensors 0 is written
+ * since the size is constant!
+ */
+ const u8 len = custom->is_steinhart ? 0 :
+ (custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1;
+ /*
+ * Check if the offset was assigned already. It should be for steinhart
+ * sensors. When coming from sleep, it should be assigned for all.
+ */
+ if (custom->offset < 0) {
+ /*
+ * This needs to be done again here because, from the moment
+ * when this test was done (successfully) for this custom
+ * sensor, a steinhart sensor might have been added changing
+ * custom_table_size...
+ */
+ if (st->custom_table_size + custom->size >
+ (LTC2983_CUST_SENS_TBL_END_REG -
+ LTC2983_CUST_SENS_TBL_START_REG) + 1) {
+ dev_err(dev,
+ "Not space left(%d) for new custom sensor(%zu)",
+ st->custom_table_size,
+ custom->size);
+ return -EINVAL;
+ }
+
+ custom->offset = st->custom_table_size /
+ LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
+ st->custom_table_size += custom->size;
+ }
+
+ reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG;
+
+ *chan_val |= LTC2983_CUSTOM_LEN(len);
+ *chan_val |= LTC2983_CUSTOM_ADDR(custom->offset);
+ dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu",
+ reg, custom->offset,
+ custom->size);
+ /* write custom sensor table */
+ return regmap_bulk_write(st->regmap, reg, custom->table, custom->size);
+}
+
+static struct ltc2983_custom_sensor *__ltc2983_custom_sensor_new(
+ struct ltc2983_data *st,
+ const struct device_node *np,
+ const char *propname,
+ const bool is_steinhart,
+ const u32 resolution,
+ const bool has_signed)
+{
+ struct ltc2983_custom_sensor *new_custom;
+ u8 index, n_entries, tbl = 0;
+ struct device *dev = &st->spi->dev;
+ /*
+ * For custom steinhart, the full u32 is taken. For all the others
+ * the MSB is discarded.
+ */
+ const u8 n_size = (is_steinhart == true) ? 4 : 3;
+ const u8 e_size = (is_steinhart == true) ? sizeof(u32) : sizeof(u64);
+
+ n_entries = of_property_count_elems_of_size(np, propname, e_size);
+ /* n_entries must be an even number */
+ if (!n_entries || (n_entries % 2) != 0) {
+ dev_err(dev, "Number of entries either 0 or not even\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
+ if (!new_custom)
+ return ERR_PTR(-ENOMEM);
+
+ new_custom->size = n_entries * n_size;
+ /* check Steinhart size */
+ if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
+ dev_err(dev, "Steinhart sensors size(%zu) must be 24",
+ new_custom->size);
+ return ERR_PTR(-EINVAL);
+ }
+ /* Check space on the table. */
+ if (st->custom_table_size + new_custom->size >
+ (LTC2983_CUST_SENS_TBL_END_REG -
+ LTC2983_CUST_SENS_TBL_START_REG) + 1) {
+ dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
+ st->custom_table_size, new_custom->size);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* allocate the table */
+ new_custom->table = devm_kzalloc(dev, new_custom->size, GFP_KERNEL);
+ if (!new_custom->table)
+ return ERR_PTR(-ENOMEM);
+
+ for (index = 0; index < n_entries; index++) {
+ u64 temp = 0, j;
+ /*
+ * Steinhart sensors are configured with raw values in the
+ * devicetree. For the other sensors we must convert the
+ * value to raw. The odd index's correspond to temperarures
+ * and always have 1/1024 of resolution. Temperatures also
+ * come in kelvin, so signed values is not possible
+ */
+ if (!is_steinhart) {
+ of_property_read_u64_index(np, propname, index, &temp);
+
+ if ((index % 2) != 0)
+ temp = __convert_to_raw(temp, 1024);
+ else if (has_signed && (s64)temp < 0)
+ temp = __convert_to_raw_sign(temp, resolution);
+ else
+ temp = __convert_to_raw(temp, resolution);
+ } else {
+ of_property_read_u32_index(np, propname, index,
+ (u32 *)&temp);
+ }
+
+ for (j = 0; j < n_size; j++)
+ new_custom->table[tbl++] =
+ temp >> (8 * (n_size - j - 1));
+ }
+
+ new_custom->is_steinhart = is_steinhart;
+ /*
+ * This is done to first add all the steinhart sensors to the table,
+ * in order to maximize the table usage. If we mix adding steinhart
+ * with the other sensors, we might have to do some roundup to make
+ * sure that sensor_addr - 0x250(start address) is a multiple of 4
+ * (for steinhart), and a multiple of 6 for all the other sensors.
+ * Since we have const 24 bytes for steinhart sensors and 24 is
+ * also a multiple of 6, we guarantee that the first non-steinhart
+ * sensor will sit in a correct address without the need of filling
+ * addresses.
+ */
+ if (is_steinhart) {
+ new_custom->offset = st->custom_table_size /
+ LTC2983_CUSTOM_STEINHART_ENTRY_SZ;
+ st->custom_table_size += new_custom->size;
+ } else {
+ /* mark as unset. This is checked later on the assign phase */
+ new_custom->offset = -1;
+ }
+
+ return new_custom;
+}
+
+static int ltc2983_thermocouple_fault_handler(const struct ltc2983_data *st,
+ const u32 result)
+{
+ return __ltc2983_fault_handler(st, result,
+ LTC2983_THERMOCOUPLE_HARD_FAULT_MASK,
+ LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK);
+}
+
+static int ltc2983_common_fault_handler(const struct ltc2983_data *st,
+ const u32 result)
+{
+ return __ltc2983_fault_handler(st, result,
+ LTC2983_COMMON_HARD_FAULT_MASK,
+ LTC2983_COMMON_SOFT_FAULT_MASK);
+}
+
+static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_thermocouple *thermo = to_thermocouple(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan);
+ chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config);
+
+ if (thermo->custom) {
+ int ret;
+
+ ret = __ltc2983_chan_custom_sensor_assign(st, thermo->custom,
+ &chan_val);
+ if (ret)
+ return ret;
+ }
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static int ltc2983_rtd_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_rtd *rtd = to_rtd(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan);
+ chan_val |= LTC2983_RTD_CFG(rtd->sensor_config);
+ chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current);
+ chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve);
+
+ if (rtd->custom) {
+ int ret;
+
+ ret = __ltc2983_chan_custom_sensor_assign(st, rtd->custom,
+ &chan_val);
+ if (ret)
+ return ret;
+ }
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_thermistor *thermistor = to_thermistor(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan);
+ chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config);
+ chan_val |=
+ LTC2983_THERMISTOR_EXC_CURRENT(thermistor->excitation_current);
+
+ if (thermistor->custom) {
+ int ret;
+
+ ret = __ltc2983_chan_custom_sensor_assign(st,
+ thermistor->custom,
+ &chan_val);
+ if (ret)
+ return ret;
+ }
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static int ltc2983_diode_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_diode *diode = to_diode(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_DIODE_CFG(diode->sensor_config);
+ chan_val |= LTC2983_DIODE_EXC_CURRENT(diode->excitation_current);
+ chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode->ideal_factor_value);
+
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_rsense *rsense = to_rsense(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val);
+
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static int ltc2983_adc_assign_chan(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_adc *adc = to_adc(sensor);
+ u32 chan_val;
+
+ chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended);
+
+ return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
+static struct ltc2983_sensor *ltc2983_thermocouple_new(
+ const struct device_node *child,
+ struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_thermocouple *thermo;
+ struct device_node *phandle;
+ u32 oc_current;
+ int ret;
+
+ thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
+ if (!thermo)
+ return ERR_PTR(-ENOMEM);
+
+ if (of_property_read_bool(child, "adi,single-ended"))
+ thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1);
+
+ ret = of_property_read_u32(child, "adi,sensor-oc-current-microamp",
+ &oc_current);
+ if (!ret) {
+ switch (oc_current) {
+ case 10:
+ thermo->sensor_config |=
+ LTC2983_THERMOCOUPLE_OC_CURR(0);
+ break;
+ case 100:
+ thermo->sensor_config |=
+ LTC2983_THERMOCOUPLE_OC_CURR(1);
+ break;
+ case 500:
+ thermo->sensor_config |=
+ LTC2983_THERMOCOUPLE_OC_CURR(2);
+ break;
+ case 1000:
+ thermo->sensor_config |=
+ LTC2983_THERMOCOUPLE_OC_CURR(3);
+ break;
+ default:
+ dev_err(&st->spi->dev,
+ "Invalid open circuit current:%u", oc_current);
+ return ERR_PTR(-EINVAL);
+ }
+
+ thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
+ }
+ /* validate channel index */
+ if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
+ sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev,
+ "Invalid chann:%d for differential thermocouple",
+ sensor->chan);
+ return ERR_PTR(-EINVAL);
+ }
+
+ phandle = of_parse_phandle(child, "adi,cold-junction-handle", 0);
+ if (phandle) {
+ int ret;
+
+ ret = of_property_read_u32(phandle, "reg",
+ &thermo->cold_junction_chan);
+ if (ret) {
+ /*
+ * This would be catched later but we can just return
+ * the error right away.
+ */
+ dev_err(&st->spi->dev, "Property reg must be given\n");
+ of_node_put(phandle);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /* check custom sensor */
+ if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
+ const char *propname = "adi,custom-thermocouple";
+
+ thermo->custom = __ltc2983_custom_sensor_new(st, child,
+ propname, false,
+ 16384, true);
+ if (IS_ERR(thermo->custom)) {
+ of_node_put(phandle);
+ return ERR_CAST(thermo->custom);
+ }
+ }
+
+ /* set common parameters */
+ thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
+ thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
+
+ of_node_put(phandle);
+ return &thermo->sensor;
+}
+
+static struct ltc2983_sensor *ltc2983_rtd_new(const struct device_node *child,
+ struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_rtd *rtd;
+ int ret = 0;
+ struct device *dev = &st->spi->dev;
+ struct device_node *phandle;
+ u32 excitation_current = 0, n_wires = 0;
+
+ rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
+ if (!rtd)
+ return ERR_PTR(-ENOMEM);
+
+ phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
+ if (!phandle) {
+ dev_err(dev, "Property adi,rsense-handle missing or invalid");
+ return ERR_PTR(-EINVAL);
+ }
+
+ ret = of_property_read_u32(phandle, "reg", &rtd->r_sense_chan);
+ if (ret) {
+ dev_err(dev, "Property reg must be given\n");
+ goto fail;
+ }
+
+ ret = of_property_read_u32(child, "adi,number-of-wires", &n_wires);
+ if (!ret) {
+ switch (n_wires) {
+ case 2:
+ rtd->sensor_config = LTC2983_RTD_N_WIRES(0);
+ break;
+ case 3:
+ rtd->sensor_config = LTC2983_RTD_N_WIRES(1);
+ break;
+ case 4:
+ rtd->sensor_config = LTC2983_RTD_N_WIRES(2);
+ break;
+ case 5:
+ /* 4 wires, Kelvin Rsense */
+ rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
+ break;
+ default:
+ dev_err(dev, "Invalid number of wires:%u\n", n_wires);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ if (of_property_read_bool(child, "adi,rsense-share")) {
+ /* Current rotation is only available with rsense sharing */
+ if (of_property_read_bool(child, "adi,current-rotate")) {
+ if (n_wires == 2 || n_wires == 3) {
+ dev_err(dev,
+ "Rotation not allowed for 2/3 Wire RTDs");
+ ret = -EINVAL;
+ goto fail;
+ }
+ rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
+ } else {
+ rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
+ }
+ }
+ /*
+ * rtd channel indexes are a bit more complicated to validate.
+ * For 4wire RTD with rotation, the channel selection cannot be
+ * >=19 since the chann + 1 is used in this configuration.
+ * For 4wire RTDs with kelvin rsense, the rsense channel cannot be
+ * <=1 since chanel - 1 and channel - 2 are used.
+ */
+ if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
+ /* 4-wire */
+ u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
+ max = LTC2983_MAX_CHANNELS_NR;
+
+ if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
+ max = LTC2983_MAX_CHANNELS_NR - 1;
+
+ if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
+ == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
+ (rtd->r_sense_chan <= min)) {
+ /* kelvin rsense*/
+ dev_err(dev,
+ "Invalid rsense chann:%d to use in kelvin rsense",
+ rtd->r_sense_chan);
+
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (sensor->chan < min || sensor->chan > max) {
+ dev_err(dev, "Invalid chann:%d for the rtd config",
+ sensor->chan);
+
+ ret = -EINVAL;
+ goto fail;
+ }
+ } else {
+ /* same as differential case */
+ if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev,
+ "Invalid chann:%d for RTD", sensor->chan);
+
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ /* check custom sensor */
+ if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) {
+ rtd->custom = __ltc2983_custom_sensor_new(st, child,
+ "adi,custom-rtd",
+ false, 2048, false);
+ if (IS_ERR(rtd->custom)) {
+ of_node_put(phandle);
+ return ERR_CAST(rtd->custom);
+ }
+ }
+
+ /* set common parameters */
+ rtd->sensor.fault_handler = ltc2983_common_fault_handler;
+ rtd->sensor.assign_chan = ltc2983_rtd_assign_chan;
+
+ ret = of_property_read_u32(child, "adi,excitation-current-microamp",
+ &excitation_current);
+ if (ret) {
+ /* default to 5uA */
+ rtd->excitation_current = 1;
+ } else {
+ switch (excitation_current) {
+ case 5:
+ rtd->excitation_current = 0x01;
+ break;
+ case 10:
+ rtd->excitation_current = 0x02;
+ break;
+ case 25:
+ rtd->excitation_current = 0x03;
+ break;
+ case 50:
+ rtd->excitation_current = 0x04;
+ break;
+ case 100:
+ rtd->excitation_current = 0x05;
+ break;
+ case 250:
+ rtd->excitation_current = 0x06;
+ break;
+ case 500:
+ rtd->excitation_current = 0x07;
+ break;
+ case 1000:
+ rtd->excitation_current = 0x08;
+ break;
+ default:
+ dev_err(&st->spi->dev,
+ "Invalid value for excitation current(%u)",
+ excitation_current);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ of_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
+
+ of_node_put(phandle);
+ return &rtd->sensor;
+fail:
+ of_node_put(phandle);
+ return ERR_PTR(ret);
+}
+
+static struct ltc2983_sensor *ltc2983_thermistor_new(
+ const struct device_node *child,
+ struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_thermistor *thermistor;
+ struct device *dev = &st->spi->dev;
+ struct device_node *phandle;
+ u32 excitation_current = 0;
+ int ret = 0;
+
+ thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL);
+ if (!thermistor)
+ return ERR_PTR(-ENOMEM);
+
+ phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
+ if (!phandle) {
+ dev_err(dev, "Property adi,rsense-handle missing or invalid");
+ return ERR_PTR(-EINVAL);
+ }
+
+ ret = of_property_read_u32(phandle, "reg", &thermistor->r_sense_chan);
+ if (ret) {
+ dev_err(dev, "rsense channel must be configured...\n");
+ goto fail;
+ }
+
+ if (of_property_read_bool(child, "adi,single-ended")) {
+ thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
+ } else if (of_property_read_bool(child, "adi,rsense-share")) {
+ /* rotation is only possible if sharing rsense */
+ if (of_property_read_bool(child, "adi,current-rotate"))
+ thermistor->sensor_config =
+ LTC2983_THERMISTOR_C_ROTATE(1);
+ else
+ thermistor->sensor_config =
+ LTC2983_THERMISTOR_R_SHARE(1);
+ }
+ /* validate channel index */
+ if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
+ sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev,
+ "Invalid chann:%d for differential thermistor",
+ sensor->chan);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* check custom sensor */
+ if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
+ bool steinhart = false;
+ const char *propname;
+
+ if (sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART) {
+ steinhart = true;
+ propname = "adi,custom-steinhart";
+ } else {
+ propname = "adi,custom-thermistor";
+ }
+
+ thermistor->custom = __ltc2983_custom_sensor_new(st, child,
+ propname,
+ steinhart,
+ 64, false);
+ if (IS_ERR(thermistor->custom)) {
+ of_node_put(phandle);
+ return ERR_CAST(thermistor->custom);
+ }
+ }
+ /* set common parameters */
+ thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
+ thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan;
+
+ ret = of_property_read_u32(child, "adi,excitation-current-nanoamp",
+ &excitation_current);
+ if (ret) {
+ /* Auto range is not allowed for custom sensors */
+ if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
+ /* default to 1uA */
+ thermistor->excitation_current = 0x03;
+ else
+ /* default to auto-range */
+ thermistor->excitation_current = 0x0c;
+ } else {
+ switch (excitation_current) {
+ case 0:
+ /* auto range */
+ if (sensor->type >=
+ LTC2983_SENSOR_THERMISTOR_STEINHART) {
+ dev_err(&st->spi->dev,
+ "Auto Range not allowed for custom sensors\n");
+ ret = -EINVAL;
+ goto fail;
+ }
+ thermistor->excitation_current = 0x0c;
+ break;
+ case 250:
+ thermistor->excitation_current = 0x01;
+ break;
+ case 500:
+ thermistor->excitation_current = 0x02;
+ break;
+ case 1000:
+ thermistor->excitation_current = 0x03;
+ break;
+ case 5000:
+ thermistor->excitation_current = 0x04;
+ break;
+ case 10000:
+ thermistor->excitation_current = 0x05;
+ break;
+ case 25000:
+ thermistor->excitation_current = 0x06;
+ break;
+ case 50000:
+ thermistor->excitation_current = 0x07;
+ break;
+ case 100000:
+ thermistor->excitation_current = 0x08;
+ break;
+ case 250000:
+ thermistor->excitation_current = 0x09;
+ break;
+ case 500000:
+ thermistor->excitation_current = 0x0a;
+ break;
+ case 1000000:
+ thermistor->excitation_current = 0x0b;
+ break;
+ default:
+ dev_err(&st->spi->dev,
+ "Invalid value for excitation current(%u)",
+ excitation_current);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ of_node_put(phandle);
+ return &thermistor->sensor;
+fail:
+ of_node_put(phandle);
+ return ERR_PTR(ret);
+}
+
+static struct ltc2983_sensor *ltc2983_diode_new(
+ const struct device_node *child,
+ const struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_diode *diode;
+ u32 temp = 0, excitation_current = 0;
+ int ret;
+
+ diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
+ if (!diode)
+ return ERR_PTR(-ENOMEM);
+
+ if (of_property_read_bool(child, "adi,single-ended"))
+ diode->sensor_config = LTC2983_DIODE_SGL(1);
+
+ if (of_property_read_bool(child, "adi,three-conversion-cycles"))
+ diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1);
+
+ if (of_property_read_bool(child, "adi,average-on"))
+ diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1);
+
+ /* validate channel index */
+ if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
+ sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev,
+ "Invalid chann:%d for differential thermistor",
+ sensor->chan);
+ return ERR_PTR(-EINVAL);
+ }
+ /* set common parameters */
+ diode->sensor.fault_handler = ltc2983_common_fault_handler;
+ diode->sensor.assign_chan = ltc2983_diode_assign_chan;
+
+ ret = of_property_read_u32(child, "adi,excitation-current-microamp",
+ &excitation_current);
+ if (!ret) {
+ switch (excitation_current) {
+ case 10:
+ diode->excitation_current = 0x00;
+ break;
+ case 20:
+ diode->excitation_current = 0x01;
+ break;
+ case 40:
+ diode->excitation_current = 0x02;
+ break;
+ case 80:
+ diode->excitation_current = 0x03;
+ break;
+ default:
+ dev_err(&st->spi->dev,
+ "Invalid value for excitation current(%u)",
+ excitation_current);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ of_property_read_u32(child, "adi,ideal-factor-value", &temp);
+
+ /* 2^20 resolution */
+ diode->ideal_factor_value = __convert_to_raw(temp, 1048576);
+
+ return &diode->sensor;
+}
+
+static struct ltc2983_sensor *ltc2983_r_sense_new(struct device_node *child,
+ struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_rsense *rsense;
+ int ret;
+ u32 temp;
+
+ rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
+ if (!rsense)
+ return ERR_PTR(-ENOMEM);
+
+ /* validate channel index */
+ if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
+ sensor->chan);
+ return ERR_PTR(-EINVAL);
+ }
+
+ ret = of_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
+ if (ret) {
+ dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
+ return ERR_PTR(-EINVAL);
+ }
+ /*
+ * Times 1000 because we have milli-ohms and __convert_to_raw
+ * expects scales of 1000000 which are used for all other
+ * properties.
+ * 2^10 resolution
+ */
+ rsense->r_sense_val = __convert_to_raw((u64)temp * 1000, 1024);
+
+ /* set common parameters */
+ rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan;
+
+ return &rsense->sensor;
+}
+
+static struct ltc2983_sensor *ltc2983_adc_new(struct device_node *child,
+ struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor)
+{
+ struct ltc2983_adc *adc;
+
+ adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
+ if (!adc)
+ return ERR_PTR(-ENOMEM);
+
+ if (of_property_read_bool(child, "adi,single-ended"))
+ adc->single_ended = true;
+
+ if (!adc->single_ended &&
+ sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+ dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
+ sensor->chan);
+ return ERR_PTR(-EINVAL);
+ }
+ /* set common parameters */
+ adc->sensor.assign_chan = ltc2983_adc_assign_chan;
+ adc->sensor.fault_handler = ltc2983_common_fault_handler;
+
+ return &adc->sensor;
+}
+
+static int ltc2983_chan_read(struct ltc2983_data *st,
+ const struct ltc2983_sensor *sensor, int *val)
+{
+ u32 start_conversion = 0;
+ int ret;
+ unsigned long time;
+
+ start_conversion = LTC2983_STATUS_START(true);
+ start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan);
+ dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n",
+ sensor->chan, start_conversion);
+ /* start conversion */
+ ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion);
+ if (ret)
+ return ret;
+
+ reinit_completion(&st->completion);
+ /*
+ * wait for conversion to complete.
+ * 300 ms should be more than enough to complete the conversion.
+ * Depending on the sensor configuration, there are 2/3 conversions
+ * cycles of 82ms.
+ */
+ time = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(300));
+ if (!time) {
+ dev_warn(&st->spi->dev, "Conversion timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ /* read the converted data */
+ ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan),
+ &st->temp, sizeof(st->temp));
+ if (ret)
+ return ret;
+
+ *val = __be32_to_cpu(st->temp);
+
+ if (!(LTC2983_RES_VALID_MASK & *val)) {
+ dev_err(&st->spi->dev, "Invalid conversion detected\n");
+ return -EIO;
+ }
+
+ ret = sensor->fault_handler(st, *val);
+ if (ret)
+ return ret;
+
+ *val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT);
+ return 0;
+}
+
+static int ltc2983_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ltc2983_data *st = iio_priv(indio_dev);
+ int ret;
+
+ /* sanity check */
+ if (chan->address >= st->num_channels) {
+ dev_err(&st->spi->dev, "Invalid chan address:%ld",
+ chan->address);
+ return -EINVAL;
+ }
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&st->lock);
+ ret = ltc2983_chan_read(st, st->sensors[chan->address], val);
+ mutex_unlock(&st->lock);
+ return ret ?: IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_TEMP:
+ /* value in milli degrees */
+ *val = 1000;
+ /* 2^10 */
+ *val2 = 1024;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_VOLTAGE:
+ /* value in millivolt */
+ *val = 1000;
+ /* 2^21 */
+ *val2 = 2097152;
+ return IIO_VAL_FRACTIONAL;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int ltc2983_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg,
+ unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ltc2983_data *st = iio_priv(indio_dev);
+
+ if (readval)
+ return regmap_read(st->regmap, reg, readval);
+ else
+ return regmap_write(st->regmap, reg, writeval);
+}
+
+static irqreturn_t ltc2983_irq_handler(int irq, void *data)
+{
+ struct ltc2983_data *st = data;
+
+ complete(&st->completion);
+ return IRQ_HANDLED;
+}
+
+#define LTC2983_CHAN(__type, index, __address) ({ \
+ struct iio_chan_spec __chan = { \
+ .type = __type, \
+ .indexed = 1, \
+ .channel = index, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .address = __address, \
+ }; \
+ __chan; \
+})
+
+static int ltc2983_parse_dt(struct ltc2983_data *st)
+{
+ struct device_node *child;
+ struct device *dev = &st->spi->dev;
+ int ret = 0, chan = 0, channel_avail_mask = 0;
+
+ of_property_read_u32(dev->of_node, "adi,mux-delay-config-us",
+ &st->mux_delay_config);
+
+ of_property_read_u32(dev->of_node, "adi,filter-notch-freq",
+ &st->filter_notch_freq);
+
+ st->num_channels = of_get_available_child_count(dev->of_node);
+ st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
+ GFP_KERNEL);
+ if (!st->sensors)
+ return -ENOMEM;
+
+ st->iio_channels = st->num_channels;
+ for_each_available_child_of_node(dev->of_node, child) {
+ struct ltc2983_sensor sensor;
+
+ ret = of_property_read_u32(child, "reg", &sensor.chan);
+ if (ret) {
+ dev_err(dev, "reg property must given for child nodes\n");
+ return ret;
+ }
+
+ /* check if we have a valid channel */
+ if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
+ sensor.chan > LTC2983_MAX_CHANNELS_NR) {
+ dev_err(dev,
+ "chan:%d must be from 1 to 20\n", sensor.chan);
+ return -EINVAL;
+ } else if (channel_avail_mask & BIT(sensor.chan)) {
+ dev_err(dev, "chan:%d already in use\n", sensor.chan);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(child, "adi,sensor-type",
+ &sensor.type);
+ if (ret) {
+ dev_err(dev,
+ "adi,sensor-type property must given for child nodes\n");
+ return ret;
+ }
+
+ dev_dbg(dev, "Create new sensor, type %u, chann %u",
+ sensor.type,
+ sensor.chan);
+
+ if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
+ sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
+ st->sensors[chan] = ltc2983_thermocouple_new(child, st,
+ &sensor);
+ } else if (sensor.type >= LTC2983_SENSOR_RTD &&
+ sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) {
+ st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor);
+ } else if (sensor.type >= LTC2983_SENSOR_THERMISTOR &&
+ sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) {
+ st->sensors[chan] = ltc2983_thermistor_new(child, st,
+ &sensor);
+ } else if (sensor.type == LTC2983_SENSOR_DIODE) {
+ st->sensors[chan] = ltc2983_diode_new(child, st,
+ &sensor);
+ } else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) {
+ st->sensors[chan] = ltc2983_r_sense_new(child, st,
+ &sensor);
+ /* don't add rsense to iio */
+ st->iio_channels--;
+ } else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
+ st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
+ } else {
+ dev_err(dev, "Unknown sensor type %d\n", sensor.type);
+ return -EINVAL;
+ }
+
+ if (IS_ERR(st->sensors[chan])) {
+ dev_err(dev, "Failed to create sensor %ld",
+ PTR_ERR(st->sensors[chan]));
+ return PTR_ERR(st->sensors[chan]);
+ }
+ /* set generic sensor parameters */
+ st->sensors[chan]->chan = sensor.chan;
+ st->sensors[chan]->type = sensor.type;
+
+ channel_avail_mask |= BIT(sensor.chan);
+ chan++;
+ }
+
+ return 0;
+}
+
+static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
+{
+ u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0;
+ int ret;
+ unsigned long time;
+
+ /* make sure the device is up */
+ time = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(250));
+
+ if (!time) {
+ dev_err(&st->spi->dev, "Device startup timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ st->iio_chan = devm_kzalloc(&st->spi->dev,
+ st->iio_channels * sizeof(*st->iio_chan),
+ GFP_KERNEL);
+
+ if (!st->iio_chan)
+ return -ENOMEM;
+
+ ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
+ LTC2983_NOTCH_FREQ_MASK,
+ LTC2983_NOTCH_FREQ(st->filter_notch_freq));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG,
+ st->mux_delay_config);
+ if (ret)
+ return ret;
+
+ for (chan = 0; chan < st->num_channels; chan++) {
+ u32 chan_type = 0, *iio_chan;
+
+ ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]);
+ if (ret)
+ return ret;
+ /*
+ * The assign_iio flag is necessary for when the device is
+ * coming out of sleep. In that case, we just need to
+ * re-configure the device channels.
+ * We also don't assign iio channels for rsense.
+ */
+ if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR ||
+ !assign_iio)
+ continue;
+
+ /* assign iio channel */
+ if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) {
+ chan_type = IIO_TEMP;
+ iio_chan = &iio_chan_t;
+ } else {
+ chan_type = IIO_VOLTAGE;
+ iio_chan = &iio_chan_v;
+ }
+
+ /*
+ * add chan as the iio .address so that, we can directly
+ * reference the sensor given the iio_chan_spec
+ */
+ st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++,
+ chan);
+ }
+
+ return 0;
+}
+
+static const struct regmap_range ltc2983_reg_ranges[] = {
+ regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
+ regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
+ regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
+ regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
+ LTC2983_MULT_CHANNEL_END_REG),
+ regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
+ regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
+ LTC2983_CHAN_ASSIGN_END_REG),
+ regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG,
+ LTC2983_CUST_SENS_TBL_END_REG),
+};
+
+static const struct regmap_access_table ltc2983_reg_table = {
+ .yes_ranges = ltc2983_reg_ranges,
+ .n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges),
+};
+
+/*
+ * The reg_bits are actually 12 but the device needs the first *complete*
+ * byte for the command (R/W).
+ */
+static const struct regmap_config ltc2983_regmap_config = {
+ .reg_bits = 24,
+ .val_bits = 8,
+ .wr_table = <c2983_reg_table,
+ .rd_table = <c2983_reg_table,
+ .read_flag_mask = GENMASK(1, 0),
+ .write_flag_mask = BIT(1),
+};
+
+static const struct iio_info ltc2983_iio_info = {
+ .read_raw = ltc2983_read_raw,
+ .debugfs_reg_access = ltc2983_reg_access,
+};
+
+static int ltc2983_probe(struct spi_device *spi)
+{
+ struct ltc2983_data *st;
+ struct iio_dev *indio_dev;
+ const char *name = spi_get_device_id(spi)->name;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ st->regmap = devm_regmap_init_spi(spi, <c2983_regmap_config);
+ if (IS_ERR(st->regmap)) {
+ dev_err(&spi->dev, "Failed to initialize regmap\n");
+ return PTR_ERR(st->regmap);
+ }
+
+ mutex_init(&st->lock);
+ init_completion(&st->completion);
+ st->spi = spi;
+ spi_set_drvdata(spi, st);
+
+ ret = ltc2983_parse_dt(st);
+ if (ret)
+ return ret;
+ /*
+ * let's request the irq now so it is used to sync the device
+ * startup in ltc2983_setup()
+ */
+ ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
+ IRQF_TRIGGER_RISING, name, st);
+ if (ret) {
+ dev_err(&spi->dev, "failed to request an irq, %d", ret);
+ return ret;
+ }
+
+ ret = ltc2983_setup(st, true);
+ if (ret)
+ return ret;
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = name;
+ indio_dev->num_channels = st->iio_channels;
+ indio_dev->channels = st->iio_chan;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = <c2983_iio_info;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static int __maybe_unused ltc2983_resume(struct device *dev)
+{
+ struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
+ int dummy;
+
+ /* dummy read to bring the device out of sleep */
+ regmap_read(st->regmap, LTC2983_STATUS_REG, &dummy);
+ /* we need to re-assign the channels */
+ return ltc2983_setup(st, false);
+}
+
+static int __maybe_unused ltc2983_suspend(struct device *dev)
+{
+ struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
+
+ return regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP);
+}
+
+static SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend, ltc2983_resume);
+
+static const struct spi_device_id ltc2983_id_table[] = {
+ { "ltc2983" },
+ {},
+};
+MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
+
+static const struct of_device_id ltc2983_of_match[] = {
+ { .compatible = "adi,ltc2983" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ltc2983_of_match);
+
+static struct spi_driver ltc2983_driver = {
+ .driver = {
+ .name = "ltc2983",
+ .of_match_table = ltc2983_of_match,
+ .pm = <c2983_pm_ops,
+ },
+ .probe = ltc2983_probe,
+ .id_table = ltc2983_id_table,
+};
+
+module_spi_driver(ltc2983_driver);
+
+MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
+MODULE_LICENSE("GPL");
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