diff options
Diffstat (limited to 'drivers/iio/temperature/ltc2983.c')
| -rw-r--r-- | drivers/iio/temperature/ltc2983.c | 1583 |
1 files changed, 1583 insertions, 0 deletions
diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c new file mode 100644 index 000000000..1117991ca --- /dev/null +++ b/drivers/iio/temperature/ltc2983.c @@ -0,0 +1,1583 @@ +// 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/mod_devicetable.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/spi/spi.h> + +#include <asm/byteorder.h> +#include <asm/unaligned.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_UP_MASK GENMASK(7, 6) +#define LTC2983_STATUS_UP(reg) FIELD_GET(LTC2983_STATUS_UP_MASK, reg) + +#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) may require the + * transfer buffers to live in their own cache lines. + * Holds the converted temperature + */ + __be32 temp __aligned(IIO_DMA_MINALIGN); + __be32 chan_val; +}; + +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 */ + void *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(struct ltc2983_data *st, + const struct ltc2983_sensor *sensor, + u32 chan_val) +{ + u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan); + + chan_val |= LTC2983_CHAN_TYPE(sensor->type); + dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg, + chan_val); + st->chan_val = cpu_to_be32(chan_val); + return regmap_bulk_write(st->regmap, reg, &st->chan_val, + sizeof(st->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 fwnode_handle *fn, + const char *propname, const bool is_steinhart, + const u32 resolution, const bool has_signed) +{ + struct ltc2983_custom_sensor *new_custom; + 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 ? 4 : 3; + u8 index, n_entries; + int ret; + + if (is_steinhart) + n_entries = fwnode_property_count_u32(fn, propname); + else + n_entries = fwnode_property_count_u64(fn, propname); + /* 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 %u\n", new_custom->size, + LTC2983_CUSTOM_STEINHART_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 */ + if (is_steinhart) + new_custom->table = devm_kcalloc(dev, n_entries, sizeof(u32), GFP_KERNEL); + else + new_custom->table = devm_kcalloc(dev, n_entries, sizeof(u64), GFP_KERNEL); + if (!new_custom->table) + return ERR_PTR(-ENOMEM); + + /* + * Steinhart sensors are configured with raw values in the firmware + * node. For the other sensors we must convert the value to raw. + * The odd index's correspond to temperatures and always have 1/1024 + * of resolution. Temperatures also come in Kelvin, so signed values + * are not possible. + */ + if (is_steinhart) { + ret = fwnode_property_read_u32_array(fn, propname, new_custom->table, n_entries); + if (ret < 0) + return ERR_PTR(ret); + + cpu_to_be32_array(new_custom->table, new_custom->table, n_entries); + } else { + ret = fwnode_property_read_u64_array(fn, propname, new_custom->table, n_entries); + if (ret < 0) + return ERR_PTR(ret); + + for (index = 0; index < n_entries; index++) { + u64 temp = ((u64 *)new_custom->table)[index]; + + 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); + + put_unaligned_be24(temp, new_custom->table + index * 3); + } + } + + 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 fwnode_handle *child, struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermocouple *thermo; + struct fwnode_handle *ref; + u32 oc_current; + int ret; + + thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL); + if (!thermo) + return ERR_PTR(-ENOMEM); + + if (fwnode_property_read_bool(child, "adi,single-ended")) + thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1); + + ret = fwnode_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); + } + + ref = fwnode_find_reference(child, "adi,cold-junction-handle", 0); + if (IS_ERR(ref)) { + ref = NULL; + } else { + ret = fwnode_property_read_u32(ref, "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"); + goto fail; + } + } + + /* 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)) { + ret = PTR_ERR(thermo->custom); + goto fail; + } + } + + /* set common parameters */ + thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler; + thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan; + + fwnode_handle_put(ref); + return &thermo->sensor; + +fail: + fwnode_handle_put(ref); + return ERR_PTR(ret); +} + +static struct ltc2983_sensor * +ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_rtd *rtd; + int ret = 0; + struct device *dev = &st->spi->dev; + struct fwnode_handle *ref; + u32 excitation_current = 0, n_wires = 0; + + rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL); + if (!rtd) + return ERR_PTR(-ENOMEM); + + ref = fwnode_find_reference(child, "adi,rsense-handle", 0); + if (IS_ERR(ref)) { + dev_err(dev, "Property adi,rsense-handle missing or invalid"); + return ERR_CAST(ref); + } + + ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan); + if (ret) { + dev_err(dev, "Property reg must be given\n"); + goto fail; + } + + ret = fwnode_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 (fwnode_property_read_bool(child, "adi,rsense-share")) { + /* Current rotation is only available with rsense sharing */ + if (fwnode_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)) { + ret = PTR_ERR(rtd->custom); + goto fail; + } + } + + /* set common parameters */ + rtd->sensor.fault_handler = ltc2983_common_fault_handler; + rtd->sensor.assign_chan = ltc2983_rtd_assign_chan; + + ret = fwnode_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; + } + } + + fwnode_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve); + + fwnode_handle_put(ref); + return &rtd->sensor; +fail: + fwnode_handle_put(ref); + return ERR_PTR(ret); +} + +static struct ltc2983_sensor * +ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *st, + const struct ltc2983_sensor *sensor) +{ + struct ltc2983_thermistor *thermistor; + struct device *dev = &st->spi->dev; + struct fwnode_handle *ref; + u32 excitation_current = 0; + int ret = 0; + + thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL); + if (!thermistor) + return ERR_PTR(-ENOMEM); + + ref = fwnode_find_reference(child, "adi,rsense-handle", 0); + if (IS_ERR(ref)) { + dev_err(dev, "Property adi,rsense-handle missing or invalid"); + return ERR_CAST(ref); + } + + ret = fwnode_property_read_u32(ref, "reg", &thermistor->r_sense_chan); + if (ret) { + dev_err(dev, "rsense channel must be configured...\n"); + goto fail; + } + + if (fwnode_property_read_bool(child, "adi,single-ended")) { + thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1); + } else if (fwnode_property_read_bool(child, "adi,rsense-share")) { + /* rotation is only possible if sharing rsense */ + if (fwnode_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)) { + ret = PTR_ERR(thermistor->custom); + goto fail; + } + } + /* set common parameters */ + thermistor->sensor.fault_handler = ltc2983_common_fault_handler; + thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan; + + ret = fwnode_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; + } + } + + fwnode_handle_put(ref); + return &thermistor->sensor; +fail: + fwnode_handle_put(ref); + return ERR_PTR(ret); +} + +static struct ltc2983_sensor * +ltc2983_diode_new(const struct fwnode_handle *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 (fwnode_property_read_bool(child, "adi,single-ended")) + diode->sensor_config = LTC2983_DIODE_SGL(1); + + if (fwnode_property_read_bool(child, "adi,three-conversion-cycles")) + diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1); + + if (fwnode_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 = fwnode_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); + } + } + + fwnode_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 fwnode_handle *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 = fwnode_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 fwnode_handle *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 (fwnode_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 *dev = &st->spi->dev; + struct fwnode_handle *child; + int ret = 0, chan = 0, channel_avail_mask = 0; + + device_property_read_u32(dev, "adi,mux-delay-config-us", &st->mux_delay_config); + + device_property_read_u32(dev, "adi,filter-notch-freq", &st->filter_notch_freq); + + st->num_channels = device_get_child_node_count(dev); + if (!st->num_channels) { + dev_err(&st->spi->dev, "At least one channel must be given!"); + return -EINVAL; + } + + st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors), + GFP_KERNEL); + if (!st->sensors) + return -ENOMEM; + + st->iio_channels = st->num_channels; + device_for_each_child_node(dev, child) { + struct ltc2983_sensor sensor; + + ret = fwnode_property_read_u32(child, "reg", &sensor.chan); + if (ret) { + dev_err(dev, "reg property must given for child nodes\n"); + goto put_child; + } + + /* check if we have a valid channel */ + if (sensor.chan < LTC2983_MIN_CHANNELS_NR || + sensor.chan > LTC2983_MAX_CHANNELS_NR) { + ret = -EINVAL; + dev_err(dev, "chan:%d must be from %u to %u\n", sensor.chan, + LTC2983_MIN_CHANNELS_NR, LTC2983_MAX_CHANNELS_NR); + goto put_child; + } else if (channel_avail_mask & BIT(sensor.chan)) { + ret = -EINVAL; + dev_err(dev, "chan:%d already in use\n", sensor.chan); + goto put_child; + } + + ret = fwnode_property_read_u32(child, "adi,sensor-type", &sensor.type); + if (ret) { + dev_err(dev, + "adi,sensor-type property must given for child nodes\n"); + goto put_child; + } + + 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); + ret = -EINVAL; + goto put_child; + } + + if (IS_ERR(st->sensors[chan])) { + dev_err(dev, "Failed to create sensor %ld", + PTR_ERR(st->sensors[chan])); + ret = PTR_ERR(st->sensors[chan]); + goto put_child; + } + /* 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; +put_child: + fwnode_handle_put(child); + return ret; +} + +static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) +{ + u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status; + int ret; + + /* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */ + ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status, + LTC2983_STATUS_UP(status) == 1, 25000, + 25000 * 10); + if (ret) { + dev_err(&st->spi->dev, "Device startup timed out\n"); + return ret; + } + + 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; + struct gpio_desc *gpio; + 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; + + gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + + if (gpio) { + /* bring the device out of reset */ + usleep_range(1000, 1200); + gpiod_set_value_cansleep(gpio, 0); + } + + st->iio_chan = devm_kzalloc(&spi->dev, + st->iio_channels * sizeof(*st->iio_chan), + GFP_KERNEL); + if (!st->iio_chan) + return -ENOMEM; + + ret = ltc2983_setup(st, true); + if (ret) + return ret; + + 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; + } + + 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 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 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 DEFINE_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 = pm_sleep_ptr(<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"); |