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kernel/drivers/iio/temperature/ltc2983.c

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// 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_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) 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 ? 4 : 3;
const u8 e_size = is_steinhart ? 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 {
u32 t32;
of_property_read_u32_index(np, propname, index, &t32);
temp = t32;
}
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);
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;
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");
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 1 to 20\n", sensor.chan);
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 = 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");
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:
of_node_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;
}
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 = &ltc2983_reg_table,
.rd_table = &ltc2983_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, &ltc2983_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);
}
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 = &ltc2983_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 = &ltc2983_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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