Commit 6f7cadcf authored by Cosmin Tanislav's avatar Cosmin Tanislav Committed by Jonathan Cameron
Browse files

iio: temperature: ltc2983: support more parts 



Add support for the following parts:
 * LTC2984
 * LTC2986
 * LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Signed-off-by: default avatarCosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20221103130041.2153295-14-demonsingur@gmail.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent d2405269

drivers/iio/temperature/ltc2983.c

+176 −7
Original line number Diff line number Diff line
@@ -25,9 +25,12 @@ 
#define LTC2983_STATUS_REG			0x0000

#define LTC2983_TEMP_RES_START_REG		0x0010

#define LTC2983_TEMP_RES_END_REG		0x005F

#define LTC2983_EEPROM_KEY_REG			0x00B0

#define LTC2983_EEPROM_READ_STATUS_REG		0x00D0

#define LTC2983_GLOBAL_CONFIG_REG		0x00F0

#define LTC2983_MULT_CHANNEL_START_REG		0x00F4

#define LTC2983_MULT_CHANNEL_END_REG		0x00F7

#define LTC2986_EEPROM_STATUS_REG		0x00F9

#define LTC2983_MUX_CONFIG_REG			0x00FF

#define LTC2983_CHAN_ASSIGN_START_REG		0x0200

#define LTC2983_CHAN_ASSIGN_END_REG		0x024F
@@ -35,13 +38,21 @@ 
#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_EEPROM_KEY			0xA53C0F5A

#define LTC2983_EEPROM_WRITE_CMD		0x15

#define LTC2983_EEPROM_READ_CMD			0x16

#define LTC2983_EEPROM_STATUS_FAILURE_MASK	GENMASK(3, 1)

#define LTC2983_EEPROM_READ_FAILURE_MASK	GENMASK(7, 0)



#define LTC2983_EEPROM_WRITE_TIME_MS		2600

#define LTC2983_EEPROM_READ_TIME_MS		20



#define LTC2983_CHAN_START_ADDR(chan) \

			(((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)

#define LTC2983_CHAN_RES_ADDR(chan) \
@@ -171,6 +182,7 @@ enum { 
	LTC2983_SENSOR_DIODE = 28,

	LTC2983_SENSOR_SENSE_RESISTOR = 29,

	LTC2983_SENSOR_DIRECT_ADC = 30,

	LTC2983_SENSOR_ACTIVE_TEMP = 31,

};



#define to_thermocouple(_sensor) \
@@ -191,7 +203,17 @@ enum { 
#define to_adc(_sensor) \

		container_of(_sensor, struct ltc2983_adc, sensor)



#define to_temp(_sensor) \

		container_of(_sensor, struct ltc2983_temp, sensor)



struct ltc2983_chip_info {

	unsigned int max_channels_nr;

	bool has_temp;

	bool has_eeprom;

};



struct ltc2983_data {

	const struct ltc2983_chip_info *info;

	struct regmap *regmap;

	struct spi_device *spi;

	struct mutex lock;
@@ -210,6 +232,7 @@ struct ltc2983_data { 
	 */

	__be32 temp __aligned(IIO_DMA_MINALIGN);

	__be32 chan_val;

	__be32 eeprom_key;

};



struct ltc2983_sensor {
@@ -272,6 +295,12 @@ struct ltc2983_adc { 
	bool single_ended;

};



struct ltc2983_temp {

	struct ltc2983_sensor sensor;

	struct ltc2983_custom_sensor *custom;

	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
@@ -606,6 +635,22 @@ static int ltc2983_adc_assign_chan(struct ltc2983_data *st, 
	return __ltc2983_chan_assign_common(st, sensor, chan_val);

}



static int ltc2983_temp_assign_chan(struct ltc2983_data *st,

				    const struct ltc2983_sensor *sensor)

{

	struct ltc2983_temp *temp = to_temp(sensor);

	u32 chan_val;

	int ret;



	chan_val = LTC2983_ADC_SINGLE_ENDED(temp->single_ended);



	ret = __ltc2983_chan_custom_sensor_assign(st, temp->custom, &chan_val);

	if (ret)

		return ret;



	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)
@@ -771,10 +816,10 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st, 
	if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {

		/* 4-wire */

		u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,

			max = LTC2983_MAX_CHANNELS_NR;

			max = st->info->max_channels_nr;



		if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)

			max = LTC2983_MAX_CHANNELS_NR - 1;

			max = st->info->max_channels_nr - 1;



		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)

		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
@@ -1143,6 +1188,38 @@ static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child, 
	return &adc->sensor;

}



static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,

					       struct ltc2983_data *st,

					       const struct ltc2983_sensor *sensor)

{

	struct ltc2983_temp *temp;



	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);

	if (!temp)

		return ERR_PTR(-ENOMEM);



	if (fwnode_property_read_bool(child, "adi,single-ended"))

		temp->single_ended = true;



	if (!temp->single_ended &&

	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {

		dev_err(&st->spi->dev, "Invalid chan:%d for differential temp\n",

			sensor->chan);

		return ERR_PTR(-EINVAL);

	}



	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",

						   false, 4096, true);

	if (IS_ERR(temp->custom))

		return ERR_CAST(temp->custom);



	/* set common parameters */

	temp->sensor.assign_chan = ltc2983_temp_assign_chan;

	temp->sensor.fault_handler = ltc2983_common_fault_handler;



	return &temp->sensor;

}



static int ltc2983_chan_read(struct ltc2983_data *st,

			const struct ltc2983_sensor *sensor, int *val)

{
@@ -1302,10 +1379,10 @@ static int ltc2983_parse_dt(struct ltc2983_data *st) 


		/* check if we have a valid channel */

		if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||

		    sensor.chan > LTC2983_MAX_CHANNELS_NR) {

		    sensor.chan > st->info->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);

				LTC2983_MIN_CHANNELS_NR, st->info->max_channels_nr);

			goto put_child;

		} else if (channel_avail_mask & BIT(sensor.chan)) {

			ret = -EINVAL;
@@ -1345,6 +1422,9 @@ static int ltc2983_parse_dt(struct ltc2983_data *st) 
			st->iio_channels--;

		} else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {

			st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);

		} else if (st->info->has_temp &&

			   sensor.type == LTC2983_SENSOR_ACTIVE_TEMP) {

			st->sensors[chan] = ltc2983_temp_new(child, st, &sensor);

		} else {

			dev_err(dev, "Unknown sensor type %d\n", sensor.type);

			ret = -EINVAL;
@@ -1371,6 +1451,45 @@ static int ltc2983_parse_dt(struct ltc2983_data *st) 
	return ret;

}



static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,

			      unsigned int wait_time, unsigned int status_reg,

			      unsigned long status_fail_mask)

{

	unsigned long time;

	unsigned int val;

	int ret;



	ret = regmap_bulk_write(st->regmap, LTC2983_EEPROM_KEY_REG,

				&st->eeprom_key, sizeof(st->eeprom_key));

	if (ret)

		return ret;



	reinit_completion(&st->completion);



	ret = regmap_write(st->regmap, LTC2983_STATUS_REG,

			   LTC2983_STATUS_START(true) | cmd);

	if (ret)

		return ret;



	time = wait_for_completion_timeout(&st->completion,

					   msecs_to_jiffies(wait_time));

	if (!time) {

		dev_err(&st->spi->dev, "EEPROM command timed out\n");

		return -ETIMEDOUT;

	}



	ret = regmap_read(st->regmap, status_reg, &val);

	if (ret)

		return ret;



	if (val & status_fail_mask) {

		dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);

		return -EINVAL;

	}



	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, status;
@@ -1396,6 +1515,15 @@ static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) 
	if (ret)

		return ret;



	if (st->info->has_eeprom && !assign_iio) {

		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_READ_CMD,

					 LTC2983_EEPROM_READ_TIME_MS,

					 LTC2983_EEPROM_READ_STATUS_REG,

					 LTC2983_EEPROM_READ_FAILURE_MASK);

		if (!ret)

			return 0;

	}



	for (chan = 0; chan < st->num_channels; chan++) {

		u32 chan_type = 0, *iio_chan;
@@ -1435,9 +1563,13 @@ static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio) 
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_EEPROM_KEY_REG, LTC2983_EEPROM_KEY_REG),

	regmap_reg_range(LTC2983_EEPROM_READ_STATUS_REG,

			 LTC2983_EEPROM_READ_STATUS_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(LTC2986_EEPROM_STATUS_REG, LTC2986_EEPROM_STATUS_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),
@@ -1482,6 +1614,12 @@ static int ltc2983_probe(struct spi_device *spi) 


	st = iio_priv(indio_dev);



	st->info = device_get_match_data(&spi->dev);

	if (!st->info)

		st->info = (void *)spi_get_device_id(spi)->driver_data;

	if (!st->info)

		return -ENODEV;



	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);

	if (IS_ERR(st->regmap)) {

		dev_err(&spi->dev, "Failed to initialize regmap\n");
@@ -1491,6 +1629,7 @@ static int ltc2983_probe(struct spi_device *spi) 
	mutex_init(&st->lock);

	init_completion(&st->completion);

	st->spi = spi;

	st->eeprom_key = cpu_to_be32(LTC2983_EEPROM_KEY);

	spi_set_drvdata(spi, st);



	ret = ltc2983_parse_dt(st);
@@ -1524,6 +1663,15 @@ static int ltc2983_probe(struct spi_device *spi) 
		return ret;

	}



	if (st->info->has_eeprom) {

		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,

					 LTC2983_EEPROM_WRITE_TIME_MS,

					 LTC2986_EEPROM_STATUS_REG,

					 LTC2983_EEPROM_STATUS_FAILURE_MASK);

		if (ret)

			return ret;

	}



	indio_dev->name = name;

	indio_dev->num_channels = st->iio_channels;

	indio_dev->channels = st->iio_chan;
@@ -1554,14 +1702,35 @@ static int ltc2983_suspend(struct device *dev) 
static DEFINE_SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend,

				ltc2983_resume);



static const struct ltc2983_chip_info ltc2983_chip_info_data = {

	.max_channels_nr = 20,

};



static const struct ltc2983_chip_info ltc2984_chip_info_data = {

	.max_channels_nr = 20,

	.has_eeprom = true,

};



static const struct ltc2983_chip_info ltc2986_chip_info_data = {

	.max_channels_nr = 10,

	.has_temp = true,

	.has_eeprom = true,

};



static const struct spi_device_id ltc2983_id_table[] = {

	{ "ltc2983" },

	{ "ltc2983", (kernel_ulong_t)&ltc2983_chip_info_data },

	{ "ltc2984", (kernel_ulong_t)&ltc2984_chip_info_data },

	{ "ltc2986", (kernel_ulong_t)&ltc2986_chip_info_data },

	{ "ltm2985", (kernel_ulong_t)&ltc2986_chip_info_data },

	{},

};

MODULE_DEVICE_TABLE(spi, ltc2983_id_table);



static const struct of_device_id ltc2983_of_match[] = {

	{ .compatible = "adi,ltc2983" },

	{ .compatible = "adi,ltc2983", .data = &ltc2983_chip_info_data },

	{ .compatible = "adi,ltc2984", .data = &ltc2984_chip_info_data },

	{ .compatible = "adi,ltc2986", .data = &ltc2986_chip_info_data },

	{ .compatible = "adi,ltm2985", .data = &ltc2986_chip_info_data },

	{},

};

MODULE_DEVICE_TABLE(of, ltc2983_of_match);