Commit b4a95b8f authored by Dimitri Fedrau's avatar Dimitri Fedrau Committed by Sebastian Reichel
Browse files

power: supply: max1720x: add support for reading internal and thermistor temperatures 



If enabled in the nPackCfg register, the Temp1, Temp2 and IntTemp registers
contain the temperature readings from the AIN1 thermistor, AIN2 thermistor
and internal die temperature respectively. Registers are shared between SBS
and normal IC functions and are always readable regardless of IC settings.

Signed-off-by: default avatarDimitri Fedrau <dimitri.fedrau@liebherr.com>
Link: https://lore.kernel.org/r/20250116-max1720x-temperature-v2-1-9638969d091a@liebherr.com


Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 92c71aa1

Documentation/ABI/testing/sysfs-class-power-max1720x

0 → 100644
+32 −0
Original line number Diff line number Diff line 
What:		/sys/class/power_supply/max1720x/temp_ain1

Date:		January 2025

KernelVersion:	6.14

Contact:	Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Description:

		Reports the current temperature reading from AIN1 thermistor.



		Access: Read



		Valid values: Represented in 1/10 Degrees Celsius



What:		/sys/class/power_supply/max1720x/temp_ain2

Date:		January 2025

KernelVersion:	6.14

Contact:	Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Description:

		Reports the current temperature reading from AIN2 thermistor.



		Access: Read



		Valid values: Represented in 1/10 Degrees Celsius



What:		/sys/class/power_supply/max1720x/temp_int

Date:		January 2025

KernelVersion:	6.14

Contact:	Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Description:

		Reports the current temperature reading from internal die.



		Access: Read



		Valid values: Represented in 1/10 Degrees Celsius

drivers/power/supply/max1720x_battery.c

+59 −1
Original line number Diff line number Diff line
@@ -16,6 +16,11 @@ 


#include <linux/unaligned.h>



/* SBS compliant registers */

#define MAX172XX_TEMP1			0x34

#define MAX172XX_INT_TEMP		0x35

#define MAX172XX_TEMP2			0x3B



/* Nonvolatile registers */

#define MAX1720X_NXTABLE0		0x80

#define MAX1720X_NRSENSE		0xCF	/* RSense in 10^-5 Ohm */
@@ -113,11 +118,15 @@ static const struct regmap_config max1720x_regmap_cfg = { 
};



static const struct regmap_range max1720x_nvmem_allow[] = {

	regmap_reg_range(MAX172XX_TEMP1, MAX172XX_INT_TEMP),

	regmap_reg_range(MAX172XX_TEMP2, MAX172XX_TEMP2),

	regmap_reg_range(MAX1720X_NXTABLE0, MAX1720X_NDEVICE_NAME4),

};



static const struct regmap_range max1720x_nvmem_deny[] = {

	regmap_reg_range(0x00, 0x7F),

	regmap_reg_range(0x00, 0x33),

	regmap_reg_range(0x36, 0x3A),

	regmap_reg_range(0x3C, 0x7F),

	regmap_reg_range(0xE0, 0xFF),

};
@@ -388,6 +397,54 @@ static int max1720x_battery_get_property(struct power_supply *psy, 
	return ret;

}



static int max1720x_read_temp(struct device *dev, u8 reg, char *buf)

{

	struct power_supply *psy = dev_get_drvdata(dev);

	struct max1720x_device_info *info = power_supply_get_drvdata(psy);

	unsigned int val;

	int ret;



	ret = regmap_read(info->regmap_nv, reg, &val);

	if (ret < 0)

		return ret;



	/*

	 * Temperature in degrees Celsius starting at absolute zero, -273C or

	 * 0K with an LSb of 0.1C

	 */

	return sysfs_emit(buf, "%d\n", val - 2730);

}



static ssize_t temp_ain1_show(struct device *dev, struct device_attribute *attr,

			      char *buf)

{

	return max1720x_read_temp(dev, MAX172XX_TEMP1, buf);

}



static ssize_t temp_ain2_show(struct device *dev, struct device_attribute *attr,

			      char *buf)

{

	return max1720x_read_temp(dev, MAX172XX_TEMP2, buf);

}



static ssize_t temp_int_show(struct device *dev, struct device_attribute *attr,

			     char *buf)

{

	return max1720x_read_temp(dev, MAX172XX_INT_TEMP, buf);

}



static DEVICE_ATTR_RO(temp_ain1);

static DEVICE_ATTR_RO(temp_ain2);

static DEVICE_ATTR_RO(temp_int);



static struct attribute *max1720x_attrs[] = {

	&dev_attr_temp_ain1.attr,

	&dev_attr_temp_ain2.attr,

	&dev_attr_temp_int.attr,

	NULL

};

ATTRIBUTE_GROUPS(max1720x);



static

int max1720x_nvmem_reg_read(void *priv, unsigned int off, void *val, size_t len)

{
@@ -488,6 +545,7 @@ static int max1720x_probe(struct i2c_client *client) 


	psy_cfg.drv_data = info;

	psy_cfg.fwnode = dev_fwnode(dev);

	psy_cfg.attr_grp = max1720x_groups;

	i2c_set_clientdata(client, info);

	info->regmap = devm_regmap_init_i2c(client, &max1720x_regmap_cfg);

	if (IS_ERR(info->regmap))