Commit ec5d234f authored by Amna Waseem's avatar Amna Waseem Committed by Guenter Roeck
Browse files

hwmon: (ina2xx) Add device tree support to pass alert polarity 



The INA230 has an Alert pin which is asserted when the alert
function selected in the Mask/Enable register exceeds the
value programmed into the Alert Limit register. Assertion is based
on the Alert Polarity Bit (APOL, bit 1 of the Mask/Enable register).
It is default set to value 0 i.e Normal (active-low open collector).
However, hardware can be designed in such a way that expects Alert pin
to become active high if a user-defined threshold in Alert limit
register has been exceeded. This patch adds a way to pass alert polarity
value to the driver via device tree.

Signed-off-by: default avatarAmna Waseem <Amna.Waseem@axis.com>
Link: https://lore.kernel.org/r/20240611-apol-ina2xx-fix-v4-2-8df1d2282fc5@axis.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 94e33109

drivers/hwmon/ina2xx.c

+32 −0
Original line number Diff line number Diff line
@@ -73,6 +73,11 @@ 
#define INA226_READ_AVG(reg)		(((reg) & INA226_AVG_RD_MASK) >> 9)

#define INA226_SHIFT_AVG(val)		((val) << 9)



#define INA226_ALERT_POLARITY_MASK		0x0002

#define INA226_SHIFT_ALERT_POLARITY(val)	((val) << 1)

#define INA226_ALERT_POL_LOW			0

#define INA226_ALERT_POL_HIGH			1



/* bit number of alert functions in Mask/Enable Register */

#define INA226_SHUNT_OVER_VOLTAGE_BIT	15

#define INA226_SHUNT_UNDER_VOLTAGE_BIT	14
@@ -178,6 +183,14 @@ static u16 ina226_interval_to_reg(int interval) 
	return INA226_SHIFT_AVG(avg_bits);

}



static int ina2xx_set_alert_polarity(struct ina2xx_data *data,

				     unsigned long val)

{

	return regmap_update_bits(data->regmap, INA226_MASK_ENABLE,

				 INA226_ALERT_POLARITY_MASK,

				 INA226_SHIFT_ALERT_POLARITY(val));

}



/*

 * Calibration register is set to the best value, which eliminates

 * truncation errors on calculating current register in hardware.
@@ -654,6 +667,25 @@ static int ina2xx_probe(struct i2c_client *client) 
	if (ret)

		return dev_err_probe(dev, ret, "failed to enable vs regulator\n");



	if (chip == ina226) {

		if (of_property_read_bool(dev->of_node, "ti,alert-polarity-active-high")) {

			ret = ina2xx_set_alert_polarity(data,

							INA226_ALERT_POL_HIGH);

			if (ret < 0) {

				return dev_err_probe(dev, ret,

					"failed to set alert polarity active high\n");

			}

		} else {

			/* Set default value i.e active low */

			ret = ina2xx_set_alert_polarity(data,

							INA226_ALERT_POL_LOW);

			if (ret < 0) {

				return dev_err_probe(dev, ret,

					"failed to set alert polarity active low\n");

			}

		}

	}



	ret = ina2xx_init(data);

	if (ret < 0) {

		dev_err(dev, "error configuring the device: %d\n", ret);