Commit 023912db authored by Nicolin Chen's avatar Nicolin Chen Committed by Guenter Roeck
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hwmon: (ina3221) Add voltage conversion time settings 



The CONFIG register has two 3-bit fields for conversion time
settings of Bus-voltage and Shunt-voltage, respectively. The
conversion settings, along with averaging mode, allow users
to optimize available timing requirement.

This patch adds an 'update_interval' sysfs node through the
hwmon_chip_info of hwmon core. It reflects a total hardware
conversion time:
    samples * channels * (Bus + Shunt conversion times)

Though INA3221 supports different conversion time setups for
Bus and Shunt voltages, this patch only adds the support of
a unified setting for both conversion times, by dividing the
conversion time into two equal values.

Signed-off-by: default avatarNicolin Chen <nicoleotsuka@gmail.com>
[groeck: .rst related formatting changes in documentation]
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 521c0b61

Documentation/hwmon/ina3221.rst

+13 −0
Original line number Diff line number Diff line
@@ -46,4 +46,17 @@ samples Number of samples using in the averaging mode. 
                        Supports the list of number of samples:



                          1, 4, 16, 64, 128, 256, 512, 1024



update_interval         Data conversion time in millisecond, following:



                          update_interval = C x S x (BC + SC)



                          * C:	number of enabled channels

                          * S:	number of samples

                          * BC:	bus-voltage conversion time in millisecond

                          * SC:	shunt-voltage conversion time in millisecond



                        Affects both Bus- and Shunt-voltage conversion time.

                        Note that setting update_interval to 0ms sets both BC

                        and SC to 140 us (minimum conversion time).

======================= =======================================================

drivers/hwmon/ina3221.c

+50 −8
Original line number Diff line number Diff line
@@ -144,19 +144,37 @@ static const int ina3221_avg_samples[] = { 
	1, 4, 16, 64, 128, 256, 512, 1024,

};



static inline int ina3221_wait_for_data(struct ina3221_data *ina)

/* Converting update_interval in msec to conversion time in usec */

static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)

{

	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);

	u32 samples_idx = INA3221_CONFIG_AVG(config);

	u32 samples = ina3221_avg_samples[samples_idx];



	/* Bisect the result to Bus and Shunt conversion times */

	return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);

}



/* Converting CONFIG register value to update_interval in usec */

static inline u32 ina3221_reg_to_interval_us(u16 config)

{

	u32 channels = hweight16(ina->reg_config & INA3221_CONFIG_CHs_EN_MASK);

	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(ina->reg_config);

	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(ina->reg_config);

	u32 samples_idx = INA3221_CONFIG_AVG(ina->reg_config);

	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);

	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);

	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);

	u32 samples_idx = INA3221_CONFIG_AVG(config);

	u32 samples = ina3221_avg_samples[samples_idx];

	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];

	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];

	u32 wait, cvrf;



	/* Calculate total conversion time */

	wait = channels * (vbus_ct + vsh_ct) * samples;

	return channels * (vbus_ct + vsh_ct) * samples;

}



static inline int ina3221_wait_for_data(struct ina3221_data *ina)

{

	u32 wait, cvrf;



	wait = ina3221_reg_to_interval_us(ina->reg_config);



	/* Polling the CVRF bit to make sure read data is ready */

	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
@@ -197,6 +215,11 @@ static int ina3221_read_chip(struct device *dev, u32 attr, long *val) 
		regval = INA3221_CONFIG_AVG(ina->reg_config);

		*val = ina3221_avg_samples[regval];

		return 0;

	case hwmon_chip_update_interval:

		/* Return in msec */

		*val = ina3221_reg_to_interval_us(ina->reg_config);

		*val = DIV_ROUND_CLOSEST(*val, 1000);

		return 0;

	default:

		return -EOPNOTSUPP;

	}
@@ -322,6 +345,23 @@ static int ina3221_write_chip(struct device *dev, u32 attr, long val) 
		if (ret)

			return ret;



		/* Update reg_config accordingly */

		ina->reg_config = tmp;

		return 0;

	case hwmon_chip_update_interval:

		tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);

		idx = find_closest(tmp, ina3221_conv_time,

				   ARRAY_SIZE(ina3221_conv_time));



		/* Update Bus and Shunt voltage conversion times */

		tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;

		tmp = (ina->reg_config & ~tmp) |

		      (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |

		      (idx << INA3221_CONFIG_VSH_CT_SHIFT);

		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);

		if (ret)

			return ret;



		/* Update reg_config accordingly */

		ina->reg_config = tmp;

		return 0;
@@ -483,6 +523,7 @@ static umode_t ina3221_is_visible(const void *drvdata, 
	case hwmon_chip:

		switch (attr) {

		case hwmon_chip_samples:

		case hwmon_chip_update_interval:

			return 0644;

		default:

			return 0;
@@ -528,7 +569,8 @@ static umode_t ina3221_is_visible(const void *drvdata, 


static const struct hwmon_channel_info *ina3221_info[] = {

	HWMON_CHANNEL_INFO(chip,

			   HWMON_C_SAMPLES),

			   HWMON_C_SAMPLES,

			   HWMON_C_UPDATE_INTERVAL),

	HWMON_CHANNEL_INFO(in,

			   /* 0: dummy, skipped in is_visible */

			   HWMON_I_INPUT,

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