[PATCH 00/11] hwmon: (ina2xx) Cleanup and convert to use with_info API

[PATCH 00/11] hwmon: (ina2xx) Cleanup and convert to use with_info API

[Guenter Roeck]

Clean up driver and convert to use with_info API to simplify driver
maintenance.

----------------------------------------------------------------
Guenter Roeck (11):
      hwmon: (ina2xx) Reorder include files to alphabetic order
      hwmon: (ina2xx) Replace platform data with device properties
      hwmon: (ina2xx) Use bit operations
      hwmon: (ina2xx) Mark regmap_config as const
      hwmon: (ina2xx) Use local regmap pointer if used more than once
      hwmon: (ina2xx) Re-initialize chip using regmap functions
      hwmon: (ina2xx) Set alert latch when enabling alerts
      hwmon: (ina2xx) Fix various overflow issues
      hwmon: (ina2xx) Consolidate chip initialization code
      hwmon: (ina2xx) Move ina2xx_get_value()
      hwmon: (ina2xx) Convert to use with_info hwmon API

 drivers/hwmon/ina2xx.c | 822 +++++++++++++++++++++++++++----------------------
 1 file changed, 453 insertions(+), 369 deletions(-)

[PATCH 01/11] hwmon: (ina2xx) Reorder include files to alphabetic order

[Guenter Roeck]

Simplify driver maintenance by reordering include files to alphabetic
order.

Whule at it, drop unnecessary / unused jiffies.h.

No functional change.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 9ab4205622e2..a6a619a85eb6 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -22,19 +22,18 @@
  * Thanks to Jan Volkering
  */
 
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
-#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
-#include <linux/delay.h>
-#include <linux/util_macros.h>
 #include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/util_macros.h>
 
 #include <linux/platform_data/ina2xx.h>
 
-- 
2.45.2

Re: [PATCH 01/11] hwmon: (ina2xx) Reorder include files to alphabetic order

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:45AM -0700, Guenter Roeck wrote:
> Simplify driver maintenance by reordering include files to alphabetic
> order.
> 
> Whule at it, drop unnecessary / unused jiffies.h.
> 
> No functional change.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

[PATCH 02/11] hwmon: (ina2xx) Replace platform data with device properties

[Guenter Roeck]

There are no in-tree users of ina2xx platform data. Drop it and support
device properties instead as alternative if it should ever be needed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index a6a619a85eb6..897657f8d685 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -30,13 +30,11 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/util_macros.h>
 
-#include <linux/platform_data/ina2xx.h>
-
 /* common register definitions */
 #define INA2XX_CONFIG			0x00
 #define INA2XX_SHUNT_VOLTAGE		0x01 /* readonly */
@@ -643,14 +641,8 @@ static int ina2xx_probe(struct i2c_client *client)
 	data->config = &ina2xx_config[chip];
 	mutex_init(&data->config_lock);
 
-	if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
-		struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
-
-		if (pdata)
-			val = pdata->shunt_uohms;
-		else
-			val = INA2XX_RSHUNT_DEFAULT;
-	}
+	if (device_property_read_u32(dev, "shunt-resistor", &val) < 0)
+		val = INA2XX_RSHUNT_DEFAULT;
 
 	ina2xx_set_shunt(data, val);
 
@@ -667,7 +659,7 @@ static int ina2xx_probe(struct i2c_client *client)
 		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")) {
+		if (device_property_read_bool(dev, "ti,alert-polarity-active-high")) {
 			ret = ina2xx_set_alert_polarity(data,
 							INA226_ALERT_POL_HIGH);
 			if (ret < 0) {
-- 
2.45.2

Re: [PATCH 02/11] hwmon: (ina2xx) Replace platform data with device properties

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:46AM -0700, Guenter Roeck wrote:
> There are no in-tree users of ina2xx platform data. Drop it and support
> device properties instead as alternative if it should ever be needed.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

[PATCH 03/11] hwmon: (ina2xx) Use bit operations

[Guenter Roeck]

Use bit operations where possible to make the code more generic and to
align it with other drivers. Also use compile time conversion from bit
to mask to reduce runtime overhead.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 84 +++++++++++++++++++++---------------------
 1 file changed, 42 insertions(+), 42 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 897657f8d685..1b4170d02c94 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -22,6 +22,8 @@
  * Thanks to Jan Volkering
  */
 
+#include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
@@ -65,25 +67,23 @@
 #define INA2XX_RSHUNT_DEFAULT		10000
 
 /* bit mask for reading the averaging setting in the configuration register */
-#define INA226_AVG_RD_MASK		0x0E00
+#define INA226_AVG_RD_MASK		GENMASK(11, 9)
 
-#define INA226_READ_AVG(reg)		(((reg) & INA226_AVG_RD_MASK) >> 9)
-#define INA226_SHIFT_AVG(val)		((val) << 9)
+#define INA226_READ_AVG(reg)		FIELD_GET(INA226_AVG_RD_MASK, reg)
 
-#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
+#define INA226_ALERT_POLARITY_MASK	BIT(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
-#define INA226_BUS_OVER_VOLTAGE_BIT	13
-#define INA226_BUS_UNDER_VOLTAGE_BIT	12
-#define INA226_POWER_OVER_LIMIT_BIT	11
+#define INA226_SHUNT_OVER_VOLTAGE_MASK	BIT(15)
+#define INA226_SHUNT_UNDER_VOLTAGE_MASK	BIT(14)
+#define INA226_BUS_OVER_VOLTAGE_MASK	BIT(13)
+#define INA226_BUS_UNDER_VOLTAGE_MASK	BIT(12)
+#define INA226_POWER_OVER_LIMIT_MASK	BIT(11)
 
 /* bit mask for alert config bits of Mask/Enable Register */
-#define INA226_ALERT_CONFIG_MASK	0xFC00
+#define INA226_ALERT_CONFIG_MASK	GENMASK(15, 10)
 #define INA226_ALERT_FUNCTION_FLAG	BIT(4)
 
 /* common attrs, ina226 attrs and NULL */
@@ -177,7 +177,7 @@ static u16 ina226_interval_to_reg(int interval)
 	avg_bits = find_closest(avg, ina226_avg_tab,
 				ARRAY_SIZE(ina226_avg_tab));
 
-	return INA226_SHIFT_AVG(avg_bits);
+	return FIELD_PREP(INA226_AVG_RD_MASK, avg_bits);
 }
 
 static int ina2xx_set_alert_polarity(struct ina2xx_data *data,
@@ -185,7 +185,7 @@ static int ina2xx_set_alert_polarity(struct ina2xx_data *data,
 {
 	return regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
 				 INA226_ALERT_POLARITY_MASK,
-				 INA226_SHIFT_ALERT_POLARITY(val));
+				 FIELD_PREP(INA226_ALERT_POLARITY_MASK, val));
 }
 
 /*
@@ -322,20 +322,20 @@ static ssize_t ina2xx_value_show(struct device *dev,
 	return sysfs_emit(buf, "%d\n", ina2xx_get_value(data, attr->index, regval));
 }
 
-static int ina226_reg_to_alert(struct ina2xx_data *data, u8 bit, u16 regval)
+static int ina226_reg_to_alert(struct ina2xx_data *data, u32 mask, u16 regval)
 {
 	int reg;
 
-	switch (bit) {
-	case INA226_SHUNT_OVER_VOLTAGE_BIT:
-	case INA226_SHUNT_UNDER_VOLTAGE_BIT:
+	switch (mask) {
+	case INA226_SHUNT_OVER_VOLTAGE_MASK:
+	case INA226_SHUNT_UNDER_VOLTAGE_MASK:
 		reg = INA2XX_SHUNT_VOLTAGE;
 		break;
-	case INA226_BUS_OVER_VOLTAGE_BIT:
-	case INA226_BUS_UNDER_VOLTAGE_BIT:
+	case INA226_BUS_OVER_VOLTAGE_MASK:
+	case INA226_BUS_UNDER_VOLTAGE_MASK:
 		reg = INA2XX_BUS_VOLTAGE;
 		break;
-	case INA226_POWER_OVER_LIMIT_BIT:
+	case INA226_POWER_OVER_LIMIT_MASK:
 		reg = INA2XX_POWER;
 		break;
 	default:
@@ -351,19 +351,19 @@ static int ina226_reg_to_alert(struct ina2xx_data *data, u8 bit, u16 regval)
  * Turns alert limit values into register values.
  * Opposite of the formula in ina2xx_get_value().
  */
-static s16 ina226_alert_to_reg(struct ina2xx_data *data, u8 bit, int val)
+static s16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, int val)
 {
-	switch (bit) {
-	case INA226_SHUNT_OVER_VOLTAGE_BIT:
-	case INA226_SHUNT_UNDER_VOLTAGE_BIT:
+	switch (mask) {
+	case INA226_SHUNT_OVER_VOLTAGE_MASK:
+	case INA226_SHUNT_UNDER_VOLTAGE_MASK:
 		val *= data->config->shunt_div;
 		return clamp_val(val, SHRT_MIN, SHRT_MAX);
-	case INA226_BUS_OVER_VOLTAGE_BIT:
-	case INA226_BUS_UNDER_VOLTAGE_BIT:
+	case INA226_BUS_OVER_VOLTAGE_MASK:
+	case INA226_BUS_UNDER_VOLTAGE_MASK:
 		val = (val * 1000) << data->config->bus_voltage_shift;
 		val = DIV_ROUND_CLOSEST(val, data->config->bus_voltage_lsb);
 		return clamp_val(val, 0, SHRT_MAX);
-	case INA226_POWER_OVER_LIMIT_BIT:
+	case INA226_POWER_OVER_LIMIT_MASK:
 		val = DIV_ROUND_CLOSEST(val, data->power_lsb_uW);
 		return clamp_val(val, 0, USHRT_MAX);
 	default:
@@ -387,7 +387,7 @@ static ssize_t ina226_alert_show(struct device *dev,
 	if (ret)
 		goto abort;
 
-	if (regval & BIT(attr->index)) {
+	if (regval & attr->index) {
 		ret = regmap_read(data->regmap, INA226_ALERT_LIMIT, &regval);
 		if (ret)
 			goto abort;
@@ -432,7 +432,7 @@ static ssize_t ina226_alert_store(struct device *dev,
 	if (val != 0) {
 		ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
 					 INA226_ALERT_CONFIG_MASK,
-					 BIT(attr->index));
+					 attr->index);
 		if (ret < 0)
 			goto abort;
 	}
@@ -456,7 +456,7 @@ static ssize_t ina226_alarm_show(struct device *dev,
 	if (ret)
 		return ret;
 
-	alarm = (regval & BIT(attr->index)) &&
+	alarm = (regval & attr->index) &&
 		(regval & INA226_ALERT_FUNCTION_FLAG);
 	return sysfs_emit(buf, "%d\n", alarm);
 }
@@ -552,25 +552,25 @@ static ssize_t ina226_interval_show(struct device *dev,
 static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE);
 /* shunt voltage over/under voltage alert setting and alarm */
 static SENSOR_DEVICE_ATTR_RW(in0_crit, ina226_alert,
-			     INA226_SHUNT_OVER_VOLTAGE_BIT);
+			     INA226_SHUNT_OVER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RW(in0_lcrit, ina226_alert,
-			     INA226_SHUNT_UNDER_VOLTAGE_BIT);
+			     INA226_SHUNT_UNDER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RO(in0_crit_alarm, ina226_alarm,
-			     INA226_SHUNT_OVER_VOLTAGE_BIT);
+			     INA226_SHUNT_OVER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RO(in0_lcrit_alarm, ina226_alarm,
-			     INA226_SHUNT_UNDER_VOLTAGE_BIT);
+			     INA226_SHUNT_UNDER_VOLTAGE_MASK);
 
 /* bus voltage */
 static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE);
 /* bus voltage over/under voltage alert setting and alarm */
 static SENSOR_DEVICE_ATTR_RW(in1_crit, ina226_alert,
-			     INA226_BUS_OVER_VOLTAGE_BIT);
+			     INA226_BUS_OVER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RW(in1_lcrit, ina226_alert,
-			     INA226_BUS_UNDER_VOLTAGE_BIT);
+			     INA226_BUS_UNDER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RO(in1_crit_alarm, ina226_alarm,
-			     INA226_BUS_OVER_VOLTAGE_BIT);
+			     INA226_BUS_OVER_VOLTAGE_MASK);
 static SENSOR_DEVICE_ATTR_RO(in1_lcrit_alarm, ina226_alarm,
-			     INA226_BUS_UNDER_VOLTAGE_BIT);
+			     INA226_BUS_UNDER_VOLTAGE_MASK);
 
 /* calculated current */
 static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
@@ -579,9 +579,9 @@ static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
 static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER);
 /* over-limit power alert setting and alarm */
 static SENSOR_DEVICE_ATTR_RW(power1_crit, ina226_alert,
-			     INA226_POWER_OVER_LIMIT_BIT);
+			     INA226_POWER_OVER_LIMIT_MASK);
 static SENSOR_DEVICE_ATTR_RO(power1_crit_alarm, ina226_alarm,
-			     INA226_POWER_OVER_LIMIT_BIT);
+			     INA226_POWER_OVER_LIMIT_MASK);
 
 /* shunt resistance */
 static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION);
-- 
2.45.2

Re: [PATCH 03/11] hwmon: (ina2xx) Use bit operations

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:47AM -0700, Guenter Roeck wrote:
> Use bit operations where possible to make the code more generic and to
> align it with other drivers. Also use compile time conversion from bit
> to mask to reduce runtime overhead.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

[PATCH 04/11] hwmon: (ina2xx) Mark regmap_config as const

[Guenter Roeck]

Recent versions of checkpatch complain that struct regmap_config
should be declared as const.

WARNING: struct regmap_config should normally be const

Doing so reveals a potential problem in the driver: If both supported
chips are present in a single system, the maximum number of registers
may race when devic es are instantiated since max_registers is updated
in the probe function. Solve the problem by setting .max_registers to the
maximum register address of all supported chips. This does not make a
practical difference while fixing the potential race condition and reducing
code complexity.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 1b4170d02c94..9d93190874d7 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -50,10 +50,6 @@
 #define INA226_ALERT_LIMIT		0x07
 #define INA226_DIE_ID			0xFF
 
-/* register count */
-#define INA219_REGISTERS		6
-#define INA226_REGISTERS		8
-
 #define INA2XX_MAX_REGISTERS		8
 
 /* settings - depend on use case */
@@ -95,9 +91,10 @@
  */
 #define INA226_TOTAL_CONV_TIME_DEFAULT	2200
 
-static struct regmap_config ina2xx_regmap_config = {
+static const struct regmap_config ina2xx_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
+	.max_register = INA2XX_MAX_REGISTERS,
 };
 
 enum ina2xx_ids { ina219, ina226 };
@@ -105,7 +102,6 @@ enum ina2xx_ids { ina219, ina226 };
 struct ina2xx_config {
 	u16 config_default;
 	int calibration_value;
-	int registers;
 	int shunt_div;
 	int bus_voltage_shift;
 	int bus_voltage_lsb;	/* uV */
@@ -128,7 +124,6 @@ static const struct ina2xx_config ina2xx_config[] = {
 	[ina219] = {
 		.config_default = INA219_CONFIG_DEFAULT,
 		.calibration_value = 4096,
-		.registers = INA219_REGISTERS,
 		.shunt_div = 100,
 		.bus_voltage_shift = 3,
 		.bus_voltage_lsb = 4000,
@@ -137,7 +132,6 @@ static const struct ina2xx_config ina2xx_config[] = {
 	[ina226] = {
 		.config_default = INA226_CONFIG_DEFAULT,
 		.calibration_value = 2048,
-		.registers = INA226_REGISTERS,
 		.shunt_div = 400,
 		.bus_voltage_shift = 0,
 		.bus_voltage_lsb = 1250,
@@ -646,8 +640,6 @@ static int ina2xx_probe(struct i2c_client *client)
 
 	ina2xx_set_shunt(data, val);
 
-	ina2xx_regmap_config.max_register = data->config->registers;
-
 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(dev, "failed to allocate register map\n");
-- 
2.45.2

Re: [PATCH 04/11] hwmon: (ina2xx) Mark regmap_config as const

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:48AM -0700, Guenter Roeck wrote:
> Doing so reveals a potential problem in the driver: If both supported
> chips are present in a single system, the maximum number of registers
> may race when devic es are instantiated since max_registers is updated
                     ^

> in the probe function. Solve the problem by setting .max_registers to the
> maximum register address of all supported chips. This does not make a
> practical difference while fixing the potential race condition and reducing
> code complexity.

It also makes regmap could access out-of-boundary (e.g. [1]).  Is it harmless?

[1]: https://elixir.bootlin.com/linux/v6.10/source/drivers/base/regmap/regmap-debugfs.c#L441

Re: [PATCH 04/11] hwmon: (ina2xx) Mark regmap_config as const

[Guenter Roeck]

On 8/29/24 07:54, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:48AM -0700, Guenter Roeck wrote:
>> Doing so reveals a potential problem in the driver: If both supported
>> chips are present in a single system, the maximum number of registers
>> may race when devic es are instantiated since max_registers is updated
>                       ^

Fixed, thanks.

> 
>> in the probe function. Solve the problem by setting .max_registers to the
>> maximum register address of all supported chips. This does not make a
>> practical difference while fixing the potential race condition and reducing
>> code complexity.
> 
> It also makes regmap could access out-of-boundary (e.g. [1]).  Is it harmless?
> 
> [1]: https://elixir.bootlin.com/linux/v6.10/source/drivers/base/regmap/regmap-debugfs.c#L441
> 

Yes, that is not worth bothering about. Any driver not using regmap but accessing
i2c registers directly could do the same, after all. The regmap limits are just
another level of protection against invalid accesses, but they are not essential.
On top of that, direct i2c accesses to the chip are still possible, even
while using regmap.

If we wanted to be really paranoid, we could provide chip specific readable_reg /
writeable_reg / volatile_reg callbacks, but IMO that would be overkill.

Thanks,
Guenter

[PATCH 05/11] hwmon: (ina2xx) Use local regmap pointer if used more than once

[Guenter Roeck]

If regmap is accessed more than once in a function, declare and used
local regmap variable.

While at it, drop low value debug messages.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 9d93190874d7..ed8764a29d3f 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -210,18 +210,14 @@ static int ina2xx_init(struct ina2xx_data *data)
 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 {
 	struct ina2xx_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
 	int ret, retry;
 
-	dev_dbg(dev, "Starting register %d read\n", reg);
-
 	for (retry = 5; retry; retry--) {
-
-		ret = regmap_read(data->regmap, reg, regval);
+		ret = regmap_read(regmap, reg, regval);
 		if (ret < 0)
 			return ret;
 
-		dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);
-
 		/*
 		 * If the current value in the calibration register is 0, the
 		 * power and current registers will also remain at 0. In case
@@ -233,8 +229,7 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 		if (*regval == 0) {
 			unsigned int cal;
 
-			ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
-					  &cal);
+			ret = regmap_read(regmap, INA2XX_CALIBRATION, &cal);
 			if (ret < 0)
 				return ret;
 
@@ -372,17 +367,18 @@ static ssize_t ina226_alert_show(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct ina2xx_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
 	int regval;
 	int val = 0;
 	int ret;
 
 	mutex_lock(&data->config_lock);
-	ret = regmap_read(data->regmap, INA226_MASK_ENABLE, &regval);
+	ret = regmap_read(regmap, INA226_MASK_ENABLE, &regval);
 	if (ret)
 		goto abort;
 
 	if (regval & attr->index) {
-		ret = regmap_read(data->regmap, INA226_ALERT_LIMIT, &regval);
+		ret = regmap_read(regmap, INA226_ALERT_LIMIT, &regval);
 		if (ret)
 			goto abort;
 		val = ina226_reg_to_alert(data, attr->index, regval);
@@ -400,6 +396,7 @@ static ssize_t ina226_alert_store(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct ina2xx_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
 	unsigned long val;
 	int ret;
 
@@ -413,18 +410,18 @@ static ssize_t ina226_alert_store(struct device *dev,
 	 * if the value is non-zero.
 	 */
 	mutex_lock(&data->config_lock);
-	ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
+	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
 				 INA226_ALERT_CONFIG_MASK, 0);
 	if (ret < 0)
 		goto abort;
 
-	ret = regmap_write(data->regmap, INA226_ALERT_LIMIT,
+	ret = regmap_write(regmap, INA226_ALERT_LIMIT,
 			   ina226_alert_to_reg(data, attr->index, val));
 	if (ret < 0)
 		goto abort;
 
 	if (val != 0) {
-		ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
+		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
 					 INA226_ALERT_CONFIG_MASK,
 					 attr->index);
 		if (ret < 0)
-- 
2.45.2

Re: [PATCH 05/11] hwmon: (ina2xx) Use local regmap pointer if used more than once

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:49AM -0700, Guenter Roeck wrote:
> If regmap is accessed more than once in a function, declare and used
> local regmap variable.
> 
> While at it, drop low value debug messages.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

[PATCH 06/11] hwmon: (ina2xx) Re-initialize chip using regmap functions

[Guenter Roeck]

If it is necessary to re-initialize the chip, for example because
it has been power cycled, use regmap functions to update register
contents. This ensures that all registers, including the configuration
register and alert registers, are updated to previously configured
values without having to locally cache everything.

For this to work, volatile registers have to be marked as volatile.
Also, the cache needs to be bypassed when reading the calibration
and mask_enable registers. While the calibration register is not
volatile, it will be reset to 0 if the chip has been power cycled.
Most of the bits in the mask_enable register are configuration bits,
except for bit 4 which reports if an alert has ben observed.
Both registers need to be marked as non-volatile to be updated
after a power cycle, but it is necessary to bypass the cache when
reading them to detect if the chip has been power cycled and to
read the alert status.

Another necessary change is to declare ina226_alert_to_reg() as u16.
So far it returned an s16 which is sign extended to a large negative
value which is then sent to regmap as unsigned int, causing an -EINVAL
error return.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 48 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index ed8764a29d3f..f7d78588e579 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -91,10 +91,39 @@
  */
 #define INA226_TOTAL_CONV_TIME_DEFAULT	2200
 
+static bool ina2xx_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case INA2XX_CONFIG:
+	case INA2XX_CALIBRATION:
+	case INA226_MASK_ENABLE:
+	case INA226_ALERT_LIMIT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool ina2xx_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case INA2XX_SHUNT_VOLTAGE:
+	case INA2XX_BUS_VOLTAGE:
+	case INA2XX_POWER:
+	case INA2XX_CURRENT:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static const struct regmap_config ina2xx_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
 	.max_register = INA2XX_MAX_REGISTERS,
+	.cache_type = REGCACHE_MAPLE,
+	.volatile_reg = ina2xx_volatile_reg,
+	.writeable_reg = ina2xx_writeable_reg,
 };
 
 enum ina2xx_ids { ina219, ina226 };
@@ -229,16 +258,16 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 		if (*regval == 0) {
 			unsigned int cal;
 
-			ret = regmap_read(regmap, INA2XX_CALIBRATION, &cal);
+			ret = regmap_read_bypassed(regmap, INA2XX_CALIBRATION, &cal);
 			if (ret < 0)
 				return ret;
 
 			if (cal == 0) {
 				dev_warn(dev, "chip not calibrated, reinitializing\n");
 
-				ret = ina2xx_init(data);
-				if (ret < 0)
-					return ret;
+				regcache_mark_dirty(regmap);
+				regcache_sync(regmap);
+
 				/*
 				 * Let's make sure the power and current
 				 * registers have been updated before trying
@@ -340,7 +369,7 @@ static int ina226_reg_to_alert(struct ina2xx_data *data, u32 mask, u16 regval)
  * Turns alert limit values into register values.
  * Opposite of the formula in ina2xx_get_value().
  */
-static s16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, int val)
+static u16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, int val)
 {
 	switch (mask) {
 	case INA226_SHUNT_OVER_VOLTAGE_MASK:
@@ -439,16 +468,17 @@ static ssize_t ina226_alarm_show(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct ina2xx_data *data = dev_get_drvdata(dev);
-	int regval;
+	unsigned int mask;
 	int alarm = 0;
 	int ret;
 
-	ret = regmap_read(data->regmap, INA226_MASK_ENABLE, &regval);
+	ret = regmap_read_bypassed(data->regmap, INA226_MASK_ENABLE, &mask);
 	if (ret)
 		return ret;
 
-	alarm = (regval & attr->index) &&
-		(regval & INA226_ALERT_FUNCTION_FLAG);
+	alarm = (mask & attr->index) &&
+		(mask & INA226_ALERT_FUNCTION_FLAG);
+
 	return sysfs_emit(buf, "%d\n", alarm);
 }
 
-- 
2.45.2

Re: [PATCH 06/11] hwmon: (ina2xx) Re-initialize chip using regmap functions

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:50AM -0700, Guenter Roeck wrote:
> [...]
> except for bit 4 which reports if an alert has ben observed.
                                                  ^
With fixing the typo,
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH 06/11] hwmon: (ina2xx) Re-initialize chip using regmap functions

[Guenter Roeck]

On 8/29/24 07:54, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:50AM -0700, Guenter Roeck wrote:
>> [...]
>> except for bit 4 which reports if an alert has ben observed.
>                                                    ^
> With fixing the typo,
> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
> 
Done, and thanks!

Guenter

[PATCH 07/11] hwmon: (ina2xx) Set alert latch when enabling alerts

[Guenter Roeck]

Alerts should only be cleared after reported, not immediately after the
alert condition has been cleared. Set the latch enable bit to keep alerts
latched until the alert register has been read from the chip.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index f7d78588e579..9016c90f23c9 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -67,6 +67,7 @@
 
 #define INA226_READ_AVG(reg)		FIELD_GET(INA226_AVG_RD_MASK, reg)
 
+#define INA226_ALERT_LATCH_ENABLE	BIT(0)
 #define INA226_ALERT_POLARITY_MASK	BIT(1)
 #define INA226_ALERT_POL_LOW		0
 #define INA226_ALERT_POL_HIGH		1
@@ -440,7 +441,7 @@ static ssize_t ina226_alert_store(struct device *dev,
 	 */
 	mutex_lock(&data->config_lock);
 	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
-				 INA226_ALERT_CONFIG_MASK, 0);
+				 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE, 0);
 	if (ret < 0)
 		goto abort;
 
@@ -451,8 +452,8 @@ static ssize_t ina226_alert_store(struct device *dev,
 
 	if (val != 0) {
 		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
-					 INA226_ALERT_CONFIG_MASK,
-					 attr->index);
+					 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE,
+					 attr->index | INA226_ALERT_LATCH_ENABLE);
 		if (ret < 0)
 			goto abort;
 	}
-- 
2.45.2

Re: [PATCH 07/11] hwmon: (ina2xx) Set alert latch when enabling alerts

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:51AM -0700, Guenter Roeck wrote:
> @@ -440,7 +441,7 @@ static ssize_t ina226_alert_store(struct device *dev,
>  	 */
>  	mutex_lock(&data->config_lock);
>  	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
> -				 INA226_ALERT_CONFIG_MASK, 0);
> +				 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE, 0);
>  	if (ret < 0)
>  		goto abort;
>  
> @@ -451,8 +452,8 @@ static ssize_t ina226_alert_store(struct device *dev,
>  
>  	if (val != 0) {
>  		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
> -					 INA226_ALERT_CONFIG_MASK,
> -					 attr->index);
> +					 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE,
> +					 attr->index | INA226_ALERT_LATCH_ENABLE);

Does it really need to clear and set every time?  Could it set only once in
ina2xx_probe() just like ina2xx_set_alert_polarity()?

Re: [PATCH 07/11] hwmon: (ina2xx) Set alert latch when enabling alerts

[Guenter Roeck]

On 8/29/24 07:54, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:51AM -0700, Guenter Roeck wrote:
>> @@ -440,7 +441,7 @@ static ssize_t ina226_alert_store(struct device *dev,
>>   	 */
>>   	mutex_lock(&data->config_lock);
>>   	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
>> -				 INA226_ALERT_CONFIG_MASK, 0);
>> +				 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE, 0);
>>   	if (ret < 0)
>>   		goto abort;
>>   
>> @@ -451,8 +452,8 @@ static ssize_t ina226_alert_store(struct device *dev,
>>   
>>   	if (val != 0) {
>>   		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
>> -					 INA226_ALERT_CONFIG_MASK,
>> -					 attr->index);
>> +					 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE,
>> +					 attr->index | INA226_ALERT_LATCH_ENABLE);
> 
> Does it really need to clear and set every time?  Could it set only once in
> ina2xx_probe() just like ina2xx_set_alert_polarity()?
> 

The idea was to clear any pending alerts when changing the monitored limit.
As it turns out (I checked with real chips), this is not necessary;
pending alerts are cleared if the mask is cleared/updated even if the latch
bit is set. I made the change as you suggested.

Thanks!

Guenter

[PATCH 08/11] hwmon: (ina2xx) Fix various overflow issues

[Guenter Roeck]

Module tests show various overflow problems when writing limits
and other attributes.

in0_crit: Suspected overflow: [max=82, read 0, written 2147483648]
in0_lcrit: Suspected overflow: [max=82, read 0, written 2147483648]
in1_crit: Suspected overflow: [max=40959, read 0, written 2147483647]
in1_lcrit: Suspected overflow: [max=40959, read 0, written 2147483647]
power1_crit: Suspected overflow: [max=134218750, read 0, written 2147483648]
update_interval: Suspected overflow: [max=2253, read 2, written 2147483647]

Implement missing clamping on attribute write operations to avoid those
problems.

While at it, check in the probe function if the shunt resistor value
passed from devicetree is valid, and bail out if it isn't. Also limit
mutex use to the code calling ina2xx_set_shunt() since it isn't needed
when called from the probe function.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 9016c90f23c9..b40fc808bf3d 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -192,10 +192,16 @@ static int ina226_reg_to_interval(u16 config)
  * Return the new, shifted AVG field value of CONFIG register,
  * to use with regmap_update_bits
  */
-static u16 ina226_interval_to_reg(int interval)
+static u16 ina226_interval_to_reg(unsigned long interval)
 {
 	int avg, avg_bits;
 
+	/*
+	 * The maximum supported interval is 1,024 * (2 * 8.244ms) ~= 16.8s.
+	 * Clamp to 32 seconds before calculations to avoid overflows.
+	 */
+	interval = clamp_val(interval, 0, 32000);
+
 	avg = DIV_ROUND_CLOSEST(interval * 1000,
 				INA226_TOTAL_CONV_TIME_DEFAULT);
 	avg_bits = find_closest(avg, ina226_avg_tab,
@@ -301,8 +307,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
 		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
 		break;
 	case INA2XX_BUS_VOLTAGE:
-		val = (regval >> data->config->bus_voltage_shift)
-		  * data->config->bus_voltage_lsb;
+		val = (regval >> data->config->bus_voltage_shift) *
+		  data->config->bus_voltage_lsb;
 		val = DIV_ROUND_CLOSEST(val, 1000);
 		break;
 	case INA2XX_POWER:
@@ -370,19 +376,22 @@ static int ina226_reg_to_alert(struct ina2xx_data *data, u32 mask, u16 regval)
  * Turns alert limit values into register values.
  * Opposite of the formula in ina2xx_get_value().
  */
-static u16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, int val)
+static u16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, unsigned long val)
 {
 	switch (mask) {
 	case INA226_SHUNT_OVER_VOLTAGE_MASK:
 	case INA226_SHUNT_UNDER_VOLTAGE_MASK:
+		val = clamp_val(val, 0, SHRT_MAX * data->config->shunt_div);
 		val *= data->config->shunt_div;
-		return clamp_val(val, SHRT_MIN, SHRT_MAX);
+		return clamp_val(val, 0, SHRT_MAX);
 	case INA226_BUS_OVER_VOLTAGE_MASK:
 	case INA226_BUS_UNDER_VOLTAGE_MASK:
+		val = clamp_val(val, 0, 200000);
 		val = (val * 1000) << data->config->bus_voltage_shift;
 		val = DIV_ROUND_CLOSEST(val, data->config->bus_voltage_lsb);
-		return clamp_val(val, 0, SHRT_MAX);
+		return clamp_val(val, 0, USHRT_MAX);
 	case INA226_POWER_OVER_LIMIT_MASK:
+		val = clamp_val(val, 0, UINT_MAX - data->power_lsb_uW);
 		val = DIV_ROUND_CLOSEST(val, data->power_lsb_uW);
 		return clamp_val(val, 0, USHRT_MAX);
 	default:
@@ -489,19 +498,17 @@ static ssize_t ina226_alarm_show(struct device *dev,
  * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
  * to keep the scale.
  */
-static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
+static int ina2xx_set_shunt(struct ina2xx_data *data, unsigned long val)
 {
 	unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
 						  data->config->shunt_div);
-	if (val <= 0 || val > dividend)
+	if (!val || val > dividend)
 		return -EINVAL;
 
-	mutex_lock(&data->config_lock);
 	data->rshunt = val;
 	data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
 	data->power_lsb_uW = data->config->power_lsb_factor *
 			     data->current_lsb_uA;
-	mutex_unlock(&data->config_lock);
 
 	return 0;
 }
@@ -526,7 +533,9 @@ static ssize_t ina2xx_shunt_store(struct device *dev,
 	if (status < 0)
 		return status;
 
+	mutex_lock(&data->config_lock);
 	status = ina2xx_set_shunt(data, val);
+	mutex_unlock(&data->config_lock);
 	if (status < 0)
 		return status;
 	return count;
@@ -544,9 +553,6 @@ static ssize_t ina226_interval_store(struct device *dev,
 	if (status < 0)
 		return status;
 
-	if (val > INT_MAX || val == 0)
-		return -EINVAL;
-
 	status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
 				    INA226_AVG_RD_MASK,
 				    ina226_interval_to_reg(val));
@@ -666,7 +672,9 @@ static int ina2xx_probe(struct i2c_client *client)
 	if (device_property_read_u32(dev, "shunt-resistor", &val) < 0)
 		val = INA2XX_RSHUNT_DEFAULT;
 
-	ina2xx_set_shunt(data, val);
+	ret = ina2xx_set_shunt(data, val);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Invalid shunt resistor value\n");
 
 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 	if (IS_ERR(data->regmap)) {
-- 
2.45.2

Re: [PATCH 08/11] hwmon: (ina2xx) Fix various overflow issues

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:52AM -0700, Guenter Roeck wrote:
> @@ -301,8 +307,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
>  		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
>  		break;
>  	case INA2XX_BUS_VOLTAGE:
> -		val = (regval >> data->config->bus_voltage_shift)
> -		  * data->config->bus_voltage_lsb;
> +		val = (regval >> data->config->bus_voltage_shift) *
> +		  data->config->bus_voltage_lsb;

The change looks irrelevant to the patch.

Either with removing the change or not,
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH 08/11] hwmon: (ina2xx) Fix various overflow issues

[Guenter Roeck]

On 8/29/24 07:55, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:52AM -0700, Guenter Roeck wrote:
>> @@ -301,8 +307,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
>>   		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
>>   		break;
>>   	case INA2XX_BUS_VOLTAGE:
>> -		val = (regval >> data->config->bus_voltage_shift)
>> -		  * data->config->bus_voltage_lsb;
>> +		val = (regval >> data->config->bus_voltage_shift) *
>> +		  data->config->bus_voltage_lsb;
> 
> The change looks irrelevant to the patch.
> 
> Either with removing the change or not,

You are correct; that is not needed. Dropped.

> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
> 

Thanks!

Guenter

[PATCH 09/11] hwmon: (ina2xx) Consolidate chip initialization code

[Guenter Roeck]

Move all chip initialization code into a single function.

No functional change.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 109 ++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 68 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index b40fc808bf3d..d1bd998645b6 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -68,9 +68,7 @@
 #define INA226_READ_AVG(reg)		FIELD_GET(INA226_AVG_RD_MASK, reg)
 
 #define INA226_ALERT_LATCH_ENABLE	BIT(0)
-#define INA226_ALERT_POLARITY_MASK	BIT(1)
-#define INA226_ALERT_POL_LOW		0
-#define INA226_ALERT_POL_HIGH		1
+#define INA226_ALERT_POLARITY		BIT(1)
 
 /* bit number of alert functions in Mask/Enable Register */
 #define INA226_SHUNT_OVER_VOLTAGE_MASK	BIT(15)
@@ -140,6 +138,7 @@ struct ina2xx_config {
 
 struct ina2xx_data {
 	const struct ina2xx_config *config;
+	enum ina2xx_ids chip;
 
 	long rshunt;
 	long current_lsb_uA;
@@ -210,39 +209,6 @@ static u16 ina226_interval_to_reg(unsigned long interval)
 	return FIELD_PREP(INA226_AVG_RD_MASK, 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,
-				 FIELD_PREP(INA226_ALERT_POLARITY_MASK, val));
-}
-
-/*
- * Calibration register is set to the best value, which eliminates
- * truncation errors on calculating current register in hardware.
- * According to datasheet (eq. 3) the best values are 2048 for
- * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
- */
-static int ina2xx_calibrate(struct ina2xx_data *data)
-{
-	return regmap_write(data->regmap, INA2XX_CALIBRATION,
-			    data->config->calibration_value);
-}
-
-/*
- * Initialize the configuration and calibration registers.
- */
-static int ina2xx_init(struct ina2xx_data *data)
-{
-	int ret = regmap_write(data->regmap, INA2XX_CONFIG,
-			       data->config->config_default);
-	if (ret < 0)
-		return ret;
-
-	return ina2xx_calibrate(data);
-}
-
 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 {
 	struct ina2xx_data *data = dev_get_drvdata(dev);
@@ -650,12 +616,46 @@ static const struct attribute_group ina226_group = {
 	.attrs = ina226_attrs,
 };
 
+/*
+ * Initialize chip
+ */
+static int ina2xx_init(struct device *dev, struct ina2xx_data *data)
+{
+	u16 config = data->config->config_default;
+	struct regmap *regmap = data->regmap;
+	u32 shunt;
+	int ret;
+
+	if (device_property_read_u32(dev, "shunt-resistor", &shunt) < 0)
+		shunt = INA2XX_RSHUNT_DEFAULT;
+
+	ret = ina2xx_set_shunt(data, shunt);
+	if (ret < 0)
+		return ret;
+
+	if (data->chip == ina226 &&
+	    device_property_read_bool(dev, "ti,alert-polarity-active-high"))
+		config |= INA226_ALERT_POLARITY;
+
+	ret = regmap_write(regmap, INA2XX_CONFIG, config);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Calibration register is set to the best value, which eliminates
+	 * truncation errors on calculating current register in hardware.
+	 * According to datasheet (eq. 3) the best values are 2048 for
+	 * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
+	 */
+	return regmap_write(regmap, INA2XX_CALIBRATION,
+			    data->config->calibration_value);
+}
+
 static int ina2xx_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct ina2xx_data *data;
 	struct device *hwmon_dev;
-	u32 val;
 	int ret, group = 0;
 	enum ina2xx_ids chip;
 
@@ -667,15 +667,9 @@ static int ina2xx_probe(struct i2c_client *client)
 
 	/* set the device type */
 	data->config = &ina2xx_config[chip];
+	data->chip = chip;
 	mutex_init(&data->config_lock);
 
-	if (device_property_read_u32(dev, "shunt-resistor", &val) < 0)
-		val = INA2XX_RSHUNT_DEFAULT;
-
-	ret = ina2xx_set_shunt(data, val);
-	if (ret < 0)
-		return dev_err_probe(dev, ret, "Invalid shunt resistor value\n");
-
 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(dev, "failed to allocate register map\n");
@@ -686,30 +680,9 @@ 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 (device_property_read_bool(dev, "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);
-		return -ENODEV;
-	}
+	ret = ina2xx_init(dev, data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to configure device\n");
 
 	data->groups[group++] = &ina2xx_group;
 	if (chip == ina226)
-- 
2.45.2

Re: [PATCH 09/11] hwmon: (ina2xx) Consolidate chip initialization code

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:53AM -0700, Guenter Roeck wrote:
> +static int ina2xx_init(struct device *dev, struct ina2xx_data *data)
> +{
> +	u16 config = data->config->config_default;
> +	struct regmap *regmap = data->regmap;
> +	u32 shunt;
> +	int ret;
[...]
> +	if (data->chip == ina226 &&
> +	    device_property_read_bool(dev, "ti,alert-polarity-active-high"))
> +		config |= INA226_ALERT_POLARITY;

This looks wrong to me.  The polarity setting should be in INA226_MASK_ENABLE
instead of INA2XX_CONFIG.

> +
> +	ret = regmap_write(regmap, INA2XX_CONFIG, config);
> +	if (ret < 0)
> +		return ret;
> +

Re: [PATCH 09/11] hwmon: (ina2xx) Consolidate chip initialization code

[Guenter Roeck]

On 8/29/24 07:55, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:53AM -0700, Guenter Roeck wrote:
>> +static int ina2xx_init(struct device *dev, struct ina2xx_data *data)
>> +{
>> +	u16 config = data->config->config_default;
>> +	struct regmap *regmap = data->regmap;
>> +	u32 shunt;
>> +	int ret;
> [...]
>> +	if (data->chip == ina226 &&
>> +	    device_property_read_bool(dev, "ti,alert-polarity-active-high"))
>> +		config |= INA226_ALERT_POLARITY;
> 
> This looks wrong to me.  The polarity setting should be in INA226_MASK_ENABLE
> instead of INA2XX_CONFIG.
> 

Yes, I fixed that already. Thanks for noticing!

Guenter

[PATCH 10/11] hwmon: (ina2xx) Move ina2xx_get_value()

[Guenter Roeck]

ina2xx_get_value() will be needed earlier in the next patch, so move it.
No functional change.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 72 +++++++++++++++++++++---------------------
 1 file changed, 36 insertions(+), 36 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index d1bd998645b6..14136c96533f 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -209,6 +209,42 @@ static u16 ina226_interval_to_reg(unsigned long interval)
 	return FIELD_PREP(INA226_AVG_RD_MASK, avg_bits);
 }
 
+static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
+			    unsigned int regval)
+{
+	int val;
+
+	switch (reg) {
+	case INA2XX_SHUNT_VOLTAGE:
+		/* signed register */
+		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
+		break;
+	case INA2XX_BUS_VOLTAGE:
+		val = (regval >> data->config->bus_voltage_shift) *
+		  data->config->bus_voltage_lsb;
+		val = DIV_ROUND_CLOSEST(val, 1000);
+		break;
+	case INA2XX_POWER:
+		val = regval * data->power_lsb_uW;
+		break;
+	case INA2XX_CURRENT:
+		/* signed register, result in mA */
+		val = (s16)regval * data->current_lsb_uA;
+		val = DIV_ROUND_CLOSEST(val, 1000);
+		break;
+	case INA2XX_CALIBRATION:
+		val = regval;
+		break;
+	default:
+		/* programmer goofed */
+		WARN_ON_ONCE(1);
+		val = 0;
+		break;
+	}
+
+	return val;
+}
+
 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 {
 	struct ina2xx_data *data = dev_get_drvdata(dev);
@@ -262,42 +298,6 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 	return -ENODEV;
 }
 
-static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
-			    unsigned int regval)
-{
-	int val;
-
-	switch (reg) {
-	case INA2XX_SHUNT_VOLTAGE:
-		/* signed register */
-		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
-		break;
-	case INA2XX_BUS_VOLTAGE:
-		val = (regval >> data->config->bus_voltage_shift) *
-		  data->config->bus_voltage_lsb;
-		val = DIV_ROUND_CLOSEST(val, 1000);
-		break;
-	case INA2XX_POWER:
-		val = regval * data->power_lsb_uW;
-		break;
-	case INA2XX_CURRENT:
-		/* signed register, result in mA */
-		val = (s16)regval * data->current_lsb_uA;
-		val = DIV_ROUND_CLOSEST(val, 1000);
-		break;
-	case INA2XX_CALIBRATION:
-		val = regval;
-		break;
-	default:
-		/* programmer goofed */
-		WARN_ON_ONCE(1);
-		val = 0;
-		break;
-	}
-
-	return val;
-}
-
 static ssize_t ina2xx_value_show(struct device *dev,
 				 struct device_attribute *da, char *buf)
 {
-- 
2.45.2

Re: [PATCH 10/11] hwmon: (ina2xx) Move ina2xx_get_value()

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:54AM -0700, Guenter Roeck wrote:
> ina2xx_get_value() will be needed earlier in the next patch, so move it.
> No functional change.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

[PATCH 11/11] hwmon: (ina2xx) Convert to use with_info hwmon API

[Guenter Roeck]

Convert driver to use the with_info hardware monitoring API
to reduce its dependency on sysfs attribute functions.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 494 ++++++++++++++++++++++++-----------------
 1 file changed, 293 insertions(+), 201 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 14136c96533f..e9e8482c32bc 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -25,9 +25,9 @@
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/delay.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -35,6 +35,7 @@
 #include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
+#include <linux/sysfs.h>
 #include <linux/util_macros.h>
 
 /* common register definitions */
@@ -81,9 +82,6 @@
 #define INA226_ALERT_CONFIG_MASK	GENMASK(15, 10)
 #define INA226_ALERT_FUNCTION_FLAG	BIT(4)
 
-/* common attrs, ina226 attrs and NULL */
-#define INA2XX_MAX_ATTRIBUTE_GROUPS	3
-
 /*
  * Both bus voltage and shunt voltage conversion times for ina226 are set
  * to 0b0100 on POR, which translates to 2200 microseconds in total.
@@ -145,8 +143,6 @@ struct ina2xx_data {
 	long power_lsb_uW;
 	struct mutex config_lock;
 	struct regmap *regmap;
-
-	const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
 };
 
 static const struct ina2xx_config ina2xx_config[] = {
@@ -191,7 +187,7 @@ static int ina226_reg_to_interval(u16 config)
  * Return the new, shifted AVG field value of CONFIG register,
  * to use with regmap_update_bits
  */
-static u16 ina226_interval_to_reg(unsigned long interval)
+static u16 ina226_interval_to_reg(long interval)
 {
 	int avg, avg_bits;
 
@@ -245,14 +241,19 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
 	return val;
 }
 
-static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
+/*
+ * Read and convert register value from chip. If the register value is 0,
+ * check if the chip has been power cycled or reset. If so, re-initialize it.
+ */
+static int ina2xx_read_init(struct device *dev, int reg, long *val)
 {
 	struct ina2xx_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
+	unsigned int regval;
 	int ret, retry;
 
 	for (retry = 5; retry; retry--) {
-		ret = regmap_read(regmap, reg, regval);
+		ret = regmap_read(regmap, reg, &regval);
 		if (ret < 0)
 			return ret;
 
@@ -264,7 +265,7 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 		 * We do that extra read of the calibration register if there
 		 * is some hint of a chip reset.
 		 */
-		if (*regval == 0) {
+		if (regval == 0) {
 			unsigned int cal;
 
 			ret = regmap_read_bypassed(regmap, INA2XX_CALIBRATION, &cal);
@@ -286,6 +287,7 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 				continue;
 			}
 		}
+		*val = ina2xx_get_value(data, reg, regval);
 		return 0;
 	}
 
@@ -298,46 +300,6 @@ static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 	return -ENODEV;
 }
 
-static ssize_t ina2xx_value_show(struct device *dev,
-				 struct device_attribute *da, char *buf)
-{
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
-	struct ina2xx_data *data = dev_get_drvdata(dev);
-	unsigned int regval;
-
-	int err = ina2xx_read_reg(dev, attr->index, &regval);
-
-	if (err < 0)
-		return err;
-
-	return sysfs_emit(buf, "%d\n", ina2xx_get_value(data, attr->index, regval));
-}
-
-static int ina226_reg_to_alert(struct ina2xx_data *data, u32 mask, u16 regval)
-{
-	int reg;
-
-	switch (mask) {
-	case INA226_SHUNT_OVER_VOLTAGE_MASK:
-	case INA226_SHUNT_UNDER_VOLTAGE_MASK:
-		reg = INA2XX_SHUNT_VOLTAGE;
-		break;
-	case INA226_BUS_OVER_VOLTAGE_MASK:
-	case INA226_BUS_UNDER_VOLTAGE_MASK:
-		reg = INA2XX_BUS_VOLTAGE;
-		break;
-	case INA226_POWER_OVER_LIMIT_MASK:
-		reg = INA2XX_POWER;
-		break;
-	default:
-		/* programmer goofed */
-		WARN_ON_ONCE(1);
-		return 0;
-	}
-
-	return ina2xx_get_value(data, reg, regval);
-}
-
 /*
  * Turns alert limit values into register values.
  * Opposite of the formula in ina2xx_get_value().
@@ -367,14 +329,10 @@ static u16 ina226_alert_to_reg(struct ina2xx_data *data, u32 mask, unsigned long
 	}
 }
 
-static ssize_t ina226_alert_show(struct device *dev,
-				 struct device_attribute *da, char *buf)
+static int ina226_alert_limit_read(struct ina2xx_data *data, u32 mask, int reg, long *val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
-	struct ina2xx_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
 	int regval;
-	int val = 0;
 	int ret;
 
 	mutex_lock(&data->config_lock);
@@ -382,32 +340,26 @@ static ssize_t ina226_alert_show(struct device *dev,
 	if (ret)
 		goto abort;
 
-	if (regval & attr->index) {
+	if (regval & mask) {
 		ret = regmap_read(regmap, INA226_ALERT_LIMIT, &regval);
 		if (ret)
 			goto abort;
-		val = ina226_reg_to_alert(data, attr->index, regval);
+		*val = ina2xx_get_value(data, reg, regval);
+	} else {
+		*val = 0;
 	}
-
-	ret = sysfs_emit(buf, "%d\n", val);
 abort:
 	mutex_unlock(&data->config_lock);
 	return ret;
 }
 
-static ssize_t ina226_alert_store(struct device *dev,
-				  struct device_attribute *da,
-				  const char *buf, size_t count)
+static int ina226_alert_limit_write(struct ina2xx_data *data, u32 mask, long val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
-	struct ina2xx_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
-	unsigned long val;
 	int ret;
 
-	ret = kstrtoul(buf, 10, &val);
-	if (ret < 0)
-		return ret;
+	if (val < 0)
+		return -EINVAL;
 
 	/*
 	 * Clear all alerts first to avoid accidentally triggering ALERT pin
@@ -421,43 +373,286 @@ static ssize_t ina226_alert_store(struct device *dev,
 		goto abort;
 
 	ret = regmap_write(regmap, INA226_ALERT_LIMIT,
-			   ina226_alert_to_reg(data, attr->index, val));
+			   ina226_alert_to_reg(data, mask, val));
 	if (ret < 0)
 		goto abort;
 
-	if (val != 0) {
+	if (val)
 		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
 					 INA226_ALERT_CONFIG_MASK | INA226_ALERT_LATCH_ENABLE,
-					 attr->index | INA226_ALERT_LATCH_ENABLE);
-		if (ret < 0)
-			goto abort;
-	}
-
-	ret = count;
+					 mask | INA226_ALERT_LATCH_ENABLE);
 abort:
 	mutex_unlock(&data->config_lock);
 	return ret;
 }
 
-static ssize_t ina226_alarm_show(struct device *dev,
-				 struct device_attribute *da, char *buf)
+static int ina2xx_chip_read(struct device *dev, u32 attr, long *val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct ina2xx_data *data = dev_get_drvdata(dev);
-	unsigned int mask;
-	int alarm = 0;
+	u32 regval;
 	int ret;
 
-	ret = regmap_read_bypassed(data->regmap, INA226_MASK_ENABLE, &mask);
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		ret = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
+		if (ret)
+			return ret;
+
+		*val = ina226_reg_to_interval(regval);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ina226_alert_read(struct regmap *regmap, u32 mask, long *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read_bypassed(regmap, INA226_MASK_ENABLE, &regval);
 	if (ret)
 		return ret;
 
-	alarm = (mask & attr->index) &&
-		(mask & INA226_ALERT_FUNCTION_FLAG);
+	*val = (regval & mask) && (regval & INA226_ALERT_FUNCTION_FLAG);
 
-	return sysfs_emit(buf, "%d\n", alarm);
+	return 0;
 }
 
+static int ina2xx_in_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	int voltage_reg = channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE;
+	u32 under_voltage_mask = channel ? INA226_BUS_UNDER_VOLTAGE_MASK
+					 : INA226_SHUNT_UNDER_VOLTAGE_MASK;
+	u32 over_voltage_mask = channel ? INA226_BUS_OVER_VOLTAGE_MASK
+					: INA226_SHUNT_OVER_VOLTAGE_MASK;
+	struct ina2xx_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	unsigned int regval;
+	int ret;
+
+	switch (attr) {
+	case hwmon_in_input:
+		ret = regmap_read(regmap, voltage_reg, &regval);
+		if (ret)
+			return ret;
+		*val = ina2xx_get_value(data, voltage_reg, regval);
+		break;
+	case hwmon_in_lcrit:
+		return ina226_alert_limit_read(data, under_voltage_mask,
+					       voltage_reg, val);
+	case hwmon_in_crit:
+		return ina226_alert_limit_read(data, over_voltage_mask,
+					       voltage_reg, val);
+	case hwmon_in_lcrit_alarm:
+		return ina226_alert_read(regmap, under_voltage_mask, val);
+	case hwmon_in_crit_alarm:
+		return ina226_alert_read(regmap, over_voltage_mask, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ina2xx_power_read(struct device *dev, u32 attr, long *val)
+{
+	struct ina2xx_data *data = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_power_input:
+		return ina2xx_read_init(dev, INA2XX_POWER, val);
+	case hwmon_power_crit:
+		return ina226_alert_limit_read(data, INA226_POWER_OVER_LIMIT_MASK,
+					       INA2XX_POWER, val);
+	case hwmon_power_crit_alarm:
+		return ina226_alert_read(data->regmap, INA226_POWER_OVER_LIMIT_MASK, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina2xx_curr_read(struct device *dev, u32 attr, long *val)
+{
+	switch (attr) {
+	case hwmon_curr_input:
+		return ina2xx_read_init(dev, INA2XX_CURRENT, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina2xx_read(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return ina2xx_chip_read(dev, attr, val);
+	case hwmon_in:
+		return ina2xx_in_read(dev, attr, channel, val);
+	case hwmon_power:
+		return ina2xx_power_read(dev, attr, val);
+	case hwmon_curr:
+		return ina2xx_curr_read(dev, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina2xx_chip_write(struct device *dev, u32 attr, long val)
+{
+	struct ina2xx_data *data = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		return regmap_update_bits(data->regmap, INA2XX_CONFIG,
+					  INA226_AVG_RD_MASK,
+					  ina226_interval_to_reg(val));
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina2xx_in_write(struct device *dev, u32 attr, int channel, long val)
+{
+	struct ina2xx_data *data = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_in_lcrit:
+		return ina226_alert_limit_write(data,
+			channel ? INA226_BUS_UNDER_VOLTAGE_MASK : INA226_SHUNT_UNDER_VOLTAGE_MASK,
+			val);
+	case hwmon_in_crit:
+		return ina226_alert_limit_write(data,
+			channel ? INA226_BUS_OVER_VOLTAGE_MASK : INA226_SHUNT_OVER_VOLTAGE_MASK,
+			val);
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ina2xx_power_write(struct device *dev, u32 attr, long val)
+{
+	struct ina2xx_data *data = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_power_crit:
+		return ina226_alert_limit_write(data, INA226_POWER_OVER_LIMIT_MASK, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ina2xx_write(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return ina2xx_chip_write(dev, attr, val);
+	case hwmon_in:
+		return ina2xx_in_write(dev, attr, channel, val);
+	case hwmon_power:
+		return ina2xx_power_write(dev, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t ina2xx_is_visible(const void *_data, enum hwmon_sensor_types type,
+				 u32 attr, int channel)
+{
+	const struct ina2xx_data *data = _data;
+	enum ina2xx_ids chip = data->chip;
+
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			return 0444;
+		case hwmon_in_lcrit:
+		case hwmon_in_crit:
+			if (chip == ina226)
+				return 0644;
+			break;
+		case hwmon_in_lcrit_alarm:
+		case hwmon_in_crit_alarm:
+			if (chip == ina226)
+				return 0444;
+			break;
+		default:
+			break;
+		}
+		break;
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+			return 0444;
+		case hwmon_power_crit:
+			if (chip == ina226)
+				return 0644;
+			break;
+		case hwmon_power_crit_alarm:
+			if (chip == ina226)
+				return 0444;
+			break;
+		default:
+			break;
+		}
+		break;
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			if (chip == ina226)
+				return 0644;
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const ina2xx_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_UPDATE_INTERVAL),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT | HWMON_I_CRIT | HWMON_I_CRIT_ALARM |
+			   HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM,
+			   HWMON_I_INPUT | HWMON_I_CRIT | HWMON_I_CRIT_ALARM |
+			   HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM
+			   ),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT),
+	HWMON_CHANNEL_INFO(power,
+			   HWMON_P_INPUT | HWMON_P_CRIT | HWMON_P_CRIT_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops ina2xx_hwmon_ops = {
+	.is_visible = ina2xx_is_visible,
+	.read = ina2xx_read,
+	.write = ina2xx_write,
+};
+
+static const struct hwmon_chip_info ina2xx_chip_info = {
+	.ops = &ina2xx_hwmon_ops,
+	.info = ina2xx_info,
+};
+
+/* shunt resistance */
+
 /*
  * In order to keep calibration register value fixed, the product
  * of current_lsb and shunt_resistor should also be fixed and equal
@@ -479,21 +674,21 @@ static int ina2xx_set_shunt(struct ina2xx_data *data, unsigned long val)
 	return 0;
 }
 
-static ssize_t ina2xx_shunt_show(struct device *dev,
-				 struct device_attribute *da, char *buf)
+static ssize_t shunt_resistor_show(struct device *dev,
+				   struct device_attribute *da, char *buf)
 {
 	struct ina2xx_data *data = dev_get_drvdata(dev);
 
 	return sysfs_emit(buf, "%li\n", data->rshunt);
 }
 
-static ssize_t ina2xx_shunt_store(struct device *dev,
-				  struct device_attribute *da,
-				  const char *buf, size_t count)
+static ssize_t shunt_resistor_store(struct device *dev,
+				    struct device_attribute *da,
+				    const char *buf, size_t count)
 {
+	struct ina2xx_data *data = dev_get_drvdata(dev);
 	unsigned long val;
 	int status;
-	struct ina2xx_data *data = dev_get_drvdata(dev);
 
 	status = kstrtoul(buf, 10, &val);
 	if (status < 0)
@@ -507,114 +702,14 @@ static ssize_t ina2xx_shunt_store(struct device *dev,
 	return count;
 }
 
-static ssize_t ina226_interval_store(struct device *dev,
-				     struct device_attribute *da,
-				     const char *buf, size_t count)
-{
-	struct ina2xx_data *data = dev_get_drvdata(dev);
-	unsigned long val;
-	int status;
-
-	status = kstrtoul(buf, 10, &val);
-	if (status < 0)
-		return status;
-
-	status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
-				    INA226_AVG_RD_MASK,
-				    ina226_interval_to_reg(val));
-	if (status < 0)
-		return status;
-
-	return count;
-}
-
-static ssize_t ina226_interval_show(struct device *dev,
-				    struct device_attribute *da, char *buf)
-{
-	struct ina2xx_data *data = dev_get_drvdata(dev);
-	int status;
-	unsigned int regval;
-
-	status = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
-	if (status)
-		return status;
-
-	return sysfs_emit(buf, "%d\n", ina226_reg_to_interval(regval));
-}
-
-/* shunt voltage */
-static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE);
-/* shunt voltage over/under voltage alert setting and alarm */
-static SENSOR_DEVICE_ATTR_RW(in0_crit, ina226_alert,
-			     INA226_SHUNT_OVER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RW(in0_lcrit, ina226_alert,
-			     INA226_SHUNT_UNDER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RO(in0_crit_alarm, ina226_alarm,
-			     INA226_SHUNT_OVER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RO(in0_lcrit_alarm, ina226_alarm,
-			     INA226_SHUNT_UNDER_VOLTAGE_MASK);
-
-/* bus voltage */
-static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE);
-/* bus voltage over/under voltage alert setting and alarm */
-static SENSOR_DEVICE_ATTR_RW(in1_crit, ina226_alert,
-			     INA226_BUS_OVER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RW(in1_lcrit, ina226_alert,
-			     INA226_BUS_UNDER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RO(in1_crit_alarm, ina226_alarm,
-			     INA226_BUS_OVER_VOLTAGE_MASK);
-static SENSOR_DEVICE_ATTR_RO(in1_lcrit_alarm, ina226_alarm,
-			     INA226_BUS_UNDER_VOLTAGE_MASK);
-
-/* calculated current */
-static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
-
-/* calculated power */
-static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER);
-/* over-limit power alert setting and alarm */
-static SENSOR_DEVICE_ATTR_RW(power1_crit, ina226_alert,
-			     INA226_POWER_OVER_LIMIT_MASK);
-static SENSOR_DEVICE_ATTR_RO(power1_crit_alarm, ina226_alarm,
-			     INA226_POWER_OVER_LIMIT_MASK);
-
-/* shunt resistance */
-static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION);
-
-/* update interval (ina226 only) */
-static SENSOR_DEVICE_ATTR_RW(update_interval, ina226_interval, 0);
+static DEVICE_ATTR_RW(shunt_resistor);
 
 /* pointers to created device attributes */
 static struct attribute *ina2xx_attrs[] = {
-	&sensor_dev_attr_in0_input.dev_attr.attr,
-	&sensor_dev_attr_in1_input.dev_attr.attr,
-	&sensor_dev_attr_curr1_input.dev_attr.attr,
-	&sensor_dev_attr_power1_input.dev_attr.attr,
-	&sensor_dev_attr_shunt_resistor.dev_attr.attr,
+	&dev_attr_shunt_resistor.attr,
 	NULL,
 };
-
-static const struct attribute_group ina2xx_group = {
-	.attrs = ina2xx_attrs,
-};
-
-static struct attribute *ina226_attrs[] = {
-	&sensor_dev_attr_in0_crit.dev_attr.attr,
-	&sensor_dev_attr_in0_lcrit.dev_attr.attr,
-	&sensor_dev_attr_in0_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_in0_lcrit_alarm.dev_attr.attr,
-	&sensor_dev_attr_in1_crit.dev_attr.attr,
-	&sensor_dev_attr_in1_lcrit.dev_attr.attr,
-	&sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_in1_lcrit_alarm.dev_attr.attr,
-	&sensor_dev_attr_power1_crit.dev_attr.attr,
-	&sensor_dev_attr_power1_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_update_interval.dev_attr.attr,
-	NULL,
-};
-
-static const struct attribute_group ina226_group = {
-	.attrs = ina226_attrs,
-};
+ATTRIBUTE_GROUPS(ina2xx);
 
 /*
  * Initialize chip
@@ -656,8 +751,8 @@ static int ina2xx_probe(struct i2c_client *client)
 	struct device *dev = &client->dev;
 	struct ina2xx_data *data;
 	struct device *hwmon_dev;
-	int ret, group = 0;
 	enum ina2xx_ids chip;
+	int ret;
 
 	chip = (uintptr_t)i2c_get_match_data(client);
 
@@ -684,12 +779,9 @@ static int ina2xx_probe(struct i2c_client *client)
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "failed to configure device\n");
 
-	data->groups[group++] = &ina2xx_group;
-	if (chip == ina226)
-		data->groups[group++] = &ina226_group;
-
-	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
-							   data, data->groups);
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data, &ina2xx_chip_info,
+							 ina2xx_groups);
 	if (IS_ERR(hwmon_dev))
 		return PTR_ERR(hwmon_dev);
 
-- 
2.45.2

Re: [PATCH 11/11] hwmon: (ina2xx) Convert to use with_info hwmon API

[Tzung-Bi Shih]

On Tue, Aug 27, 2024 at 08:34:55AM -0700, Guenter Roeck wrote:
> +static int ina2xx_in_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	int voltage_reg = channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE;
> +	u32 under_voltage_mask = channel ? INA226_BUS_UNDER_VOLTAGE_MASK
> +					 : INA226_SHUNT_UNDER_VOLTAGE_MASK;
> +	u32 over_voltage_mask = channel ? INA226_BUS_OVER_VOLTAGE_MASK
> +					: INA226_SHUNT_OVER_VOLTAGE_MASK;
> +	struct ina2xx_data *data = dev_get_drvdata(dev);
> +	struct regmap *regmap = data->regmap;
> +	unsigned int regval;
> +	int ret;
> +
> +	switch (attr) {
> +	case hwmon_in_input:
> +		ret = regmap_read(regmap, voltage_reg, &regval);
> +		if (ret)
> +			return ret;
> +		*val = ina2xx_get_value(data, voltage_reg, regval);

Doesn't it need to call ina2xx_read_init() too?  Originally, [1][2] call
ina2xx_value_show() and then ina2xx_read_reg() and detect if the chip has
been reset.

[1]: https://elixir.bootlin.com/linux/v6.10/source/drivers/hwmon/ina2xx.c#L542
[2]: https://elixir.bootlin.com/linux/v6.10/source/drivers/hwmon/ina2xx.c#L554

Re: [PATCH 11/11] hwmon: (ina2xx) Convert to use with_info hwmon API

[Guenter Roeck]

On 8/29/24 07:55, Tzung-Bi Shih wrote:
> On Tue, Aug 27, 2024 at 08:34:55AM -0700, Guenter Roeck wrote:
>> +static int ina2xx_in_read(struct device *dev, u32 attr, int channel, long *val)
>> +{
>> +	int voltage_reg = channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE;
>> +	u32 under_voltage_mask = channel ? INA226_BUS_UNDER_VOLTAGE_MASK
>> +					 : INA226_SHUNT_UNDER_VOLTAGE_MASK;
>> +	u32 over_voltage_mask = channel ? INA226_BUS_OVER_VOLTAGE_MASK
>> +					: INA226_SHUNT_OVER_VOLTAGE_MASK;
>> +	struct ina2xx_data *data = dev_get_drvdata(dev);
>> +	struct regmap *regmap = data->regmap;
>> +	unsigned int regval;
>> +	int ret;
>> +
>> +	switch (attr) {
>> +	case hwmon_in_input:
>> +		ret = regmap_read(regmap, voltage_reg, &regval);
>> +		if (ret)
>> +			return ret;
>> +		*val = ina2xx_get_value(data, voltage_reg, regval);
> 
> Doesn't it need to call ina2xx_read_init() too?  Originally, [1][2] call
> ina2xx_value_show() and then ina2xx_read_reg() and detect if the chip has
> been reset.
> 

No, because reading the voltage does not require calibration. If a voltage
happens to report 0V, it is just 0V, and does not indicate that the chip
has been reset. That applies to both shunt and bus voltage.

Thanks,
Guenter