2024-05-29 09:48:15

by Amna Waseem

[permalink] [raw]
Subject: [PATCH v2 2/2] 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: Amna Waseem <[email protected]>
---
drivers/hwmon/ina2xx.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index d8415d1f21fc..9afaabdc367d 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -73,6 +73,9 @@
#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)
+
/* 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 +181,21 @@ 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)
+{
+ int ret;
+
+ if (val > INT_MAX || !(val == 0 || val == 1))
+ return -EINVAL;
+
+ ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
+ INA226_ALERT_POLARITY_MASK,
+ INA226_SHIFT_ALERT_POLARITY(val));
+
+ return ret;
+}
+
/*
* Calibration register is set to the best value, which eliminates
* truncation errors on calculating current register in hardware.
@@ -659,6 +677,15 @@ static int ina2xx_probe(struct i2c_client *client)
if (ret)
return dev_err_probe(dev, ret, "failed to enable vs regulator\n");

+ if (!of_property_read_u32(dev->of_node, "ti,alert-polarity", &val)) {
+ ret = ina2xx_set_alert_polarity(data, val);
+ if (ret < 0) {
+ return dev_err_probe(
+ dev, ret,
+ "failed to set APOL bit of Enable/Mask register\n");
+ }
+ }
+
ret = ina2xx_init(data);
if (ret < 0) {
dev_err(dev, "error configuring the device: %d\n", ret);

--
2.30.2



2024-05-29 14:26:37

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] hwmon: (ina2xx) Add device tree support to pass alert polarity

On 5/29/24 02:47, Amna Waseem wrote:
> 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: Amna Waseem <[email protected]>

Please address my earlier comments, and in the future please wait a few minutes
before sending another version to give people time to provide feedback
on the earlier version(s).

> ---
> drivers/hwmon/ina2xx.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
> index d8415d1f21fc..9afaabdc367d 100644
> --- a/drivers/hwmon/ina2xx.c
> +++ b/drivers/hwmon/ina2xx.c
> @@ -73,6 +73,9 @@
> #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)
> +
> /* 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 +181,21 @@ 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)
> +{
> + int ret;
> +
> + if (val > INT_MAX || !(val == 0 || val == 1))
> + return -EINVAL;
> +
> + ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
> + INA226_ALERT_POLARITY_MASK,
> + INA226_SHIFT_ALERT_POLARITY(val));
> +
> + return ret;

ret is an unnecessary variable.
return regmap_update_bits(...);


> +}
> +
> /*
> * Calibration register is set to the best value, which eliminates
> * truncation errors on calculating current register in hardware.
> @@ -659,6 +677,15 @@ static int ina2xx_probe(struct i2c_client *client)
> if (ret)
> return dev_err_probe(dev, ret, "failed to enable vs regulator\n");
>
> + if (!of_property_read_u32(dev->of_node, "ti,alert-polarity", &val)) {
> + ret = ina2xx_set_alert_polarity(data, val);
> + if (ret < 0) {
> + return dev_err_probe(
> + dev, ret,
> + "failed to set APOL bit of Enable/Mask register\n");

Line split is still as bad as before.

Guenter


2024-05-30 08:02:29

by Amna Waseem

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] hwmon: (ina2xx) Add device tree support to pass alert polarity

On 5/29/24 16:11, Guenter Roeck wrote:
> On 5/29/24 02:47, Amna Waseem wrote:
>> 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: Amna Waseem <[email protected]>
>
> Please address my earlier comments, and in the future please wait a
> few minutes
> before sending another version to give people time to provide feedback
> on the earlier version(s).
Ok.
>> ---
>>   drivers/hwmon/ina2xx.c | 27 +++++++++++++++++++++++++++
>>   1 file changed, 27 insertions(+)
>>
>> diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
>> index d8415d1f21fc..9afaabdc367d 100644
>> --- a/drivers/hwmon/ina2xx.c
>> +++ b/drivers/hwmon/ina2xx.c
>> @@ -73,6 +73,9 @@
>>   #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)
>> +
>>   /* 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 +181,21 @@ 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)
>> +{
>> +    int ret;
>> +
>> +    if (val > INT_MAX || !(val == 0 || val == 1))
>> +        return -EINVAL;
>> +
>> +    ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
>> +                 INA226_ALERT_POLARITY_MASK,
>> +                 INA226_SHIFT_ALERT_POLARITY(val));
>> +
>> +    return ret;
>
> ret is an unnecessary variable.
>     return regmap_update_bits(...);
>
Agreed. Will do it in next patch
>
>> +}
>> +
>>   /*
>>    * Calibration register is set to the best value, which eliminates
>>    * truncation errors on calculating current register in hardware.
>> @@ -659,6 +677,15 @@ static int ina2xx_probe(struct i2c_client *client)
>>       if (ret)
>>           return dev_err_probe(dev, ret, "failed to enable vs
>> regulator\n");
>>   +    if (!of_property_read_u32(dev->of_node, "ti,alert-polarity",
>> &val)) {
>> +        ret = ina2xx_set_alert_polarity(data, val);
>> +        if (ret < 0) {
>> +            return dev_err_probe(
>> +               dev, ret,
>> +               "failed to set APOL bit of Enable/Mask register\n");
>
> Line split is still as bad as before.
>
> Guenter
>
I have tried to apply clang-format and it still shows the line split as
follows:

    if (!of_property_read_u32(dev->of_node, "ti,alert-polarity", &val)) {
        ret = ina2xx_set_alert_polarity(data, val);
        if (ret < 0) {
            return dev_err_probe(
                dev, ret,
                "failed to set APOL bit of Enable/Mask register\n");
        }
    }

What format will you suggest for line split? Is there any reference you
can provide for splitting up the lines in Linux kernel drivers' code?

Amna