Re: [PATCH 1/3] hwmon: (sht3x) convert some of sysfs interface to hwmon

From: Guenter Roeck
Date: Sat Jun 24 2023 - 12:59:27 EST


On 6/24/23 09:01, JuenKit_Yip@xxxxxxxxxxx wrote:
From: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>

update_interval, temperature/humidity max/min and hyst
were moved to new hwmon interface, and only heater and
repeatability were reserved as non-stardard sysfs interface.

Signed-off-by: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>

Please version your patches and provide change logs.

---
drivers/hwmon/sht3x.c | 359 ++++++++++++++++++++++++++++--------------
1 file changed, 244 insertions(+), 115 deletions(-)

diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
index bf18630619e0..9b2dadd11eeb 100644
--- a/drivers/hwmon/sht3x.c
+++ b/drivers/hwmon/sht3x.c
@@ -147,6 +147,19 @@ static const u16 mode_to_update_interval[] = {
100,
};
+static const struct hwmon_channel_info * const sht3x_channel_info[] = {
+ HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN |
+ HWMON_T_MIN_HYST | HWMON_T_MAX |
+ HWMON_T_MAX_HYST | HWMON_T_ALARM),
+ HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN |
+ HWMON_H_MIN_HYST | HWMON_H_MAX |
+ HWMON_H_MAX_HYST | HWMON_H_ALARM),
+ NULL,
+};
+
+static const struct i2c_device_id sht3x_ids[];
+

Again, please avoid forward declarations. More on that below.

struct sht3x_data {
struct i2c_client *client;
struct mutex i2c_lock; /* lock for sending i2c commands */
@@ -276,27 +289,24 @@ static struct sht3x_data *sht3x_update_client(struct device *dev)
return data;
}
-/* sysfs attributes */
-static ssize_t temp1_input_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static int temp1_input_read(struct device *dev)
{
struct sht3x_data *data = sht3x_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
- return sprintf(buf, "%d\n", data->temperature);
+ return data->temperature;
}
-static ssize_t humidity1_input_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static int humidity1_input_read(struct device *dev)
{
struct sht3x_data *data = sht3x_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
- return sprintf(buf, "%u\n", data->humidity);
+ return data->humidity;
}
/*
@@ -332,33 +342,24 @@ static int limits_update(struct sht3x_data *data)
return ret;
}
-static ssize_t temp1_limit_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static int temp1_limit_read(struct device *dev, int index)
{
struct sht3x_data *data = dev_get_drvdata(dev);
- u8 index = to_sensor_dev_attr(attr)->index;
- int temperature_limit = data->temperature_limits[index];
- return sysfs_emit(buf, "%d\n", temperature_limit);
+ return data->temperature_limits[index];
}
-static ssize_t humidity1_limit_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static int humidity1_limit_read(struct device *dev, int index)
{
struct sht3x_data *data = dev_get_drvdata(dev);
- u8 index = to_sensor_dev_attr(attr)->index;
- u32 humidity_limit = data->humidity_limits[index];
- return sysfs_emit(buf, "%u\n", humidity_limit);
+ return data->humidity_limits[index];
}
/*
- * limit_store must only be called with data_lock held
+ * limit_write must only be called with data_lock held
*/
-static size_t limit_store(struct device *dev,
- size_t count,
+static size_t limit_write(struct device *dev,
u8 index,
int temperature,
u32 humidity)
@@ -379,7 +380,7 @@ static size_t limit_store(struct device *dev,
* ST = (T + 45) / 175 * 2^16
* SRH = RH / 100 * 2^16
* adapted for fixed point arithmetic and packed the same as
- * in limit_show()
+ * in limit_read()
*/
raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
raw |= ((humidity * 42950) >> 16) & 0xfe00;
@@ -400,50 +401,43 @@ static size_t limit_store(struct device *dev,
data->temperature_limits[index] = temperature;
data->humidity_limits[index] = humidity;
- return count;
+
+ return 0;
}
-static ssize_t temp1_limit_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
+static int temp1_limit_write(struct device *dev, int index, const char *val)
{
int temperature;
int ret;
struct sht3x_data *data = dev_get_drvdata(dev);
- u8 index = to_sensor_dev_attr(attr)->index;
- ret = kstrtoint(buf, 0, &temperature);
+ ret = kstrtoint(val, 0, &temperature);
if (ret)
return ret;
temperature = clamp_val(temperature, SHT3X_MIN_TEMPERATURE,
SHT3X_MAX_TEMPERATURE);
mutex_lock(&data->data_lock);
- ret = limit_store(dev, count, index, temperature,
+ ret = limit_write(dev, index, temperature,
data->humidity_limits[index]);
mutex_unlock(&data->data_lock);
return ret;
}
-static ssize_t humidity1_limit_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
+static int humidity1_limit_write(struct device *dev, int index, const char *val)
{
u32 humidity;
int ret;
struct sht3x_data *data = dev_get_drvdata(dev);
- u8 index = to_sensor_dev_attr(attr)->index;
- ret = kstrtou32(buf, 0, &humidity);
+ ret = kstrtou32(val, 0, &humidity);
if (ret)
return ret;
humidity = clamp_val(humidity, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
mutex_lock(&data->data_lock);
- ret = limit_store(dev, count, index, data->temperature_limits[index],
+ ret = limit_write(dev, index, data->temperature_limits[index],
humidity);
mutex_unlock(&data->data_lock);
@@ -474,7 +468,6 @@ static void sht3x_select_command(struct sht3x_data *data)
}
static int status_register_read(struct device *dev,
- struct device_attribute *attr,
char *buffer, int length)
{
int ret;
@@ -487,34 +480,30 @@ static int status_register_read(struct device *dev,
return ret;
}
-static ssize_t temp1_alarm_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static int temp1_alarm_read(struct device *dev)
{
char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
int ret;
- ret = status_register_read(dev, attr, buffer,
+ ret = status_register_read(dev, buffer,
SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
if (ret)
return ret;
- return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x04));
+ return !!(buffer[0] & 0x04);
}
-static ssize_t humidity1_alarm_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static int humidity1_alarm_read(struct device *dev)
{
char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
int ret;
- ret = status_register_read(dev, attr, buffer,
+ ret = status_register_read(dev, buffer,
SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
if (ret)
return ret;
- return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x08));
+ return !!(buffer[0] & 0x08);
}
static ssize_t heater_enable_show(struct device *dev,
@@ -524,7 +513,7 @@ static ssize_t heater_enable_show(struct device *dev,
char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
int ret;
- ret = status_register_read(dev, attr, buffer,
+ ret = status_register_read(dev, buffer,
SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
if (ret)
return ret;
@@ -560,20 +549,14 @@ static ssize_t heater_enable_store(struct device *dev,
return ret;
}
-static ssize_t update_interval_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static int update_interval_read(struct device *dev)
{
struct sht3x_data *data = dev_get_drvdata(dev);
- return sysfs_emit(buf, "%u\n",
- mode_to_update_interval[data->mode]);
+ return mode_to_update_interval[data->mode];
}
-static ssize_t update_interval_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
+static int update_interval_write(struct device *dev, const char *val)
{
u16 update_interval;
u8 mode;
@@ -582,7 +565,7 @@ static ssize_t update_interval_store(struct device *dev,
struct sht3x_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
- ret = kstrtou16(buf, 0, &update_interval);
+ ret = kstrtou16(val, 0, &update_interval);
if (ret)
return ret;
@@ -592,7 +575,7 @@ static ssize_t update_interval_store(struct device *dev,
/* mode did not change */
if (mode == data->mode) {
mutex_unlock(&data->data_lock);
- return count;
+ return 0;
}
mutex_lock(&data->i2c_lock);
@@ -634,7 +617,7 @@ static ssize_t update_interval_store(struct device *dev,
if (ret != SHT3X_CMD_LENGTH)
return ret < 0 ? ret : -EIO;
- return count;
+ return 0;
}
static ssize_t repeatability_show(struct device *dev,
@@ -668,60 +651,211 @@ static ssize_t repeatability_store(struct device *dev,
return count;
}
-static SENSOR_DEVICE_ATTR_RO(temp1_input, temp1_input, 0);
-static SENSOR_DEVICE_ATTR_RO(humidity1_input, humidity1_input, 0);
-static SENSOR_DEVICE_ATTR_RW(temp1_max, temp1_limit, limit_max);
-static SENSOR_DEVICE_ATTR_RW(humidity1_max, humidity1_limit, limit_max);
-static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp1_limit, limit_max_hyst);
-static SENSOR_DEVICE_ATTR_RW(humidity1_max_hyst, humidity1_limit,
- limit_max_hyst);
-static SENSOR_DEVICE_ATTR_RW(temp1_min, temp1_limit, limit_min);
-static SENSOR_DEVICE_ATTR_RW(humidity1_min, humidity1_limit, limit_min);
-static SENSOR_DEVICE_ATTR_RW(temp1_min_hyst, temp1_limit, limit_min_hyst);
-static SENSOR_DEVICE_ATTR_RW(humidity1_min_hyst, humidity1_limit,
- limit_min_hyst);
-static SENSOR_DEVICE_ATTR_RO(temp1_alarm, temp1_alarm, 0);
-static SENSOR_DEVICE_ATTR_RO(humidity1_alarm, humidity1_alarm, 0);
static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0);
-static SENSOR_DEVICE_ATTR_RW(update_interval, update_interval, 0);
static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0);
static struct attribute *sht3x_attrs[] = {
- &sensor_dev_attr_temp1_input.dev_attr.attr,
- &sensor_dev_attr_humidity1_input.dev_attr.attr,
- &sensor_dev_attr_temp1_max.dev_attr.attr,
- &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
- &sensor_dev_attr_humidity1_max.dev_attr.attr,
- &sensor_dev_attr_humidity1_max_hyst.dev_attr.attr,
- &sensor_dev_attr_temp1_min.dev_attr.attr,
- &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
- &sensor_dev_attr_humidity1_min.dev_attr.attr,
- &sensor_dev_attr_humidity1_min_hyst.dev_attr.attr,
- &sensor_dev_attr_temp1_alarm.dev_attr.attr,
- &sensor_dev_attr_humidity1_alarm.dev_attr.attr,
&sensor_dev_attr_heater_enable.dev_attr.attr,
- &sensor_dev_attr_update_interval.dev_attr.attr,
- &sensor_dev_attr_repeatability.dev_attr.attr,
- NULL
-};
-
-static struct attribute *sts3x_attrs[] = {
- &sensor_dev_attr_temp1_input.dev_attr.attr,
- &sensor_dev_attr_temp1_max.dev_attr.attr,
- &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
- &sensor_dev_attr_temp1_min.dev_attr.attr,
- &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
- &sensor_dev_attr_temp1_alarm.dev_attr.attr,
- &sensor_dev_attr_heater_enable.dev_attr.attr,
- &sensor_dev_attr_update_interval.dev_attr.attr,
&sensor_dev_attr_repeatability.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(sht3x);
-ATTRIBUTE_GROUPS(sts3x);
-static const struct i2c_device_id sht3x_ids[];
+static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct sht3x_data *chip_data = data;
+ struct i2c_client *client = chip_data->client;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ return 0644;
+ default:
+ break;
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ case hwmon_temp_alarm:
+ return 0444;
+ case hwmon_temp_max:
+ case hwmon_temp_max_hyst:
+ case hwmon_temp_min:
+ case hwmon_temp_min_hyst:
+ return 0644;
+ default:
+ break;
+ }
+ break;
+ case hwmon_humidity:
+ if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x)

It would be better to save the chip id in struct sht3x_data to avoid
having to dereference driver_data here, and to avoid needing a pointer
to struct i2c_client.

+ return 0;

Maybe break; for consistency.

+ switch (attr) {
+ case hwmon_humidity_input:
+ case hwmon_humidity_alarm:
+ return 0444;
+ case hwmon_humidity_max:
+ case hwmon_humidity_max_hyst:
+ case hwmon_humidity_min:
+ case hwmon_humidity_min_hyst:
+ return 0644;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int sht3x_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ enum sht3x_limits index;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ *val = update_interval_read(dev);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ *val = temp1_input_read(dev);
+ break;
+ case hwmon_temp_alarm:
+ *val = temp1_alarm_read(dev);
+ break;
+ case hwmon_temp_max:
+ index = limit_max;
+ *val = temp1_limit_read(dev, index);
+ break;
+ case hwmon_temp_max_hyst:
+ index = limit_max_hyst;
+ *val = temp1_limit_read(dev, index);
+ break;
+ case hwmon_temp_min:
+ index = limit_min;
+ *val = temp1_limit_read(dev, index);
+ break;
+ case hwmon_temp_min_hyst:
+ index = limit_min_hyst;
+ *val = temp1_limit_read(dev, index);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ case hwmon_humidity:
+ switch (attr) {
+ case hwmon_humidity_input:
+ *val = humidity1_input_read(dev);
+ break;
+ case hwmon_humidity_alarm:
+ *val = humidity1_alarm_read(dev);
+ break;
+ case hwmon_humidity_max:
+ index = limit_max;
+ *val = humidity1_limit_read(dev, index);
+ break;
+ case hwmon_humidity_max_hyst:
+ index = limit_max_hyst;
+ *val = humidity1_limit_read(dev, index);
+ break;
+ case hwmon_humidity_min:
+ index = limit_min;
+ *val = humidity1_limit_read(dev, index);
+ break;
+ case hwmon_humidity_min_hyst:
+ index = limit_min_hyst;
+ *val = humidity1_limit_read(dev, index);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int sht3x_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ enum sht3x_limits index;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ return update_interval_write(dev, (const char *)&val);
+ default:
+ return -EOPNOTSUPP;
+ }
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_max:
+ index = limit_max;
+ break;
+ case hwmon_temp_max_hyst:
+ index = limit_max_hyst;
+ break;
+ case hwmon_temp_min:
+ index = limit_min;
+ break;
+ case hwmon_temp_min_hyst:
+ index = limit_min_hyst;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ return temp1_limit_write(dev, index, (const char *)&val);

This does not work. The val parameter passed to the write function
is already the value, not a pointer to a string. There is no need
to parse it again, and trying to do so will fail (or, with bad luck,
crash).

Guenter

+ case hwmon_humidity:
+ switch (attr) {
+ case hwmon_humidity_max:
+ index = limit_max;
+ break;
+ case hwmon_humidity_max_hyst:
+ index = limit_max_hyst;
+ break;
+ case hwmon_humidity_min:
+ index = limit_min;
+ break;
+ case hwmon_humidity_min_hyst:
+ index = limit_min_hyst;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ return humidity1_limit_write(dev, index, (const char *)val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static const struct hwmon_ops sht3x_ops = {
+ .is_visible = sht3x_is_visible,
+ .read = sht3x_read,
+ .write = sht3x_write,
+};
+
+static const struct hwmon_chip_info sht3x_chip_info = {
+ .ops = &sht3x_ops,
+ .info = sht3x_channel_info,
+};
static int sht3x_probe(struct i2c_client *client)
{
@@ -730,7 +864,6 @@ static int sht3x_probe(struct i2c_client *client)
struct device *hwmon_dev;
struct i2c_adapter *adap = client->adapter;
struct device *dev = &client->dev;
- const struct attribute_group **attribute_groups;
/*
* we require full i2c support since the sht3x uses multi-byte read and
@@ -771,15 +904,11 @@ static int sht3x_probe(struct i2c_client *client)
if (ret)
return ret;
- if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x)
- attribute_groups = sts3x_groups;
- else
- attribute_groups = sht3x_groups;
-
- hwmon_dev = devm_hwmon_device_register_with_groups(dev,
- client->name,
- data,
- attribute_groups);
+ hwmon_dev = devm_hwmon_device_register_with_info(dev,
+ client->name,
+ data,
+ &sht3x_chip_info,
+ sht3x_groups);
if (IS_ERR(hwmon_dev))
dev_dbg(dev, "unable to register hwmon device\n");