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hwmon: (sht4x) Fix sht4x_read_values return value

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Kernel doc for sht4x_read_values() shows 0 on success, 1 on failure but
the return value on success is actually always positive as it is set to
SHT4X_RESPONSE_LENGTH by a successful call to i2c_master_recv().

Miscellanea:

o Update the kernel doc for sht4x_read_values to 0 for success or -ERRNO
o Remove incorrectly used kernel doc /** header for other _read functions
o Typo fix succesfull->successful
o Reverse a test to unindent a block and use goto unlock
o Declare cmd[SHT4X_CMD_LEN] rather than cmd[]

At least for gcc 10.2, object size is reduced a tiny bit.

$ size drivers/hwmon/sht4x.o*
   text	   data	    bss	    dec	    hex	filename
   1752	    404	    256	   2412	    96c	drivers/hwmon/sht4x.o.new
   1825	    404	    256	   2485	    9b5	drivers/hwmon/sht4x.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/60eedce497137eb34448c0c77e01ec9d9c972ad7.camel@perches.com
Reviewed by: Navin Sankar Velliangiri <navin@linumiz.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Joe Perches 2021-05-29 02:13:52 -07:00 committed by Guenter Roeck
parent 505c254937
commit 07c6621a37
1 changed files with 41 additions and 46 deletions
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87
drivers/hwmon/sht4x.c
View File

@ -67,7 +67,7 @@ struct sht4x_data {
/**
* sht4x_read_values() - read and parse the raw data from the SHT4X
* @sht4x_data: the struct sht4x_data to use for the lock
* Return: 0 if succesfull, 1 if not
* Return: 0 if successful, -ERRNO if not
*/
static int sht4x_read_values(struct sht4x_data *data)
{
@ -75,51 +75,53 @@ static int sht4x_read_values(struct sht4x_data *data)
u16 t_ticks, rh_ticks;
unsigned long next_update;
struct i2c_client *client = data->client;
u8 crc, raw_data[SHT4X_RESPONSE_LENGTH],
cmd[] = {SHT4X_CMD_MEASURE_HPM};
u8 crc;
u8 cmd[SHT4X_CMD_LEN] = {SHT4X_CMD_MEASURE_HPM};
u8 raw_data[SHT4X_RESPONSE_LENGTH];
mutex_lock(&data->lock);
next_update = data->last_updated +
msecs_to_jiffies(data->update_interval);
if (!data->valid || time_after(jiffies, next_update)) {
ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN);
if (ret < 0)
goto unlock;
usleep_range(SHT4X_MEAS_DELAY,
SHT4X_MEAS_DELAY + SHT4X_DELAY_EXTRA);
if (data->valid && time_before_eq(jiffies, next_update))
goto unlock;
ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH);
if (ret != SHT4X_RESPONSE_LENGTH) {
if (ret >= 0)
ret = -ENODATA;
ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN);
if (ret < 0)
goto unlock;
goto unlock;
}
usleep_range(SHT4X_MEAS_DELAY, SHT4X_MEAS_DELAY + SHT4X_DELAY_EXTRA);
t_ticks = raw_data[0] << 8 | raw_data[1];
rh_ticks = raw_data[3] << 8 | raw_data[4];
crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
if (crc != raw_data[2]) {
dev_err(&client->dev, "data integrity check failed\n");
ret = -EIO;
goto unlock;
}
crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
if (crc != raw_data[5]) {
dev_err(&client->dev, "data integrity check failed\n");
ret = -EIO;
goto unlock;
}
data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000;
data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000;
data->last_updated = jiffies;
data->valid = true;
ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH);
if (ret != SHT4X_RESPONSE_LENGTH) {
if (ret >= 0)
ret = -ENODATA;
goto unlock;
}
t_ticks = raw_data[0] << 8 | raw_data[1];
rh_ticks = raw_data[3] << 8 | raw_data[4];
crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
if (crc != raw_data[2]) {
dev_err(&client->dev, "data integrity check failed\n");
ret = -EIO;
goto unlock;
}
crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
if (crc != raw_data[5]) {
dev_err(&client->dev, "data integrity check failed\n");
ret = -EIO;
goto unlock;
}
data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000;
data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000;
data->last_updated = jiffies;
data->valid = true;
ret = 0;
unlock:
mutex_unlock(&data->lock);
return ret;
@ -132,19 +134,14 @@ static ssize_t sht4x_interval_write(struct sht4x_data *data, long val)
return 0;
}
/**
* sht4x_interval_read() - read the minimum poll interval
* in milliseconds
*/
/* sht4x_interval_read() - read the minimum poll interval in milliseconds */
static size_t sht4x_interval_read(struct sht4x_data *data, long *val)
{
*val = data->update_interval;
return 0;
}
/**
* sht4x_temperature1_read() - read the temperature in millidegrees
*/
/* sht4x_temperature1_read() - read the temperature in millidegrees */
static int sht4x_temperature1_read(struct sht4x_data *data, long *val)
{
int ret;
@ -158,9 +155,7 @@ static int sht4x_temperature1_read(struct sht4x_data *data, long *val)
return 0;
}
/**
* sht4x_humidity1_read() - read a relative humidity in millipercent
*/
/* sht4x_humidity1_read() - read a relative humidity in millipercent */
static int sht4x_humidity1_read(struct sht4x_data *data, long *val)
{
int ret;