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staging: iio: tsl2583: i2c_smbus_write_byte() / i2c_smbus_read_byte() migration 

There were several places where the driver would first call
i2c_smbus_write_byte() to select the register on the device, and then
call i2c_smbus_read_byte() to get the contents of that register. The
code would look roughly like:

/* Select register */
i2c_smbus_write_byte(client, REGISTER);

/* Read the the last register that was written to */
int data = i2c_smbus_read_byte(client);

Rewrite this to use i2c_smbus_read_byte_data() to combine the two
calls into one:

int data = i2c_smbus_read_byte_data(chip->client, REGISTER);

Verified that the driver still functions correctly using a TSL2581
hooked up to a Raspberry Pi 2.

This fixes the following warnings that were found by the
kbuild test robot that were introduced by commit 8ba355cce3c6 ("staging:
iio: tsl2583: check for error code from i2c_smbus_read_byte()").

drivers/staging/iio/light/tsl2583.c:365:5-12: WARNING: Unsigned
expression compared with zero: reg_val < 0

drivers/staging/iio/light/tsl2583.c:388:5-12: WARNING: Unsigned
expression compared with zero: reg_val < 0

This also removes the need for the taos_i2c_read() function since all
callers were only calling the function with a length of 1.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Brian Masney 2016-11-03 08:56:12 -04:00 committed by Jonathan Cameron
parent 25acb3986f
commit 6ba5dee90b
1 changed files with 16 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
drivers/staging/iio/light/tsl2583.c
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@ -154,39 +154,6 @@ static void taos_defaults(struct tsl2583_chip *chip)
/* Known external ALS reading used for calibration */
}
/*
* Read a number of bytes starting at register (reg) location.
* Return 0, or i2c_smbus_write_byte ERROR code.
*/
static int
taos_i2c_read(struct i2c_client *client, u8 reg, u8 *val, unsigned int len)
{
int i, ret;
for (i = 0; i < len; i++) {
/* select register to write */
ret = i2c_smbus_write_byte(client, (TSL258X_CMD_REG | reg));
if (ret < 0) {
dev_err(&client->dev,
"taos_i2c_read failed to write register %x\n",
reg);
return ret;
}
/* read the data */
ret = i2c_smbus_read_byte(client);
if (ret < 0) {
dev_err(&client->dev,
"%s failed to read byte after writing to register %x\n",
__func__, reg);
return ret;
}
*val = ret;
val++;
reg++;
}
return 0;
}
/*
* Reads and calculates current lux value.
* The raw ch0 and ch1 values of the ambient light sensed in the last
@ -220,13 +187,14 @@ static int taos_get_lux(struct iio_dev *indio_dev)
goto done;
}
ret = taos_i2c_read(chip->client, (TSL258X_CMD_REG), &buf[0], 1);
ret = i2c_smbus_read_byte_data(chip->client, TSL258X_CMD_REG);
if (ret < 0) {
dev_err(&chip->client->dev, "taos_get_lux failed to read CMD_REG\n");
goto done;
}
/* is data new & valid */
if (!(buf[0] & TSL258X_STA_ADC_INTR)) {
if (!(ret & TSL258X_STA_ADC_INTR)) {
dev_err(&chip->client->dev, "taos_get_lux data not valid\n");
ret = chip->als_cur_info.lux; /* return LAST VALUE */
goto done;
@ -235,13 +203,14 @@ static int taos_get_lux(struct iio_dev *indio_dev)
for (i = 0; i < 4; i++) {
int reg = TSL258X_CMD_REG | (TSL258X_ALS_CHAN0LO + i);
ret = taos_i2c_read(chip->client, reg, &buf[i], 1);
ret = i2c_smbus_read_byte_data(chip->client, reg);
if (ret < 0) {
dev_err(&chip->client->dev,
"taos_get_lux failed to read register %x\n",
reg);
goto done;
}
buf[i] = ret;
}
/*
@ -343,52 +312,36 @@ static int taos_get_lux(struct iio_dev *indio_dev)
static int taos_als_calibrate(struct iio_dev *indio_dev)
{
struct tsl2583_chip *chip = iio_priv(indio_dev);
u8 reg_val;
unsigned int gain_trim_val;
int ret;
int lux_val;
ret = i2c_smbus_write_byte(chip->client,
(TSL258X_CMD_REG | TSL258X_CNTRL));
ret = i2c_smbus_read_byte_data(chip->client,
TSL258X_CMD_REG | TSL258X_CNTRL);
if (ret < 0) {
dev_err(&chip->client->dev,
"taos_als_calibrate failed to reach the CNTRL register, ret=%d\n",
ret);
return ret;
}
reg_val = i2c_smbus_read_byte(chip->client);
if (reg_val < 0) {
dev_err(&chip->client->dev,
"%s failed to read after writing to the CNTRL register\n",
"%s failed to read from the CNTRL register\n",
__func__);
return ret;
}
if ((reg_val & (TSL258X_CNTL_ADC_ENBL | TSL258X_CNTL_PWR_ON))
if ((ret & (TSL258X_CNTL_ADC_ENBL | TSL258X_CNTL_PWR_ON))
!= (TSL258X_CNTL_ADC_ENBL | TSL258X_CNTL_PWR_ON)) {
dev_err(&chip->client->dev,
"taos_als_calibrate failed: device not powered on with ADC enabled\n");
return -EINVAL;
}
ret = i2c_smbus_write_byte(chip->client,
(TSL258X_CMD_REG | TSL258X_CNTRL));
ret = i2c_smbus_read_byte_data(chip->client,
TSL258X_CMD_REG | TSL258X_CNTRL);
if (ret < 0) {
dev_err(&chip->client->dev,
"taos_als_calibrate failed to reach the STATUS register, ret=%d\n",
ret);
return ret;
}
reg_val = i2c_smbus_read_byte(chip->client);
if (reg_val < 0) {
dev_err(&chip->client->dev,
"%s failed to read after writing to the STATUS register\n",
"%s failed to read from the CNTRL register\n",
__func__);
return ret;
}
if ((reg_val & TSL258X_STA_ADC_VALID) != TSL258X_STA_ADC_VALID) {
if ((ret & TSL258X_STA_ADC_VALID) != TSL258X_STA_ADC_VALID) {
dev_err(&chip->client->dev,
"taos_als_calibrate failed: STATUS - ADC not valid.\n");
return -ENODATA;
@ -847,15 +800,9 @@ static int taos_probe(struct i2c_client *clientp,
memcpy(chip->taos_config, taos_config, sizeof(chip->taos_config));
for (i = 0; i < TSL258X_MAX_DEVICE_REGS; i++) {
ret = i2c_smbus_write_byte(clientp,
(TSL258X_CMD_REG | (TSL258X_CNTRL + i)));
if (ret < 0) {
dev_err(&clientp->dev,
"i2c_smbus_write_byte to cmd reg failed in taos_probe(), err = %d\n",
ret);
return ret;
}
ret = i2c_smbus_read_byte(clientp);
ret = i2c_smbus_read_byte_data(clientp,
(TSL258X_CMD_REG |
(TSL258X_CNTRL + i)));
if (ret < 0) {
dev_err(&clientp->dev,
"i2c_smbus_read_byte from reg failed in taos_probe(), err = %d\n",