[PATCH v2 5/9] staging: iio: tsl2x7x: cleaned up i2c calls in tsl2x7x_als_calibrate()

From: Brian Masney
Date: Thu Jul 06 2017 - 18:57:25 EST


The calibration function calls i2c_smbus_write_byte() and
i2c_smbus_read_byte(). These two function calls are replaced with a
single call to i2c_smbus_read_byte_data() by this patch. This patch
also removes an unnecessary call that reads the CNTRL register
a second time. One of the error paths returned -1 if the ADC was not
enabled and this patch changes that return value to -EINVAL.

Signed-off-by: Brian Masney <masneyb@xxxxxxxxxxxxx>
---
drivers/staging/iio/light/tsl2x7x.c | 34 ++++++++++++----------------------
1 file changed, 12 insertions(+), 22 deletions(-)

diff --git a/drivers/staging/iio/light/tsl2x7x.c b/drivers/staging/iio/light/tsl2x7x.c
index 6c9f06b..5734628 100644
--- a/drivers/staging/iio/light/tsl2x7x.c
+++ b/drivers/staging/iio/light/tsl2x7x.c
@@ -542,39 +542,29 @@ static void tsl2x7x_defaults(struct tsl2X7X_chip *chip)
static int tsl2x7x_als_calibrate(struct iio_dev *indio_dev)
{
struct tsl2X7X_chip *chip = iio_priv(indio_dev);
- u8 reg_val;
int gain_trim_val;
int ret;
int lux_val;

- ret = i2c_smbus_write_byte(chip->client,
- (TSL2X7X_CMD_REG | TSL2X7X_CNTRL));
+ ret = i2c_smbus_read_byte_data(chip->client,
+ TSL2X7X_CMD_REG | TSL2X7X_CNTRL);
if (ret < 0) {
dev_err(&chip->client->dev,
- "failed to write CNTRL register, ret=%d\n", ret);
+ "%s: failed to read from the CNTRL register\n",
+ __func__);
return ret;
}

- reg_val = i2c_smbus_read_byte(chip->client);
- if ((reg_val & (TSL2X7X_CNTL_ADC_ENBL | TSL2X7X_CNTL_PWR_ON))
- != (TSL2X7X_CNTL_ADC_ENBL | TSL2X7X_CNTL_PWR_ON)) {
- dev_err(&chip->client->dev,
- "%s: failed: ADC not enabled\n", __func__);
- return -1;
- }
-
- ret = i2c_smbus_write_byte(chip->client,
- (TSL2X7X_CMD_REG | TSL2X7X_CNTRL));
- if (ret < 0) {
+ if ((ret & (TSL2X7X_CNTL_ADC_ENBL | TSL2X7X_CNTL_PWR_ON))
+ != (TSL2X7X_CNTL_ADC_ENBL | TSL2X7X_CNTL_PWR_ON)) {
dev_err(&chip->client->dev,
- "failed to write ctrl reg: ret=%d\n", ret);
- return ret;
- }
-
- reg_val = i2c_smbus_read_byte(chip->client);
- if ((reg_val & TSL2X7X_STA_ADC_VALID) != TSL2X7X_STA_ADC_VALID) {
+ "%s: Device is not powered on and/or ADC is not enabled\n",
+ __func__);
+ return -EINVAL;
+ } else if ((ret & TSL2X7X_STA_ADC_VALID) != TSL2X7X_STA_ADC_VALID) {
dev_err(&chip->client->dev,
- "%s: failed: STATUS - ADC not valid.\n", __func__);
+ "%s: The two ADC channels have not completed an integration cycle\n",
+ __func__);
return -ENODATA;
}

--
2.9.4