From: Brian Masney Date: Thu, 3 Nov 2016 12:56:12 +0000 (-0400) Subject: staging: iio: tsl2583: i2c_smbus_write_byte() / i2c_smbus_read_byte() migration X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6ba5dee90b2483f8a78081376f56e6b65c10ea92;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Cc: Julia Lawall Signed-off-by: Jonathan Cameron --- diff --git a/drivers/staging/iio/light/tsl2583.c b/drivers/staging/iio/light/tsl2583.c index 49b19f5c1d84..a3a909560c88 100644 --- a/drivers/staging/iio/light/tsl2583.c +++ b/drivers/staging/iio/light/tsl2583.c @@ -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 @@ done: 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",