From: Brian Masney Date: Thu, 3 Nov 2016 12:56:15 +0000 (-0400) Subject: staging: iio: tsl2583: remove redundant power off sequence in taos_chip_on() X-Git-Tag: v5.15~12305^2~367^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=babe444798ebfe02f2e870322927c7018957c7f3;p=platform%2Fkernel%2Flinux-starfive.git staging: iio: tsl2583: remove redundant power off sequence in taos_chip_on() taos_chip_on() explicitly turns the sensor power on and then writes the 8 registers that are stored in taos_config. The first register in taos_config is the CONTROL register and the configuration is set to turn the power off. The existing state sequence in taos_chip_on() is: - Turn device power on - Turn device power off (via taos_config) - Configure other 7 registers (via taos_config) - Turn device power on, enable ADC This patch changes the code so that the device is not powered off via taos_config. Verified that the driver still functions correctly using a TSL2581 hooked up to a Raspberry Pi 2. Signed-off-by: Brian Masney Signed-off-by: Jonathan Cameron --- diff --git a/drivers/staging/iio/light/tsl2583.c b/drivers/staging/iio/light/tsl2583.c index 709f446..7fb09c6 100644 --- a/drivers/staging/iio/light/tsl2583.c +++ b/drivers/staging/iio/light/tsl2583.c @@ -410,17 +410,8 @@ static int taos_chip_on(struct iio_dev *indio_dev) chip->als_saturation = als_count * 922; /* 90% of full scale */ chip->als_time_scale = (als_time + 25) / 50; - /* - * TSL258x Specific power-on / adc enable sequence - * Power on the device 1st. - */ - utmp = TSL258X_CNTL_PWR_ON; - ret = i2c_smbus_write_byte_data(chip->client, - TSL258X_CMD_REG | TSL258X_CNTRL, utmp); - if (ret < 0) { - dev_err(&chip->client->dev, "taos_chip_on failed on CNTRL reg.\n"); - return ret; - } + /* Power on the device; ADC off. */ + chip->taos_config[TSL258X_CNTRL] = TSL258X_CNTL_PWR_ON; /* * Use the following shadow copy for our delay before enabling ADC.