From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757739AbcKCM7N (ORCPT ); Thu, 3 Nov 2016 08:59:13 -0400 Received: from onstation.org ([52.200.56.107]:35470 "EHLO onstation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756866AbcKCM5o (ORCPT ); Thu, 3 Nov 2016 08:57:44 -0400 From: Brian Masney To: jic23@kernel.org, linux-iio@vger.kernel.org Cc: devel@driverdev.osuosl.org, gregkh@linuxfoundation.org, lars@metafoo.de, pmeerw@pmeerw.net, knaack.h@gmx.de, linux-kernel@vger.kernel.org, Jon.Brenner@ams.com Subject: [PATCH 4/9] staging: iio: tsl2583: remove redundant power off sequence in taos_chip_on() Date: Thu, 3 Nov 2016 08:56:15 -0400 Message-Id: <1478177780-28699-5-git-send-email-masneyb@onstation.org> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1478177780-28699-1-git-send-email-masneyb@onstation.org> References: <1478177780-28699-1-git-send-email-masneyb@onstation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/staging/iio/light/tsl2583.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) 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. -- 2.5.5