From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-sn1nam01on0057.outbound.protection.outlook.com ([104.47.32.57]:52544 "EHLO NAM01-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751386AbdIEMO7 (ORCPT ); Tue, 5 Sep 2017 08:14:59 -0400 From: Dragos Bogdan To: Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron CC: Hartmut Knaack , Peter Meerwald-Stadler , , , Dragos Bogdan Subject: [PATCH 1/2] iio: ad_sigma_delta: Implement a dedicated reset function Date: Tue, 5 Sep 2017 15:14:45 +0300 Message-ID: <20170905121445.26913-1-dragos.bogdan@analog.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org Since most of the SD ADCs have the option of reseting the serial interface by sending a number of SCLKs with CS = 0 and DIN = 1, a dedicated function that can do this is usefull. Signed-off-by: Dragos Bogdan --- drivers/iio/adc/ad_sigma_delta.c | 28 ++++++++++++++++++++++++++++ include/linux/iio/adc/ad_sigma_delta.h | 3 +++ 2 files changed, 31 insertions(+) diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index d10bd0c97233..22c4c17cd996 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -177,6 +177,34 @@ int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, } EXPORT_SYMBOL_GPL(ad_sd_read_reg); +/** + * ad_sd_reset() - Reset the serial interface + * + * @sigma_delta: The sigma delta device + * @reset_length: Number of SCLKs with DIN = 1 + * + * Returns 0 on success, an error code otherwise. + **/ +int ad_sd_reset(struct ad_sigma_delta *sigma_delta, + unsigned int reset_length) +{ + uint8_t *buf; + unsigned int size; + int ret; + + size = DIV_ROUND_UP(reset_length, 8); + buf = kcalloc(size, sizeof(*buf), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + memset(buf, 0xff, size); + ret = spi_write(sigma_delta->spi, buf, size); + kfree(buf); + + return ret; +} +EXPORT_SYMBOL_GPL(ad_sd_reset); + static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, unsigned int mode, unsigned int channel) { diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index 5ba430cc9a87..1fc7abd28b0b 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -111,6 +111,9 @@ int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, unsigned int size, unsigned int *val); +int ad_sd_reset(struct ad_sigma_delta *sigma_delta, + unsigned int reset_length); + int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val); int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, -- 2.11.0