Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754984AbdIHNzn (ORCPT ); Fri, 8 Sep 2017 09:55:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34310 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756253AbdIHNUN (ORCPT ); Fri, 8 Sep 2017 09:20:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Baluta , Akinobu Mita , Jonathan Cameron Subject: [PATCH 4.13 13/47] iio: adc: ti-ads1015: fix scale information for ADS1115 Date: Fri, 8 Sep 2017 15:18:45 +0200 Message-Id: <20170908131824.148764372@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170908131823.546721606@linuxfoundation.org> References: <20170908131823.546721606@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4512 Lines: 139 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita commit 8d0e8e795623bd6229cf48bb7777a1c456c370ed upstream. The ti-ads1015 driver supports ADS1015 and ADS1115 devices. The same scale information is used for both devices in this driver, however they have actually different values and the ADS1115's one is not correct. These devices have the same full-scale input voltage range for each PGA selection. So instead of adding another hardcoded scale information, compute a correct scale on demand from each device's resolution. Cc: Daniel Baluta Signed-off-by: Akinobu Mita Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/ti-ads1015.c | 48 +++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 24 deletions(-) --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -81,18 +81,12 @@ static const unsigned int ads1115_data_r 8, 16, 32, 64, 128, 250, 475, 860 }; -static const struct { - int scale; - int uscale; -} ads1015_scale[] = { - {3, 0}, - {2, 0}, - {1, 0}, - {0, 500000}, - {0, 250000}, - {0, 125000}, - {0, 125000}, - {0, 125000}, +/* + * Translation from PGA bits to full-scale positive and negative input voltage + * range in mV + */ +static int ads1015_fullscale_range[] = { + 6144, 4096, 2048, 1024, 512, 256, 256, 256 }; #define ADS1015_V_CHAN(_chan, _addr) { \ @@ -300,17 +294,20 @@ err: return IRQ_HANDLED; } -static int ads1015_set_scale(struct ads1015_data *data, int chan, +static int ads1015_set_scale(struct ads1015_data *data, + struct iio_chan_spec const *chan, int scale, int uscale) { int i, ret, rindex = -1; + int fullscale = div_s64((scale * 1000000LL + uscale) << + (chan->scan_type.realbits - 1), 1000000); - for (i = 0; i < ARRAY_SIZE(ads1015_scale); i++) - if (ads1015_scale[i].scale == scale && - ads1015_scale[i].uscale == uscale) { + for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) { + if (ads1015_fullscale_range[i] == fullscale) { rindex = i; break; } + } if (rindex < 0) return -EINVAL; @@ -320,7 +317,7 @@ static int ads1015_set_scale(struct ads1 if (ret < 0) return ret; - data->channel_data[chan].pga = rindex; + data->channel_data[chan->address].pga = rindex; return 0; } @@ -378,9 +375,9 @@ static int ads1015_read_raw(struct iio_d } case IIO_CHAN_INFO_SCALE: idx = data->channel_data[chan->address].pga; - *val = ads1015_scale[idx].scale; - *val2 = ads1015_scale[idx].uscale; - ret = IIO_VAL_INT_PLUS_MICRO; + *val = ads1015_fullscale_range[idx]; + *val2 = chan->scan_type.realbits - 1; + ret = IIO_VAL_FRACTIONAL_LOG2; break; case IIO_CHAN_INFO_SAMP_FREQ: idx = data->channel_data[chan->address].data_rate; @@ -407,7 +404,7 @@ static int ads1015_write_raw(struct iio_ mutex_lock(&data->lock); switch (mask) { case IIO_CHAN_INFO_SCALE: - ret = ads1015_set_scale(data, chan->address, val, val2); + ret = ads1015_set_scale(data, chan, val, val2); break; case IIO_CHAN_INFO_SAMP_FREQ: ret = ads1015_set_data_rate(data, chan->address, val); @@ -439,7 +436,10 @@ static const struct iio_buffer_setup_ops .validate_scan_mask = &iio_validate_scan_mask_onehot, }; -static IIO_CONST_ATTR(scale_available, "3 2 1 0.5 0.25 0.125"); +static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available, + "3 2 1 0.5 0.25 0.125"); +static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available, + "0.1875 0.125 0.0625 0.03125 0.015625 0.007813"); static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available, sampling_frequency_available, "128 250 490 920 1600 2400 3300"); @@ -447,7 +447,7 @@ static IIO_CONST_ATTR_NAMED(ads1115_samp sampling_frequency_available, "8 16 32 64 128 250 475 860"); static struct attribute *ads1015_attributes[] = { - &iio_const_attr_scale_available.dev_attr.attr, + &iio_const_attr_ads1015_scale_available.dev_attr.attr, &iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr, NULL, }; @@ -457,7 +457,7 @@ static const struct attribute_group ads1 }; static struct attribute *ads1115_attributes[] = { - &iio_const_attr_scale_available.dev_attr.attr, + &iio_const_attr_ads1115_scale_available.dev_attr.attr, &iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr, NULL, };