From: Olivier Moysan <olivier.moysan@st.com> To: <jic23@kernel.org>, <robh+dt@kernel.org>, <olivier.moysan@st.com> Cc: <mark.rutland@arm.com>, <knaack.h@gmx.de>, <lars@metafoo.de>, <devicetree@vger.kernel.org>, <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <pmeerw@pmeerw.net>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH 4/4] iio: adc: stm32-dfsdm: add scale and offset support Date: Tue, 4 Feb 2020 11:10:08 +0100 [thread overview] Message-ID: <20200204101008.11411-5-olivier.moysan@st.com> (raw) In-Reply-To: <20200204101008.11411-1-olivier.moysan@st.com> Add scale and offset attributes support to STM32 DFSDM. Signed-off-by: Olivier Moysan <olivier.moysan@st.com> --- drivers/iio/adc/stm32-dfsdm-adc.c | 105 +++++++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 07b9dfdf8e76..b85fd3e90496 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -10,6 +10,7 @@ #include <linux/dma-mapping.h> #include <linux/iio/adc/stm32-dfsdm-adc.h> #include <linux/iio/buffer.h> +#include <linux/iio/consumer.h> #include <linux/iio/hw-consumer.h> #include <linux/iio/sysfs.h> #include <linux/iio/timer/stm32-lptim-trigger.h> @@ -67,6 +68,13 @@ struct stm32_dfsdm_dev_data { const struct regmap_config *regmap_cfg; }; +struct stm32_dfsdm_sd_chan_info { + int scale_val; + int scale_val2; + int offset; + unsigned int differential; +}; + struct stm32_dfsdm_adc { struct stm32_dfsdm *dfsdm; const struct stm32_dfsdm_dev_data *dev_data; @@ -79,6 +87,7 @@ struct stm32_dfsdm_adc { struct iio_hw_consumer *hwc; struct completion completion; u32 *buffer; + struct stm32_dfsdm_sd_chan_info *sd_chan; /* Audio specific */ unsigned int spi_freq; /* SPI bus clock frequency */ @@ -1271,7 +1280,10 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, int *val2, long mask) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - int ret; + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; + u32 max = flo->max << (flo->lshift - chan->scan_type.shift); + int ret, idx = chan->scan_index; switch (mask) { case IIO_CHAN_INFO_RAW: @@ -1307,6 +1319,41 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, *val = adc->sample_freq; return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + /* + * Scale is expressed in mV. + * When fast mode is disabled, actual resolution may be lower + * than 2^n, where n=realbits-1. + * This leads to underestimating input voltage. To + * compensate this deviation, the voltage reference can be + * corrected with a factor = realbits resolution / actual max + */ + *val = div_u64((u64)adc->sd_chan[idx].scale_val * + (u64)BIT(DFSDM_DATA_RES - 1), max); + *val2 = chan->scan_type.realbits; + if (adc->sd_chan[idx].differential) + *val *= 2; + + return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_OFFSET: + /* + * DFSDM output data are in the range [-2^n,2^n-1], + * with n=realbits-1. + * - Differential modulator: + * Offset correspond to SD modulator offset. + * - Single ended modulator: + * Input is in [0V,Vref] range, where 0V corresponds to -2^n. + * Add 2^n to offset. (i.e. middle of input range) + * offset = offset(sd) * vref / res(sd) * max / vref. + */ + *val = div_u64((u64)max * adc->sd_chan[idx].offset, + BIT(adc->sd_chan[idx].scale_val2 - 1)); + if (!adc->sd_chan[idx].differential) + *val += max; + + return IIO_VAL_INT; } return -EINVAL; @@ -1430,7 +1477,9 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, * IIO_CHAN_INFO_RAW: used to compute regular conversion * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling */ - ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); + ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET); ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | BIT(IIO_CHAN_INFO_SAMP_FREQ); @@ -1481,8 +1530,10 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) { struct iio_chan_spec *ch; struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct iio_channel *channels, *chan; + struct stm32_dfsdm_sd_chan_info *sd_chan; int num_ch; - int ret, chan_idx; + int ret, chan_idx, val2; adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp); @@ -1506,6 +1557,22 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) if (!ch) return -ENOMEM; + /* Get SD modulator channels */ + channels = iio_channel_get_all(&indio_dev->dev); + if (IS_ERR(channels)) { + dev_err(&indio_dev->dev, "Failed to get channel %ld\n", + PTR_ERR(channels)); + return PTR_ERR(channels); + } + chan = &channels[0]; + + adc->sd_chan = devm_kzalloc(&indio_dev->dev, + sizeof(*adc->sd_chan) * num_ch, GFP_KERNEL); + if (!adc->sd_chan) + return -ENOMEM; + + sd_chan = adc->sd_chan; + for (chan_idx = 0; chan_idx < num_ch; chan_idx++) { ch[chan_idx].scan_index = chan_idx; ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]); @@ -1513,6 +1580,38 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) dev_err(&indio_dev->dev, "Channels init failed\n"); return ret; } + + if (!chan->indio_dev) + return -EINVAL; + + ret = iio_read_channel_scale(chan, &sd_chan->scale_val, + &sd_chan->scale_val2); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to get channel %d scale\n", chan_idx); + return ret; + } + + if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_OFFSET)) { + ret = iio_read_channel_offset(chan, &sd_chan->offset, + &val2); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to get channel %d offset\n", + chan_idx); + return ret; + } + } + + sd_chan->differential = chan->channel->differential; + + dev_dbg(&indio_dev->dev, "Channel %d %s scale ref=%d offset=%d", + chan_idx, chan->channel->differential ? + "differential" : "single-ended", + sd_chan->scale_val, sd_chan->offset); + + chan++; + sd_chan++; } indio_dev->num_channels = num_ch; -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Olivier Moysan <olivier.moysan@st.com> To: <jic23@kernel.org>, <robh+dt@kernel.org>, <olivier.moysan@st.com> Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, lars@metafoo.de, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, pmeerw@pmeerw.net, knaack.h@gmx.de, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH 4/4] iio: adc: stm32-dfsdm: add scale and offset support Date: Tue, 4 Feb 2020 11:10:08 +0100 [thread overview] Message-ID: <20200204101008.11411-5-olivier.moysan@st.com> (raw) In-Reply-To: <20200204101008.11411-1-olivier.moysan@st.com> Add scale and offset attributes support to STM32 DFSDM. Signed-off-by: Olivier Moysan <olivier.moysan@st.com> --- drivers/iio/adc/stm32-dfsdm-adc.c | 105 +++++++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 07b9dfdf8e76..b85fd3e90496 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -10,6 +10,7 @@ #include <linux/dma-mapping.h> #include <linux/iio/adc/stm32-dfsdm-adc.h> #include <linux/iio/buffer.h> +#include <linux/iio/consumer.h> #include <linux/iio/hw-consumer.h> #include <linux/iio/sysfs.h> #include <linux/iio/timer/stm32-lptim-trigger.h> @@ -67,6 +68,13 @@ struct stm32_dfsdm_dev_data { const struct regmap_config *regmap_cfg; }; +struct stm32_dfsdm_sd_chan_info { + int scale_val; + int scale_val2; + int offset; + unsigned int differential; +}; + struct stm32_dfsdm_adc { struct stm32_dfsdm *dfsdm; const struct stm32_dfsdm_dev_data *dev_data; @@ -79,6 +87,7 @@ struct stm32_dfsdm_adc { struct iio_hw_consumer *hwc; struct completion completion; u32 *buffer; + struct stm32_dfsdm_sd_chan_info *sd_chan; /* Audio specific */ unsigned int spi_freq; /* SPI bus clock frequency */ @@ -1271,7 +1280,10 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, int *val2, long mask) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - int ret; + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; + u32 max = flo->max << (flo->lshift - chan->scan_type.shift); + int ret, idx = chan->scan_index; switch (mask) { case IIO_CHAN_INFO_RAW: @@ -1307,6 +1319,41 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, *val = adc->sample_freq; return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + /* + * Scale is expressed in mV. + * When fast mode is disabled, actual resolution may be lower + * than 2^n, where n=realbits-1. + * This leads to underestimating input voltage. To + * compensate this deviation, the voltage reference can be + * corrected with a factor = realbits resolution / actual max + */ + *val = div_u64((u64)adc->sd_chan[idx].scale_val * + (u64)BIT(DFSDM_DATA_RES - 1), max); + *val2 = chan->scan_type.realbits; + if (adc->sd_chan[idx].differential) + *val *= 2; + + return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_OFFSET: + /* + * DFSDM output data are in the range [-2^n,2^n-1], + * with n=realbits-1. + * - Differential modulator: + * Offset correspond to SD modulator offset. + * - Single ended modulator: + * Input is in [0V,Vref] range, where 0V corresponds to -2^n. + * Add 2^n to offset. (i.e. middle of input range) + * offset = offset(sd) * vref / res(sd) * max / vref. + */ + *val = div_u64((u64)max * adc->sd_chan[idx].offset, + BIT(adc->sd_chan[idx].scale_val2 - 1)); + if (!adc->sd_chan[idx].differential) + *val += max; + + return IIO_VAL_INT; } return -EINVAL; @@ -1430,7 +1477,9 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, * IIO_CHAN_INFO_RAW: used to compute regular conversion * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling */ - ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); + ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET); ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | BIT(IIO_CHAN_INFO_SAMP_FREQ); @@ -1481,8 +1530,10 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) { struct iio_chan_spec *ch; struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct iio_channel *channels, *chan; + struct stm32_dfsdm_sd_chan_info *sd_chan; int num_ch; - int ret, chan_idx; + int ret, chan_idx, val2; adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp); @@ -1506,6 +1557,22 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) if (!ch) return -ENOMEM; + /* Get SD modulator channels */ + channels = iio_channel_get_all(&indio_dev->dev); + if (IS_ERR(channels)) { + dev_err(&indio_dev->dev, "Failed to get channel %ld\n", + PTR_ERR(channels)); + return PTR_ERR(channels); + } + chan = &channels[0]; + + adc->sd_chan = devm_kzalloc(&indio_dev->dev, + sizeof(*adc->sd_chan) * num_ch, GFP_KERNEL); + if (!adc->sd_chan) + return -ENOMEM; + + sd_chan = adc->sd_chan; + for (chan_idx = 0; chan_idx < num_ch; chan_idx++) { ch[chan_idx].scan_index = chan_idx; ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]); @@ -1513,6 +1580,38 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) dev_err(&indio_dev->dev, "Channels init failed\n"); return ret; } + + if (!chan->indio_dev) + return -EINVAL; + + ret = iio_read_channel_scale(chan, &sd_chan->scale_val, + &sd_chan->scale_val2); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to get channel %d scale\n", chan_idx); + return ret; + } + + if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_OFFSET)) { + ret = iio_read_channel_offset(chan, &sd_chan->offset, + &val2); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to get channel %d offset\n", + chan_idx); + return ret; + } + } + + sd_chan->differential = chan->channel->differential; + + dev_dbg(&indio_dev->dev, "Channel %d %s scale ref=%d offset=%d", + chan_idx, chan->channel->differential ? + "differential" : "single-ended", + sd_chan->scale_val, sd_chan->offset); + + chan++; + sd_chan++; } indio_dev->num_channels = num_ch; -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-02-04 10:11 UTC|newest] Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-04 10:10 [PATCH 0/4] iio: adc: stm32-dfsdm: add scale and offset support Olivier Moysan 2020-02-04 10:10 ` Olivier Moysan 2020-02-04 10:10 ` [PATCH 1/4] dt-bindings: iio: adc: sd modulator: add vref support Olivier Moysan 2020-02-04 10:10 ` Olivier Moysan 2020-02-06 19:08 ` Rob Herring 2020-02-06 19:08 ` Rob Herring 2020-02-08 16:04 ` Jonathan Cameron 2020-02-08 16:04 ` Jonathan Cameron 2020-02-11 15:24 ` Olivier MOYSAN 2020-02-11 15:24 ` Olivier MOYSAN 2020-02-04 10:10 ` [PATCH 2/4] iio: adc: sd modulator: add scale support Olivier Moysan 2020-02-04 10:10 ` Olivier Moysan 2020-02-08 16:03 ` Jonathan Cameron 2020-02-08 16:03 ` Jonathan Cameron 2020-02-11 15:22 ` Olivier MOYSAN 2020-02-11 15:22 ` Olivier MOYSAN 2020-02-04 10:10 ` [PATCH 3/4] iio: adc: stm32-dfsdm: use resolution define Olivier Moysan 2020-02-04 10:10 ` Olivier Moysan 2020-02-04 10:10 ` Olivier Moysan [this message] 2020-02-04 10:10 ` [PATCH 4/4] iio: adc: stm32-dfsdm: add scale and offset support Olivier Moysan 2020-02-08 16:18 ` Jonathan Cameron 2020-02-08 16:18 ` Jonathan Cameron 2020-02-11 15:19 ` Olivier MOYSAN 2020-02-11 15:19 ` Olivier MOYSAN 2020-02-14 13:11 ` Jonathan Cameron 2020-02-14 13:11 ` Jonathan Cameron 2020-02-14 14:49 ` Olivier MOYSAN 2020-02-14 14:49 ` Olivier MOYSAN 2020-02-14 15:10 ` Jonathan Cameron 2020-02-14 15:10 ` Jonathan Cameron [not found] ` <AM9PR10MB43558CEB8DAE7F373E9E7A5DF9D69@AM9PR10MB4355.EURPRD10.PROD.OUTLOOK.COM> 2021-09-10 15:56 ` Olivier MOYSAN 2021-09-10 15:56 ` Olivier MOYSAN 2021-09-12 17:26 ` Jonathan Cameron 2021-09-12 17:26 ` Jonathan Cameron 2021-09-14 15:43 ` Olivier MOYSAN 2021-09-14 15:43 ` Olivier MOYSAN 2021-09-19 18:14 ` Jonathan Cameron 2021-09-19 18:14 ` Jonathan Cameron 2021-09-24 13:14 ` Olivier MOYSAN 2021-09-24 13:14 ` Olivier MOYSAN 2021-09-26 14:56 ` Jonathan Cameron 2021-09-26 14:56 ` Jonathan Cameron 2021-09-29 16:44 ` Olivier MOYSAN 2021-09-29 16:44 ` Olivier MOYSAN 2021-09-30 15:21 ` Jonathan Cameron 2021-09-30 15:21 ` Jonathan Cameron
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