From patchwork Wed Jun 19 13:03:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier MOYSAN X-Patchwork-Id: 11004123 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 07D2D1395 for ; Wed, 19 Jun 2019 13:04:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EC36F289FA for ; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DFD6A28581; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 289D12891F for ; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731738AbfFSNE0 (ORCPT ); Wed, 19 Jun 2019 09:04:26 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:63838 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727882AbfFSNE0 (ORCPT ); Wed, 19 Jun 2019 09:04:26 -0400 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5JCu1vq023624; Wed, 19 Jun 2019 15:03:56 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=d7sGyUyVXBZreZ6CcBeax+9pcueTuZNghW6i/WrA9vs=; b=tlAqSjCOwLDGJtElz5Cez30MrbLy+kl1n+o1YvQ1VhM3B0LH0/b/pT0q2cTy1vBUXvll eMdeB6hlCdxMzDZwI/x8nIvmSBAn0TzshYTObd0PPC9g3vsJKVJaD/P6cDdFfQxVWDZb CPutcFuIht8qWEP83eDy5RyQpfjy1lSgcmJHvtFPOi3CiH2ak60CwXTRC/KceoccS2zT o9savlqchD0zo5eGlelRhffqXeC8m5SPLaYiiJTnnO0K9VyssMw7SbLFzPANQVd4GdXg XCgBcYJkhAj32xjWQY74GliJKGN3h28xBxUPMeNTl1dofLrL6UfQJ52nA4zR6xZGOvM9 sA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2t7813c0a1-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 19 Jun 2019 15:03:56 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id E30B931; Wed, 19 Jun 2019 13:03:55 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas24.st.com [10.75.90.94]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id B42332831; Wed, 19 Jun 2019 13:03:55 +0000 (GMT) Received: from SAFEX1HUBCAS21.st.com (10.75.90.45) by Safex1hubcas24.st.com (10.75.90.94) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:55 +0200 Received: from localhost (10.201.23.16) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:55 +0200 From: Olivier Moysan To: , , , , , , , , , , , , Subject: [PATCH 1/5] iio: adc: stm32-dfsdm: fix output resolution Date: Wed, 19 Jun 2019 15:03:47 +0200 Message-ID: <1560949431-22948-2-git-send-email-olivier.moysan@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> References: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.16] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-19_07:,, signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In buffered mode, output samples are shifted left unconditionally. This works for filter order 3, but this shift is not adapted for other filter orders. Compute required shift, left or right, and shift output data accordingly. Add also saturation management to avoid wrap-around when maximum positive sample is reached. Fixes: eca949800d2d ("IIO: ADC: add stm32 DFSDM support for PDM microphone") Signed-off-by: Olivier Moysan --- drivers/iio/adc/stm32-dfsdm-adc.c | 158 +++++++++++++++++++++++++++++--------- drivers/iio/adc/stm32-dfsdm.h | 24 ++++-- 2 files changed, 142 insertions(+), 40 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 588907cc3b6b..cb596f104919 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -39,9 +39,16 @@ #define DFSDM_MAX_INT_OVERSAMPLING 256 #define DFSDM_MAX_FL_OVERSAMPLING 1024 -/* Max sample resolutions */ -#define DFSDM_MAX_RES BIT(31) -#define DFSDM_DATA_RES BIT(23) +/* Limit filter output resolution to 31 bits. (i.e. sample range is +/-2^30) */ +#define DFSDM_DATA_MAX BIT(30) +/* + * Data are output as two's complement data in a 24 bit field. + * Data from filters are in the range +/-2^(n-1) + * 2^(n-1) maximum positive value cannot be coded in 2's complement n bits + * An extra bit is required to avoid wrap-around of the binary code for 2^(n-1) + * So, the resolution of samples from filter is actually limited to 23 bits + */ +#define DFSDM_DATA_RES 24 /* Filter configuration */ #define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \ @@ -181,14 +188,15 @@ static int stm32_dfsdm_get_jextsel(struct iio_dev *indio_dev, return -EINVAL; } -static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, - unsigned int fast, unsigned int oversamp) +static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl, + unsigned int fast, unsigned int oversamp) { unsigned int i, d, fosr, iosr; - u64 res; - s64 delta; + u64 res, max; + int bits, shift; unsigned int m = 1; /* multiplication factor */ unsigned int p = fl->ford; /* filter order (ford) */ + struct stm32_dfsdm_filter_osr *flo = &fl->flo; pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp); /* @@ -207,11 +215,9 @@ static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, /* * Look for filter and integrator oversampling ratios which allows - * to reach 24 bits data output resolution. - * Leave as soon as if exact resolution if reached. - * Otherwise the higher resolution below 32 bits is kept. + * to maximize data output resolution. */ - fl->res = 0; + flo->res = 0; for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { if (fast) @@ -236,32 +242,68 @@ static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, res = fosr; for (i = p - 1; i > 0; i--) { res = res * (u64)fosr; - if (res > DFSDM_MAX_RES) + if (res > DFSDM_DATA_MAX) break; } - if (res > DFSDM_MAX_RES) + if (res > DFSDM_DATA_MAX) continue; + res = res * (u64)m * (u64)iosr; - if (res > DFSDM_MAX_RES) + if (res > DFSDM_DATA_MAX) continue; - delta = res - DFSDM_DATA_RES; - - if (res >= fl->res) { - fl->res = res; - fl->fosr = fosr; - fl->iosr = iosr; - fl->fast = fast; - pr_debug("%s: fosr = %d, iosr = %d\n", - __func__, fl->fosr, fl->iosr); + if (res >= flo->res) { + flo->res = res; + flo->fosr = fosr; + flo->iosr = iosr; + + bits = fls(flo->res); + /* 8 LBSs in data register contain chan info */ + max = flo->res << 8; + + /* if resolution is not a power of two */ + if (flo->res > BIT(bits - 1)) + bits++; + else + max--; + + shift = DFSDM_DATA_RES - bits; + /* + * Compute right/left shift + * Right shift is performed by hardware + * when transferring samples to data register. + * Left shift is done by software on buffer + */ + if (shift > 0) { + /* Resolution is lower than 24 bits */ + flo->rshift = 0; + flo->lshift = shift; + } else { + /* + * If resolution is 24 bits or more, + * max positive value may be ambiguous + * (equal to max negative value as sign + * bit is dropped). + * Reduce resolution to 23 bits (rshift) + * to keep the sign on bit 23 and treat + * saturation before rescaling on 24 + * bits (lshift). + */ + flo->rshift = 1 - shift; + flo->lshift = 1; + max >>= flo->rshift; + } + flo->max = (s32)max; + + pr_debug("%s: fast %d, fosr %d, iosr %d, res 0x%llx/%d bits, rshift %d, lshift %d\n", + __func__, fast, flo->fosr, flo->iosr, + flo->res, bits, flo->rshift, + flo->lshift); } - - if (!delta) - return 0; } } - if (!fl->res) + if (!flo->res) return -EINVAL; return 0; @@ -384,6 +426,36 @@ static int stm32_dfsdm_filter_set_trig(struct stm32_dfsdm_adc *adc, return 0; } +static int stm32_dfsdm_channels_configure(struct stm32_dfsdm_adc *adc, + unsigned int fl_id, + struct iio_trigger *trig) +{ + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + struct regmap *regmap = adc->dfsdm->regmap; + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo; + const struct iio_chan_spec *chan; + unsigned int bit; + int ret; + + if (!flo->res) + return -EINVAL; + + for_each_set_bit(bit, &adc->smask, + sizeof(adc->smask) * BITS_PER_BYTE) { + chan = indio_dev->channels + bit; + + ret = regmap_update_bits(regmap, + DFSDM_CHCFGR2(chan->channel), + DFSDM_CHCFGR2_DTRBS_MASK, + DFSDM_CHCFGR2_DTRBS(flo->rshift)); + if (ret) + return ret; + } + + return 0; +} + static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc, unsigned int fl_id, struct iio_trigger *trig) @@ -391,6 +463,7 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc, struct iio_dev *indio_dev = iio_priv_to_dev(adc); struct regmap *regmap = adc->dfsdm->regmap; struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo; u32 cr1; const struct iio_chan_spec *chan; unsigned int bit, jchg = 0; @@ -398,13 +471,13 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc, /* Average integrator oversampling */ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK, - DFSDM_FCR_IOSR(fl->iosr - 1)); + DFSDM_FCR_IOSR(flo->iosr - 1)); if (ret) return ret; /* Filter order and Oversampling */ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK, - DFSDM_FCR_FOSR(fl->fosr - 1)); + DFSDM_FCR_FOSR(flo->fosr - 1)); if (ret) return ret; @@ -573,7 +646,7 @@ static int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev, "Rate not accurate. requested (%u), actual (%u)\n", sample_freq, spi_freq / oversamp); - ret = stm32_dfsdm_set_osrs(fl, 0, oversamp); + ret = stm32_dfsdm_compute_osrs(fl, 0, oversamp); if (ret < 0) { dev_err(&indio_dev->dev, "No filter parameters that match!\n"); return ret; @@ -623,6 +696,10 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, struct regmap *regmap = adc->dfsdm->regmap; int ret; + ret = stm32_dfsdm_channels_configure(adc, adc->fl_id, trig); + if (ret < 0) + return ret; + ret = stm32_dfsdm_start_channel(adc); if (ret < 0) return ret; @@ -729,6 +806,8 @@ static void stm32_dfsdm_dma_buffer_done(void *data) { struct iio_dev *indio_dev = data; struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo; int available = stm32_dfsdm_adc_dma_residue(adc); size_t old_pos; @@ -751,10 +830,19 @@ static void stm32_dfsdm_dma_buffer_done(void *data) old_pos = adc->bufi; while (available >= indio_dev->scan_bytes) { - u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi]; + s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; /* Mask 8 LSB that contains the channel ID */ - *buffer = (*buffer & 0xFFFFFF00) << 8; + *buffer &= 0xFFFFFF00; + /* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */ + if (*buffer > flo->max) + *buffer -= 1; + /* + * Samples from filter are retrieved with 23 bits resolution + * or less. Shift left to align MSB on 24 bits. + */ + *buffer <<= flo->lshift; + available -= indio_dev->scan_bytes; adc->bufi += indio_dev->scan_bytes; if (adc->bufi >= adc->buf_sz) { @@ -1078,7 +1166,7 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; - ret = stm32_dfsdm_set_osrs(fl, 0, val); + ret = stm32_dfsdm_compute_osrs(fl, 0, val); if (!ret) adc->oversamp = val; iio_device_release_direct_mode(indio_dev); @@ -1327,8 +1415,8 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) int ret, chan_idx; adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; - ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0, - adc->oversamp); + ret = stm32_dfsdm_compute_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0, + adc->oversamp); if (ret < 0) return ret; diff --git a/drivers/iio/adc/stm32-dfsdm.h b/drivers/iio/adc/stm32-dfsdm.h index 8708394b0725..18b06ee6ed7b 100644 --- a/drivers/iio/adc/stm32-dfsdm.h +++ b/drivers/iio/adc/stm32-dfsdm.h @@ -243,19 +243,33 @@ enum stm32_dfsdm_sinc_order { }; /** - * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter + * struct stm32_dfsdm_filter_osr - DFSDM filter settings linked to oversampling * @iosr: integrator oversampling * @fosr: filter oversampling - * @ford: filter order + * @rshift: output sample right shift (hardware shift) + * @lshift: output sample left shift (software shift) * @res: output sample resolution + * @max: output sample maximum positive value + */ +struct stm32_dfsdm_filter_osr { + unsigned int iosr; + unsigned int fosr; + unsigned int rshift; + unsigned int lshift; + u64 res; + s32 max; +}; + +/** + * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter + * @ford: filter order + * @flo: filter oversampling structure * @sync_mode: filter synchronized with filter 0 * @fast: filter fast mode */ struct stm32_dfsdm_filter { - unsigned int iosr; - unsigned int fosr; enum stm32_dfsdm_sinc_order ford; - u64 res; + struct stm32_dfsdm_filter_osr flo; unsigned int sync_mode; unsigned int fast; }; From patchwork Wed Jun 19 13:03:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier MOYSAN X-Patchwork-Id: 11004113 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 67C3F1395 for ; Wed, 19 Jun 2019 13:04:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5670D1FFB1 for ; Wed, 19 Jun 2019 13:04:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4A9DF28A1F; Wed, 19 Jun 2019 13:04:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EABBD289E9 for ; Wed, 19 Jun 2019 13:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727882AbfFSNE3 (ORCPT ); Wed, 19 Jun 2019 09:04:29 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:21868 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727076AbfFSNE1 (ORCPT ); Wed, 19 Jun 2019 09:04:27 -0400 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5JCu4JD023632; Wed, 19 Jun 2019 15:03:58 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=Snd2JSaEu7Z6XLdmFflA+YpQRWPbEmDirJH8rOIN+Hg=; b=gC2g+F4FLTf8VKpowhrkPjLvh3D1Z8GAwMlQcrwkCJqInZztHxLKi7EiFOGIcoW/A0cL 8qsClG8aWxwyaxd89UcdM43p0QwEZiFKeuAqzkvXm/7AX7654e6Oi3VztmklY/ptDJ+Z ON680YGi/YAgsylciwmqJxfMhGQl+Zcujqu5qegb6YZNYEaJW9zSpAI00nCPkTc4WgVs JjSH9/rKKd4mn3knLbjuJfJPNAHl9H6OYJYKQstqcgim0+rMWdMXFBrGcDnYmfDH60dh yXu4eSrkGkzxLufxNpNl4FCKC1B1kzHH4X+XNHxz7QZivq5DI7HLCL+SwW583U7btRVG /A== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2t7813c0a8-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 19 Jun 2019 15:03:57 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 639B631; Wed, 19 Jun 2019 13:03:57 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas24.st.com [10.75.90.94]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 42B362831; Wed, 19 Jun 2019 13:03:57 +0000 (GMT) Received: from SAFEX1HUBCAS21.st.com (10.75.90.45) by Safex1hubcas24.st.com (10.75.90.94) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:57 +0200 Received: from localhost (10.201.23.16) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:56 +0200 From: Olivier Moysan To: , , , , , , , , , , , , Subject: [PATCH 2/5] iio: adc: stm32-dfsdm: fix data type Date: Wed, 19 Jun 2019 15:03:48 +0200 Message-ID: <1560949431-22948-3-git-send-email-olivier.moysan@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> References: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.16] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-19_07:,, signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Fix the data type as DFSDM raw output is complements 2, 24bits left aligned in a 32-bit register. This change does not affect AUDIO path - Set data as signed for IIO (as for AUDIO) - Set 8 bit right shift for IIO. The 8 LSBs bits of data contains channel info and are masked. Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support") Signed-off-by: Olivier Moysan --- drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index cb596f104919..6b90a40882f2 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -1365,11 +1365,11 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, BIT(IIO_CHAN_INFO_SAMP_FREQ); if (adc->dev_data->type == DFSDM_AUDIO) { - ch->scan_type.sign = 's'; ch->ext_info = dfsdm_adc_audio_ext_info; } else { - ch->scan_type.sign = 'u'; + ch->scan_type.shift = 8; } + ch->scan_type.sign = 's'; ch->scan_type.realbits = 24; ch->scan_type.storagebits = 32; From patchwork Wed Jun 19 13:03:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier MOYSAN X-Patchwork-Id: 11004115 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9A5D576 for ; Wed, 19 Jun 2019 13:04:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A43D1FF1E for ; Wed, 19 Jun 2019 13:04:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E41B289B5; Wed, 19 Jun 2019 13:04:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 14F8A1FFB1 for ; Wed, 19 Jun 2019 13:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731910AbfFSNEf (ORCPT ); Wed, 19 Jun 2019 09:04:35 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:21770 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731893AbfFSNEe (ORCPT ); Wed, 19 Jun 2019 09:04:34 -0400 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5JCuBJM023659; Wed, 19 Jun 2019 15:04:01 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=C0tl/h814D0dle+nbGO9SjbYs9XOpojrEDl6X9DrGZk=; b=C+5wGk3MVghtvj2ZPqHqBd879zWEVlGy1+cHcWHfZJLamn5UpaeJmy76ZytA6VbsysO2 wux/QZZQWvad9ncNuWbKycEIZ5VTNtlIFpHb8NROBbs3Ef+n8EDgmBUKzijO7FMDYNXo Ung3f4qZmquXtoya/lHjHlSpRujkcTr46nF97aXbZxZHqA2GGS0hgsI5NYGgNrCleTPI SVl8lSHSfHlivocxiKtIooseqkw+O+q1JGnhjoO6CS9xLVljcSwPSrVA9b432Uufh087 Avjl83tOnvAbxtkEisTzNd+H/gXMapOHcAh9FSEWdIHCOJ9089S5SyfW6Vhr9kA7WnBi /A== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2t7813c0ah-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 19 Jun 2019 15:04:01 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 3BE8938; Wed, 19 Jun 2019 13:03:59 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas23.st.com [10.75.90.46]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 1D6B92835; Wed, 19 Jun 2019 13:03:59 +0000 (GMT) Received: from SAFEX1HUBCAS21.st.com (10.75.90.45) by SAFEX1HUBCAS23.st.com (10.75.90.46) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:59 +0200 Received: from localhost (10.201.23.16) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:03:58 +0200 From: Olivier Moysan To: , , , , , , , , , , , , Subject: [PATCH 3/5] iio: adc: stm32-dfsdm: manage data resolution in trigger mode Date: Wed, 19 Jun 2019 15:03:49 +0200 Message-ID: <1560949431-22948-4-git-send-email-olivier.moysan@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> References: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.16] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-19_07:,, signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add output sample resolution management in scan mode. Add stm32_dfsdm_process_data() function to share sample processing between continuous and trigger modes. Signed-off-by: Olivier Moysan --- drivers/iio/adc/stm32-dfsdm-adc.c | 41 ++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 6b90a40882f2..5b19a88412a6 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -779,6 +779,30 @@ static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc) return 0; } +static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc, + s32 *buffer) +{ + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_filter_osr *flo = &fl->flo; + unsigned int i = adc->nconv; + s32 *ptr = buffer; + + while (i--) { + /* Mask 8 LSB that contains the channel ID */ + *ptr &= 0xFFFFFF00; + /* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */ + if (*ptr > flo->max) + *ptr -= 1; + /* + * Samples from filter are retrieved with 23 bits resolution + * or less. Shift left to align MSB on 24 bits. + */ + *ptr <<= flo->lshift; + + ptr++; + } +} + static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; @@ -787,7 +811,9 @@ static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p) int available = stm32_dfsdm_adc_dma_residue(adc); while (available >= indio_dev->scan_bytes) { - u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi]; + s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; + + stm32_dfsdm_process_data(adc, buffer); iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp); @@ -806,8 +832,6 @@ static void stm32_dfsdm_dma_buffer_done(void *data) { struct iio_dev *indio_dev = data; struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; - struct stm32_dfsdm_filter_osr *flo = &fl->flo; int available = stm32_dfsdm_adc_dma_residue(adc); size_t old_pos; @@ -832,16 +856,7 @@ static void stm32_dfsdm_dma_buffer_done(void *data) while (available >= indio_dev->scan_bytes) { s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; - /* Mask 8 LSB that contains the channel ID */ - *buffer &= 0xFFFFFF00; - /* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */ - if (*buffer > flo->max) - *buffer -= 1; - /* - * Samples from filter are retrieved with 23 bits resolution - * or less. Shift left to align MSB on 24 bits. - */ - *buffer <<= flo->lshift; + stm32_dfsdm_process_data(adc, buffer); available -= indio_dev->scan_bytes; adc->bufi += indio_dev->scan_bytes; From patchwork Wed Jun 19 13:03:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier MOYSAN X-Patchwork-Id: 11004117 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 86E431395 for ; Wed, 19 Jun 2019 13:04:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 73BAA289B5 for ; Wed, 19 Jun 2019 13:04:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6012828A1A; Wed, 19 Jun 2019 13:04:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B3D8F289B5 for ; Wed, 19 Jun 2019 13:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731877AbfFSNEm (ORCPT ); Wed, 19 Jun 2019 09:04:42 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:36329 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731895AbfFSNEe (ORCPT ); Wed, 19 Jun 2019 09:04:34 -0400 Received: from pps.filterd (m0046037.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5JCuDOn030429; Wed, 19 Jun 2019 15:04:02 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=p5e2nfsElxNtsp+AWmabxwZass2bjpLHbaOSk3EXfxc=; b=xKbs6LYe8u7td8XhtcXeqRg/V8xdmFKrCFxWmC0/zvKrN5fLFw3DOaKsUJxhKt322uEk +qKfZIeBqlHL1/idmQY3TNWjkGPdrH+81v0MpKkcqsTA0nThikpRKcS7ZrPoWTx0SL6s dOeo0YBQ7FftBVl0+Pjygsff/l/RbZyNTaRyNlcSYghHOKGQ9J4ezO6wmdwfsrwSZdUp sY7qNwiLiThJ/UEWwX6wSzPUC7AchqjmKYqJH9i6KI1Ve8MyO5sD9QAwj/o88jgtBfZh uthoD49GdLN7+zR44DQ/pFmemysWLrNiJ42M8zZHsyUp/C296RY+IoSh58TLW6GcN4kz lQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2t781a3yy1-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 19 Jun 2019 15:04:02 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id C24FA3A; Wed, 19 Jun 2019 13:04:00 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas23.st.com [10.75.90.46]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 96AAB2835; Wed, 19 Jun 2019 13:04:00 +0000 (GMT) Received: from SAFEX1HUBCAS21.st.com (10.75.90.45) by SAFEX1HUBCAS23.st.com (10.75.90.46) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:04:00 +0200 Received: from localhost (10.201.23.16) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:04:00 +0200 From: Olivier Moysan To: , , , , , , , , , , , , Subject: [PATCH 4/5] iio: adc: stm32-dfsdm: add fast mode support Date: Wed, 19 Jun 2019 15:03:50 +0200 Message-ID: <1560949431-22948-5-git-send-email-olivier.moysan@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> References: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.16] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-19_07:,, signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The use of fast mode allows to get a larger set of solution for filter parameters. This can be useful to reach a better output sample resolution, when fast mode can be used. Fast mode is selected at startup if it is relevant. The startup is performed in postenable callback context, where there are too tight time constraints for filter parameters computation. For this reason both fast and non fast filter parameters are pre-computed previously. Signed-off-by: Olivier Moysan --- drivers/iio/adc/stm32-dfsdm-adc.c | 65 ++++++++++++++++++++++++++++++--------- drivers/iio/adc/stm32-dfsdm.h | 4 +-- 2 files changed, 53 insertions(+), 16 deletions(-) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 5b19a88412a6..d855a605eab6 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -196,7 +196,7 @@ static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl, int bits, shift; unsigned int m = 1; /* multiplication factor */ unsigned int p = fl->ford; /* filter order (ford) */ - struct stm32_dfsdm_filter_osr *flo = &fl->flo; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[fast]; pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp); /* @@ -217,7 +217,6 @@ static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl, * Look for filter and integrator oversampling ratios which allows * to maximize data output resolution. */ - flo->res = 0; for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { if (fast) @@ -309,6 +308,28 @@ static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl, return 0; } +static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev, + unsigned int oversamp) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + int ret0, ret1; + + memset(&fl->flo[0], 0, sizeof(fl->flo[0])); + memset(&fl->flo[1], 0, sizeof(fl->flo[1])); + + ret0 = stm32_dfsdm_compute_osrs(fl, 0, oversamp); + ret1 = stm32_dfsdm_compute_osrs(fl, 1, oversamp); + if (ret0 < 0 && ret1 < 0) { + dev_err(&indio_dev->dev, + "Filter parameters not found: errors %d/%d\n", + ret0, ret1); + return -EINVAL; + } + + return 0; +} + static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); @@ -433,11 +454,25 @@ static int stm32_dfsdm_channels_configure(struct stm32_dfsdm_adc *adc, struct iio_dev *indio_dev = iio_priv_to_dev(adc); struct regmap *regmap = adc->dfsdm->regmap; struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; - struct stm32_dfsdm_filter_osr *flo = &fl->flo; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[0]; const struct iio_chan_spec *chan; unsigned int bit; int ret; + fl->fast = 0; + + /* + * In continuous mode, use fast mode configuration, + * if it provides a better resolution. + */ + if (adc->nconv == 1 && !trig && + (indio_dev->currentmode & INDIO_BUFFER_SOFTWARE)) { + if (fl->flo[1].res >= fl->flo[0].res) { + fl->fast = 1; + flo = &fl->flo[1]; + } + } + if (!flo->res) return -EINVAL; @@ -463,7 +498,7 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc, struct iio_dev *indio_dev = iio_priv_to_dev(adc); struct regmap *regmap = adc->dfsdm->regmap; struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; - struct stm32_dfsdm_filter_osr *flo = &fl->flo; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; u32 cr1; const struct iio_chan_spec *chan; unsigned int bit, jchg = 0; @@ -490,6 +525,12 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc, if (ret) return ret; + ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_FAST_MASK, + DFSDM_CR1_FAST(fl->fast)); + if (ret) + return ret; + /* * DFSDM modes configuration W.R.T audio/iio type modes * ---------------------------------------------------------------- @@ -636,7 +677,6 @@ static int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev, unsigned int spi_freq) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; unsigned int oversamp; int ret; @@ -646,11 +686,10 @@ static int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev, "Rate not accurate. requested (%u), actual (%u)\n", sample_freq, spi_freq / oversamp); - ret = stm32_dfsdm_compute_osrs(fl, 0, oversamp); - if (ret < 0) { - dev_err(&indio_dev->dev, "No filter parameters that match!\n"); + ret = stm32_dfsdm_compute_all_osrs(indio_dev, oversamp); + if (ret < 0) return ret; - } + adc->sample_freq = spi_freq / oversamp; adc->oversamp = oversamp; @@ -783,7 +822,7 @@ static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc, s32 *buffer) { struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; - struct stm32_dfsdm_filter_osr *flo = &fl->flo; + struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; unsigned int i = adc->nconv; s32 *ptr = buffer; @@ -1171,7 +1210,6 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, int val, int val2, long mask) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel]; unsigned int spi_freq; int ret = -EINVAL; @@ -1181,7 +1219,7 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; - ret = stm32_dfsdm_compute_osrs(fl, 0, val); + ret = stm32_dfsdm_compute_all_osrs(indio_dev, val); if (!ret) adc->oversamp = val; iio_device_release_direct_mode(indio_dev); @@ -1430,8 +1468,7 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) int ret, chan_idx; adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; - ret = stm32_dfsdm_compute_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0, - adc->oversamp); + ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp); if (ret < 0) return ret; diff --git a/drivers/iio/adc/stm32-dfsdm.h b/drivers/iio/adc/stm32-dfsdm.h index 18b06ee6ed7b..5dbdae4ed881 100644 --- a/drivers/iio/adc/stm32-dfsdm.h +++ b/drivers/iio/adc/stm32-dfsdm.h @@ -263,13 +263,13 @@ struct stm32_dfsdm_filter_osr { /** * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter * @ford: filter order - * @flo: filter oversampling structure + * @flo: filter oversampling data table indexed by fast mode flag * @sync_mode: filter synchronized with filter 0 * @fast: filter fast mode */ struct stm32_dfsdm_filter { enum stm32_dfsdm_sinc_order ford; - struct stm32_dfsdm_filter_osr flo; + struct stm32_dfsdm_filter_osr flo[2]; unsigned int sync_mode; unsigned int fast; }; From patchwork Wed Jun 19 13:03:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier MOYSAN X-Patchwork-Id: 11004121 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3366B1395 for ; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2482A1FFB1 for ; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18DF428A15; Wed, 19 Jun 2019 13:04:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BDB2528581 for ; Wed, 19 Jun 2019 13:04:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731888AbfFSNEe (ORCPT ); Wed, 19 Jun 2019 09:04:34 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:63798 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731894AbfFSNEe (ORCPT ); Wed, 19 Jun 2019 09:04:34 -0400 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5JCu1vs023624; Wed, 19 Jun 2019 15:04:03 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=1RIed4PSnLNoF/Qg8Sp7JJ0Sajo64o3gdxbSWUs/b4M=; b=0xenS9bcGVcF8713j77nhv9uVF0N+3rssP3bIA4M00CmyUSAdrwem78TNJJNHfTMdReb hibMRJP0HII90WclTnhXFen799MWDD/raHoZnqsHbOBbPWUJFplV8tYCsdK8h7BOWAgB xk1FVwbkGYx828MwMagijwfaNOg1olBktgZfIZ5utfW8B/d5l+iFdSI+juK5e5c9iuKR x4dpT76VUixZ5pa0Yz+5LRtRPnSyXKu7GCWx+etdZhJt7Ei2O0LF3lXSLgV/jD/V4e1U Rs27nGZcFT54Z0W4601g8h6Ui5MHlqxcEanwRD+C6rqGePLtRs9XHJiNAg7pWbj8FW+J cA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2t7813c0aq-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 19 Jun 2019 15:04:03 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id DC7D638; Wed, 19 Jun 2019 13:04:02 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas23.st.com [10.75.90.46]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id B5A452834; Wed, 19 Jun 2019 13:04:02 +0000 (GMT) Received: from SAFEX1HUBCAS21.st.com (10.75.90.45) by SAFEX1HUBCAS23.st.com (10.75.90.46) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:04:02 +0200 Received: from localhost (10.201.23.16) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 19 Jun 2019 15:04:02 +0200 From: Olivier Moysan To: , , , , , , , , , , , , Subject: [PATCH 5/5] iio: adc: stm32-dfsdm: add comment for 16 bits record Date: Wed, 19 Jun 2019 15:03:51 +0200 Message-ID: <1560949431-22948-6-git-send-email-olivier.moysan@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> References: <1560949431-22948-1-git-send-email-olivier.moysan@st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.23.16] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-19_07:,, signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a comment on DMA configuration for 16 bits record. Signed-off-by: Olivier Moysan --- drivers/iio/adc/stm32-dfsdm-adc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index d855a605eab6..ee1e0569d0e1 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -918,6 +918,11 @@ static void stm32_dfsdm_dma_buffer_done(void *data) static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + /* + * The DFSDM supports half-word transfers. However, for 16 bits record, + * 4 bytes buswidth is kept, to avoid losing samples LSBs when left + * shift is required. + */ struct dma_slave_config config = { .src_addr = (dma_addr_t)adc->dfsdm->phys_base, .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,