From patchwork Mon Jul 16 23:35:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Lechner X-Patchwork-Id: 10527757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 430DD603ED for ; Mon, 16 Jul 2018 23:36:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2894028C3B for ; Mon, 16 Jul 2018 23:36:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1C88728D50; Mon, 16 Jul 2018 23:36:16 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID 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 B35E528C3B for ; Mon, 16 Jul 2018 23:36:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729603AbeGQAFt (ORCPT ); Mon, 16 Jul 2018 20:05:49 -0400 Received: from vern.gendns.com ([206.190.152.46]:55068 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729593AbeGQAFt (ORCPT ); Mon, 16 Jul 2018 20:05:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lechnology.com; s=default; h=Message-Id:Date:Subject:Cc:To:From:Sender: Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=uwXQkWav0Ka/VVU2KBeDT2x7s4BhxMjd8D6QCYMB1/Y=; b=kz7wPN1l92RUbeU8Pwp9OWfTyn P3WEU5MblWeXT9CJtoraCxI0uLPW50wSPy4mrfWjALG1bCjzrqRRHi2FDFMGRMfjnsJebFCtYrvoo +29geTR2QYECm0oloqyKIUSffJfdOUK7emoffkGEn9mQ9HpHIPxX91Kl67KqyPj4Ln3hYylQbli/n HnADiUSQeIBuJfKnROetGsf1L7OnuvmahrwQdqxUm6pukuf+Zq7nwN5MfYpSe0X3PQrfsgrHk+so8 +Gr2QVtOVstyfDLKwbL3F+EKKu2vh9ZbxpMahRerD3W7U/pwTS6UeF37tpuCd5LKMHaGsF/O9W9De hZV0pxZA==; Received: from 108-198-5-147.lightspeed.okcbok.sbcglobal.net ([108.198.5.147]:49732 helo=freyr.lechnology.com) by vern.gendns.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1ffD2F-00CMu1-TQ; Mon, 16 Jul 2018 19:36:08 -0400 From: David Lechner To: linux-iio@vger.kernel.org Cc: David Lechner , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-kernel@vger.kernel.org Subject: [PATCH] iio: adc: ti-ads7950: allow simultaneous use of buffer and direct mode Date: Mon, 16 Jul 2018 18:35:50 -0500 Message-Id: <20180716233550.6449-1-david@lechnology.com> X-Mailer: git-send-email 2.17.1 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: 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 This modifies the TI ADS7950 A/DC driver to allow the simultaneous use of both the triggered buffer and reading channels directly (via in- kernel API or sysfs). The use case for this is on LEGO MINDSTORMS EV3. Two of the voltage channels are used in-kernel by a power supply driver, which reads the values using iio_read_channel_processed(). These channels are only read at a slow rate (<= 1Hz). However, we want to be able to read 12 other channels at the same time using the triggered buffer at a high rate (>= 100Hz) without breaking the power supply driver. Signed-off-by: David Lechner --- drivers/iio/adc/ti-ads7950.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c index 0225c1b333ab..ba7e5a027490 100644 --- a/drivers/iio/adc/ti-ads7950.c +++ b/drivers/iio/adc/ti-ads7950.c @@ -58,6 +58,7 @@ (((val) >> (dec)) & ((1 << (bits)) - 1)) struct ti_ads7950_state { + struct iio_dev *indio_dev; struct spi_device *spi; struct spi_transfer ring_xfer[TI_ADS7950_MAX_CHAN + 2]; struct spi_transfer scan_single_xfer[3]; @@ -68,6 +69,8 @@ struct ti_ads7950_state { unsigned int vref_mv; unsigned int settings; + __be16 single_tx; + __be16 single_rx; /* * DMA (thus cache coherency maintenance) requires the @@ -299,14 +302,21 @@ static int ti_ads7950_scan_direct(struct ti_ads7950_state *st, unsigned int ch) { int ret, cmd; + mutex_lock(&st->indio_dev->mlock); + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; - st->tx_buf[0] = cpu_to_be16(cmd); + st->single_tx = cpu_to_be16(cmd); ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) - return ret; + goto out; + + ret = be16_to_cpu(st->single_rx); + +out: + mutex_unlock(&st->indio_dev->mlock); - return be16_to_cpu(st->rx_buf[0]); + return ret; } static int ti_ads7950_get_range(struct ti_ads7950_state *st) @@ -338,13 +348,7 @@ static int ti_ads7950_read_raw(struct iio_dev *indio_dev, switch (m) { case IIO_CHAN_INFO_RAW: - - ret = iio_device_claim_direct_mode(indio_dev); - if (ret < 0) - return ret; - ret = ti_ads7950_scan_direct(st, chan->address); - iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; @@ -389,6 +393,7 @@ static int ti_ads7950_probe(struct spi_device *spi) spi_set_drvdata(spi, indio_dev); + st->indio_dev = indio_dev; st->spi = spi; st->settings = TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_RANGE_5V; @@ -410,13 +415,13 @@ static int ti_ads7950_probe(struct spi_device *spi) * was read at the end of the first transfer. */ - st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; + st->scan_single_xfer[0].tx_buf = &st->single_tx; st->scan_single_xfer[0].len = 2; st->scan_single_xfer[0].cs_change = 1; - st->scan_single_xfer[1].tx_buf = &st->tx_buf[0]; + st->scan_single_xfer[1].tx_buf = &st->single_tx; st->scan_single_xfer[1].len = 2; st->scan_single_xfer[1].cs_change = 1; - st->scan_single_xfer[2].rx_buf = &st->rx_buf[0]; + st->scan_single_xfer[2].rx_buf = &st->single_rx; st->scan_single_xfer[2].len = 2; spi_message_init_with_transfers(&st->scan_single_msg,