From patchwork Sat Sep 23 22:58:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Stefan_Br=C3=BCns?= X-Patchwork-Id: 9967659 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 5FA2A60384 for ; Sat, 23 Sep 2017 22:59:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5591728BB3 for ; Sat, 23 Sep 2017 22:59:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4A57629114; Sat, 23 Sep 2017 22:59:06 +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=-6.9 required=2.0 tests=BAYES_00,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 94F7228BB3 for ; Sat, 23 Sep 2017 22:59:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751618AbdIWW6h (ORCPT ); Sat, 23 Sep 2017 18:58:37 -0400 Received: from mail-out-2.itc.rwth-aachen.de ([134.130.5.47]:51602 "EHLO mail-out-2.itc.rwth-aachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751465AbdIWW6g (ORCPT ); Sat, 23 Sep 2017 18:58:36 -0400 X-IronPort-AV: E=Sophos;i="5.42,431,1500933600"; d="scan'208";a="14803246" Received: from rwthex-w2-a.rwth-ad.de ([134.130.26.158]) by mail-in-2.itc.rwth-aachen.de with ESMTP; 24 Sep 2017 00:58:34 +0200 Received: from pebbles.fritz.box (77.181.79.149) by rwthex-w2-a.rwth-ad.de (2002:8682:1a9e::8682:1a9e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1034.26; Sun, 24 Sep 2017 00:58:33 +0200 From: =?UTF-8?q?Stefan=20Br=C3=BCns?= To: CC: , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler Subject: [PATCH v2 3/4] iio: light: vl6180: Cleanup als_gain lookup, avoid register readback Date: Sun, 24 Sep 2017 00:58:23 +0200 Message-ID: <20170923225824.8435-4-stefan.bruens@rwth-aachen.de> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170923225824.8435-1-stefan.bruens@rwth-aachen.de> References: <20170923225824.8435-1-stefan.bruens@rwth-aachen.de> MIME-Version: 1.0 X-Originating-IP: [77.181.79.149] X-ClientProxiedBy: rwthex-w1-b.rwth-ad.de (2002:8682:1a9d::8682:1a9d) To rwthex-w2-a.rwth-ad.de (2002:8682:1a9e::8682:1a9e) 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 Instead of manually iterating the array of allowed gain values, use find_closest. Storing the current gain setting avoids accessing the hardware on each query. Signed-off-by: Stefan Brüns --- v2: add missing spaces drivers/iio/light/vl6180.c | 85 ++++++++++++++++++++++++---------------------- 1 file changed, 44 insertions(+), 41 deletions(-) diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c index e6466cc81766..5de64bce305c 100644 --- a/drivers/iio/light/vl6180.c +++ b/drivers/iio/light/vl6180.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -86,6 +87,7 @@ struct vl6180_data { struct i2c_client *client; struct mutex lock; + unsigned int als_gain_milli; unsigned int als_it_ms; }; @@ -276,19 +278,17 @@ static const struct iio_chan_spec vl6180_channels[] = { }; /* - * Columns 3 & 4 represent the same value in decimal and hex notations. - * Kept in order to avoid the datatype conversion while reading the - * hardware_gain. + * Available Ambient Light Sensor gain settings, 1/1000th, and + * corresponding setting for the VL6180_ALS_GAIN register */ -static const int vl6180_als_gain[8][4] = { - { 1, 0, 70, VL6180_ALS_GAIN_1 }, - { 1, 250000, 69, VL6180_ALS_GAIN_1_25 }, - { 1, 670000, 68, VL6180_ALS_GAIN_1_67 }, - { 2, 500000, 67, VL6180_ALS_GAIN_2_5 }, - { 5, 0, 66, VL6180_ALS_GAIN_5 }, - { 10, 0, 65, VL6180_ALS_GAIN_10 }, - { 20, 0, 64, VL6180_ALS_GAIN_20 }, - { 40, 0, 71, VL6180_ALS_GAIN_40 } +static const int vl6180_als_gain_tab[8] = { + 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000 +}; +static const u8 vl6180_als_gain_tab_bits[8] = { + VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25, + VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5, + VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10, + VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40 }; static int vl6180_read_raw(struct iio_dev *indio_dev, @@ -296,7 +296,7 @@ static int vl6180_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct vl6180_data *data = iio_priv(indio_dev); - int ret, i; + int ret; switch (mask) { case IIO_CHAN_INFO_RAW: @@ -328,17 +328,11 @@ static int vl6180_read_raw(struct iio_dev *indio_dev, return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_HARDWAREGAIN: - ret = vl6180_read_byte(data->client, VL6180_ALS_GAIN); - if (ret < 0) - return -EINVAL; - for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) { - if (ret == vl6180_als_gain[i][2]) { - *val = vl6180_als_gain[i][0]; - *val2 = vl6180_als_gain[i][1]; - } - } + *val = data->als_gain_milli; + *val2 = 1000; + + return IIO_VAL_FRACTIONAL; - return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } @@ -364,25 +358,33 @@ static int vl6180_hold(struct vl6180_data *data, bool hold) static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2) { - int i, ret; - - for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) { - if (val == vl6180_als_gain[i][0] && - val2 == vl6180_als_gain[i][1]) { - mutex_lock(&data->lock); - ret = vl6180_hold(data, true); - if (ret < 0) - goto fail; - ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, - vl6180_als_gain[i][3]); -fail: - vl6180_hold(data, false); - mutex_unlock(&data->lock); - return ret; - } - } + int i, ret, gain; + + if (val < 1 || val > 40) + return -EINVAL; + + gain = (val * 1000000 + val2) / 1000; + if (gain < 1 || gain > 40000) + return -EINVAL; + + i = find_closest(gain, vl6180_als_gain_tab, + ARRAY_SIZE(vl6180_als_gain_tab)); + + mutex_lock(&data->lock); + ret = vl6180_hold(data, true); + if (ret < 0) + goto fail; - return -EINVAL; + ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, + vl6180_als_gain_tab_bits[i]); + + if (ret >= 0) + data->als_gain_milli = vl6180_als_gain_tab[i]; + +fail: + vl6180_hold(data, false); + mutex_unlock(&data->lock); + return ret; } static int vl6180_set_it(struct vl6180_data *data, int val, int val2) @@ -480,6 +482,7 @@ static int vl6180_init(struct vl6180_data *data) return ret; /* ALS gain: 1 */ + data->als_gain_milli = 1000; ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1); if (ret < 0) return ret;