From patchwork Tue Mar 24 20:27:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gwendal Grignou X-Patchwork-Id: 11456411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5440213A4 for ; Tue, 24 Mar 2020 20:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CD9A2074D for ; Tue, 24 Mar 2020 20:27:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="fXYNnIEJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727894AbgCXU1w (ORCPT ); Tue, 24 Mar 2020 16:27:52 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:40015 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725953AbgCXU1v (ORCPT ); Tue, 24 Mar 2020 16:27:51 -0400 Received: by mail-pf1-f194.google.com with SMTP id l184so9902582pfl.7 for ; Tue, 24 Mar 2020 13:27:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4Qj04WM6WV1292DERlnygQnUZFPOVeWCGyavY3CnVo0=; b=fXYNnIEJFXbsceM0cn/xg1RpPl8jXKwcjoLAfK0PWctuEX6zp2mL7GpQ0VFTmDdC+p oc6f7ZCKl/Gyhykq8+WeC7b80Lk4Fdl2h2Fz1EGZw5XUeSeuFjID6OWBqDXYtWLDUuPR s5cJykmdeB4VT3Heg521Cvd/i4LJ8J5ftkJek= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4Qj04WM6WV1292DERlnygQnUZFPOVeWCGyavY3CnVo0=; b=TZoa39fhsw7/8e+aWHNOsf2+wWDF//RHK2zVKOcZGok44H9+zA1B0brc3GPYg3ELbo /WIQifwj/8HrEiKc27jU01HYf7VzorGPDRmQk6P9AfMiHLXxPzBQvGKxYYteQ/8WbS+h 8I1cJHe07xMQtzvReD1NCD3EfFKF5FMuTbLZ6py76Tkv9qKUndZ9uzq39N20C74LVRQz S5nk4TratKR7kW3OzXwrVIBIkX3g2484VAMW0u4WoigWZHmGy64byPk4cwpx6krLTjgN Gu8lifvDxoYRjlAzCTMrpwLhn+suVQvCcTPWqqFC5EP/ekERVtv8gCqH8ma5ypCVbNAs MXyQ== X-Gm-Message-State: ANhLgQ0nyxdyqfbb8pqyTzP7PsQDTwKcn9cMFl7rjivnXsKQUV6jnhWB wQEBHBkkKD10yN8WtgM4s0/AuQ== X-Google-Smtp-Source: ADFU+vvV6/M+B723trEGCiueLFYow5J7/7xqL4+vICG4fHYjhKVj5bqOHjB+yrQ/U37Fav1oYYRxLQ== X-Received: by 2002:aa7:96c8:: with SMTP id h8mr25009032pfq.49.1585081668670; Tue, 24 Mar 2020 13:27:48 -0700 (PDT) Received: from localhost ([2620:15c:202:1:4cc0:7eee:97c9:3c1a]) by smtp.gmail.com with ESMTPSA id i23sm16760643pfq.157.2020.03.24.13.27.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 24 Mar 2020 13:27:48 -0700 (PDT) From: Gwendal Grignou To: bleung@chromium.org, enric.balletbo@collabora.com, Jonathan.Cameron@huawei.com Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Gwendal Grignou , Lee Jones Subject: [PATCH v6 02/11] platform: chrome: sensorhub: Add code to spread timestmap Date: Tue, 24 Mar 2020 13:27:27 -0700 Message-Id: <20200324202736.243314-3-gwendal@chromium.org> X-Mailer: git-send-email 2.25.1.696.g5e7596f4ac-goog In-Reply-To: <20200324202736.243314-1-gwendal@chromium.org> References: <20200324202736.243314-1-gwendal@chromium.org> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org EC FIFO can send sensor events in batch. Spread them based on previous (TSa) and currnet timestamp (TSb) EC FIFO iio events +-----------+ | TSa | +-----------+ +---------------------------------------+ | event 1 | | event 1 | TSb - (TSb - TSa)/n * (n-1) | +-----------+ +---------------------------------------+ | event 2 | | event 2 | TSb - (TSb - TSa)/n * (n-2) | +-----------+ +---------------------------------------+ | ... | ------> | .... | | +-----------+ +---------------------------------------+ | event n-1 | | event 2 | TSb - (TSb - TSa)/n | +-----------+ +---------------------------------------+ | event n | | event 2 | TSb | +-----------+ +---------------------------------------+ | TSb | +-----------+ Acked-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Gwendal Grignou --- Changes in v6: Comment fixes Changes in v5: Added ack. Changes in v4: - Check patch with --strict option Alignement No changes in v3. Changes in v2: - Use CROS_EC_SENSOR_LAST_TS instead of LAST_TS to avoid name colisions. .../platform/chrome/cros_ec_sensorhub_ring.c | 112 ++++++++++++++++-- 1 file changed, 105 insertions(+), 7 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c index 436f306899252..efe726171bf00 100644 --- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c +++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c @@ -189,6 +189,101 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub, return true; } +/* + * cros_ec_sensor_ring_spread_add: Calculate proper timestamps then add to + * ringbuffer. + * + * If there is a sample with a proper timestamp + * + * timestamp | count + * ----------------- + * older_unprocess_out --> TS1 | 1 + * TS1 | 2 + * out --> TS1 | 3 + * next_out --> TS2 | + * + * We spread time for the samples [older_unprocess_out .. out] + * between TS1 and TS2: [TS1+1/4, TS1+2/4, TS1+3/4, TS2]. + * + * If we reach the end of the samples, we compare with the + * current timestamp: + * + * older_unprocess_out --> TS1 | 1 + * TS1 | 2 + * out --> TS1 | 3 + * + * We know have [TS1+1/3, TS1+2/3, current timestamp] + */ +static void cros_ec_sensor_ring_spread_add(struct cros_ec_sensorhub *sensorhub, + unsigned long sensor_mask, + s64 current_timestamp, + struct cros_ec_sensors_ring_sample + *last_out) +{ + struct cros_ec_sensors_ring_sample *out; + int i; + + for_each_set_bit(i, &sensor_mask, BITS_PER_LONG) { + s64 older_timestamp; + s64 timestamp; + struct cros_ec_sensors_ring_sample *older_unprocess_out = + sensorhub->ring; + struct cros_ec_sensors_ring_sample *next_out; + int count = 1; + + for (out = sensorhub->ring; out < last_out; out = next_out) { + s64 time_period; + + next_out = out + 1; + if (out->sensor_id != i) + continue; + + /* Timestamp to start with */ + older_timestamp = out->timestamp; + + /* Find next sample. */ + while (next_out < last_out && next_out->sensor_id != i) + next_out++; + + if (next_out >= last_out) { + timestamp = current_timestamp; + } else { + timestamp = next_out->timestamp; + if (timestamp == older_timestamp) { + count++; + continue; + } + } + + /* + * The next sample has a new timestamp, spread the + * unprocessed samples. + */ + if (next_out < last_out) + count++; + time_period = div_s64(timestamp - older_timestamp, + count); + + for (; older_unprocess_out <= out; + older_unprocess_out++) { + if (older_unprocess_out->sensor_id != i) + continue; + older_timestamp += time_period; + older_unprocess_out->timestamp = + older_timestamp; + } + count = 1; + /* The next_out sample has a valid timestamp, skip. */ + next_out++; + older_unprocess_out = next_out; + } + } + + /* Push the event into the kfifo */ + for (out = sensorhub->ring; out < last_out; out++) + cros_sensorhub_send_sample(sensorhub, out); +} + /** * cros_ec_sensorhub_ring_handler() - The trigger handler function * @@ -300,10 +395,10 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub) goto ring_handler_end; /* - * Check if current_timestamp is ahead of the last sample. - * Normally, the EC appends a timestamp after the last sample, but if - * the AP is slow to respond to the IRQ, the EC may have added new - * samples. Use the FIFO info timestamp as last timestamp then. + * Check if current_timestamp is ahead of the last sample. Normally, + * the EC appends a timestamp after the last sample, but if the AP + * is slow to respond to the IRQ, the EC may have added new samples. + * Use the FIFO info timestamp as last timestamp then. */ if ((last_out - 1)->timestamp == current_timestamp) current_timestamp = fifo_timestamp; @@ -323,9 +418,12 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub) } } - /* Push the event into the FIFO. */ - for (out = sensorhub->ring; out < last_out; out++) - cros_sensorhub_send_sample(sensorhub, out); + /* + * Spread samples in case of batching, then add them to the + * ringbuffer. + */ + cros_ec_sensor_ring_spread_add(sensorhub, sensor_mask, + current_timestamp, last_out); ring_handler_end: sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp;