From patchwork Fri Jun 29 05:03:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "\(Exiting\) Baolin Wang" X-Patchwork-Id: 140490 Delivered-To: patch@linaro.org Received: by 2002:a2e:9754:0:0:0:0:0 with SMTP id f20-v6csp386790ljj; Thu, 28 Jun 2018 22:04:04 -0700 (PDT) X-Google-Smtp-Source: ADUXVKLseKcRWIuXbOM0eYxIil6vS2TGff5/XU/QZoVePuBf3BZWxJS8atlLbuR3VwasLipK0ziI X-Received: by 2002:a17:902:1005:: with SMTP id b5-v6mr13454219pla.207.1530248644489; Thu, 28 Jun 2018 22:04:04 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1530248644; cv=none; d=google.com; s=arc-20160816; b=xEl9etD3Z/54+8I+SW8zjqewGqnhJwKv6+8+Br7nc5wm3dBOKq1Rjac4kiK2gWWcn0 YTYLBVYS2ZOs0WwzW8A0+gi3qMxN8SHPRl9AgSLmdx48yXs8iwqLBKfpeSaDFSLvI/rt so2T7OedvUYGvznB2m47ZulJWFPQ+CB53wKwPWAyXjntAdrdqtrxAO2S3R82IAZW2Qtt kovx3xbd8tx4rXj2fkJcpOYl51YBASyVmRavKRA8VfBFmI6xQXcX6+3W23ikv8ZmVYHb 56a7OBwRdBHmOif8gfEK+OxqmHulsVEnkXNePmd8+I4D1zHUj0XFaRmhRwGGM+LJ/5zL rwXg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=t74VJqRfQJYguZJiqO/bhZrwB44TL3f1SU93gGHRsZ4=; b=JZ3U2O+AT85liCPQu/OQE9oOZj71zsqTPUEAXSqbGu83KXlmP81WQro+VuviInj1XF jFDK4IK2s4L7syhBUglOqHG6CwY8Wwrfejo0KWp5/JoLFvRoVp7jd4eDz28nTrBmQWOG VMKfgXeJCtoBZB37rZDs2Gbk7pN5OHuyBzqIE+bK8Vgw3ldBpwEe/aPnszyRlsIBIbnQ m/YNwkQRbyVxuvtmNw7NDKil6spyr9/qdALBsZZg5xCRAcw+DEpTXGGL8avXn+4y+mJX h6xuXg9csNGt+xzSooQcOZXEGU33omD4tj7bkhR5M5mWIgxQq3PNI5KK5XwoSTZZm2KX rEVg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=aWDKpYLa; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id e3-v6si7546939pgn.523.2018.06.28.22.04.04; Thu, 28 Jun 2018 22:04:04 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=aWDKpYLa; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753404AbeF2FEC (ORCPT + 31 others); Fri, 29 Jun 2018 01:04:02 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:36841 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbeF2FEA (ORCPT ); Fri, 29 Jun 2018 01:04:00 -0400 Received: by mail-pf0-f193.google.com with SMTP id u16-v6so3650935pfh.3 for ; Thu, 28 Jun 2018 22:04:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=t74VJqRfQJYguZJiqO/bhZrwB44TL3f1SU93gGHRsZ4=; b=aWDKpYLamf57iFwqT6n3y0K/HawUqGtHy2R3hz7cLYmXhaxNCxwghPLY1spnXIQ0Lj VBPaYHAJYxyrnE2xlBVlui3c7M5rIyjLuguTOaTJTgVJoLvwOgJC4qWjJB40fw3uYs2E lxRE/NAHUxWsqBtQOnYN90rtNMAu39+6e6Tc0= 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; bh=t74VJqRfQJYguZJiqO/bhZrwB44TL3f1SU93gGHRsZ4=; b=maJpESaftneTX6Y2F67+4KqrBmODcevvQjpZR2wD0zqshAhArE24ChKWuDbEFrEReR FWnr1fGelDwHV9hN5m8KYD86IyaSNF1quv0n9uLs8cdK+IZlSCHWncNz8QLJow24jxJL 58H94F+YXIKUxGS/n7EtkCI9rZDxBa69M3QOe27uPwvAEbLokVWBaSgTftv1zYGF4D/g IPZg/2FA3KptOgl9rFspxCYaEld2gF8GyHUxzZMQJtKd2/1dTPIKa2ZpYm0WU4a/MPyU HUjFgPZm1X5pd0fddQYRIn93nx3+OcVKVxSrw2/QO32BI/GEz136niEgQ1uNxW0FeaHg FHaA== X-Gm-Message-State: APt69E2LcY9NtTUMgam8DGyKf9n629SzyetbPBt9oT9NeokVvAnadp4a oj7r3bkCznMSIrm9svNGe4hU+g== X-Received: by 2002:a65:4841:: with SMTP id i1-v6mr11077689pgs.75.1530248639697; Thu, 28 Jun 2018 22:03:59 -0700 (PDT) Received: from baolinwangubtpc.spreadtrum.com ([117.18.48.102]) by smtp.gmail.com with ESMTPSA id z10-v6sm12752359pgo.58.2018.06.28.22.03.57 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 28 Jun 2018 22:03:59 -0700 (PDT) From: Baolin Wang To: jacek.anaszewski@gmail.com, pavel@ucw.cz Cc: bjorn.andersson@linaro.org, baolin.wang@linaro.org, broonie@kernel.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/2] leds: core: Introduce generic pattern interface Date: Fri, 29 Jun 2018 13:03:00 +0800 Message-Id: <1665b877dc2f886a90a00e3ca3b7425372d99b6e.1530248085.git.baolin.wang@linaro.org> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bjorn Andersson Some LED controllers have support for autonomously controlling brightness over time, according to some preprogrammed pattern or function. This adds a new optional operator that LED class drivers can implement if they support such functionality as well as a new device attribute to configure the pattern for a given LED. [Baolin Wang did some minor improvements.] Signed-off-by: Bjorn Andersson Signed-off-by: Baolin Wang --- Changes from v2: - Change kernel version to 4.19. - Force user to return error pointer if failed to issue pattern_get(). - Use strstrip() to trim trailing newline. - Other optimization. Changes from v1: - Add some comments suggested by Pavel. - Change 'delta_t' can be 0. Note: I removed the pattern repeat check and will get the repeat number by adding one extra file named 'pattern_repeat' according to previous discussion. --- Documentation/ABI/testing/sysfs-class-led | 17 +++++ drivers/leds/led-class.c | 119 +++++++++++++++++++++++++++++ include/linux/leds.h | 19 +++++ 3 files changed, 155 insertions(+) -- 1.7.9.5 diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led index 5f67f7a..e01ac55 100644 --- a/Documentation/ABI/testing/sysfs-class-led +++ b/Documentation/ABI/testing/sysfs-class-led @@ -61,3 +61,20 @@ Description: gpio and backlight triggers. In case of the backlight trigger, it is useful when driving a LED which is intended to indicate a device in a standby like state. + +What: /sys/class/leds//pattern +Date: June 2018 +KernelVersion: 4.19 +Description: + Specify a pattern for the LED, for LED hardware that support + altering the brightness as a function of time. + + The pattern is given by a series of tuples, of brightness and + duration (ms). The LED is expected to traverse the series and + each brightness value for the specified duration. Duration of + 0 means brightness should immediately change to new value. + + As LED hardware might have different capabilities and precision + the requested pattern might be slighly adjusted by the driver + and the resulting pattern of such operation should be returned + when this file is read. diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 3c7e348..8a685a2 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -74,6 +74,123 @@ static ssize_t max_brightness_show(struct device *dev, } static DEVICE_ATTR_RO(max_brightness); +static ssize_t pattern_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_pattern *pattern; + size_t offset = 0; + int count, n, i; + + if (!led_cdev->pattern_get) + return -EOPNOTSUPP; + + pattern = led_cdev->pattern_get(led_cdev, &count); + if (IS_ERR(pattern)) + return PTR_ERR(pattern); + + for (i = 0; i < count; i++) { + n = snprintf(buf + offset, PAGE_SIZE - offset, "%d %d ", + pattern[i].brightness, pattern[i].delta_t); + + if (offset + n >= PAGE_SIZE) + goto err_nospc; + + offset += n; + } + + buf[offset - 1] = '\n'; + + kfree(pattern); + return offset; + +err_nospc: + kfree(pattern); + return -ENOSPC; +} + +static ssize_t pattern_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_pattern *pattern = NULL; + unsigned long val; + char *sbegin; + char *elem; + char *s; + int ret, len = 0; + bool odd = true; + + sbegin = kstrndup(buf, size, GFP_KERNEL); + if (!sbegin) + return -ENOMEM; + + /* + * Trim trailing newline, if the remaining string is empty, + * clear the pattern. + */ + s = strstrip(sbegin); + if (!*s) { + ret = led_cdev->pattern_clear(led_cdev); + goto out; + } + + pattern = kcalloc(size, sizeof(*pattern), GFP_KERNEL); + if (!pattern) { + ret = -ENOMEM; + goto out; + } + + /* Parse out the brightness & delta_t touples */ + while ((elem = strsep(&s, " ")) != NULL) { + ret = kstrtoul(elem, 10, &val); + if (ret) + goto out; + + if (odd) { + pattern[len].brightness = val; + } else { + pattern[len].delta_t = val; + len++; + } + + odd = !odd; + } + + /* + * Fail if we didn't find any data points or last data point was partial + */ + if (!len || !odd) { + ret = -EINVAL; + goto out; + } + + ret = led_cdev->pattern_set(led_cdev, pattern, len); + +out: + kfree(pattern); + kfree(sbegin); + return ret < 0 ? ret : size; +} +static DEVICE_ATTR_RW(pattern); + +static umode_t led_class_attrs_mode(struct kobject *kobj, + struct attribute *attr, int index) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + if (attr == &dev_attr_brightness.attr) + return attr->mode; + if (attr == &dev_attr_max_brightness.attr) + return attr->mode; + if (attr == &dev_attr_pattern.attr && led_cdev->pattern_set) + return attr->mode; + + return 0; +} + #ifdef CONFIG_LEDS_TRIGGERS static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); static struct attribute *led_trigger_attrs[] = { @@ -88,11 +205,13 @@ static ssize_t max_brightness_show(struct device *dev, static struct attribute *led_class_attrs[] = { &dev_attr_brightness.attr, &dev_attr_max_brightness.attr, + &dev_attr_pattern.attr, NULL, }; static const struct attribute_group led_group = { .attrs = led_class_attrs, + .is_visible = led_class_attrs_mode, }; static const struct attribute_group *led_groups[] = { diff --git a/include/linux/leds.h b/include/linux/leds.h index b7e8255..acdbb2f 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -22,6 +22,7 @@ #include struct device; +struct led_pattern; /* * LED Core */ @@ -88,6 +89,14 @@ struct led_classdev { unsigned long *delay_on, unsigned long *delay_off); + int (*pattern_set)(struct led_classdev *led_cdev, + struct led_pattern *pattern, int len); + + int (*pattern_clear)(struct led_classdev *led_cdev); + + struct led_pattern *(*pattern_get)(struct led_classdev *led_cdev, + int *len); + struct device *dev; const struct attribute_group **groups; @@ -446,4 +455,14 @@ static inline void led_classdev_notify_brightness_hw_changed( struct led_classdev *led_cdev, enum led_brightness brightness) { } #endif +/** + * struct led_pattern - brigheness value in a pattern + * @delta_t: delay until next entry, in milliseconds + * @brightness: brightness at time = 0 + */ +struct led_pattern { + int delta_t; + int brightness; +}; + #endif /* __LINUX_LEDS_H_INCLUDED */