LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Ian Pilcher <arequipeno@gmail.com>
To: linux-block@vger.kernel.org, linux-leds@vger.kernel.org
Cc: axboe@kernel.dk, pavel@ucw.cz, kabel@kernel.org,
	linux-kernel@vger.kernel.org, kernelnewbies@kernelnewbies.org
Subject: [RFC PATCH v3 12/18] ledtrig-blkdev: Add sysfs attributes to [dis]associate LEDs & devices
Date: Wed, 18 Aug 2021 21:50:47 -0500	[thread overview]
Message-ID: <20210819025053.222710-13-arequipeno@gmail.com> (raw)
In-Reply-To: <20210819025053.222710-1-arequipeno@gmail.com>

/sys/class/leds/<led>/add_blkdev - to create device/LED associations

/sys/class/leds/<led>/delete_blkdev to remove device/LED associations

For both attributes, accept multiple device names separated by whitespace

Signed-off-by: Ian Pilcher <arequipeno@gmail.com>
---
 drivers/leds/trigger/ledtrig-blkdev.c | 48 +++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c
index a1646752b9a0..15b15aefdfd8 100644
--- a/drivers/leds/trigger/ledtrig-blkdev.c
+++ b/drivers/leds/trigger/ledtrig-blkdev.c
@@ -480,3 +480,51 @@ static int blkdev_disk_add(struct ledtrig_blkdev_led *const led,
 exit_return:
 	return ret;
 }
+
+
+/*
+ *
+ *	sysfs attributes to add & delete devices from LEDs
+ *
+ */
+
+static ssize_t blkdev_add_or_del(struct device *const dev,
+				 struct device_attribute *const attr,
+				 const char *const buf, const size_t count);
+
+static struct device_attribute ledtrig_blkdev_attr_add =
+	__ATTR(add_blkdev, 0200, NULL, blkdev_add_or_del);
+
+static struct device_attribute ledtrig_blkdev_attr_del =
+	__ATTR(delete_blkdev, 0200, NULL, blkdev_add_or_del);
+
+static ssize_t blkdev_add_or_del(struct device *const dev,
+				 struct device_attribute *const attr,
+				 const char *const buf, const size_t count)
+{
+	struct ledtrig_blkdev_led *const led = led_trigger_get_drvdata(dev);
+	const char *const disk_name = blkdev_skip_space(buf);
+	const char *const endp = blkdev_find_space(disk_name);
+	const ptrdiff_t name_len = endp - disk_name;	/* always >= 0 */
+	int ret;
+
+	if (name_len == 0) {
+		pr_info("blkdev LED: empty block device name\n");
+		return -EINVAL;
+	}
+
+	if (attr == &ledtrig_blkdev_attr_del) {
+		blkdev_disk_delete(led, disk_name, name_len);
+	} else {	/* attr == &ledtrig_blkdev_attr_add */
+		ret = blkdev_disk_add(led, disk_name, name_len);
+		if (ret != 0)
+			return ret;
+	}
+
+	/*
+	 * Consume everything up to the next non-whitespace token (or the end
+	 * of the input).  Avoids "empty block device name" error if there is
+	 * whitespace after the last token (e.g. a newline).
+	 */
+	return blkdev_skip_space(endp) - buf;
+}
-- 
2.31.1


  parent reply	other threads:[~2021-08-19  2:51 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-19  2:50 [RFC PATCH v3 00/18] Add block device LED trigger Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 01/18] docs: Add block device (blkdev) LED trigger documentation Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 02/18] block: Add get_disk_by_name() for use by blkdev LED trigger Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 03/18] ledtrig-blkdev: Add file (ledtrig-blkdev.c) for block device " Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 04/18] ledtrig-blkdev: Add misc. helper functions to blkdev " Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 05/18] ledtrig-blkdev: Periodically check devices for activity & blink LEDs Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 06/18] block: Add LED trigger pointer to struct gendisk Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 07/18] ledtrig-blkdev: Add function to initialize gendisk ledtrig member Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 08/18] ledtrig-blkdev: Add function to remove LED/device association Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 09/18] ledtrig-blkdev: Add function to disassociate a device from all LEDs Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 10/18] block: Call LED trigger init/cleanup functions Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 11/18] ledtrig-blkdev: Add function to associate a device with an LED Ian Pilcher
2021-08-19  2:50 ` Ian Pilcher [this message]
2021-08-19  2:50 ` [RFC PATCH v3 13/18] ledtrig-blkdev: Add blink_time & interval sysfs attributes Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 14/18] ledtrig-blkdev: Add mode (read/write/rw) sysfs attributue Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 15/18] ledtrig-blkdev: Add function to associate blkdev trigger with LED Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 16/18] ledtrig-blkdev: Add function to disassociate an LED from the trigger Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 17/18] ledtrig-blkdev: Add initialization function Ian Pilcher
2021-08-19  2:50 ` [RFC PATCH v3 18/18] ledtrig-blkdev: Add config option to enable the trigger Ian Pilcher

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210819025053.222710-13-arequipeno@gmail.com \
    --to=arequipeno@gmail.com \
    --cc=axboe@kernel.dk \
    --cc=kabel@kernel.org \
    --cc=kernelnewbies@kernelnewbies.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-leds@vger.kernel.org \
    --cc=pavel@ucw.cz \
    --subject='Re: [RFC PATCH v3 12/18] ledtrig-blkdev: Add sysfs attributes to [dis]associate LEDs & devices' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).