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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 04/18] ledtrig-blkdev: Add misc. helper functions to blkdev LED trigger
Date: Wed, 18 Aug 2021 21:50:39 -0500	[thread overview]
Message-ID: <20210819025053.222710-5-arequipeno@gmail.com> (raw)
In-Reply-To: <20210819025053.222710-1-arequipeno@gmail.com>

Add various helper functions to the block device LED trigger:

  * blkdev_mkdir() - create a sysfs directory (and don't swallow error
    codes)

  * blkdev_streq(), blkdev_skip_space() & blkdev_find_space() - for
    parsing writes to sysfs attributes

  * blkdev_read_mode() & blkdev_write_mode() - LED mode activity type
    helpers

Signed-off-by: Ian Pilcher <arequipeno@gmail.com>
---
 drivers/leds/trigger/ledtrig-blkdev.c | 74 +++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c
index 28ccbd7946ba..fcae7ce63b92 100644
--- a/drivers/leds/trigger/ledtrig-blkdev.c
+++ b/drivers/leds/trigger/ledtrig-blkdev.c
@@ -6,6 +6,7 @@
  *	Copyright 2021 Ian Pilcher <arequipeno@gmail.com>
  */
 
+#include <linux/ctype.h>
 #include <linux/leds.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
@@ -64,3 +65,76 @@ static unsigned int ledtrig_blkdev_count;
 
 /* How often to check for drive activity - in jiffies */
 static unsigned int ledtrig_blkdev_interval;
+
+
+/*
+ *
+ *	Miscellaneous helper functions
+ *
+ */
+
+/* Like kobject_create_and_add(), but doesn't swallow error codes */
+static struct kobject *blkdev_mkdir(const char *const name,
+				    struct kobject *const parent)
+{
+	struct kobject *dir;
+	int ret;
+
+	dir = kobject_create();
+	if (dir == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	ret = kobject_add(dir, parent, "%s", name);
+	if (ret != 0) {
+		kobject_put(dir);
+		return ERR_PTR(ret);
+	}
+
+	return dir;
+}
+
+/*
+ * Compare a null-terminated C string with a non-null-terminated character
+ * sequence of a known length.  Returns true if equal, false if not.
+ */
+static bool blkdev_streq(const char *const cstr,
+			 const char *const cbuf, const size_t buf_len)
+{
+	return (strlen(cstr) == buf_len) && (memcmp(cstr, cbuf, buf_len) == 0);
+}
+
+/*
+ * Returns a pointer to the first non-whitespace character in s
+ * (or a pointer to the terminating null).
+ */
+static const char *blkdev_skip_space(const char *s)
+{
+	while (*s != 0 && isspace(*s))
+		++s;
+
+	return s;
+}
+
+/*
+ * Returns a pointer to the first whitespace character in s (or a pointer to the
+ * terminating null), which is effectively a pointer to the position *after* the
+ * last character in the non-whitespace token at the beginning of s.  (s is
+ * expected to be the result of a previous call to blkdev_skip_space()).
+ */
+static const char *blkdev_find_space(const char *s)
+{
+	while (*s != 0 && !isspace(*s))
+		++s;
+
+	return s;
+}
+
+static bool blkdev_read_mode(const enum ledtrig_blkdev_mode mode)
+{
+	return mode != LEDTRIG_BLKDEV_MODE_WO;
+}
+
+static bool blkdev_write_mode(const enum ledtrig_blkdev_mode mode)
+{
+	return mode != LEDTRIG_BLKDEV_MODE_RO;
+}
-- 
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 " 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 ` Ian Pilcher [this message]
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 ` [RFC PATCH v3 12/18] ledtrig-blkdev: Add sysfs attributes to [dis]associate LEDs & devices Ian Pilcher
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

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