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
next prev 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 ` 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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