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@xxxxxxxxx>
---
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@xxxxxxxxx>
*/
+#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
