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From:   Ian Pilcher <arequipeno@gmail.com>
To:     axboe@kernel.dk, pavel@ucw.cz
Cc:     linux-leds@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
        kabel@kernel.org
Subject: [PATCH v2 07/15] leds: trigger: blkdev: Add constants and types
Date:   Thu,  9 Sep 2021 17:25:05 -0500
Message-Id: <20210909222513.2184795-8-arequipeno@gmail.com>
In-Reply-To: <20210909222513.2184795-1-arequipeno@gmail.com>
References: <20210909222513.2184795-1-arequipeno@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Avoid bloating gendisk structure by storing per-device trigger data in
ledtrig_blkdev_disk

Support many-to-many device/LED associations with ledtrig_blkdev_link
struct.  Per-device (ledtrig_blkdev_disk) and per-LED (ledtrig_blkdev_led)
structures both include a list of links, so a device can be linked to
multiple LEDs, and an LED can be linked to multiple devices.

Signed-off-by: Ian Pilcher <arequipeno@gmail.com>
---
 drivers/leds/trigger/ledtrig-blkdev.c | 44 +++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c
index 7f85e6080ea1..38a2cd2df85c 100644
--- a/drivers/leds/trigger/ledtrig-blkdev.c
+++ b/drivers/leds/trigger/ledtrig-blkdev.c
@@ -15,3 +15,47 @@ MODULE_DESCRIPTION("Block device LED trigger");
 MODULE_AUTHOR("Ian Pilcher <arequipeno@gmail.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(LEDTRIG_BLKDEV);
+
+/* Default blink time & check interval (milliseconds) */
+#define LEDTRIG_BLKDEV_BLINK_MSEC	75
+#define LEDTRIG_BLKDEV_INTERVAL		100
+
+/* Minimum blink time & check interval (milliseconds) */
+#define LEDTRIG_BLKDEV_MIN_BLINK	10
+#define LEDTRIG_BLKDEV_MIN_INT		25
+
+enum ledtrig_blkdev_mode {
+	LEDTRIG_BLKDEV_MODE_RO	= 0,	/* blink for reads */
+	LEDTRIG_BLKDEV_MODE_WO	= 1,	/* blink for writes */
+	LEDTRIG_BLKDEV_MODE_RW	= 2	/* blink for reads and writes */
+};
+
+/* Per-block device information */
+struct ledtrig_blkdev_disk {
+	struct gendisk		*gd;
+	struct kobject		*dir;		/* linked_leds dir */
+	struct hlist_head	leds;
+	unsigned long		read_ios;
+	unsigned long		write_ios;
+	unsigned int		generation;
+	bool			read_act;
+	bool			write_act;
+};
+
+/* For many-to-many relationships between "disks" (block devices) and LEDs */
+struct ledtrig_blkdev_link {
+	struct hlist_node		disk_leds_node;
+	struct hlist_node		led_disks_node;
+	struct ledtrig_blkdev_disk	*disk;
+	struct ledtrig_blkdev_led	*led;
+};
+
+/* Every LED associated with the blkdev trigger gets one of these */
+struct ledtrig_blkdev_led {
+	struct kobject			*dir;		/* linked_devices dir */
+	struct led_classdev		*led_dev;
+	unsigned int			blink_msec;
+	struct hlist_head		disks;		/* linked block devs */
+	struct hlist_node		leds_node;
+	enum ledtrig_blkdev_mode	mode;
+};
-- 
2.31.1