greybus: loopback: register a struct device.

Instead of having the loopback attributes in the bundle device,
Add a struct device to the gb_loopback struct and register it on
connection_init, deregister it at connection_exit, and move the
loopback attribute group over to the new device.

Use device_create_with_groups to create sysfs attributes
together with device.

Suggested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Suggested-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index 6a5eee3..6837291 100644 (file)
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -71,6 +71,7 @@ struct gb_loopback {
        struct mutex mutex;
        struct task_struct *task;
        struct list_head entry;
+       struct device *dev;
        wait_queue_head_t wq;
 
        /* Per connection stats */
@@ -82,6 +83,7 @@ struct gb_loopback {
 
        int type;
        int async;
+       int id;
        u32 size;
        u32 iteration_max;
        u32 iteration_count;
@@ -99,6 +101,12 @@ struct gb_loopback {
        u32 gpbridge_latency_ts;
 };
 
+static struct class loopback_class = {
+       .name           = "gb_loopback",
+       .owner          = THIS_MODULE,
+};
+static DEFINE_IDA(loopback_ida);
+
 /* Min/max values in jiffies */
 #define GB_LOOPBACK_TIMEOUT_MIN                                1
 #define GB_LOOPBACK_TIMEOUT_MAX                                10000
@@ -119,10 +127,7 @@ static ssize_t field##_show(struct device *dev,                    \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
 {                                                                      \
-       struct gb_bundle *bundle;                                       \
-       struct gb_loopback *gb;                                         \
-       bundle = to_gb_bundle(dev);                             \
-       gb = bundle->private;                                   \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        return sprintf(buf, "%u\n", gb->field);                 \
 }                                                                      \
 static DEVICE_ATTR_RO(field)
@@ -132,10 +137,7 @@ static ssize_t name##_##field##_show(struct device *dev,   \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
 {                                                                      \
-       struct gb_bundle *bundle;                                       \
-       struct gb_loopback *gb;                                         \
-       bundle = to_gb_bundle(dev);                             \
-       gb = bundle->private;                                   \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        return sprintf(buf, "%"#type"\n", gb->name.field);      \
 }                                                                      \
 static DEVICE_ATTR_RO(name##_##field)
@@ -146,12 +148,10 @@ static ssize_t name##_avg_show(struct device *dev,                \
                            char *buf)                                  \
 {                                                                      \
        struct gb_loopback_stats *stats;                                \
-       struct gb_bundle *bundle;                                       \
        struct gb_loopback *gb;                                         \
        u64 avg;                                                        \
        u32 count, rem;                                                 \
-       bundle = to_gb_bundle(dev);                             \
-       gb = bundle->private;                                   \
+       gb = dev_get_drvdata(dev);                      \
        stats = &gb->name;                                      \
        count = stats->count ? stats->count : 1;                        \
        avg = stats->sum + count / 2;   /* round closest */             \
@@ -170,8 +170,7 @@ static ssize_t field##_show(struct device *dev,                             \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
 {                                                                      \
-       struct gb_bundle *bundle = to_gb_bundle(dev);                   \
-       struct gb_loopback *gb = bundle->private;                       \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        return sprintf(buf, "%"#type"\n", gb->field);                   \
 }                                                                      \
 static ssize_t field##_store(struct device *dev,                       \
@@ -180,8 +179,7 @@ static ssize_t field##_store(struct device *dev,                    \
                            size_t len)                                 \
 {                                                                      \
        int ret;                                                        \
-       struct gb_bundle *bundle = to_gb_bundle(dev);                   \
-       struct gb_loopback *gb = bundle->private;                       \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        mutex_lock(&gb->mutex);                                         \
        ret = sscanf(buf, "%"#type, &gb->field);                        \
        if (ret != 1)                                                   \
@@ -198,8 +196,7 @@ static ssize_t field##_show(struct device *dev,             \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
 {                                                                      \
-       struct gb_bundle *bundle = to_gb_bundle(dev);                   \
-       struct gb_loopback *gb = bundle->private;                       \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        return sprintf(buf, "%u\n", gb->field);                         \
 }                                                                      \
 static DEVICE_ATTR_RO(field)
@@ -209,8 +206,7 @@ static ssize_t field##_show(struct device *dev,                             \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
 {                                                                      \
-       struct gb_bundle *bundle = to_gb_bundle(dev);                   \
-       struct gb_loopback *gb = bundle->private;                       \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        return sprintf(buf, "%"#type"\n", gb->field);                   \
 }                                                                      \
 static ssize_t field##_store(struct device *dev,                       \
@@ -219,22 +215,20 @@ static ssize_t field##_store(struct device *dev,                  \
                            size_t len)                                 \
 {                                                                      \
        int ret;                                                        \
-       struct gb_bundle *bundle = to_gb_bundle(dev);                   \
-       struct gb_loopback *gb = bundle->private;                       \
+       struct gb_loopback *gb = dev_get_drvdata(dev);                  \
        mutex_lock(&gb->mutex);                                         \
        ret = sscanf(buf, "%"#type, &gb->field);                        \
        if (ret != 1)                                                   \
                len = -EINVAL;                                          \
        else                                                            \
-               gb_loopback_check_attr(gb, bundle);             \
+               gb_loopback_check_attr(gb);             \
        mutex_unlock(&gb->mutex);                                       \
        return len;                                                     \
 }                                                                      \
 static DEVICE_ATTR_RW(field)
 
 static void gb_loopback_reset_stats(struct gb_loopback *gb);
-static void gb_loopback_check_attr(struct gb_loopback *gb,
-                                  struct gb_bundle *bundle)
+static void gb_loopback_check_attr(struct gb_loopback *gb)
 {
        if (gb->us_wait > GB_LOOPBACK_US_WAIT_MAX)
                gb->us_wait = GB_LOOPBACK_US_WAIT_MAX;
@@ -246,7 +240,7 @@ static void gb_loopback_check_attr(struct gb_loopback *gb,
        gb->error = 0;
 
        if (kfifo_depth < gb->iteration_max) {
-               dev_warn(&bundle->dev,
+               dev_warn(gb->dev,
                         "cannot log bytes %u kfifo_depth %u\n",
                         gb->iteration_max, kfifo_depth);
        }
@@ -1062,6 +1056,7 @@ static void gb_loopback_insert_id(struct gb_loopback *gb)
 static int gb_loopback_connection_init(struct gb_connection *connection)
 {
        struct gb_loopback *gb;
+       struct device *dev;
        int retval;
        char name[DEBUGFS_NAMELEN];
        unsigned long flags;
@@ -1095,16 +1090,28 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
                                       &gb_loopback_debugfs_latency_ops);
        gb->connection = connection;
        connection->bundle->private = gb;
-       retval = sysfs_create_groups(&connection->bundle->dev.kobj,
-                                    loopback_groups);
-       if (retval)
-               goto out_sysfs;
+
+       gb->id = ida_simple_get(&loopback_ida, 0, 0, GFP_KERNEL);
+       if (gb->id < 0) {
+               retval = gb->id;
+               goto out_ida;
+       }
+
+       dev = device_create_with_groups(&loopback_class,
+                                       &connection->bundle->dev,
+                                       MKDEV(0, 0), gb, loopback_groups,
+                                       "gb_loopback%d", gb->id);
+       if (IS_ERR(dev)) {
+               retval = PTR_ERR(dev);
+               goto out_dev;
+       }
+       gb->dev = dev;
 
        /* Allocate kfifo */
        if (kfifo_alloc(&gb->kfifo_lat, kfifo_depth * sizeof(u32),
                          GFP_KERNEL)) {
                retval = -ENOMEM;
-               goto out_sysfs_conn;
+               goto out_conn;
        }
        if (kfifo_alloc(&gb->kfifo_ts, kfifo_depth * sizeof(struct timeval) * 2,
                          GFP_KERNEL)) {
@@ -1132,9 +1139,11 @@ out_kfifo1:
        kfifo_free(&gb->kfifo_ts);
 out_kfifo0:
        kfifo_free(&gb->kfifo_lat);
-out_sysfs_conn:
-       sysfs_remove_groups(&connection->bundle->dev.kobj, loopback_groups);
-out_sysfs:
+out_conn:
+       device_unregister(dev);
+out_dev:
+       ida_simple_remove(&loopback_ida, gb->id);
+out_ida:
        debugfs_remove(gb->file);
        connection->bundle->private = NULL;
 out_kzalloc:
@@ -1155,8 +1164,6 @@ static void gb_loopback_connection_exit(struct gb_connection *connection)
        kfifo_free(&gb->kfifo_lat);
        kfifo_free(&gb->kfifo_ts);
        gb_connection_latency_tag_disable(connection);
-       sysfs_remove_groups(&connection->bundle->dev.kobj,
-                           loopback_groups);
        debugfs_remove(gb->file);
 
        spin_lock_irqsave(&gb_dev.lock, flags);
@@ -1164,6 +1171,9 @@ static void gb_loopback_connection_exit(struct gb_connection *connection)
        list_del(&gb->entry);
        spin_unlock_irqrestore(&gb_dev.lock, flags);
 
+       device_unregister(gb->dev);
+       ida_simple_remove(&loopback_ida, gb->id);
+
        kfree(gb);
 }
 
@@ -1186,10 +1196,19 @@ static int loopback_init(void)
        spin_lock_init(&gb_dev.lock);
        gb_dev.root = debugfs_create_dir("gb_loopback", NULL);
 
+       retval = class_register(&loopback_class);
+       if (retval)
+               goto err;
+
        retval = gb_protocol_register(&loopback_protocol);
-       if (!retval)
-               return retval;
+       if (retval)
+               goto err_unregister;
+
+       return 0;
 
+err_unregister:
+       class_unregister(&loopback_class);
+err:
        debugfs_remove_recursive(gb_dev.root);
        return retval;
 }
@@ -1199,6 +1218,8 @@ static void __exit loopback_exit(void)
 {
        debugfs_remove_recursive(gb_dev.root);
        gb_protocol_deregister(&loopback_protocol);
+       class_unregister(&loopback_class);
+       ida_destroy(&loopback_ida);
 }
 module_exit(loopback_exit);