Input: extend the number of event (and other) devices
Extend the amount of character devices, such as eventX, mouseX and jsX,
from a hard limit of 32 per input handler to about 1024 shared across
all handlers.
To be compatible with legacy installations input handlers will start
creating char devices with minors in their legacy range, however once
legacy range is exhausted they will start allocating minors from the
dynamic range 256-1024.
Reviewed-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 78f323e..b62b589 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -27,6 +27,7 @@
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/device.h>
+#include <linux/cdev.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Joystick device interfaces");
@@ -39,13 +40,13 @@
struct joydev {
int open;
- int minor;
struct input_handle handle;
wait_queue_head_t wait;
struct list_head client_list;
spinlock_t client_lock; /* protects client_list */
struct mutex mutex;
struct device dev;
+ struct cdev cdev;
bool exist;
struct js_corr corr[ABS_CNT];
@@ -70,9 +71,6 @@
struct list_head node;
};
-static struct joydev *joydev_table[JOYDEV_MINORS];
-static DEFINE_MUTEX(joydev_table_mutex);
-
static int joydev_correct(int value, struct js_corr *corr)
{
switch (corr->type) {
@@ -252,30 +250,14 @@
static int joydev_open(struct inode *inode, struct file *file)
{
+ struct joydev *joydev =
+ container_of(inode->i_cdev, struct joydev, cdev);
struct joydev_client *client;
- struct joydev *joydev;
- int i = iminor(inode) - JOYDEV_MINOR_BASE;
int error;
- if (i >= JOYDEV_MINORS)
- return -ENODEV;
-
- error = mutex_lock_interruptible(&joydev_table_mutex);
- if (error)
- return error;
- joydev = joydev_table[i];
- if (joydev)
- get_device(&joydev->dev);
- mutex_unlock(&joydev_table_mutex);
-
- if (!joydev)
- return -ENODEV;
-
client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
- if (!client) {
- error = -ENOMEM;
- goto err_put_joydev;
- }
+ if (!client)
+ return -ENOMEM;
spin_lock_init(&client->buffer_lock);
client->joydev = joydev;
@@ -288,13 +270,12 @@
file->private_data = client;
nonseekable_open(inode, file);
+ get_device(&joydev->dev);
return 0;
err_free_client:
joydev_detach_client(joydev, client);
kfree(client);
- err_put_joydev:
- put_device(&joydev->dev);
return error;
}
@@ -742,19 +723,6 @@
.llseek = no_llseek,
};
-static int joydev_install_chrdev(struct joydev *joydev)
-{
- joydev_table[joydev->minor] = joydev;
- return 0;
-}
-
-static void joydev_remove_chrdev(struct joydev *joydev)
-{
- mutex_lock(&joydev_table_mutex);
- joydev_table[joydev->minor] = NULL;
- mutex_unlock(&joydev_table_mutex);
-}
-
/*
* Mark device non-existent. This disables writes, ioctls and
* prevents new users from opening the device. Already posted
@@ -773,7 +741,8 @@
joydev_mark_dead(joydev);
joydev_hangup(joydev);
- joydev_remove_chrdev(joydev);
+
+ cdev_del(&joydev->cdev);
/* joydev is marked dead so no one else accesses joydev->open */
if (joydev->open)
@@ -798,30 +767,33 @@
const struct input_device_id *id)
{
struct joydev *joydev;
- int i, j, t, minor;
+ int i, j, t, minor, dev_no;
int error;
- for (minor = 0; minor < JOYDEV_MINORS; minor++)
- if (!joydev_table[minor])
- break;
-
- if (minor == JOYDEV_MINORS) {
- pr_err("no more free joydev devices\n");
- return -ENFILE;
+ minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
+ if (minor < 0) {
+ error = minor;
+ pr_err("failed to reserve new minor: %d\n", error);
+ return error;
}
joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
- if (!joydev)
- return -ENOMEM;
+ if (!joydev) {
+ error = -ENOMEM;
+ goto err_free_minor;
+ }
INIT_LIST_HEAD(&joydev->client_list);
spin_lock_init(&joydev->client_lock);
mutex_init(&joydev->mutex);
init_waitqueue_head(&joydev->wait);
-
- dev_set_name(&joydev->dev, "js%d", minor);
joydev->exist = true;
- joydev->minor = minor;
+
+ dev_no = minor;
+ /* Normalize device number if it falls into legacy range */
+ if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
+ dev_no -= JOYDEV_MINOR_BASE;
+ dev_set_name(&joydev->dev, "js%d", dev_no);
joydev->handle.dev = input_get_device(dev);
joydev->handle.name = dev_name(&joydev->dev);
@@ -875,7 +847,7 @@
}
}
- joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
+ joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
joydev->dev.class = &input_class;
joydev->dev.parent = &dev->dev;
joydev->dev.release = joydev_free;
@@ -885,7 +857,8 @@
if (error)
goto err_free_joydev;
- error = joydev_install_chrdev(joydev);
+ cdev_init(&joydev->cdev, &joydev_fops);
+ error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
if (error)
goto err_unregister_handle;
@@ -901,6 +874,8 @@
input_unregister_handle(&joydev->handle);
err_free_joydev:
put_device(&joydev->dev);
+ err_free_minor:
+ input_free_minor(minor);
return error;
}
@@ -910,6 +885,7 @@
device_del(&joydev->dev);
joydev_cleanup(joydev);
+ input_free_minor(MINOR(joydev->dev.devt));
input_unregister_handle(handle);
put_device(&joydev->dev);
}
@@ -961,7 +937,7 @@
.match = joydev_match,
.connect = joydev_connect,
.disconnect = joydev_disconnect,
- .fops = &joydev_fops,
+ .legacy_minors = true,
.minor = JOYDEV_MINOR_BASE,
.name = "joydev",
.id_table = joydev_ids,