Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

Pull input layer updates from Dmitry Torokhov:
 "2nd round of updates for the input subsystem.  With it input core no
  longer limits number of character devices per event handler (such as
  evdev) to 32, but switches to dynamic minors once legacy range is
  exhausted.  This should get multi-seat installations that currently
  run our of event devices very quickly.

  You will also get an update for Wacom driver and a couple of driver
  fixes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: extend the number of event (and other) devices
  Input: mousedev - mark mousedev interfaces as non-seekable
  Input: mousedev - rename mixdev_open to opened_by_mixdev
  Input: mousedev - reformat structure initializers
  Input: mousedev - factor out psaux code to reduce #ifdefery
  Input: samsung-keypad - add clk_prepare and clk_unprepare
  Input: atmel_mxt_ts - simplify mxt_dump_message
  Input: wacom - clean up wacom_query_tablet_data
  Input: wacom - introduce wacom_fix_phy_from_hid
  Input: wacom - allow any multi-input Intuos device to set prox
  Input: wacom - report correct touch contact size for I5/Bamboo

1 files changed, 53 insertions, 61 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index ace3f7c4226..53a0ddee787 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -14,6 +14,7 @@
 
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/idr.h>
 #include <linux/input/mt.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -32,7 +33,9 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
 MODULE_DESCRIPTION("Input core");
 MODULE_LICENSE("GPL");
 
-#define INPUT_DEVICES   256
+#define INPUT_MAX_CHAR_DEVICES          1024
+#define INPUT_FIRST_DYNAMIC_DEV         256
+static DEFINE_IDA(input_ida);
 
 static LIST_HEAD(input_dev_list);
 static LIST_HEAD(input_handler_list);
@@ -45,8 +48,6 @@ static LIST_HEAD(input_handler_list);
  */
 static DEFINE_MUTEX(input_mutex);
 
-static struct input_handler *input_table[8];
-
 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
 
 static inline int is_event_supported(unsigned int code,
@@ -1218,7 +1219,7 @@ static int input_handlers_seq_show(struct seq_file *seq, void *v)
         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
         if (handler->filter)
                 seq_puts(seq, " (filter)");
-        if (handler->fops)
+        if (handler->legacy_minors)
                 seq_printf(seq, " Minor=%d", handler->minor);
         seq_putc(seq, '\n');
 
@@ -2016,22 +2017,14 @@ EXPORT_SYMBOL(input_unregister_device);
 int input_register_handler(struct input_handler *handler)
 {
         struct input_dev *dev;
-        int retval;
+        int error;
 
-        retval = mutex_lock_interruptible(&input_mutex);
-        if (retval)
-                return retval;
+        error = mutex_lock_interruptible(&input_mutex);
+        if (error)
+                return error;
 
         INIT_LIST_HEAD(&handler->h_list);
 
-        if (handler->fops != NULL) {
-                if (input_table[handler->minor >> 5]) {
-                        retval = -EBUSY;
-                        goto out;
-                }
-                input_table[handler->minor >> 5] = handler;
-        }
-
         list_add_tail(&handler->node, &input_handler_list);
 
         list_for_each_entry(dev, &input_dev_list, node)
@@ -2039,9 +2032,8 @@ int input_register_handler(struct input_handler *handler)
 
         input_wakeup_procfs_readers();
 
- out:
         mutex_unlock(&input_mutex);
-        return retval;
+        return 0;
 }
 EXPORT_SYMBOL(input_register_handler);
 
@@ -2064,9 +2056,6 @@ void input_unregister_handler(struct input_handler *handler)
 
         list_del_init(&handler->node);
 
-        if (handler->fops != NULL)
-                input_table[handler->minor >> 5] = NULL;
-
         input_wakeup_procfs_readers();
 
         mutex_unlock(&input_mutex);
@@ -2183,51 +2172,52 @@ void input_unregister_handle(struct input_handle *handle)
 }
 EXPORT_SYMBOL(input_unregister_handle);
 
-static int input_open_file(struct inode *inode, struct file *file)
+/**
+ * input_get_new_minor - allocates a new input minor number
+ * @legacy_base: beginning or the legacy range to be searched
+ * @legacy_num: size of legacy range
+ * @allow_dynamic: whether we can also take ID from the dynamic range
+ *
+ * This function allocates a new device minor for from input major namespace.
+ * Caller can request legacy minor by specifying @legacy_base and @legacy_num
+ * parameters and whether ID can be allocated from dynamic range if there are
+ * no free IDs in legacy range.
+ */
+int input_get_new_minor(int legacy_base, unsigned int legacy_num,
+                        bool allow_dynamic)
 {
-        struct input_handler *handler;
-        const struct file_operations *old_fops, *new_fops = NULL;
-        int err;
-
-        err = mutex_lock_interruptible(&input_mutex);
-        if (err)
-                return err;
-
-        /* No load-on-demand here? */
-        handler = input_table[iminor(inode) >> 5];
-        if (handler)
-                new_fops = fops_get(handler->fops);
-
-        mutex_unlock(&input_mutex);
-
         /*
-         * That's _really_ odd. Usually NULL ->open means "nothing special",
-         * not "no device". Oh, well...
+         * This function should be called from input handler's ->connect()
+         * methods, which are serialized with input_mutex, so no additional
+         * locking is needed here.
          */
-        if (!new_fops || !new_fops->open) {
-                fops_put(new_fops);
-                err = -ENODEV;
-                goto out;
+        if (legacy_base >= 0) {
+                int minor = ida_simple_get(&input_ida,
+                                           legacy_base,
+                                           legacy_base + legacy_num,
+                                           GFP_KERNEL);
+                if (minor >= 0 || !allow_dynamic)
+                        return minor;
         }
 
-        old_fops = file->f_op;
-        file->f_op = new_fops;
-
-        err = new_fops->open(inode, file);
-        if (err) {
-                fops_put(file->f_op);
-                file->f_op = fops_get(old_fops);
-        }
-        fops_put(old_fops);
-out:
-        return err;
+        return ida_simple_get(&input_ida,
+                              INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
+                              GFP_KERNEL);
 }
+EXPORT_SYMBOL(input_get_new_minor);
 
-static const struct file_operations input_fops = {
-        .owner = THIS_MODULE,
-        .open = input_open_file,
-        .llseek = noop_llseek,
-};
+/**
+ * input_free_minor - release previously allocated minor
+ * @minor: minor to be released
+ *
+ * This function releases previously allocated input minor so that it can be
+ * reused later.
+ */
+void input_free_minor(unsigned int minor)
+{
+        ida_simple_remove(&input_ida, minor);
+}
+EXPORT_SYMBOL(input_free_minor);
 
 static int __init input_init(void)
 {
@@ -2243,7 +2233,8 @@ static int __init input_init(void)
         if (err)
                 goto fail1;
 
-        err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
+        err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
+                                     INPUT_MAX_CHAR_DEVICES, "input");
         if (err) {
                 pr_err("unable to register char major %d", INPUT_MAJOR);
                 goto fail2;
@@ -2259,7 +2250,8 @@ static int __init input_init(void)
 static void __exit input_exit(void)
 {
         input_proc_exit();
-        unregister_chrdev(INPUT_MAJOR, "input");
+        unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
+                                 INPUT_MAX_CHAR_DEVICES);
         class_unregister(&input_class);
 }