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

drivers/input/evdev.c

@@ -23,11 +23,11 @@
 #include <linux/input/mt.h>
 #include <linux/major.h>
 #include <linux/device.h>
+#include <linux/cdev.h>
 #include "input-compat.h"
 
 struct evdev {
 	int open;
-	int minor;
 	struct input_handle handle;
 	wait_queue_head_t wait;
 	struct evdev_client __rcu *grab;
@@ -35,6 +35,7 @@ struct evdev {
 	spinlock_t client_lock; /* protects client_list */
 	struct mutex mutex;
 	struct device dev;
+	struct cdev cdev;
 	bool exist;
 };
 
@@ -51,9 +52,6 @@ struct evdev_client {
 	struct input_event buffer[];
 };
 
-static struct evdev *evdev_table[EVDEV_MINORS];
-static DEFINE_MUTEX(evdev_table_mutex);
-
 static void __pass_event(struct evdev_client *client,
 			 const struct input_event *event)
 {
@@ -310,35 +308,16 @@ static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 
 static int evdev_open(struct inode *inode, struct file *file)
 {
-	struct evdev *evdev;
+	struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
+	unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 	struct evdev_client *client;
-	int i = iminor(inode) - EVDEV_MINOR_BASE;
-	unsigned int bufsize;
 	int error;
 
-	if (i >= EVDEV_MINORS)
-		return -ENODEV;
-
-	error = mutex_lock_interruptible(&evdev_table_mutex);
-	if (error)
-		return error;
-	evdev = evdev_table[i];
-	if (evdev)
-		get_device(&evdev->dev);
-	mutex_unlock(&evdev_table_mutex);
-
-	if (!evdev)
-		return -ENODEV;
-
-	bufsize = evdev_compute_buffer_size(evdev->handle.dev);
-
 	client = kzalloc(sizeof(struct evdev_client) +
 				bufsize * sizeof(struct input_event),
 			 GFP_KERNEL);
-	if (!client) {
-		error = -ENOMEM;
-		goto err_put_evdev;
-	}
+	if (!client)
+		return -ENOMEM;
 
 	client->bufsize = bufsize;
 	spin_lock_init(&client->buffer_lock);
@@ -352,13 +331,12 @@ static int evdev_open(struct inode *inode, struct file *file)
 	file->private_data = client;
 	nonseekable_open(inode, file);
 
+	get_device(&evdev->dev);
 	return 0;
 
  err_free_client:
 	evdev_detach_client(evdev, client);
 	kfree(client);
- err_put_evdev:
-	put_device(&evdev->dev);
 	return error;
 }
 
@@ -942,26 +920,6 @@ static const struct file_operations evdev_fops = {
 	.llseek		= no_llseek,
 };
 
-static int evdev_install_chrdev(struct evdev *evdev)
-{
-	/*
-	 * No need to do any locking here as calls to connect and
-	 * disconnect are serialized by the input core
-	 */
-	evdev_table[evdev->minor] = evdev;
-	return 0;
-}
-
-static void evdev_remove_chrdev(struct evdev *evdev)
-{
-	/*
-	 * Lock evdev table to prevent race with evdev_open()
-	 */
-	mutex_lock(&evdev_table_mutex);
-	evdev_table[evdev->minor] = NULL;
-	mutex_unlock(&evdev_table_mutex);
-}
-
 /*
  * Mark device non-existent. This disables writes, ioctls and
  * prevents new users from opening the device. Already posted
@@ -980,7 +938,8 @@ static void evdev_cleanup(struct evdev *evdev)
 
 	evdev_mark_dead(evdev);
 	evdev_hangup(evdev);
-	evdev_remove_chrdev(evdev);
+
+	cdev_del(&evdev->cdev);
 
 	/* evdev is marked dead so no one else accesses evdev->open */
 	if (evdev->open) {
@@ -991,43 +950,47 @@ static void evdev_cleanup(struct evdev *evdev)
 
 /*
  * Create new evdev device. Note that input core serializes calls
- * to connect and disconnect so we don't need to lock evdev_table here.
+ * to connect and disconnect.
  */
 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 			 const struct input_device_id *id)
 {
 	struct evdev *evdev;
 	int minor;
+	int dev_no;
 	int error;
 
-	for (minor = 0; minor < EVDEV_MINORS; minor++)
-		if (!evdev_table[minor])
-			break;
-
-	if (minor == EVDEV_MINORS) {
-		pr_err("no more free evdev devices\n");
-		return -ENFILE;
+	minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
+	if (minor < 0) {
+		error = minor;
+		pr_err("failed to reserve new minor: %d\n", error);
+		return error;
 	}
 
 	evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
-	if (!evdev)
-		return -ENOMEM;
+	if (!evdev) {
+		error = -ENOMEM;
+		goto err_free_minor;
+	}
 
 	INIT_LIST_HEAD(&evdev->client_list);
 	spin_lock_init(&evdev->client_lock);
 	mutex_init(&evdev->mutex);
 	init_waitqueue_head(&evdev->wait);
-
-	dev_set_name(&evdev->dev, "event%d", minor);
 	evdev->exist = true;
-	evdev->minor = minor;
+
+	dev_no = minor;
+	/* Normalize device number if it falls into legacy range */
+	if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
+		dev_no -= EVDEV_MINOR_BASE;
+	dev_set_name(&evdev->dev, "event%d", dev_no);
 
 	evdev->handle.dev = input_get_device(dev);
 	evdev->handle.name = dev_name(&evdev->dev);
 	evdev->handle.handler = handler;
 	evdev->handle.private = evdev;
 
-	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
+	evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 	evdev->dev.class = &input_class;
 	evdev->dev.parent = &dev->dev;
 	evdev->dev.release = evdev_free;
@@ -1037,7 +1000,8 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 	if (error)
 		goto err_free_evdev;
 
-	error = evdev_install_chrdev(evdev);
+	cdev_init(&evdev->cdev, &evdev_fops);
+	error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
 	if (error)
 		goto err_unregister_handle;
 
@@ -1053,6 +1017,8 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 	input_unregister_handle(&evdev->handle);
  err_free_evdev:
 	put_device(&evdev->dev);
+ err_free_minor:
+	input_free_minor(minor);
 	return error;
 }
 
@@ -1062,6 +1028,7 @@ static void evdev_disconnect(struct input_handle *handle)
 
 	device_del(&evdev->dev);
 	evdev_cleanup(evdev);
+	input_free_minor(MINOR(evdev->dev.devt));
 	input_unregister_handle(handle);
 	put_device(&evdev->dev);
 }
@@ -1078,7 +1045,7 @@ static struct input_handler evdev_handler = {
 	.events		= evdev_events,
 	.connect	= evdev_connect,
 	.disconnect	= evdev_disconnect,
-	.fops		= &evdev_fops,
+	.legacy_minors	= true,
 	.minor		= EVDEV_MINOR_BASE,
 	.name		= "evdev",
 	.id_table	= evdev_ids,

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);
 }
 

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 @@ MODULE_LICENSE("GPL");
 
 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 joydev_client {
 	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_release(struct inode *inode, struct file *file)
 
 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 @@ static int joydev_open(struct inode *inode, struct file *file)
 	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 @@ static const struct file_operations joydev_fops = {
 	.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 @@ static void joydev_cleanup(struct joydev *joydev)
 
 	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 @@ static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 			  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 @@ static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 		}
 	}
 
-	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 @@ static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 	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 @@ static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 	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 @@ static void joydev_disconnect(struct input_handle *handle)
 
 	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 @@ static struct input_handler joydev_handler = {
 	.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,

drivers/input/keyboard/samsung-keypad.c

@@ -431,6 +431,12 @@ static int __devinit samsung_keypad_probe(struct platform_device *pdev)
 		goto err_unmap_base;
 	}
 
+	error = clk_prepare(keypad->clk);
+	if (error) {
+		dev_err(&pdev->dev, "keypad clock prepare failed\n");
+		goto err_put_clk;
+	}
+
 	keypad->input_dev = input_dev;
 	keypad->pdev = pdev;
 	keypad->row_shift = row_shift;
@@ -461,7 +467,7 @@ static int __devinit samsung_keypad_probe(struct platform_device *pdev)
 					   keypad->keycodes, input_dev);
 	if (error) {
 		dev_err(&pdev->dev, "failed to build keymap\n");
-		goto err_put_clk;
+		goto err_unprepare_clk;
 	}
 
 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
@@ -503,6 +509,8 @@ static int __devinit samsung_keypad_probe(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	device_init_wakeup(&pdev->dev, 0);
 	platform_set_drvdata(pdev, NULL);
+err_unprepare_clk:
+	clk_unprepare(keypad->clk);
 err_put_clk:
 	clk_put(keypad->clk);
 	samsung_keypad_dt_gpio_free(keypad);
@@ -531,6 +539,7 @@ static int __devexit samsung_keypad_remove(struct platform_device *pdev)
 	 */
 	free_irq(keypad->irq, keypad);
 
+	clk_unprepare(keypad->clk);
 	clk_put(keypad->clk);
 	samsung_keypad_dt_gpio_free(keypad);
 

drivers/input/tablet/wacom_sys.c

@@ -171,6 +171,76 @@ static void wacom_close(struct input_dev *dev)
 		usb_autopm_put_interface(wacom->intf);
 }
 
+/*
+ * Calculate the resolution of the X or Y axis, given appropriate HID data.
+ * This function is little more than hidinput_calc_abs_res stripped down.
+ */
+static int wacom_calc_hid_res(int logical_extents, int physical_extents,
+                              unsigned char unit, unsigned char exponent)
+{
+	int prev, unit_exponent;
+
+	/* Check if the extents are sane */
+	if (logical_extents <= 0 || physical_extents <= 0)
+		return 0;
+
+	/* Get signed value of nybble-sized twos-compliment exponent */
+	unit_exponent = exponent;
+	if (unit_exponent > 7)
+		unit_exponent -= 16;
+
+	/* Convert physical_extents to millimeters */
+	if (unit == 0x11) {		/* If centimeters */
+		unit_exponent += 1;
+	} else if (unit == 0x13) {	/* If inches */
+		prev = physical_extents;
+		physical_extents *= 254;
+		if (physical_extents < prev)
+			return 0;
+		unit_exponent -= 1;
+	} else {
+		return 0;
+	}
+
+	/* Apply negative unit exponent */
+	for (; unit_exponent < 0; unit_exponent++) {
+		prev = logical_extents;
+		logical_extents *= 10;
+		if (logical_extents < prev)
+			return 0;
+	}
+	/* Apply positive unit exponent */
+	for (; unit_exponent > 0; unit_exponent--) {
+		prev = physical_extents;
+		physical_extents *= 10;
+		if (physical_extents < prev)
+			return 0;
+	}
+
+	/* Calculate resolution */
+	return logical_extents / physical_extents;
+}
+
+/*
+ * The physical dimension specified by the HID descriptor is likely not in
+ * the "100th of a mm" units expected by wacom_calculate_touch_res. This
+ * function adjusts the value of [xy]_phy based on the unit and exponent
+ * provided by the HID descriptor. If an error occurs durring conversion
+ * (e.g. from the unit being left unspecified) [xy]_phy is not modified.
+ */
+static void wacom_fix_phy_from_hid(struct wacom_features *features)
+{
+	int xres = wacom_calc_hid_res(features->x_max, features->x_phy,
+					features->unit, features->unitExpo);
+	int yres = wacom_calc_hid_res(features->y_max, features->y_phy,
+					features->unit, features->unitExpo);
+
+	if (xres > 0 && yres > 0) {
+		features->x_phy = (100 * features->x_max) / xres;
+		features->y_phy = (100 * features->y_max) / yres;
+	}
+}
+
 /*
  * Static values for max X/Y and resolution of Pen interface is stored in
  * features. This mean physical size of active area can be computed.
@@ -432,58 +502,54 @@ static int wacom_parse_hid(struct usb_interface *intf,
 	return result;
 }
 
-static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_features *features)
+static int wacom_set_device_mode(struct usb_interface *intf, int report_id, int length, int mode)
 {
 	unsigned char *rep_data;
-	int limit = 0, report_id = 2;
-	int error = -ENOMEM;
+	int error = -ENOMEM, limit = 0;
 
-	rep_data = kmalloc(4, GFP_KERNEL);
+	rep_data = kzalloc(length, GFP_KERNEL);
 	if (!rep_data)
 		return error;
 
-	/* ask to report Wacom data */
-	if (features->device_type == BTN_TOOL_FINGER) {
-		/* if it is an MT Tablet PC touch */
-		if (features->type > TABLETPC) {
-			do {
-				rep_data[0] = 3;
-				rep_data[1] = 4;
-				rep_data[2] = 0;
-				rep_data[3] = 0;
-				report_id = 3;
-				error = wacom_set_report(intf,
-							 WAC_HID_FEATURE_REPORT,
-							 report_id,
-							 rep_data, 4, 1);
-				if (error >= 0)
-					error = wacom_get_report(intf,
-							WAC_HID_FEATURE_REPORT,
-							report_id,
-							rep_data, 4, 1);
-			} while ((error < 0 || rep_data[1] != 4) &&
-				 limit++ < WAC_MSG_RETRIES);
-		}
-	} else if (features->type <= BAMBOO_PT &&
-		   features->type != WIRELESS &&
-		   features->device_type == BTN_TOOL_PEN) {
+	rep_data[0] = report_id;
+	rep_data[1] = mode;
+
 	do {
-			rep_data[0] = 2;
-			rep_data[1] = 2;
 		error = wacom_set_report(intf, WAC_HID_FEATURE_REPORT,
-						 report_id, rep_data, 2, 1);
+		                         report_id, rep_data, length, 1);
 		if (error >= 0)
-				error = wacom_get_report(intf,
-						WAC_HID_FEATURE_REPORT,
-						report_id, rep_data, 2, 1);
-		} while ((error < 0 || rep_data[1] != 2) && limit++ < WAC_MSG_RETRIES);
-	}
+			error = wacom_get_report(intf, WAC_HID_FEATURE_REPORT,
+			                         report_id, rep_data, length, 1);
+	} while ((error < 0 || rep_data[1] != mode) && limit++ < WAC_MSG_RETRIES);
 
 	kfree(rep_data);
 
 	return error < 0 ? error : 0;
 }
 
+/*
+ * Switch the tablet into its most-capable mode. Wacom tablets are
+ * typically configured to power-up in a mode which sends mouse-like
+ * reports to the OS. To get absolute position, pressure data, etc.
+ * from the tablet, it is necessary to switch the tablet out of this
+ * mode and into one which sends the full range of tablet data.
+ */
+static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_features *features)
+{
+	if (features->device_type == BTN_TOOL_FINGER) {
+		if (features->type > TABLETPC) {
+			/* MT Tablet PC touch */
+			return wacom_set_device_mode(intf, 3, 4, 4);
+		}
+	} else if (features->device_type == BTN_TOOL_PEN) {
+		if (features->type <= BAMBOO_PT && features->type != WIRELESS) {
+			return wacom_set_device_mode(intf, 2, 2, 2);
+		}
+	}
+
+	return 0;
+}
+
 static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
 					 struct wacom_features *features)
 {
@@ -531,6 +597,7 @@ static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
 	error = wacom_parse_hid(intf, hid_desc, features);
 	if (error)
 		goto out;
+	wacom_fix_phy_from_hid(features);
 
  out:
 	return error;

drivers/input/tablet/wacom_wac.c

@@ -25,6 +25,11 @@
 #define WACOM_INTUOS_RES	100
 #define WACOM_INTUOS3_RES	200
 
+/* Scale factor relating reported contact size to logical contact area.
+ * 2^14/pi is a good approximation on Intuos5 and 3rd-gen Bamboo
+ */
+#define WACOM_CONTACT_AREA_SCALE 2607
+
 static int wacom_penpartner_irq(struct wacom_wac *wacom)
 {
 	unsigned char *data = wacom->data;
@@ -326,7 +331,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 
 	/* Enter report */
 	if ((data[1] & 0xfc) == 0xc0) {
-		if (features->type >= INTUOS5S && features->type <= INTUOS5L)
+		if (features->quirks == WACOM_QUIRK_MULTI_INPUT)
 			wacom->shared->stylus_in_proximity = true;
 
 		/* serial number of the tool */
@@ -414,7 +419,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 
 	/* Exit report */
 	if ((data[1] & 0xfe) == 0x80) {
-		if (features->type >= INTUOS5S && features->type <= INTUOS5L)
+		if (features->quirks == WACOM_QUIRK_MULTI_INPUT)
 			wacom->shared->stylus_in_proximity = false;
 
 		/*
@@ -1043,11 +1048,19 @@ static void wacom_bpt3_touch_msg(struct wacom_wac *wacom, unsigned char *data)
 	if (touch) {
 		int x = (data[2] << 4) | (data[4] >> 4);
 		int y = (data[3] << 4) | (data[4] & 0x0f);
-		int w = data[6];
+		int a = data[5];
+
+		// "a" is a scaled-down area which we assume is roughly
+		// circular and which can be described as: a=(pi*r^2)/C.
+		int x_res  = input_abs_get_res(input, ABS_X);
+		int y_res  = input_abs_get_res(input, ABS_Y);
+		int width  = 2 * int_sqrt(a * WACOM_CONTACT_AREA_SCALE);
+		int height = width * y_res / x_res;
 
 		input_report_abs(input, ABS_MT_POSITION_X, x);
 		input_report_abs(input, ABS_MT_POSITION_Y, y);
-		input_report_abs(input, ABS_MT_TOUCH_MAJOR, w);
+		input_report_abs(input, ABS_MT_TOUCH_MAJOR, width);
+		input_report_abs(input, ABS_MT_TOUCH_MINOR, height);
 	}
 }
 
@@ -1533,7 +1546,9 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 			input_mt_init_slots(input_dev, features->touch_max, 0);
 
 			input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
-			                     0, 255, 0, 0);
+			                     0, features->x_max, 0, 0);
+			input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
+			                     0, features->y_max, 0, 0);
 
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 					     0, features->x_max,
@@ -1641,7 +1656,10 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 
 				input_set_abs_params(input_dev,
 						     ABS_MT_TOUCH_MAJOR,
-						     0, 255, 0, 0);
+						     0, features->x_max, 0, 0);
+				input_set_abs_params(input_dev,
+						     ABS_MT_TOUCH_MINOR,
+						     0, features->y_max, 0, 0);
 			}
 
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,

drivers/input/touchscreen/atmel_mxt_ts.c

@@ -320,10 +320,8 @@ static bool mxt_object_writable(unsigned int type)
 static void mxt_dump_message(struct device *dev,
 			     struct mxt_message *message)
 {
-	dev_dbg(dev, "reportid: %u\tmessage: %02x %02x %02x %02x %02x %02x %02x\n",
-		message->reportid, message->message[0], message->message[1],
-		message->message[2], message->message[3], message->message[4],
-		message->message[5], message->message[6]);
+	dev_dbg(dev, "reportid: %u\tmessage: %*ph\n",
+		message->reportid, 7, message->message);
 }
 
 static int mxt_check_bootloader(struct i2c_client *client,

include/linux/input.h

@@ -1396,8 +1396,8 @@ struct input_handle;
  * @start: starts handler for given handle. This function is called by
  *	input core right after connect() method and also when a process
  *	that "grabbed" a device releases it
- * @fops: file operations this driver implements
- * @minor: beginning of range of 32 minors for devices this driver
+ * @legacy_minors: set to %true by drivers using legacy minor ranges
+ * @minor: beginning of range of 32 legacy minors for devices this driver
  *	can provide
  * @name: name of the handler, to be shown in /proc/bus/input/handlers
  * @id_table: pointer to a table of input_device_ids this driver can
@@ -1431,7 +1431,7 @@ struct input_handler {
 	void (*disconnect)(struct input_handle *handle);
 	void (*start)(struct input_handle *handle);
 
-	const struct file_operations *fops;
+	bool legacy_minors;
 	int minor;
 	const char *name;
 
@@ -1499,6 +1499,10 @@ void input_reset_device(struct input_dev *);
 int __must_check input_register_handler(struct input_handler *);
 void input_unregister_handler(struct input_handler *);
 
+int __must_check input_get_new_minor(int legacy_base, unsigned int legacy_num,
+				     bool allow_dynamic);
+void input_free_minor(unsigned int minor);
+
 int input_handler_for_each_handle(struct input_handler *, void *data,
 				  int (*fn)(struct input_handle *, void *));