[PATCH 1/6] Haptic: add haptic class

[PATCH 1/6] Haptic: add haptic class

[Kyungmin Park]

New haptic class support.
This class handles the haptic devices.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/haptic/Kconfig        |   14 +++
 drivers/haptic/Makefile       |    2 +
 drivers/haptic/haptic-class.c |  255 +++++++++++++++++++++++++++++++++++++++++
 drivers/haptic/haptic.h       |   35 ++++++
 include/linux/haptic.h        |   85 ++++++++++++++
 5 files changed, 391 insertions(+), 0 deletions(-)
 create mode 100644 drivers/haptic/Kconfig
 create mode 100644 drivers/haptic/Makefile
 create mode 100644 drivers/haptic/haptic-class.c
 create mode 100644 drivers/haptic/haptic.h
 create mode 100644 include/linux/haptic.h

diff --git a/drivers/haptic/Kconfig b/drivers/haptic/Kconfig
new file mode 100644
index 0000000..656b022
--- /dev/null
+++ b/drivers/haptic/Kconfig
@@ -0,0 +1,14 @@
+menuconfig HAPTIC
+	bool "Haptic support"
+	help
+	  Say Y to enable haptic support. It enables the haptic and controls
+	  from userspace.
+
+if HAPTIC
+
+config HAPTIC_CLASS
+	tristate "Haptic Class Support"
+	help
+	  This option enables the haptic sysfs class in /sys/class/haptic.
+
+endif	# HAPTIC
diff --git a/drivers/haptic/Makefile b/drivers/haptic/Makefile
new file mode 100644
index 0000000..d30f8cd
--- /dev/null
+++ b/drivers/haptic/Makefile
@@ -0,0 +1,2 @@
+# Haptic Core
+obj-$(CONFIG_HAPTIC_CLASS)		+= haptic-class.o
diff --git a/drivers/haptic/haptic-class.c b/drivers/haptic/haptic-class.c
new file mode 100644
index 0000000..d2151bc
--- /dev/null
+++ b/drivers/haptic/haptic-class.c
@@ -0,0 +1,255 @@
+/*
+ *  Haptic Class Core
+ *
+ *  Copyright (C) 2008 - 2009 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/rwsem.h>
+#include <linux/sysdev.h>
+#include <linux/timer.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+#include <linux/haptic.h>
+#include "haptic.h"
+
+static DECLARE_RWSEM(haptic_list_lock);
+static LIST_HEAD(haptic_list);
+static struct class *haptic_class;
+static struct class_dev_iter *iter;
+
+static void haptic_update_value(struct haptic_classdev *haptic_cdev)
+{
+	if (haptic_cdev->get)
+		haptic_cdev->value = haptic_cdev->get(haptic_cdev);
+}
+
+#define ATTR_DEF_SHOW(name) \
+static ssize_t haptic_show_##name(struct class *class, \
+		char *buf) \
+{ \
+	struct device *dev; \
+	struct haptic_classdev *haptic_cdev; \
+	ssize_t ret = -EINVAL; \
+  \
+	class_dev_iter_init(iter, haptic_class, NULL, NULL); \
+	while ((dev = class_dev_iter_next(iter))) { \
+		haptic_cdev = dev_get_drvdata(dev); \
+		if (haptic_cdev->show_##name) \
+			ret = haptic_cdev->show_##name(dev, NULL, buf); \
+	} \
+  \
+	return ret; \
+}
+
+#define ATTR_DEF_STORE(name) \
+static ssize_t haptic_store_##name(struct class *class, \
+		const char *buf, size_t count) \
+{ \
+	struct device *dev; \
+	struct haptic_classdev *haptic_cdev; \
+	ssize_t ret = -EINVAL; \
+  \
+	class_dev_iter_init(iter, haptic_class, NULL, NULL); \
+	while ((dev = class_dev_iter_next(iter))) { \
+		haptic_cdev = dev_get_drvdata(dev); \
+		if (haptic_cdev->store_##name) \
+			ret = haptic_cdev->store_##name( \
+					dev, NULL, buf, count); \
+	} \
+  \
+	return ret; \
+}
+
+ATTR_DEF_SHOW(enable);
+ATTR_DEF_STORE(enable);
+static CLASS_ATTR(enable, 0644, haptic_show_enable, haptic_store_enable);
+
+ATTR_DEF_STORE(oneshot);
+static CLASS_ATTR(oneshot, 0200, NULL, haptic_store_oneshot);
+
+ATTR_DEF_SHOW(level);
+ATTR_DEF_STORE(level);
+static CLASS_ATTR(level, 0644, haptic_show_level, haptic_store_level);
+
+ATTR_DEF_SHOW(level_max);
+static CLASS_ATTR(level_max, 0444, haptic_show_level_max, NULL);
+
+static ssize_t haptic_show_value(struct class *class,
+		char *buf)
+{
+	struct device *dev;
+	struct haptic_classdev *haptic_cdev;
+	ssize_t ret = 0;
+
+	class_dev_iter_init(iter, haptic_class, NULL, NULL);
+	while ((dev = class_dev_iter_next(iter))) {
+		haptic_cdev = dev_get_drvdata(dev);
+
+		/* no lock needed for this */
+		haptic_update_value(haptic_cdev);
+		sprintf(buf, "%u\n", haptic_get_value(haptic_cdev));
+		ret = strlen(buf) + 1;
+	}
+
+	return ret;
+}
+
+static ssize_t haptic_store_value(struct class *class,
+		const char *buf, size_t count)
+{
+	struct device *dev;
+	struct haptic_classdev *haptic_cdev;
+	ssize_t ret = -EINVAL;
+	unsigned long val;
+
+	class_dev_iter_init(iter, haptic_class, NULL, NULL);
+	while ((dev = class_dev_iter_next(iter))) {
+		haptic_cdev = dev_get_drvdata(dev);
+		ret = strict_strtoul(buf, 10, &val);
+		if (ret == 0) {
+			ret = count;
+			haptic_set_value(haptic_cdev, val);
+		}
+	}
+
+	return ret;
+}
+static CLASS_ATTR(value, 0644, haptic_show_value, haptic_store_value);
+
+/**
+ * haptic_classdev_suspend - suspend an haptic_classdev.
+ * @haptic_cdev: the haptic_classdev to suspend.
+ */
+void haptic_classdev_suspend(struct haptic_classdev *haptic_cdev)
+{
+	haptic_cdev->flags |= HAPTIC_SUSPENDED;
+	haptic_cdev->set(haptic_cdev, HAPTIC_OFF);
+}
+EXPORT_SYMBOL_GPL(haptic_classdev_suspend);
+
+/**
+ * haptic_classdev_resume - resume an haptic_classdev.
+ * @haptic_cdev: the haptic_classdev to resume.
+ */
+void haptic_classdev_resume(struct haptic_classdev *haptic_cdev)
+{
+	haptic_cdev->set(haptic_cdev, haptic_cdev->value);
+	haptic_cdev->flags &= ~HAPTIC_SUSPENDED;
+}
+EXPORT_SYMBOL_GPL(haptic_classdev_resume);
+
+/**
+ * haptic_classdev_register - register a new object of haptic_classdev class.
+ * @dev: The device to register.
+ * @haptic_cdev: the haptic_classdev structure for this device.
+ */
+int haptic_classdev_register(struct device *parent,
+				struct haptic_classdev *haptic_cdev)
+{
+	int ret;
+
+	haptic_cdev->dev = device_create(haptic_class, parent, 0,
+				haptic_cdev, "%s", haptic_cdev->name);
+	if (IS_ERR(haptic_cdev->dev))
+		return PTR_ERR(haptic_cdev->dev);
+
+	/* register the attributes */
+	ret = class_create_file(haptic_class, &class_attr_enable);
+	if (ret) {
+		printk(KERN_ERR "%s: class_create_file(enable) failed\n",
+				 __func__);
+		return ret;
+	}
+	ret = class_create_file(haptic_class, &class_attr_oneshot);
+	if (ret) {
+		printk(KERN_ERR "%s: class_create_file(oneshot) failed\n",
+				 __func__);
+		return ret;
+	}
+	ret = class_create_file(haptic_class, &class_attr_level);
+	if (ret) {
+		printk(KERN_ERR "%s: class_create_file(level) failed\n",
+				 __func__);
+		return ret;
+	}
+	ret = class_create_file(haptic_class, &class_attr_level_max);
+	if (ret) {
+		printk(KERN_ERR "%s: class_create_file(level_max) failed\n",
+				 __func__);
+		return ret;
+	}
+	ret = class_create_file(haptic_class, &class_attr_value);
+	if (ret) {
+		printk(KERN_ERR "%s: class_create_file(value) failed\n",
+				 __func__);
+		return ret;
+	}
+
+	/* add to the list of haptic */
+	down_write(&haptic_list_lock);
+	list_add_tail(&haptic_cdev->node, &haptic_list);
+	up_write(&haptic_list_lock);
+
+	haptic_update_value(haptic_cdev);
+
+	printk(KERN_INFO "Registered haptic device: %s\n", haptic_cdev->name);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(haptic_classdev_register);
+
+/**
+ * haptic_classdev_unregister - unregisters a object of haptic class.
+ * @haptic_cdev: the haptic device to unregister
+ *
+ * Unregisters a previously registered via haptic_classdev_register object.
+ */
+void haptic_classdev_unregister(struct haptic_classdev *haptic_cdev)
+{
+	class_remove_file(haptic_class, &class_attr_enable);
+	class_remove_file(haptic_class, &class_attr_oneshot);
+	class_remove_file(haptic_class, &class_attr_level);
+	class_remove_file(haptic_class, &class_attr_level_max);
+	class_remove_file(haptic_class, &class_attr_value);
+
+	device_unregister(haptic_cdev->dev);
+
+	down_write(&haptic_list_lock);
+	list_del(&haptic_cdev->node);
+	up_write(&haptic_list_lock);
+}
+EXPORT_SYMBOL_GPL(haptic_classdev_unregister);
+
+static int __init haptic_init(void)
+{
+	haptic_class = class_create(THIS_MODULE, "haptic");
+	if (IS_ERR(haptic_class))
+		return PTR_ERR(haptic_class);
+
+	iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
+	if (!iter)
+		return -ENOMEM;
+	return 0;
+}
+subsys_initcall(haptic_init);
+
+static void __exit haptic_exit(void)
+{
+	class_destroy(haptic_class);
+	kfree(iter);
+}
+module_exit(haptic_exit);
+
+MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Haptic Class Interface");
diff --git a/drivers/haptic/haptic.h b/drivers/haptic/haptic.h
new file mode 100644
index 0000000..888aaa3
--- /dev/null
+++ b/drivers/haptic/haptic.h
@@ -0,0 +1,35 @@
+/*
+ *  Haptic Core
+ *
+ *  Copyright (C) 2008 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __HAPTIC_H_INCLUDED
+#define __HAPTIC_H_INCLUDED
+
+#include <linux/device.h>
+#include <linux/rwsem.h>
+#include <linux/haptic.h>
+
+static inline void haptic_set_value(struct haptic_classdev *haptic_cdev,
+					enum haptic_value value)
+{
+	if (value > HAPTIC_FULL)
+		value = HAPTIC_FULL;
+	haptic_cdev->value = value;
+	if (!(haptic_cdev->flags & HAPTIC_SUSPENDED))
+		haptic_cdev->set(haptic_cdev, value);
+}
+
+static inline int haptic_get_value(struct haptic_classdev *haptic_cdev)
+{
+	return haptic_cdev->value;
+}
+
+#endif	/* __HAPTIC_H_INCLUDED */
diff --git a/include/linux/haptic.h b/include/linux/haptic.h
new file mode 100644
index 0000000..c8c0778
--- /dev/null
+++ b/include/linux/haptic.h
@@ -0,0 +1,85 @@
+/*
+ *  Driver model for haptic
+ *
+ *  Copyright (C) 2008 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __LINUX_HAPTIC_H_INCLUDED
+#define __LINUX_HAPTIC_H_INCLUDED
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+
+struct device;
+/*
+ * Motor Core
+ */
+
+enum haptic_value {
+	HAPTIC_OFF	= 0,
+	HAPTIC_HALF	= 127,
+	HAPTIC_FULL	= 255,
+};
+
+struct haptic_classdev {
+	const char		*name;
+	int			value;
+#define HAPTIC_SUSPENDED		(1 << 0)
+	int			flags;
+
+	/* Set haptic value */
+	/* Must not sleep, use a workqueue if needed */
+	void			(*set)(struct haptic_classdev *self,
+					  enum haptic_value value);
+	/* Get haptic value */
+	enum haptic_value	(*get)(struct haptic_classdev *self);
+
+	ssize_t (*show_enable)(struct device *dev,
+			struct device_attribute *attr, char *buf);
+	ssize_t (*store_enable)(struct device *dev,
+			struct device_attribute *attr,
+			const char *buf, size_t size);
+
+	ssize_t (*store_oneshot)(struct device *dev,
+			struct device_attribute *attr,
+			const char *buf, size_t size);
+
+	ssize_t (*show_level)(struct device *dev,
+			struct device_attribute *attr, char *buf);
+	ssize_t (*store_level)(struct device *dev,
+			struct device_attribute *attr,
+			const char *buf, size_t size);
+
+	ssize_t (*show_level_max)(struct device *dev,
+			struct device_attribute *attr, char *buf);
+
+	struct device		*dev;
+	struct list_head	node;	/* Motor Device list */
+};
+
+extern int haptic_classdev_register(struct device *parent,
+				 struct haptic_classdev *haptic_cdev);
+extern void haptic_classdev_unregister(struct haptic_classdev *lcd);
+extern void haptic_classdev_suspend(struct haptic_classdev *haptic_cdev);
+extern void haptic_classdev_resume(struct haptic_classdev *haptic_cdev);
+
+/*
+ * Generic and gpio haptic platform data for describing haptic names.
+ */
+struct haptic_platform_data {
+	const char	*name;
+	int		pwm_timer;
+	int		gpio;
+	void	(*setup_pin)(void);
+	u8		active_low;
+	int		ldo_level;
+};
+
+#endif	/* __LINUX_HAPTIC_H_INCLUDED */
-- 
1.5.3.3

Re: [PATCH 1/6] Haptic: add haptic class

[Trilok Soni]

Hi Kyungmin,

On Wed, Oct 7, 2009 at 11:47 AM, Kyungmin Park
<kyungmin.park@samsung.com> wrote:
> New haptic class support.
> This class handles the haptic devices.
>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

Reviewed-by: Trilok Soni <soni.trilok@gmail.com>

---Trilok Soni

Re: [PATCH 1/6] Haptic: add haptic class

[Jani Nikula]

On Wed, Oct 7, 2009 at 09:17, Kyungmin Park <kyungmin.park@samsung.com> wrote:
> New haptic class support.
> This class handles the haptic devices.

I'm wondering why a haptic class is needed when there is force
feedback support. Admittedly, I don't know the force feedback
implementation too well, but could someone please enlighten me on
this? Am I missing something here?

I see haptics as simple force feedback, just with (usually) small
force and short duration. There are devices out there doing haptics
using vibra motors, which I think would be limited if implemented
using this haptics class driver. Would it be somehow problematic
interfacing with the simple haptic hardware using the force feedback
API?

BR,
Jani.

Re: [PATCH 1/6] Haptic: add haptic class

[Trilok Soni]

Hi Kyungmin, Dmitry,

On Tue, Oct 13, 2009 at 4:05 PM, Jani Nikula
<ext-jani.1.nikula@nokia.com> wrote:
> On Wed, Oct 7, 2009 at 09:17, Kyungmin Park <kyungmin.park@samsung.com> wrote:
>> New haptic class support.
>> This class handles the haptic devices.
>
> I'm wondering why a haptic class is needed when there is force
> feedback support. Admittedly, I don't know the force feedback
> implementation too well, but could someone please enlighten me on
> this? Am I missing something here?
>
> I see haptics as simple force feedback, just with (usually) small
> force and short duration. There are devices out there doing haptics
> using vibra motors, which I think would be limited if implemented
> using this haptics class driver. Would it be somehow problematic
> interfacing with the simple haptic hardware using the force feedback
> API?

Please share your inputs on ff_device usage instead of haptics class.
I think Dmitry could add some points here as I don't see much users of
ff_device and I don't see any embedded device (like mobile) using it.

-- 
---Trilok Soni
http://triloksoni.wordpress.com
http://www.linkedin.com/in/triloksoni

Re: [PATCH 1/6] Haptic: add haptic class

[Dmitry Torokhov]

On Tue, Oct 13, 2009 at 04:43:43PM +0530, Trilok Soni wrote:
> Hi Kyungmin, Dmitry,
> 
> On Tue, Oct 13, 2009 at 4:05 PM, Jani Nikula
> <ext-jani.1.nikula@nokia.com> wrote:
> > On Wed, Oct 7, 2009 at 09:17, Kyungmin Park <kyungmin.park@samsung.com> wrote:
> >> New haptic class support.
> >> This class handles the haptic devices.
> >
> > I'm wondering why a haptic class is needed when there is force
> > feedback support. Admittedly, I don't know the force feedback
> > implementation too well, but could someone please enlighten me on
> > this? Am I missing something here?
> >
> > I see haptics as simple force feedback, just with (usually) small
> > force and short duration. There are devices out there doing haptics
> > using vibra motors, which I think would be limited if implemented
> > using this haptics class driver. Would it be somehow problematic
> > interfacing with the simple haptic hardware using the force feedback
> > API?
> 
> Please share your inputs on ff_device usage instead of haptics class.
> I think Dmitry could add some points here as I don't see much users of
> ff_device and I don't see any embedded device (like mobile) using it.
> 

Using ff_device was considered when Jiri Slaby was trying to merge
PHANTOM driver, bit for that device FF infrastructure was too limited
and this it was decided that phantom would need a special userpsace that
knows what it is and how to handle it.

The curtrent haptic class seems to be bery limited and may be served via
FF (constant or other effect in a single direction) but I don't know
what kind of plans you have to extend it. I guess it warrants another
discussion.

-- 
Dmitry

Re: [PATCH 1/6] Haptic: add haptic class

[Trilok Soni]

Hi Dmitry,

On Wed, Oct 14, 2009 at 1:29 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Tue, Oct 13, 2009 at 04:43:43PM +0530, Trilok Soni wrote:
>> Hi Kyungmin, Dmitry,
>>
>> On Tue, Oct 13, 2009 at 4:05 PM, Jani Nikula
>> <ext-jani.1.nikula@nokia.com> wrote:
>> > On Wed, Oct 7, 2009 at 09:17, Kyungmin Park <kyungmin.park@samsung.com> wrote:
>> >> New haptic class support.
>> >> This class handles the haptic devices.
>> >
>> > I'm wondering why a haptic class is needed when there is force
>> > feedback support. Admittedly, I don't know the force feedback
>> > implementation too well, but could someone please enlighten me on
>> > this? Am I missing something here?
>> >
>> > I see haptics as simple force feedback, just with (usually) small
>> > force and short duration. There are devices out there doing haptics
>> > using vibra motors, which I think would be limited if implemented
>> > using this haptics class driver. Would it be somehow problematic
>> > interfacing with the simple haptic hardware using the force feedback
>> > API?
>>
>> Please share your inputs on ff_device usage instead of haptics class.
>> I think Dmitry could add some points here as I don't see much users of
>> ff_device and I don't see any embedded device (like mobile) using it.
>>
>
> Using ff_device was considered when Jiri Slaby was trying to merge
> PHANTOM driver, bit for that device FF infrastructure was too limited
> and this it was decided that phantom would need a special userpsace that
> knows what it is and how to handle it.
>
> The curtrent haptic class seems to be bery limited and may be served via
> FF (constant or other effect in a single direction) but I don't know
> what kind of plans you have to extend it. I guess it warrants another
> discussion.

Probably Kyungmin is the right person to analyze the ff_device
infrastructure in input_device framework and see it fits haptics class
or not. As per me, for the mobile like applications current haptics
class should meet the needs.


-- 
---Trilok Soni
http://triloksoni.wordpress.com
http://www.linkedin.com/in/triloksoni