Staging: add frontier tranzport and alphatrack drivers

Adds the tranzport and alphatrack drivers to the staging tree.

Cc: David Taht <d@teklibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -89,5 +89,7 @@ source "drivers/staging/rspiusb/Kconfig"
 
 source "drivers/staging/mimio/Kconfig"
 
+source "drivers/staging/frontier/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

@@ -27,3 +27,4 @@ obj-$(CONFIG_ALTERA_PCIE_CHDMA)	+= altpciechdma/
 obj-$(CONFIG_RTL8187SE)		+= rtl8187se/
 obj-$(CONFIG_USB_RSPI)		+= rspiusb/
 obj-$(CONFIG_INPUT_MIMIO)	+= mimio/
+obj-$(CONFIG_TRANZPORT)		+= frontier/

drivers/staging/frontier/Kconfig

+config TRANZPORT
+	tristate "Frontier Tranzport and Alphatrack support"
+	depends on USB
+	default N
+	---help---
+	  Enable support for the Frontier Tranzport and Alphatrack devices.

drivers/staging/frontier/Makefile

+obj-$(CONFIG_TRANZPORT)		+= tranzport.o
+obj-$(CONFIG_TRANZPORT)		+= alphatrack.o

drivers/staging/frontier/README

+This directory contains the USB Tranzport and Alphatrack Kernel drivers for Linux.
+
+At present the tranzport does reads/writes of 8 byte cmds to /dev/tranzport0 to control
+the lights and screen and wheel
+
+At present the alphatrack accepts reads/writes of 12 byte cmds to /dev/tranzport0 to control
+the lights and screen and fader.
+
+Both drivers also have some sysfs hooks that are non-functional at the moment.
+
+The API is currently closely tied to the ardour revision and WILL change.
+
+A sysfs interface is PERFECT for simple userspace apps to do fun things with the
+lights and screen. It's fairly lousy for handling input events and very lousy
+for watching the state of the shuttle wheel.
+
+A linux input events interface is great for the input events and shuttle wheel. It's
+theoretically OK on LEDs. A Fader can be mapped to an absolute mouse device.
+But there is no LCD support at all.
+
+In the end this is going to be driven by a midi layer, which handles all those
+cases via a defined API, but - among other things - is slow, doesn't do
+flow control, and is a LOT of extra work. Frankly, I'd like to keep the
+core driver simple because the only realtime work really required is
+the bottom half interrupt handler and the output overlapping.
+
+Exposing some sort of clean aio api to userspace would be perfect. What that
+API looks like? Gah. beats me.

drivers/staging/frontier/TODO

+TODO:
+	- checkpatch.pl clean
+	- sparse clean
+	- fix userspace interface to be sane
+	- possibly just port to userspace with libusb
+	- review by the USB developer community
+
+Please send any patches for this driver to Greg Kroah-Hartman <greg@kroah.com>
+and David Taht <d@teklibre.com>.

drivers/staging/frontier/alphatrack.h

+#define show_set_bit(a) show_set_mbit(alphatrack,a)
+#define show_set_cmd(a) show_set_mcmd(alphatrack,a)
+#define show_set_int(a) show_set_mint(alphatrack,a)
+#define show_set_char(a) show_set_mchar(alphatrack,a)
+#define show_set_light(a) show_set_ebit(alphatrack,LightID,lights,a)
+#define show_set_button(a) show_set_ebit(alphatrack,ButtonID,button,a)
+
+struct alphatrack_icmd {
+    unsigned char cmd[12];
+};
+
+struct alphatrack_ocmd {
+    unsigned char cmd[8];
+};
+
+enum LightID {
+        LIGHT_EQ = 0,
+        LIGHT_OUT,
+        LIGHT_F2,
+        LIGHT_SEND,
+        LIGHT_IN,
+        LIGHT_F1,
+        LIGHT_PAN,
+        LIGHT_UNDEF1,
+        LIGHT_UNDEF2,
+        LIGHT_SHIFT,
+        LIGHT_TRACKMUTE,
+        LIGHT_TRACKSOLO,
+        LIGHT_TRACKREC,
+        LIGHT_READ,
+        LIGHT_WRITE,
+        LIGHT_ANYSOLO,
+        LIGHT_AUTO,
+        LIGHT_F4,
+        LIGHT_RECORD,
+        LIGHT_WINDOW,
+        LIGHT_PLUGIN,
+        LIGHT_F3,
+        LIGHT_LOOP
+};
+
+static const char *Lightname[] = { "eq",
+"out",
+"f2",
+"send",
+"in",
+"f1",
+"pan",
+"undef1",
+"undef2",
+"shift",
+"mute",
+"tracksolo",
+"trackrec",
+"read",
+"write",
+"anysolo",
+"auto",
+"f4",
+"record",
+"window",
+"plugin",
+"f3",
+"loop",
+NULL };
+
+#define BUTTONMASK_BATTERY     0x00004000
+#define BUTTONMASK_BACKLIGHT   0x00008000
+#define BUTTONMASK_FASTFORWARD 0x04000000
+#define BUTTONMASK_TRACKMUTE   0x00040000
+#define BUTTONMASK_TRACKSOLO   0x00800000
+#define BUTTONMASK_TRACKLEFT   0x80000000
+#define BUTTONMASK_RECORD      0x02000000
+#define BUTTONMASK_SHIFT       0x20000000
+#define BUTTONMASK_PUNCH       0x00800000
+#define BUTTONMASK_TRACKRIGHT  0x00020000
+#define BUTTONMASK_REWIND      0x01000000
+#define BUTTONMASK_STOP        0x10000000
+#define BUTTONMASK_LOOP        0x00010000
+#define BUTTONMASK_TRACKREC    0x00001000
+#define BUTTONMASK_PLAY        0x08000000
+#define BUTTONMASK_TOUCH1      0x00000008
+#define BUTTONMASK_TOUCH2      0x00000010
+#define BUTTONMASK_TOUCH3      0x00000020
+
+#define BUTTONMASK_PRESS1      0x00000009
+#define BUTTONMASK_PRESS2      0x00008010
+#define BUTTONMASK_PRESS3      0x00002020
+
+// last 3 bytes are the slider position
+// 40 is the actual slider moving, the most sig bits, and 3 lsb
+
+#define BUTTONMASK_FLIP         0x40000000
+#define BUTTONMASK_F1           0x00100000
+#define BUTTONMASK_F2           0x00400000
+#define BUTTONMASK_F3           0x00200000
+#define BUTTONMASK_F4           0x00080000
+#define BUTTONMASK_PAN          0x00000200
+#define BUTTONMASK_SEND         0x00000800
+#define BUTTONMASK_EQ           0x00004000
+#define BUTTONMASK_PLUGIN       0x00000400
+#define BUTTONMASK_AUTO         0x00000100
+
+
+// #define BUTTONMASK_FOOTSWITCH FIXME
+
+// Lookup. name. midi out. midi in.
+
+struct buttonmap_t {
+	u32 mask;
+	short midi_in;
+	short midi_out;
+	char *name;
+//  	void (*function) (buttonmap_t *);
+  	void (*function) (void);
+};
+

drivers/staging/frontier/alphatrack_sysfs.c

+/* This was an attempt - ultimately proved pointless - at making a full fledged sysfs interface to the alphatrack */
+/* won't even compile at present */
+
+char *alphatrack_sys_margs;
+spinlock_t alphatrack_sys_margs_lock;
+
+struct alphatrack_attr {
+        struct attribute attr;
+        ssize_t (*show)(struct device *, char *);
+        ssize_t (*store)(struct device *, const char *, size_t);
+};
+
+#define ALPHATRACK_ATTR(name, mode, show, store) \
+static struct alphatrack_attr alphatrack_attr_##name = __ATTR(name, mode, show, store)
+
+/* now a great deal of callback code generation */
+
+// FOREACH_LIGHT(show_set_light)
+// FOREACH_BUTTON(show_set_button)
+
+show_set_light(LIGHT_RECORD); show_set_light(LIGHT_EQ); show_set_light(LIGHT_OUT);
+show_set_light(LIGHT_F2); show_set_light(LIGHT_SEND);   show_set_light(LIGHT_IN);
+show_set_light(LIGHT_F1); show_set_light(LIGHT_PAN);    show_set_light(LIGHT_UNDEF1);
+show_set_light(LIGHT_UNDEF2); show_set_light(LIGHT_SHIFT); show_set_light(LIGHT_TRACKMUTE);
+show_set_light(LIGHT_TRACKSOLO); show_set_light(LIGHT_TRACKREC); show_set_light(LIGHT_READ);
+show_set_light(LIGHT_WRITE); show_set_light(LIGHT_ANYSOLO); show_set_light(LIGHT_AUTO);
+show_set_light(LIGHT_F4); show_set_light(LIGHT_RECORD); show_set_light(LIGHT_WINDOW);
+show_set_light(LIGHT_PLUGIN); show_set_light(LIGHT_F3); show_set_light(LIGHT_LOOP);
+
+show_set_opt(enable); show_set_opt(offline); show_set_opt(compress_fader); show_set_opt(dump_state);
+show_set_int(fader); show_set_int(event);
+
+
+static ssize_t show_lights(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_alphatrack *t = usb_get_intfdata(intf);
+	return sprintf(buf, "%d\n", t->lights);
+}
+
+static ssize_t set_lights(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_alphatrack *t = usb_get_intfdata(intf);
+	int temp = simple_strtoul(buf, NULL, 10);
+	t->lights = temp;
+	return count;
+}
+
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_lights, set_lights);
+
+
+ALPHATRACK_ATTR(LightRecord, 0200, NULL,          LightRecord_store);
+
+static struct attribute *alphatrack_attrs[] = {
+        &alphatrack_attr_LightRecord.attr,
+        NULL,
+};
+
+static ssize_t alphatrack_attr_show(struct kobject *kobj, struct attribute *attr,
+                              char *buf)
+{
+        struct device *sdp = container_of(kobj, struct device, kobj);
+        struct alphatrack_attr *a = container_of(attr, struct alphatrack_attr, attr);
+        return a->show ? a->show(sdp, buf) : 0;
+}
+
+static ssize_t alphatrack_attr_store(struct kobject *kobj, struct attribute *attr,
+                               const char *buf, size_t len)
+{
+        struct device *sdp = container_of(kobj, struct device, kobj);
+        struct alphatrack_attr *a = container_of(attr, struct alphatrack_attr, attr);
+        return a->store ? a->store(sdp, buf, len) : len;
+}
+
+static struct sysfs_ops alphatrack_attr_ops = {
+        .show  = alphatrack_attr_show,
+        .store = alphatrack_attr_store,
+};
+
+static struct kobj_type alphatrack_ktype = {
+        .default_attrs = alphatrack_attrs,
+        .sysfs_ops     = &alphatrack_attr_ops,
+};
+
+static struct kset alphatrack_kset = {
+        .subsys = &fs_subsys,
+        .kobj   = {.name = "alphatrack"},
+        .ktype  = &alphatrack_ktype,
+};
+
+
+static struct attribute *lights_attrs[] = {
+        &tune_attr_demote_secs.attr,
+        NULL,
+};
+
+
+static struct attribute_group leds_group = {
+        .name = "leds",
+        .attrs = lights_attrs,
+};
+
+static struct attribute_group faders_group = {
+        .name = "faders",
+        .attrs = faders_attrs,
+};
+
+static struct attribute_group lcds_group = {
+        .name = "lcds",
+        .attrs = lcds_attrs,
+};
+
+static struct attribute_group wheels_group = {
+        .name = "wheels",
+        .attrs = wheels_attrs,
+};
+
+static struct attribute_group touchsurfaces_group = {
+        .name = "touchsurfaces",
+        .attrs = touchsurfaces_attrs,
+};
+
+static struct attribute_group buttons_group = {
+        .name = "buttons",
+        .attrs = buttons_attrs,
+};
+
+
+int alphatrack_sys_fs_add(struct device *sdp)
+{
+        int error;
+
+        sdp->kobj.kset = &alphatrack_kset;
+        sdp->kobj.ktype = &alphatrack_ktype;
+
+//        error = kobject_set_name(&sdp->kobj, "%s", sdp->sd_table_name);
+        error = kobject_set_name(&sdp->kobj, "%s", "alphatrack");
+        if (error)
+                goto fail;
+
+        error = kobject_register(&sdp->kobj);
+        if (error)
+                goto fail;
+
+        error = sysfs_create_group(&sdp->kobj, &lcds_group);
+        if (error)
+                goto fail_reg;
+
+        error = sysfs_create_group(&sdp->kobj, &leds_group);
+        if (error)
+                goto fail_leds;
+
+        error = sysfs_create_group(&sdp->kobj, &wheels_group);
+        if (error)
+                goto fail_wheels;
+
+      error = sysfs_create_group(&sdp->kobj, &faders_group);
+        if (error)
+                goto fail_lcds;
+
+        error = sysfs_create_group(&sdp->kobj, &buttons_group);
+        if (error)
+                goto fail_faders;
+
+        error = sysfs_create_group(&sdp->kobj, &touchsurfaces_group);
+        if (error)
+                goto fail_buttons;
+
+        return 0;
+
+
+fail_buttons:
+        sysfs_remove_group(&sdp->kobj, &buttons_group);
+fail_faders:
+        sysfs_remove_group(&sdp->kobj, &faders_group);
+fail_wheels:
+        sysfs_remove_group(&sdp->kobj, &wheels_group);
+fail_lcds:
+        sysfs_remove_group(&sdp->kobj, &lcds_group);
+fail_leds:
+        sysfs_remove_group(&sdp->kobj, &leds_group);
+
+
+
+fail_reg:
+        kobject_unregister(&sdp->kobj);
+fail:
+        fs_err(sdp, "error %d adding sysfs files", error);
+        return error;
+}
+
+// int sysfs_create_link(struct kobject *kobj,
+//			  struct kobject *target,
+//			  char *name);
+
+void alphatrack_sys_fs_del(struct device *sdp)
+{
+        sysfs_remove_group(&sdp->kobj, &touchsurfaces_group);
+        sysfs_remove_group(&sdp->kobj, &buttons_group);
+        sysfs_remove_group(&sdp->kobj, &faders_group);
+        sysfs_remove_group(&sdp->kobj, &lcds_group);
+        sysfs_remove_group(&sdp->kobj, &wheels_group);
+        sysfs_remove_group(&sdp->kobj, &leds_group)
+//void sysfs_remove_link(struct kobject *kobj, char *name);
+					kobject_unregister(&sdp->kobj);
+}
+
+int alphatrack_sys_init(void)
+{
+        alphatrack_sys_margs = NULL;
+        spin_lock_init(&alphatrack_sys_margs_lock);
+        return kset_register(&alphatrack_kset);
+}
+
+void alphatrack_sys_uninit(void)
+{
+        kfree(alphatrack_sys_margs);
+        kset_unregister(&alphatrack_kset);
+}
+
+
+//decl_subsys(char *name, struct kobj_type *type,
+//                struct kset_hotplug_ops *hotplug_ops);
+
+/* End of all the crazy sysfs stuff */
+
+#define SYSEX_INQUIRE signed char *SYSEX_INQUIRE[] = { 0xf0,0x7e,0x00,0x06,0x01,0x17 };
+
+#define COMMAND(NAME,CONT_NAME)  { BUTTONMASK_##NAME, ((0x90 << 8) | CONT_NAME), ((0x90 << 8) | CONT_NAME), #NAME, NAME ## _set }
+#define ROTARY(NAME,CONT_NAME)  { FADER_##NAME, ((0xb0 << 8) | CONT_NAME), ((0xb0 << 8) | CONT_NAME), #NAME, NAME ## _set }
+#define SPOSITION(NAME,CONT_NAME)  { BUTTON_##NAME ((0xe9 << 8) | CONT_NAME), #NAME, NAME ## _set }
+#define ENDCOMMAND { 0,NULL,0,NULL,NULL}
+
+/* Now that we've generated all our callbacks */
+
+static struct buttonmap_t buttonmap[] =
+     {
+       COMMAND (REWIND,0x5b),
+       COMMAND (FASTFORWARD,0x5c),
+       COMMAND (STOP,0x5d),
+       COMMAND (PLAY,0x5e),
+       COMMAND (RECORD,0x5f),
+       COMMAND (SHIFT,0x46),
+       COMMAND (TRACKLEFT,0x57),
+       COMMAND (TRACKRIGHT,0x58),
+       COMMAND (LOOP,0x56),
+       COMMAND (FLIP,0x32),
+       COMMAND (MUTE,0x10),
+       COMMAND (F1,0x36),
+       COMMAND (F2,0x37),
+       COMMAND (F3,0x38),
+       COMMAND (F4,0x39),
+       COMMAND (SOLO,0x08),
+       COMMAND (ANY,0x73),
+       COMMAND (PAN,0x2a),
+       COMMAND (SEND,0x29),
+       COMMAND (EQ,0x2c),
+       COMMAND (PLUGIN,0x2b),
+       COMMAND (AUTO,0x4a),
+       COMMAND (TRACKREC,0x00),
+       COMMAND (FOOTSWITCH1,0x67),
+       COMMAND (KNOBTOUCH1,0x78),
+       COMMAND (KNOBPUSH1,0x20),
+       ROTARY  (KNOBTURN1,0x10),
+       COMMAND (KNOBTOUCH2,0x79),
+       COMMAND (KNOBPUSH2,0x21),
+       ROTARY  (KNOBTURN2,0x11),
+       COMMAND (KNOBTOUCH3,0x7a),
+       COMMAND (KNOBPUSH3,0x22),
+       ROTARY  (KNOBTURN3,0x12),
+       COMMAND (FADERTOUCH1,0x68),
+       COMMAND (STRIPTOUCH1,0x74),
+       COMMAND (STRIPTOUCH2,0x6b),
+       SPOSITION (STRIPPOS1,0x00),
+       ENDCOMMAND
+     };
+
+

drivers/staging/frontier/frontier_compat.h

+/* USB defines for older kernels */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
+
+/**
+ * usb_endpoint_dir_out - check if the endpoint has OUT direction
+ * @epd: endpoint to be checked
+ *
+ * Returns true if the endpoint is of type OUT, otherwise it returns false.
+ */
+
+static inline int usb_endpoint_dir_out(const struct usb_endpoint_descriptor *epd)
+{
+       return ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
+}
+
+static inline int usb_endpoint_dir_in(const struct usb_endpoint_descriptor *epd)
+{
+       return ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN);
+}
+
+
+/**
+ * usb_endpoint_xfer_int - check if the endpoint has interrupt transfer type
+ * @epd: endpoint to be checked
+ *
+ * Returns true if the endpoint is of type interrupt, otherwise it returns
+ * false.
+ */
+static inline int usb_endpoint_xfer_int(const struct usb_endpoint_descriptor *epd)
+{
+       return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+               USB_ENDPOINT_XFER_INT);
+}
+
+
+/**
+ * usb_endpoint_is_int_in - check if the endpoint is interrupt IN
+ * @epd: endpoint to be checked
+ *
+ * Returns true if the endpoint has interrupt transfer type and IN direction,
+ * otherwise it returns false.
+ */
+
+static inline int usb_endpoint_is_int_in(const struct usb_endpoint_descriptor *epd)
+{
+       return (usb_endpoint_xfer_int(epd) && usb_endpoint_dir_in(epd));
+}
+
+/**
+ * usb_endpoint_is_int_out - check if the endpoint is interrupt OUT
+ * @epd: endpoint to be checked
+ *
+ * Returns true if the endpoint has interrupt transfer type and OUT direction,
+ * otherwise it returns false.
+ */
+
+static inline int usb_endpoint_is_int_out(const struct usb_endpoint_descriptor *epd)
+{
+       return (usb_endpoint_xfer_int(epd) && usb_endpoint_dir_out(epd));
+}
+
+#endif /* older kernel versions */

drivers/staging/frontier/surface_sysfs.h

+/* If you are going to abuse the preprocessor, why not ABUSE the preprocessor?
+   I stuck this header in a separate file so I don't have to look at it */
+
+// FIXME Need locking or atomic ops
+
+#define show_set_mbit(dname,value,bit)																			\
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = (1 && (t->value & (1 << bit)));					\
+	return sprintf(buf, "%d\n", temp);			\
+}									\
+static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = simple_strtoul(buf, NULL, 10);			\
+	if(temp > 0) { long b = 1 << bit; t->value |= b; } \
+	else { long b = ~(1 << bit); t->value &= b ;				 \
+	return count;							\
+}									\
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
+
+#define show_set_ebit(dname,enumname,value,bit)																			\
+static ssize_t show_##bit(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+  enum enumname l = bit; \
+  int temp = t->value & (1 << l);						\
+	return sprintf(buf, "%d\n", temp);			\
+}									\
+static ssize_t set_##bit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = simple_strtoul(buf, NULL, 10);			\
+  enum enumname l = bit;\
+	long b  = 1 << l; \
+	if(temp > 0) { t->value |= b; }	\
+	else { t->value &= ~b ;				\
+	return count;							\
+}									\
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
+
+// FIXME FOR CORRECTLY SETTING HEX from a string
+#define show_set_mcmd(dname,value)																			\
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+  int count = 0;\
+	int i; \
+	for (i = 0,i<sizeof(dname); i++) count += snprintf(buf, "%02x",t->dname[i]); \
+  return(count);\
+}									\
+static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = simple_strtoul(buf, NULL, 10);			\
+	t->value = temp;						\
+	return count;							\
+}									\
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
+
+#define show_set_mint(dname,value)				\
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	return sprintf(buf, "%d\n", t->value);			\
+}									\
+static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = simple_strtoul(buf, NULL, 10);			\
+	t->value = temp;						\
+	return count;							\
+}									\
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
+
+#define show_set_mchar(dname,value)																				\
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	return sprintf(buf, "%c\n", t->value);			\
+}									\
+static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct usb_interface *intf = to_usb_interface(dev);		\
+	struct usb_##dname *t = usb_get_intfdata(intf);			\
+	int temp = simple_strtoul(buf, NULL, 10);			\
+	t->value = temp;						\
+	return count;							\
+}									\
+static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);