Input: wacom - add Intuos4 LED and OLED control

This commit enables control of the LEDs and OLED displays found on the
Wacom Intuos4 M, L, and XL. For this purpose, a new "wacom_led" attribute
group is added to the sysfs entry of the USB device.

This "wacom_led" group only shows up when the correct device (M, L, or XL)
is detected. The attributes are described in
Documentation/ABI/testing/sysfs-wacom

Signed-off-by: Eduard Hasenleithner <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/ABI/testing/sysfs-driver-wacom

···
+What:		/sys/class/hidraw/hidraw*/device/speed
+Date:		April 2010
+Kernel Version:	2.6.35
+Contact:	[e-mail]
+Description:
+		The /sys/class/hidraw/hidraw*/device/speed file controls
+		reporting speed of Wacom bluetooth tablet. Reading from
+		this file returns 1 if tablet reports in high speed mode
+		or 0 otherwise. Writing to this file one of these values
+		switches reporting speed.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/led
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		Attribute group for control of the status LEDs and the OLED
+		displays found on the Wacom Intuos 4 M, L, and XL tablets. This
+		attribute group is not available for other Wacom tablets.
+		Therefore its presence implicitly signifies the presence of
+		said LEDs and OLED displays on the tablet device.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status0_luminance
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		Writing to this file sets the status LED luminance (0..127)
+		when the stylus does not touch the tablet surface, and no
+		button is pressed on the stylus.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status1_luminance
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		Writing to this file sets the status LED luminance (0..127)
+		when the stylus touches the tablet surface, or any button is
+		pressed on the stylus.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status_led_select
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		Writing to this file sets which one of the four status LEDs is
+		active (0..3). The other three LEDs are always inactive.  By
+		means of specifying "-1" it is possible to set all status LEDs
+		to inactive.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/buttons_luminance
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		Writing to this file sets the overall luminance level (0..15)
+		of all eight button OLED displays.
+
+What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/button<n>_rawimg
+Date:		August 2011
+Contact:	[e-mail]
+Description:
+		When writing a 1024 byte raw image in Wacom Intuos 4
+		interleaving format to the file, the image shows up on Button N
+		of the device. The image is a 64x32 pixel 4-bit gray image. The
+		1024 byte binary is split up into 16x 64 byte chunks. Each 64
+		byte chunk encodes the image data for two consecutive lines on
+		the display. The low nibble of each byte contains the first
+		line, and the high nibble contains the second line.

Documentation/ABI/testing/sysfs-wacom

···
-What:		/sys/class/hidraw/hidraw*/device/speed
-Date:		April 2010
-Kernel Version:	2.6.35
-Contact:	[e-mail]
-Description:
-		The /sys/class/hidraw/hidraw*/device/speed file controls
-		reporting speed of wacom bluetooth tablet. Reading from
-		this file returns 1 if tablet reports in high speed mode
-		or 0 otherwise. Writing to this file one of these values
-		switches reporting speed.

drivers/input/tablet/wacom.h

···
 	struct mutex lock;
 	bool open;
 	char phys[32];
+	struct wacom_led {
+		u8 select; /* status led selector (0..3, -1=none) */
+		u8 llv;    /* status led brightness no button */
+		u8 hlv;    /* status led brightness button pressed */
+		u8 img_lum;   /* OLED matrix display brightness */
+	} led;
 };
 
 extern const struct usb_device_id wacom_ids[];

drivers/input/tablet/wacom_sys.c

···
 /* defines to get/set USB message */
 #define USB_REQ_GET_REPORT	0x01
 #define USB_REQ_SET_REPORT	0x09
+
 #define WAC_HID_FEATURE_REPORT	0x03
 #define WAC_MSG_RETRIES		5
 
-static int usb_get_report(struct usb_interface *intf, unsigned char type,
-				unsigned char id, void *buf, int size)
+#define WAC_CMD_LED_CONTROL	0x20
+#define WAC_CMD_ICON_START	0x21
+#define WAC_CMD_ICON_XFER	0x23
+#define WAC_CMD_RETRIES		10
+
+static int wacom_get_report(struct usb_interface *intf, u8 type, u8 id,
+			    void *buf, size_t size, unsigned int retries)
 {
-	return usb_control_msg(interface_to_usbdev(intf),
-		usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
-		USB_REQ_GET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
-		(type << 8) + id, intf->altsetting[0].desc.bInterfaceNumber,
-		buf, size, 100);
+	struct usb_device *dev = interface_to_usbdev(intf);
+	int retval;
+
+	do {
+		retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+				USB_REQ_GET_REPORT,
+				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				(type << 8) + id,
+				intf->altsetting[0].desc.bInterfaceNumber,
+				buf, size, 100);
+	} while ((retval == -ETIMEDOUT || retval == -EPIPE) && --retries);
+
+	return retval;
 }
 
-static int usb_set_report(struct usb_interface *intf, unsigned char type,
-				unsigned char id, void *buf, int size)
+static int wacom_set_report(struct usb_interface *intf, u8 type, u8 id,
+			    void *buf, size_t size, unsigned int retries)
 {
-	return usb_control_msg(interface_to_usbdev(intf),
-		usb_sndctrlpipe(interface_to_usbdev(intf), 0),
-                USB_REQ_SET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
-                (type << 8) + id, intf->altsetting[0].desc.bInterfaceNumber,
-		buf, size, 1000);
+	struct usb_device *dev = interface_to_usbdev(intf);
+	int retval;
+
+	do {
+		retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+				USB_REQ_SET_REPORT,
+				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				(type << 8) + id,
+				intf->altsetting[0].desc.bInterfaceNumber,
+				buf, size, 1000);
+	} while ((retval == -ETIMEDOUT || retval == -EPIPE) && --retries);
+
+	return retval;
 }
 
 static void wacom_sys_irq(struct urb *urb)
···
 			rep_data[2] = 0;
 			rep_data[3] = 0;
 			report_id = 3;
-			error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
-				report_id, rep_data, 4);
+			error = wacom_set_report(intf, WAC_HID_FEATURE_REPORT,
+						 report_id, rep_data, 4, 1);
 			if (error >= 0)
-				error = usb_get_report(intf,
-					WAC_HID_FEATURE_REPORT, report_id,
-					rep_data, 4);
+				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 != TABLETPC) {
 		do {
 			rep_data[0] = 2;
 			rep_data[1] = 2;
-			error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
-				report_id, rep_data, 2);
+			error = wacom_set_report(intf, WAC_HID_FEATURE_REPORT,
+						 report_id, rep_data, 2, 1);
 			if (error >= 0)
-				error = usb_get_report(intf,
-					WAC_HID_FEATURE_REPORT, report_id,
-					rep_data, 2);
+				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);
 	}
 
···
 	}
 }
 
+static int wacom_led_control(struct wacom *wacom)
+{
+	unsigned char *buf;
+	int retval;
+
+	buf = kzalloc(9, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	buf[0] = WAC_CMD_LED_CONTROL;
+	buf[1] = wacom->led.select >= 0 ? wacom->led.select | 4 : 0;
+	buf[2] = wacom->led.llv;
+	buf[3] = wacom->led.hlv;
+	buf[4] = wacom->led.img_lum;
+
+	retval = wacom_set_report(wacom->intf, 0x03, WAC_CMD_LED_CONTROL,
+				  buf, 9, WAC_CMD_RETRIES);
+	kfree(buf);
+
+	return retval;
+}
+
+static int wacom_led_putimage(struct wacom *wacom, int button_id, const void *img)
+{
+	unsigned char *buf;
+	int i, retval;
+
+	buf = kzalloc(259, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Send 'start' command */
+	buf[0] = WAC_CMD_ICON_START;
+	buf[1] = 1;
+	retval = wacom_set_report(wacom->intf, 0x03, WAC_CMD_ICON_START,
+				  buf, 2, WAC_CMD_RETRIES);
+	if (retval < 0)
+		goto out;
+
+	buf[0] = WAC_CMD_ICON_XFER;
+	buf[1] = button_id & 0x07;
+	for (i = 0; i < 4; i++) {
+		buf[2] = i;
+		memcpy(buf + 3, img + i * 256, 256);
+
+		retval = wacom_set_report(wacom->intf, 0x03, WAC_CMD_ICON_XFER,
+					  buf, 259, WAC_CMD_RETRIES);
+		if (retval < 0)
+			break;
+	}
+
+	/* Send 'stop' */
+	buf[0] = WAC_CMD_ICON_START;
+	buf[1] = 0;
+	wacom_set_report(wacom->intf, 0x03, WAC_CMD_ICON_START,
+			 buf, 2, WAC_CMD_RETRIES);
+
+out:
+	kfree(buf);
+	return retval;
+}
+
+static ssize_t wacom_led_select_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct wacom *wacom = dev_get_drvdata(dev);
+	unsigned int id;
+	int err;
+
+	err = kstrtouint(buf, 10, &id);
+	if (err)
+		return err;
+
+	mutex_lock(&wacom->lock);
+
+	wacom->led.select = id;
+	err = wacom_led_control(wacom);
+
+	mutex_unlock(&wacom->lock);
+
+	return err < 0 ? err : count;
+}
+
+static DEVICE_ATTR(status_led_select, S_IWUSR, NULL, wacom_led_select_store);
+
+static ssize_t wacom_luminance_store(struct wacom *wacom, u8 *dest,
+				     const char *buf, size_t count)
+{
+	unsigned int value;
+	int err;
+
+	err = kstrtouint(buf, 10, &value);
+	if (err)
+		return err;
+
+	mutex_lock(&wacom->lock);
+
+	*dest = value & 0x7f;
+	err = wacom_led_control(wacom);
+
+	mutex_unlock(&wacom->lock);
+
+	return err < 0 ? err : count;
+}
+
+#define DEVICE_LUMINANCE_ATTR(name, field)				\
+static ssize_t wacom_##name##_luminance_store(struct device *dev,	\
+	struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct wacom *wacom = dev_get_drvdata(dev);			\
+									\
+	return wacom_luminance_store(wacom, &wacom->led.field,		\
+				     buf, count);			\
+}									\
+static DEVICE_ATTR(name##_luminance, S_IWUSR,				\
+		   NULL, wacom_##name##_luminance_store)
+
+DEVICE_LUMINANCE_ATTR(status0, llv);
+DEVICE_LUMINANCE_ATTR(status1, hlv);
+DEVICE_LUMINANCE_ATTR(buttons, img_lum);
+
+static ssize_t wacom_button_image_store(struct device *dev, int button_id,
+					const char *buf, size_t count)
+{
+	struct wacom *wacom = dev_get_drvdata(dev);
+	int err;
+
+	if (count != 1024)
+		return -EINVAL;
+
+	mutex_lock(&wacom->lock);
+
+	err = wacom_led_putimage(wacom, button_id, buf);
+
+	mutex_unlock(&wacom->lock);
+
+	return err < 0 ? err : count;
+}
+
+#define DEVICE_BTNIMG_ATTR(BUTTON_ID)					\
+static ssize_t wacom_btnimg##BUTTON_ID##_store(struct device *dev,	\
+	struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	return wacom_button_image_store(dev, BUTTON_ID, buf, count);	\
+}									\
+static DEVICE_ATTR(button##BUTTON_ID##_rawimg, S_IWUSR,			\
+		   NULL, wacom_btnimg##BUTTON_ID##_store)
+
+DEVICE_BTNIMG_ATTR(0);
+DEVICE_BTNIMG_ATTR(1);
+DEVICE_BTNIMG_ATTR(2);
+DEVICE_BTNIMG_ATTR(3);
+DEVICE_BTNIMG_ATTR(4);
+DEVICE_BTNIMG_ATTR(5);
+DEVICE_BTNIMG_ATTR(6);
+DEVICE_BTNIMG_ATTR(7);
+
+static struct attribute *wacom_led_attrs[] = {
+	&dev_attr_status0_luminance.attr,
+	&dev_attr_status1_luminance.attr,
+	&dev_attr_status_led_select.attr,
+	&dev_attr_buttons_luminance.attr,
+	&dev_attr_button0_rawimg.attr,
+	&dev_attr_button1_rawimg.attr,
+	&dev_attr_button2_rawimg.attr,
+	&dev_attr_button3_rawimg.attr,
+	&dev_attr_button4_rawimg.attr,
+	&dev_attr_button5_rawimg.attr,
+	&dev_attr_button6_rawimg.attr,
+	&dev_attr_button7_rawimg.attr,
+	NULL
+};
+
+static struct attribute_group wacom_led_attr_group = {
+	.name = "wacom_led",
+	.attrs = wacom_led_attrs,
+};
+
+static int wacom_initialize_leds(struct wacom *wacom)
+{
+	int error;
+
+	if (wacom->wacom_wac.features.type >= INTUOS4 &&
+	    wacom->wacom_wac.features.type <= INTUOS4L) {
+
+		/* Initialize default values */
+		wacom->led.select = 0;
+		wacom->led.llv = 30;
+		wacom->led.hlv = 20;
+		wacom->led.img_lum = 10;
+		wacom_led_control(wacom);
+
+		error = sysfs_create_group(&wacom->intf->dev.kobj,
+					   &wacom_led_attr_group);
+		if (error) {
+			dev_err(&wacom->intf->dev,
+				"cannot create sysfs group err: %d\n", error);
+			return error;
+		}
+	}
+
+	return 0;
+}
+
+static void wacom_destroy_leds(struct wacom *wacom)
+{
+	if (wacom->wacom_wac.features.type >= INTUOS4 &&
+	    wacom->wacom_wac.features.type <= INTUOS4L) {
+		sysfs_remove_group(&wacom->intf->dev.kobj,
+				   &wacom_led_attr_group);
+	}
+}
+
 static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct usb_device *dev = interface_to_usbdev(intf);
···
 	wacom->irq->transfer_dma = wacom->data_dma;
 	wacom->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
-	error = input_register_device(input_dev);
+	error = wacom_initialize_leds(wacom);
 	if (error)
 		goto fail4;
+
+	error = input_register_device(input_dev);
+	if (error)
+		goto fail5;
 
 	/* Note that if query fails it is not a hard failure */
 	wacom_query_tablet_data(intf, features);
···
 	usb_set_intfdata(intf, wacom);
 	return 0;
 
+ fail5: wacom_destroy_leds(wacom);
  fail4:	wacom_remove_shared_data(wacom_wac);
  fail3:	usb_free_urb(wacom->irq);
  fail2:	usb_free_coherent(dev, WACOM_PKGLEN_MAX, wacom_wac->data, wacom->data_dma);
···
 
 	usb_kill_urb(wacom->irq);
 	input_unregister_device(wacom->wacom_wac.input);
+	wacom_destroy_leds(wacom);
 	usb_free_urb(wacom->irq);
 	usb_free_coherent(interface_to_usbdev(intf), WACOM_PKGLEN_MAX,
 			wacom->wacom_wac.data, wacom->data_dma);
···
 {
 	struct wacom *wacom = usb_get_intfdata(intf);
 	struct wacom_features *features = &wacom->wacom_wac.features;
-	int rv;
+	int rv = 0;
 
 	mutex_lock(&wacom->lock);
 
 	/* switch to wacom mode first */
 	wacom_query_tablet_data(intf, features);
+	wacom_led_control(wacom);
 
-	if (wacom->open)
-		rv = usb_submit_urb(wacom->irq, GFP_NOIO);
-	else
-		rv = 0;
+	if (wacom->open && usb_submit_urb(wacom->irq, GFP_NOIO) < 0)
+		rv = -EIO;
 
 	mutex_unlock(&wacom->lock);