HID: wacom: Add LED selector control for Wacom Intuos4 WL

Add sysfs attribute to control LED selector on Wacom Intuos4. There are 4
different LEDs on the tablet and they can be turned on by something like:

echo 50 > /sys/class/leds/(device # here)\:selector\:1/brightness

Only one can be lit at a time. The brightness range is 0 to 127. This patch
also contains short ABI description.

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/Documentation/ABI/testing/sysfs-driver-wacom b/Documentation/ABI/testing/sysfs-driver-wacom
index 0130d6683c14eecf01c3a9b6226aec0549487a81..56c54558c8a48e2163015b441f21aeecf58f950a 100644 (file)
--- a/Documentation/ABI/testing/sysfs-driver-wacom
+++ b/Documentation/ABI/testing/sysfs-driver-wacom
@@ -9,6 +9,14 @@ Description:
                or 0 otherwise. Writing to this file one of these values
                switches reporting speed.
 
+What:          /sys/class/leds/0005\:056A\:00BD.0001\:selector\:*/
+Date:          May 2012
+Kernel Version:        3.5
+Contact:       linux-bluetooth@vger.kernel.org
+Description:
+               LED selector for Intuos4 WL. There are 4 leds, but only one LED
+               can be lit at a time. Max brightness is 127.
+
 What:          /sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/led
 Date:          August 2011
 Contact:       linux-input@vger.kernel.org

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4ecc25629a45bda26a30d92ba532d9dd266e44b1..6e0d65aca3087eb23b72d7aaa22ef6e559f99f2d 100644 (file)
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -596,6 +596,7 @@ config HID_WACOM
        tristate "Wacom Bluetooth devices support"
        depends on BT_HIDP
        select POWER_SUPPLY
+       select LEDS_CLASS
        ---help---
        Support for Wacom Graphire Bluetooth and Intuos4 WL tablets.
 

diff --git a/drivers/hid/hid-wacom.c b/drivers/hid/hid-wacom.c
index a66e1aa25caca3003b107416db4e3dffb0e45d56..29372edc31c0fdebefc54317020aba4ce7e01c69 100644 (file)
--- a/drivers/hid/hid-wacom.c
+++ b/drivers/hid/hid-wacom.c
@@ -24,6 +24,7 @@
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
+#include <linux/leds.h>
 #include <linux/slab.h>
 #include <linux/power_supply.h>
 
@@ -31,6 +32,8 @@
 
 #define PAD_DEVICE_ID  0x0F
 
+#define WAC_CMD_LED_CONTROL     0x20
+
 struct wacom_data {
        __u16 tool;
        __u16 butstate;
@@ -44,6 +47,8 @@ struct wacom_data {
        __u8 ps_connected;
        struct power_supply battery;
        struct power_supply ac;
+       __u8 led_selector;
+       struct led_classdev *leds[4];
 };
 
 /*percent of battery capacity for Graphire
@@ -64,6 +69,117 @@ static enum power_supply_property wacom_ac_props[] = {
        POWER_SUPPLY_PROP_SCOPE,
 };
 
+static void wacom_leds_set_brightness(struct led_classdev *led_dev,
+                                               enum led_brightness value)
+{
+       struct device *dev = led_dev->dev->parent;
+       struct hid_device *hdev;
+       struct wacom_data *wdata;
+       unsigned char *buf;
+       __u8 led = 0;
+       int i;
+
+       hdev = container_of(dev, struct hid_device, dev);
+       wdata = hid_get_drvdata(hdev);
+       for (i = 0; i < 4; ++i) {
+               if (wdata->leds[i] == led_dev)
+                       wdata->led_selector = i;
+       }
+
+       led = wdata->led_selector | 0x04;
+       buf = kzalloc(9, GFP_KERNEL);
+       if (buf) {
+               buf[0] = WAC_CMD_LED_CONTROL;
+               buf[1] = led;
+               buf[2] = value;
+               hdev->hid_output_raw_report(hdev, buf, 9, HID_FEATURE_REPORT);
+               kfree(buf);
+       }
+
+       return;
+}
+
+static enum led_brightness wacom_leds_get_brightness(struct led_classdev *led_dev)
+{
+       struct wacom_data *wdata;
+       struct device *dev = led_dev->dev->parent;
+       int value = 0;
+       int i;
+
+       wdata = hid_get_drvdata(container_of(dev, struct hid_device, dev));
+
+       for (i = 0; i < 4; ++i) {
+               if (wdata->leds[i] == led_dev) {
+                       value = wdata->leds[i]->brightness;
+                       break;
+               }
+       }
+
+       return value;
+}
+
+
+static int wacom_initialize_leds(struct hid_device *hdev)
+{
+       struct wacom_data *wdata = hid_get_drvdata(hdev);
+       struct led_classdev *led;
+       struct device *dev = &hdev->dev;
+       size_t namesz = strlen(dev_name(dev)) + 12;
+       char *name;
+       int i, ret;
+
+       wdata->led_selector = 0;
+
+       for (i = 0; i < 4; i++) {
+               led = kzalloc(sizeof(struct led_classdev) + namesz, GFP_KERNEL);
+               if (!led) {
+                       hid_warn(hdev,
+                                "can't allocate memory for LED selector\n");
+                       ret = -ENOMEM;
+                       goto err;
+               }
+
+               name = (void *)&led[1];
+               snprintf(name, namesz, "%s:selector:%d", dev_name(dev), i);
+               led->name = name;
+               led->brightness = 0;
+               led->max_brightness = 127;
+               led->brightness_get = wacom_leds_get_brightness;
+               led->brightness_set = wacom_leds_set_brightness;
+
+               wdata->leds[i] = led;
+
+               ret = led_classdev_register(dev, wdata->leds[i]);
+
+               if (ret) {
+                       wdata->leds[i] = NULL;
+                       kfree(led);
+                       hid_warn(hdev, "can't register LED\n");
+                       goto err;
+               }
+       }
+
+err:
+       return ret;
+}
+
+static void wacom_destroy_leds(struct hid_device *hdev)
+{
+       struct wacom_data *wdata = hid_get_drvdata(hdev);
+       struct led_classdev *led;
+       int i;
+
+       for (i = 0; i < 4; ++i) {
+               if (wdata->leds[i]) {
+                       led = wdata->leds[i];
+                       wdata->leds[i] = NULL;
+                       led_classdev_unregister(led);
+                       kfree(led);
+               }
+       }
+
+}
+
 static int wacom_battery_get_property(struct power_supply *psy,
                                enum power_supply_property psp,
                                union power_supply_propval *val)
@@ -602,6 +718,12 @@ static int wacom_probe(struct hid_device *hdev,
                sprintf(hdev->name, "%s", "Wacom Intuos4 WL");
                wdata->features = 0;
                wacom_set_features(hdev);
+               ret = wacom_initialize_leds(hdev);
+               if (ret) {
+                       hid_warn(hdev,
+                                "can't create led attribute, err: %d\n", ret);
+                       goto destroy_leds;
+               }
                break;
        }
 
@@ -644,6 +766,8 @@ err_ac:
 err_battery:
        device_remove_file(&hdev->dev, &dev_attr_speed);
        hid_hw_stop(hdev);
+destroy_leds:
+       wacom_destroy_leds(hdev);
 err_free:
        kfree(wdata);
        return ret;
@@ -652,6 +776,8 @@ err_free:
 static void wacom_remove(struct hid_device *hdev)
 {
        struct wacom_data *wdata = hid_get_drvdata(hdev);
+
+       wacom_destroy_leds(hdev);
        device_remove_file(&hdev->dev, &dev_attr_speed);
        hid_hw_stop(hdev);