[PATCH] HID: wacom: Add LED selector control for Wacom Intuos4 WL

From: Przemo Firszt
Date: Mon May 07 2012 - 15:41:01 EST

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@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-driver-wacom | 8 ++
drivers/hid/Kconfig | 1 +
drivers/hid/hid-wacom.c | 126 ++++++++++++++++++++++++++
3 files changed, 135 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-driver-wacom b/Documentation/ABI/testing/sysfs-driver-wacom
index 0130d66..56c5455 100644
--- 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@xxxxxxxxxxxxxxx
+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@xxxxxxxxxxxxxxx
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 9092ae1..a9647dd 100644
--- 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 a66e1aa..336ddc8 100644
--- 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[3];
};

/*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);

--
1.7.10

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