USB: HID: Steelseries SRW-S1 Add support controlling all LEDs simultaneously

This patch to the SRW-S1 driver adds the ability to control all
LEDs simultaneously as testing showed that it was slow (noticably!!)
when seting or clearing all the LEDs in turn.

It adds a 'RPMALL' LED, whose behavoir is asserted to all the LEDs in
the bar graph, individual LEDs can subsequently be turned on/off
individually.

Signed-off-by: Simon Wood <simon@mungewell.org>
Tested-by: John Murphy <rosegardener@freeode.co.uk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 62 insertions, 4 deletions

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-srws1 b/Documentation/ABI/testing/sysfs-driver-hid-srws1
index c27b34dcaf83..d0eba70c7d40 100644
--- a/Documentation/ABI/testing/sysfs-driver-hid-srws1
+++ b/Documentation/ABI/testing/sysfs-driver-hid-srws1
@@ -13,6 +13,7 @@ What:		/sys/class/leds/SRWS1::<serial>::RPM12
 What:           /sys/class/leds/SRWS1::<serial>::RPM13
 What:           /sys/class/leds/SRWS1::<serial>::RPM14
 What:           /sys/class/leds/SRWS1::<serial>::RPM15
+What:           /sys/class/leds/SRWS1::<serial>::RPMALL
 Date:           Jan 2013
 KernelVersion:  3.9
 Contact:        Simon Wood <simon@mungewell.org>
diff --git a/drivers/hid/hid-steelseries-srws1.c b/drivers/hid/hid-steelseries-srws1.c
index a7386699ba7d..365bc9ef1e79 100644
--- a/drivers/hid/hid-steelseries-srws1.c
+++ b/drivers/hid/hid-steelseries-srws1.c
@@ -136,6 +136,42 @@ static void steelseries_srws1_set_leds(struct hid_device *hdev, __u16 leds)
         /* Note: LED change does not show on device until the device is read/polled */
 }
 
+static void steelseries_srws1_led_all_set_brightness(struct led_classdev *led_cdev,
+                        enum led_brightness value)
+{
+        struct device *dev = led_cdev->dev->parent;
+        struct hid_device *hid = container_of(dev, struct hid_device, dev);
+        struct steelseries_srws1_data *drv_data = hid_get_drvdata(hid);
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return;
+        }
+
+        if (value == LED_OFF)
+                drv_data->led_state = 0;
+        else
+                drv_data->led_state = (1 << (SRWS1_NUMBER_LEDS + 1)) - 1;
+
+        steelseries_srws1_set_leds(hid, drv_data->led_state);
+}
+
+static enum led_brightness steelseries_srws1_led_all_get_brightness(struct led_classdev *led_cdev)
+{
+        struct device *dev = led_cdev->dev->parent;
+        struct hid_device *hid = container_of(dev, struct hid_device, dev);
+        struct steelseries_srws1_data *drv_data;
+
+        drv_data = hid_get_drvdata(hid);
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return LED_OFF;
+        }
+
+        return (drv_data->led_state >> SRWS1_NUMBER_LEDS) ? LED_FULL : LED_OFF;
+}
+
 static void steelseries_srws1_led_set_brightness(struct led_classdev *led_cdev,
                         enum led_brightness value)
 {
@@ -219,13 +255,34 @@ static int steelseries_srws1_probe(struct hid_device *hdev,
 
         /* register led subsystem */
         drv_data->led_state = 0;
-        for (i = 0; i < SRWS1_NUMBER_LEDS; i++)
+        for (i = 0; i < SRWS1_NUMBER_LEDS + 1; i++)
                 drv_data->led[i] = NULL;
 
         steelseries_srws1_set_leds(hdev, 0);
 
-        name_sz = strlen(hdev->uniq) + 15;
+        name_sz = strlen(hdev->uniq) + 16;
+
+        /* 'ALL', for setting all LEDs simultaneously */
+        led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
+        if (!led) {
+                hid_err(hdev, "can't allocate memory for LED ALL\n");
+                goto err_led;
+        }
+
+        name = (void *)(&led[1]);
+        snprintf(name, name_sz, "SRWS1::%s::RPMALL", hdev->uniq);
+        led->name = name;
+        led->brightness = 0;
+        led->max_brightness = 1;
+        led->brightness_get = steelseries_srws1_led_all_get_brightness;
+        led->brightness_set = steelseries_srws1_led_all_set_brightness;
+
+        drv_data->led[SRWS1_NUMBER_LEDS] = led;
+        ret = led_classdev_register(&hdev->dev, led);
+        if (ret)
+                goto err_led;
 
+        /* Each individual LED */
         for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
                 led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
                 if (!led) {
@@ -248,7 +305,7 @@ static int steelseries_srws1_probe(struct hid_device *hdev,
                         hid_err(hdev, "failed to register LED %d. Aborting.\n", i);
 err_led:
                         /* Deregister all LEDs (if any) */
-                        for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
+                        for (i = 0; i < SRWS1_NUMBER_LEDS + 1; i++) {
                                 led = drv_data->led[i];
                                 drv_data->led[i] = NULL;
                                 if (!led)
@@ -275,7 +332,7 @@ static void steelseries_srws1_remove(struct hid_device *hdev)
 
         if (drv_data) {
                 /* Deregister LEDs (if any) */
-                for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
+                for (i = 0; i < SRWS1_NUMBER_LEDS + 1; i++) {
                         led = drv_data->led[i];
                         drv_data->led[i] = NULL;
                         if (!led)