HID: hid-lg4ff: Add support for G27 LEDs

This patch adds supports for controlling the LED 'tachometer' on
the G27 wheel, via the LED subsystem.

The 5 LEDs are arranged from right (1=grn, 2=grn, 3=yel, 4=yel, 5=red)
and 'mirrored' to the left (10 LEDs in total).

Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 157 insertions, 1 deletions

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 32c173fcb7f8..1e942a014038 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -55,7 +55,10 @@ struct lg4ff_device_entry {
         __u16 range;
         __u16 min_range;
         __u16 max_range;
-        __u8  leds;
+#ifdef CONFIG_LEDS_CLASS
+        __u8  led_state;
+        struct led_classdev *led[5];
+#endif
         struct list_head list;
         void (*set_range)(struct hid_device *hid, u16 range);
 };
@@ -335,6 +338,88 @@ static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *at
         return count;
 }
 
+#ifdef CONFIG_LEDS_CLASS
+static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
+{
+        struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+        struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+
+        report->field[0]->value[0] = 0xf8;
+        report->field[0]->value[1] = 0x12;
+        report->field[0]->value[2] = leds;
+        report->field[0]->value[3] = 0x00;
+        report->field[0]->value[4] = 0x00;
+        report->field[0]->value[5] = 0x00;
+        report->field[0]->value[6] = 0x00;
+        usbhid_submit_report(hid, report, USB_DIR_OUT);
+}
+
+static void lg4ff_led_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 lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
+        struct lg4ff_device_entry *entry;
+        int i, state = 0;
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return;
+        }
+
+        entry = (struct lg4ff_device_entry *)drv_data->device_props;
+
+        if (!entry) {
+                hid_err(hid, "Device properties not found.");
+                return;
+        }
+
+        for (i = 0; i < 5; i++) {
+                if (led_cdev != entry->led[i])
+                        continue;
+                state = (entry->led_state >> i) & 1;
+                if (value == LED_OFF && state) {
+                        entry->led_state &= ~(1 << i);
+                        lg4ff_set_leds(hid, entry->led_state);
+                } else if (value != LED_OFF && !state) {
+                        entry->led_state |= 1 << i;
+                        lg4ff_set_leds(hid, entry->led_state);
+                }
+                break;
+        }
+}
+
+static enum led_brightness lg4ff_led_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 lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
+        struct lg4ff_device_entry *entry;
+        int i, value = 0;
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return LED_OFF;
+        }
+
+        entry = (struct lg4ff_device_entry *)drv_data->device_props;
+
+        if (!entry) {
+                hid_err(hid, "Device properties not found.");
+                return LED_OFF;
+        }
+
+        for (i = 0; i < 5; i++)
+                if (led_cdev == entry->led[i]) {
+                        value = (entry->led_state >> i) & 1;
+                        break;
+                }
+
+        return value ? LED_FULL : LED_OFF;
+}
+#endif
+
 int lg4ff_init(struct hid_device *hid)
 {
         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
@@ -453,6 +538,58 @@ int lg4ff_init(struct hid_device *hid)
         if (entry->set_range != NULL)
                 entry->set_range(hid, entry->range);
 
+#ifdef CONFIG_LEDS_CLASS
+        /* register led subsystem - G27 only */
+        entry->led_state = 0;
+        for (j = 0; j < 5; j++)
+                entry->led[j] = NULL;
+
+        if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G27_WHEEL) {
+                struct led_classdev *led;
+                size_t name_sz;
+                char *name;
+
+                lg4ff_set_leds(hid, 0);
+
+                name_sz = strlen(dev_name(&hid->dev)) + 8;
+
+                for (j = 0; j < 5; j++) {
+                        led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
+                        if (!led) {
+                                hid_err(hid, "can't allocate memory for LED %d\n", j);
+                                goto err;
+                        }
+
+                        name = (void *)(&led[1]);
+                        snprintf(name, name_sz, "%s::RPM%d", dev_name(&hid->dev), j+1);
+                        led->name = name;
+                        led->brightness = 0;
+                        led->max_brightness = 1;
+                        led->brightness_get = lg4ff_led_get_brightness;
+                        led->brightness_set = lg4ff_led_set_brightness;
+
+                        entry->led[j] = led;
+                        error = led_classdev_register(&hid->dev, led);
+
+                        if (error) {
+                                hid_err(hid, "failed to register LED %d. Aborting.\n", j);
+err:
+                                /* Deregister LEDs (if any) */
+                                for (j = 0; j < 5; j++) {
+                                        led = entry->led[j];
+                                        entry->led[j] = NULL;
+                                        if (!led)
+                                                continue;
+                                        led_classdev_unregister(led);
+                                        kfree(led);
+                                }
+                                goto out;       /* Let the driver continue without LEDs */
+                        }
+                }
+        }
+#endif
+
+out:
         hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@mungewell.org>\n");
         return 0;
 }
@@ -474,6 +611,25 @@ int lg4ff_deinit(struct hid_device *hid)
                 hid_err(hid, "Error while deinitializing device, no device properties data.\n");
                 return -1;
         }
+
+#ifdef CONFIG_LEDS_CLASS
+        {
+                int j;
+                struct led_classdev *led;
+
+                /* Deregister LEDs (if any) */
+                for (j = 0; j < 5; j++) {
+
+                        led = entry->led[j];
+                        entry->led[j] = NULL;
+                        if (!led)
+                                continue;
+                        led_classdev_unregister(led);
+                        kfree(led);
+                }
+        }
+#endif
+
         /* Deallocate memory */
         kfree(entry);