USB: HID: Steelseries SRW-S1 Add support for LEDs

This patch to the SRW-S1 driver adds support for the LED RPM
meter on the front of the device. The LEDs are controlled via
/sys/class/leds interface, with an individual control for each
of the 15 LEDs.

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

1 files changed, 199 insertions, 0 deletions

diff --git a/drivers/hid/hid-steelseries-srws1.c b/drivers/hid/hid-steelseries-srws1.c
index e95434d733eb..a7386699ba7d 100644
--- a/drivers/hid/hid-steelseries-srws1.c
+++ b/drivers/hid/hid-steelseries-srws1.c
@@ -12,11 +12,21 @@
  */
 
 #include <linux/device.h>
+#include <linux/usb.h>
 #include <linux/hid.h>
 #include <linux/module.h>
 
+#include "usbhid/usbhid.h"
 #include "hid-ids.h"
 
+#if defined(CONFIG_LEDS_CLASS) || defined(CONFIG_LEDS_CLASS_MODULE)
+#define SRWS1_NUMBER_LEDS 15
+struct steelseries_srws1_data {
+        __u16 led_state;
+        struct led_classdev *led[SRWS1_NUMBER_LEDS];
+};
+#endif
+
 /* Fixed report descriptor for Steelseries SRW-S1 wheel controller
  *
  * The original descriptor hides the sensitivity and assists dials
@@ -97,6 +107,191 @@ static __u8 steelseries_srws1_rdesc_fixed[] = {
 0xC0                /*  End Collection                      */
 };
 
+#if defined(CONFIG_LEDS_CLASS) || defined(CONFIG_LEDS_CLASS_MODULE)
+static void steelseries_srws1_set_leds(struct hid_device *hdev, __u16 leds)
+{
+        struct list_head *report_list = &hdev->report_enum[HID_OUTPUT_REPORT].report_list;
+        struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+        __s32 *value = report->field[0]->value;
+
+        value[0] = 0x40;
+        value[1] = leds & 0xFF;
+        value[2] = leds >> 8;
+        value[3] = 0x00;
+        value[4] = 0x00;
+        value[5] = 0x00;
+        value[6] = 0x00;
+        value[7] = 0x00;
+        value[8] = 0x00;
+        value[9] = 0x00;
+        value[10] = 0x00;
+        value[11] = 0x00;
+        value[12] = 0x00;
+        value[13] = 0x00;
+        value[14] = 0x00;
+        value[15] = 0x00;
+
+        usbhid_submit_report(hdev, report, USB_DIR_OUT);
+
+        /* Note: LED change does not show on device until the device is read/polled */
+}
+
+static void steelseries_srws1_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 steelseries_srws1_data *drv_data = hid_get_drvdata(hid);
+        int i, state = 0;
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return;
+        }
+
+        for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
+                if (led_cdev != drv_data->led[i])
+                        continue;
+
+                state = (drv_data->led_state >> i) & 1;
+                if (value == LED_OFF && state) {
+                        drv_data->led_state &= ~(1 << i);
+                        steelseries_srws1_set_leds(hid, drv_data->led_state);
+                } else if (value != LED_OFF && !state) {
+                        drv_data->led_state |= 1 << i;
+                        steelseries_srws1_set_leds(hid, drv_data->led_state);
+                }
+                break;
+        }
+}
+
+static enum led_brightness steelseries_srws1_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 steelseries_srws1_data *drv_data;
+        int i, value = 0;
+
+        drv_data = hid_get_drvdata(hid);
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return LED_OFF;
+        }
+
+        for (i = 0; i < SRWS1_NUMBER_LEDS; i++)
+                if (led_cdev == drv_data->led[i]) {
+                        value = (drv_data->led_state >> i) & 1;
+                        break;
+                }
+
+        return value ? LED_FULL : LED_OFF;
+}
+
+static int steelseries_srws1_probe(struct hid_device *hdev,
+                const struct hid_device_id *id)
+{
+        int ret, i;
+        struct led_classdev *led;
+        size_t name_sz;
+        char *name;
+
+        struct steelseries_srws1_data *drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
+
+        if (drv_data == NULL) {
+                hid_err(hdev, "can't alloc SRW-S1 memory\n");
+                return -ENOMEM;
+        }
+
+        hid_set_drvdata(hdev, drv_data);
+
+        ret = hid_parse(hdev);
+        if (ret) {
+                hid_err(hdev, "parse failed\n");
+                goto err_free;
+        }
+
+        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+        if (ret) {
+                hid_err(hdev, "hw start failed\n");
+                goto err_free;
+        }
+
+        /* register led subsystem */
+        drv_data->led_state = 0;
+        for (i = 0; i < SRWS1_NUMBER_LEDS; i++)
+                drv_data->led[i] = NULL;
+
+        steelseries_srws1_set_leds(hdev, 0);
+
+        name_sz = strlen(hdev->uniq) + 15;
+
+        for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
+                led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
+                if (!led) {
+                        hid_err(hdev, "can't allocate memory for LED %d\n", i);
+                        goto err_led;
+                }
+
+                name = (void *)(&led[1]);
+                snprintf(name, name_sz, "SRWS1::%s::RPM%d", hdev->uniq, i+1);
+                led->name = name;
+                led->brightness = 0;
+                led->max_brightness = 1;
+                led->brightness_get = steelseries_srws1_led_get_brightness;
+                led->brightness_set = steelseries_srws1_led_set_brightness;
+
+                drv_data->led[i] = led;
+                ret = led_classdev_register(&hdev->dev, led);
+
+                if (ret) {
+                        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++) {
+                                led = drv_data->led[i];
+                                drv_data->led[i] = NULL;
+                                if (!led)
+                                        continue;
+                                led_classdev_unregister(led);
+                                kfree(led);
+                        }
+                        goto out;       /* but let the driver continue without LEDs */
+                }
+        }
+out:
+        return 0;
+err_free:
+        kfree(drv_data);
+        return ret;
+}
+
+static void steelseries_srws1_remove(struct hid_device *hdev)
+{
+        int i;
+        struct led_classdev *led;
+
+        struct steelseries_srws1_data *drv_data = hid_get_drvdata(hdev);
+
+        if (drv_data) {
+                /* Deregister LEDs (if any) */
+                for (i = 0; i < SRWS1_NUMBER_LEDS; i++) {
+                        led = drv_data->led[i];
+                        drv_data->led[i] = NULL;
+                        if (!led)
+                                continue;
+                        led_classdev_unregister(led);
+                        kfree(led);
+                }
+
+        }
+
+        hid_hw_stop(hdev);
+        kfree(drv_data);
+        return;
+}
+#endif
+
 static __u8 *steelseries_srws1_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                 unsigned int *rsize)
 {
@@ -118,6 +313,10 @@ MODULE_DEVICE_TABLE(hid, steelseries_srws1_devices);
 static struct hid_driver steelseries_srws1_driver = {
         .name = "steelseries_srws1",
         .id_table = steelseries_srws1_devices,
+#if defined(CONFIG_LEDS_CLASS) || defined(CONFIG_LEDS_CLASS_MODULE)
+        .probe = steelseries_srws1_probe,
+        .remove = steelseries_srws1_remove,
+#endif
         .report_fixup = steelseries_srws1_report_fixup
 };