/*
 *  HID driver for Steelseries SRW-S1
 *
 *  Copyright (c) 2013 Simon Wood
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/device.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/module.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;
	/* the last element is used for setting all leds simultaneously */
	struct led_classdev *led[SRWS1_NUMBER_LEDS + 1];
};
#endif

/* Fixed report descriptor for Steelseries SRW-S1 wheel controller
 *
 * The original descriptor hides the sensitivity and assists dials
 * a custom vendor usage page. This inserts a patch to make them
 * appear in the 'Generic Desktop' usage.
 */

static __u8 steelseries_srws1_rdesc_fixed[] = {
0x05, 0x01,         /*  Usage Page (Desktop)                */
0x09, 0x08,         /*  Usage (MultiAxis), Changed          */
0xA1, 0x01,         /*  Collection (Application),           */
0xA1, 0x02,         /*      Collection (Logical),           */
0x95, 0x01,         /*          Report Count (1),           */
0x05, 0x01,         /* Changed  Usage Page (Desktop),       */
0x09, 0x30,         /* Changed  Usage (X),                  */
0x16, 0xF8, 0xF8,   /*          Logical Minimum (-1800),    */
0x26, 0x08, 0x07,   /*          Logical Maximum (1800),     */
0x65, 0x14,         /*          Unit (Degrees),             */
0x55, 0x0F,         /*          Unit Exponent (15),         */
0x75, 0x10,         /*          Report Size (16),           */
0x81, 0x02,         /*          Input (Variable),           */
0x09, 0x31,         /* Changed  Usage (Y),                  */
0x15, 0x00,         /*          Logical Minimum (0),        */
0x26, 0xFF, 0x03,   /*          Logical Maximum (1023),     */
0x75, 0x0C,         /*          Report Size (12),           */
0x81, 0x02,         /*          Input (Variable),           */
0x09, 0x32,         /* Changed  Usage (Z),                  */
0x15, 0x00,         /*          Logical Minimum (0),        */
0x26, 0xFF, 0x03,   /*          Logical Maximum (1023),     */
0x75, 0x0C,         /*          Report Size (12),           */
0x81, 0x02,         /*          Input (Variable),           */
0x05, 0x01,         /*          Usage Page (Desktop),       */
0x09, 0x39,         /*          Usage (Hat Switch),         */
0x25, 0x07,         /*          Logical Maximum (7),        */
0x35, 0x00,         /*          Physical Minimum (0),       */
0x46, 0x3B, 0x01,   /*          Physical Maximum (315),     */
0x65, 0x14,         /*          Unit (Degrees),             */
0x75, 0x04,         /*          Report Size (4),            */
0x95, 0x01,         /*          Report Count (1),           */
0x81, 0x02,         /*          Input (Variable),           */
0x25, 0x01,         /*          Logical Maximum (1),        */
0x45, 0x01,         /*          Physical Maximum (1),       */
0x65, 0x00,         /*          Unit,                       */
0x75, 0x01,         /*          Report Size (1),            */
0x95, 0x03,         /*          Report Count (3),           */
0x81, 0x01,         /*          Input (Constant),           */
0x05, 0x09,         /*          Usage Page (Button),        */
0x19, 0x01,         /*          Usage Minimum (01h),        */
0x29, 0x11,         /*          Usage Maximum (11h),        */
0x95, 0x11,         /*          Report Count (17),          */
0x81, 0x02,         /*          Input (Variable),           */
                    /*   ---- Dial patch starts here ----   */
0x05, 0x01,         /*          Usage Page (Desktop),       */
0x09, 0x33,         /*          Usage (RX),                 */
0x75, 0x04,         /*          Report Size (4),            */
0x95, 0x02,         /*          Report Count (2),           */
0x15, 0x00,         /*          Logical Minimum (0),        */
0x25, 0x0b,         /*          Logical Maximum (b),        */
0x81, 0x02,         /*          Input (Variable),           */
0x09, 0x35,         /*          Usage (RZ),                 */
0x75, 0x04,         /*          Report Size (4),            */
0x95, 0x01,         /*          Report Count (1),           */
0x25, 0x03,         /*          Logical Maximum (3),        */
0x81, 0x02,         /*          Input (Variable),           */
                    /*    ---- Dial patch ends here ----    */
0x06, 0x00, 0xFF,   /*          Usage Page (FF00h),         */
0x09, 0x01,         /*          Usage (01h),                */
0x75, 0x04,         /* Changed  Report Size (4),            */
0x95, 0x0D,         /* Changed  Report Count (13),          */
0x81, 0x02,         /*          Input (Variable),           */
0xC0,               /*      End Collection,                 */
0xA1, 0x02,         /*      Collection (Logical),           */
0x09, 0x02,         /*          Usage (02h),                */
0x75, 0x08,         /*          Report Size (8),            */
0x95, 0x10,         /*          Report Count (16),          */
0x91, 0x02,         /*          Output (Variable),          */
0xC0,               /*      End Collection,                 */
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;

	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);

	/* 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)
{
	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 + 1; i++)
		drv_data->led[i] = NULL;

	steelseries_srws1_set_leds(hdev, 0);

	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) {
			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 + 1; 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 + 1; 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)
{
	if (*rsize >= 115 && rdesc[11] == 0x02 && rdesc[13] == 0xc8
			&& rdesc[29] == 0xbb && rdesc[40] == 0xc5) {
		hid_info(hdev, "Fixing up Steelseries SRW-S1 report descriptor\n");
		rdesc = steelseries_srws1_rdesc_fixed;
		*rsize = sizeof(steelseries_srws1_rdesc_fixed);
	}
	return rdesc;
}

static const struct hid_device_id steelseries_srws1_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_STEELSERIES, USB_DEVICE_ID_STEELSERIES_SRWS1) },
	{ }
};
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
};

static int __init steelseries_srws1_init(void)
{
	return hid_register_driver(&steelseries_srws1_driver);
}

static void __exit steelseries_srws1_exit(void)
{
	hid_unregister_driver(&steelseries_srws1_driver);
}

module_init(steelseries_srws1_init);
module_exit(steelseries_srws1_exit);
MODULE_LICENSE("GPL");