// SPDX-License-Identifier: GPL-2.0-only
/*
 * Simple USB RGB LED driver
 *
 * Copyright 2016 Heiner Kallweit <hkallweit1@gmail.com>
 * Based on drivers/hid/hid-thingm.c and
 * drivers/usb/misc/usbled.c
 */

#include <linux/hid.h>
#include <linux/hidraw.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>

#include "hid-ids.h"

enum hidled_report_type {
        RAW_REQUEST,
        OUTPUT_REPORT
};

enum hidled_type {
        RISO_KAGAKU,
        DREAM_CHEEKY,
        THINGM,
        DELCOM,
        LUXAFOR,
};

static unsigned const char riso_kagaku_tbl[] = {
/* R+2G+4B -> riso kagaku color index */
        [0] = 0, /* black   */
        [1] = 2, /* red     */
        [2] = 1, /* green   */
        [3] = 5, /* yellow  */
        [4] = 3, /* blue    */
        [5] = 6, /* magenta */
        [6] = 4, /* cyan    */
        [7] = 7  /* white   */
};

#define RISO_KAGAKU_IX(r, g, b) riso_kagaku_tbl[((r)?1:0)+((g)?2:0)+((b)?4:0)]

union delcom_packet {
        __u8 data[8];
        struct {
                __u8 major_cmd;
                __u8 minor_cmd;
                __u8 data_lsb;
                __u8 data_msb;
        } tx;
        struct {
                __u8 cmd;
        } rx;
        struct {
                __le16 family_code;
                __le16 security_code;
                __u8 fw_version;
        } fw;
};

#define DELCOM_GREEN_LED        0
#define DELCOM_RED_LED          1
#define DELCOM_BLUE_LED         2

struct hidled_device;
struct hidled_rgb;

struct hidled_config {
        enum hidled_type        type;
        const char              *name;
        const char              *short_name;
        enum led_brightness     max_brightness;
        int                     num_leds;
        size_t                  report_size;
        enum hidled_report_type report_type;
        int (*init)(struct hidled_device *ldev);
        int (*write)(struct led_classdev *cdev, enum led_brightness br);
};

struct hidled_led {
        struct led_classdev     cdev;
        struct hidled_rgb       *rgb;
        char                    name[32];
};

struct hidled_rgb {
        struct hidled_device    *ldev;
        struct hidled_led       red;
        struct hidled_led       green;
        struct hidled_led       blue;
        u8                      num;
};

struct hidled_device {
        const struct hidled_config *config;
        struct hid_device       *hdev;
        struct hidled_rgb       *rgb;
        u8                      *buf;
        struct mutex            lock;
};

#define MAX_REPORT_SIZE         16

#define to_hidled_led(arg) container_of(arg, struct hidled_led, cdev)

static bool riso_kagaku_switch_green_blue;
module_param(riso_kagaku_switch_green_blue, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(riso_kagaku_switch_green_blue,
        "switch green and blue RGB component for Riso Kagaku devices");

static int hidled_send(struct hidled_device *ldev, __u8 *buf)
{
        int ret;

        mutex_lock(&ldev->lock);

        /*
         * buffer provided to hid_hw_raw_request must not be on the stack
         * and must not be part of a data structure
         */
        memcpy(ldev->buf, buf, ldev->config->report_size);

        if (ldev->config->report_type == RAW_REQUEST)
                ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf,
                                         ldev->config->report_size,
                                         HID_FEATURE_REPORT,
                                         HID_REQ_SET_REPORT);
        else if (ldev->config->report_type == OUTPUT_REPORT)
                ret = hid_hw_output_report(ldev->hdev, ldev->buf,
                                           ldev->config->report_size);
        else
                ret = -EINVAL;

        mutex_unlock(&ldev->lock);

        if (ret < 0)
                return ret;

        return ret == ldev->config->report_size ? 0 : -EMSGSIZE;
}

/* reading data is supported for report type RAW_REQUEST only */
static int hidled_recv(struct hidled_device *ldev, __u8 *buf)
{
        int ret;

        if (ldev->config->report_type != RAW_REQUEST)
                return -EINVAL;

        mutex_lock(&ldev->lock);

        memcpy(ldev->buf, buf, ldev->config->report_size);

        ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf,
                                 ldev->config->report_size,
                                 HID_FEATURE_REPORT,
                                 HID_REQ_SET_REPORT);
        if (ret < 0)
                goto err;

        ret = hid_hw_raw_request(ldev->hdev, buf[0], ldev->buf,
                                 ldev->config->report_size,
                                 HID_FEATURE_REPORT,
                                 HID_REQ_GET_REPORT);

        memcpy(buf, ldev->buf, ldev->config->report_size);
err:
        mutex_unlock(&ldev->lock);

        return ret < 0 ? ret : 0;
}

static u8 riso_kagaku_index(struct hidled_rgb *rgb)
{
        enum led_brightness r, g, b;

        r = rgb->red.cdev.brightness;
        g = rgb->green.cdev.brightness;
        b = rgb->blue.cdev.brightness;

        if (riso_kagaku_switch_green_blue)
                return RISO_KAGAKU_IX(r, b, g);
        else
                return RISO_KAGAKU_IX(r, g, b);
}

static int riso_kagaku_write(struct led_classdev *cdev, enum led_brightness br)
{
        struct hidled_led *led = to_hidled_led(cdev);
        struct hidled_rgb *rgb = led->rgb;
        __u8 buf[MAX_REPORT_SIZE] = {};

        buf[1] = riso_kagaku_index(rgb);

        return hidled_send(rgb->ldev, buf);
}

static int dream_cheeky_write(struct led_classdev *cdev, enum led_brightness br)
{
        struct hidled_led *led = to_hidled_led(cdev);
        struct hidled_rgb *rgb = led->rgb;
        __u8 buf[MAX_REPORT_SIZE] = {};

        buf[1] = rgb->red.cdev.brightness;
        buf[2] = rgb->green.cdev.brightness;
        buf[3] = rgb->blue.cdev.brightness;
        buf[7] = 0x1a;
        buf[8] = 0x05;

        return hidled_send(rgb->ldev, buf);
}

static int dream_cheeky_init(struct hidled_device *ldev)
{
        __u8 buf[MAX_REPORT_SIZE] = {};

        /* Dream Cheeky magic */
        buf[1] = 0x1f;
        buf[2] = 0x02;
        buf[4] = 0x5f;
        buf[7] = 0x1a;
        buf[8] = 0x03;

        return hidled_send(ldev, buf);
}

static int _thingm_write(struct led_classdev *cdev, enum led_brightness br,
                         u8 offset)
{
        struct hidled_led *led = to_hidled_led(cdev);
        __u8 buf[MAX_REPORT_SIZE] = { 1, 'c' };

        buf[2] = led->rgb->red.cdev.brightness;
        buf[3] = led->rgb->green.cdev.brightness;
        buf[4] = led->rgb->blue.cdev.brightness;
        buf[7] = led->rgb->num + offset;

        return hidled_send(led->rgb->ldev, buf);
}

static int thingm_write_v1(struct led_classdev *cdev, enum led_brightness br)
{
        return _thingm_write(cdev, br, 0);
}

static int thingm_write(struct led_classdev *cdev, enum led_brightness br)
{
        return _thingm_write(cdev, br, 1);
}

static const struct hidled_config hidled_config_thingm_v1 = {
        .name = "ThingM blink(1) v1",
        .short_name = "thingm",
        .max_brightness = 255,
        .num_leds = 1,
        .report_size = 9,
        .report_type = RAW_REQUEST,
        .write = thingm_write_v1,
};

static int thingm_init(struct hidled_device *ldev)
{
        __u8 buf[MAX_REPORT_SIZE] = { 1, 'v' };
        int ret;

        ret = hidled_recv(ldev, buf);
        if (ret)
                return ret;

        /* Check for firmware major version 1 */
        if (buf[3] == '1')
                ldev->config = &hidled_config_thingm_v1;

        return 0;
}

static inline int delcom_get_lednum(const struct hidled_led *led)
{
        if (led == &led->rgb->red)
                return DELCOM_RED_LED;
        else if (led == &led->rgb->green)
                return DELCOM_GREEN_LED;
        else
                return DELCOM_BLUE_LED;
}

static int delcom_enable_led(struct hidled_led *led)
{
        union delcom_packet dp = { .tx.major_cmd = 101, .tx.minor_cmd = 12 };

        dp.tx.data_lsb = 1 << delcom_get_lednum(led);
        dp.tx.data_msb = 0;

        return hidled_send(led->rgb->ldev, dp.data);
}

static int delcom_set_pwm(struct hidled_led *led)
{
        union delcom_packet dp = { .tx.major_cmd = 101, .tx.minor_cmd = 34 };

        dp.tx.data_lsb = delcom_get_lednum(led);
        dp.tx.data_msb = led->cdev.brightness;

        return hidled_send(led->rgb->ldev, dp.data);
}

static int delcom_write(struct led_classdev *cdev, enum led_brightness br)
{
        struct hidled_led *led = to_hidled_led(cdev);
        int ret;

        /*
         * enable LED
         * We can't do this in the init function already because the device
         * is internally reset later.
         */
        ret = delcom_enable_led(led);
        if (ret)
                return ret;

        return delcom_set_pwm(led);
}

static int delcom_init(struct hidled_device *ldev)
{
        union delcom_packet dp = { .rx.cmd = 104 };
        int ret;

        ret = hidled_recv(ldev, dp.data);
        if (ret)
                return ret;
        /*
         * Several Delcom devices share the same USB VID/PID
         * Check for family id 2 for Visual Signal Indicator
         */
        return le16_to_cpu(dp.fw.family_code) == 2 ? 0 : -ENODEV;
}

static int luxafor_write(struct led_classdev *cdev, enum led_brightness br)
{
        struct hidled_led *led = to_hidled_led(cdev);
        __u8 buf[MAX_REPORT_SIZE] = { [1] = 1 };

        buf[2] = led->rgb->num + 1;
        buf[3] = led->rgb->red.cdev.brightness;
        buf[4] = led->rgb->green.cdev.brightness;
        buf[5] = led->rgb->blue.cdev.brightness;

        return hidled_send(led->rgb->ldev, buf);
}

static const struct hidled_config hidled_configs[] = {
        {
                .type = RISO_KAGAKU,
                .name = "Riso Kagaku Webmail Notifier",
                .short_name = "riso_kagaku",
                .max_brightness = 1,
                .num_leds = 1,
                .report_size = 6,
                .report_type = OUTPUT_REPORT,
                .write = riso_kagaku_write,
        },
        {
                .type = DREAM_CHEEKY,
                .name = "Dream Cheeky Webmail Notifier",
                .short_name = "dream_cheeky",
                .max_brightness = 63,
                .num_leds = 1,
                .report_size = 9,
                .report_type = RAW_REQUEST,
                .init = dream_cheeky_init,
                .write = dream_cheeky_write,
        },
        {
                .type = THINGM,
                .name = "ThingM blink(1)",
                .short_name = "thingm",
                .max_brightness = 255,
                .num_leds = 2,
                .report_size = 9,
                .report_type = RAW_REQUEST,
                .init = thingm_init,
                .write = thingm_write,
        },
        {
                .type = DELCOM,
                .name = "Delcom Visual Signal Indicator G2",
                .short_name = "delcom",
                .max_brightness = 100,
                .num_leds = 1,
                .report_size = 8,
                .report_type = RAW_REQUEST,
                .init = delcom_init,
                .write = delcom_write,
        },
        {
                .type = LUXAFOR,
                .name = "Greynut Luxafor",
                .short_name = "luxafor",
                .max_brightness = 255,
                .num_leds = 6,
                .report_size = 9,
                .report_type = OUTPUT_REPORT,
                .write = luxafor_write,
        },
};

static int hidled_init_led(struct hidled_led *led, const char *color_name,
                           struct hidled_rgb *rgb, unsigned int minor)
{
        const struct hidled_config *config = rgb->ldev->config;

        if (config->num_leds > 1)
                snprintf(led->name, sizeof(led->name), "%s%u:%s:led%u",
                         config->short_name, minor, color_name, rgb->num);
        else
                snprintf(led->name, sizeof(led->name), "%s%u:%s",
                         config->short_name, minor, color_name);
        led->cdev.name = led->name;
        led->cdev.max_brightness = config->max_brightness;
        led->cdev.brightness_set_blocking = config->write;
        led->cdev.flags = LED_HW_PLUGGABLE;
        led->rgb = rgb;

        return devm_led_classdev_register(&rgb->ldev->hdev->dev, &led->cdev);
}

static int hidled_init_rgb(struct hidled_rgb *rgb, unsigned int minor)
{
        int ret;

        /* Register the red diode */
        ret = hidled_init_led(&rgb->red, "red", rgb, minor);
        if (ret)
                return ret;

        /* Register the green diode */
        ret = hidled_init_led(&rgb->green, "green", rgb, minor);
        if (ret)
                return ret;

        /* Register the blue diode */
        return hidled_init_led(&rgb->blue, "blue", rgb, minor);
}

static int hidled_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct hidled_device *ldev;
        unsigned int minor;
        int ret, i;

        ldev = devm_kzalloc(&hdev->dev, sizeof(*ldev), GFP_KERNEL);
        if (!ldev)
                return -ENOMEM;

        ldev->buf = devm_kmalloc(&hdev->dev, MAX_REPORT_SIZE, GFP_KERNEL);
        if (!ldev->buf)
                return -ENOMEM;

        ret = hid_parse(hdev);
        if (ret)
                return ret;

        ldev->hdev = hdev;
        mutex_init(&ldev->lock);

        for (i = 0; !ldev->config && i < ARRAY_SIZE(hidled_configs); i++)
                if (hidled_configs[i].type == id->driver_data)
                        ldev->config = &hidled_configs[i];

        if (!ldev->config)
                return -EINVAL;

        if (ldev->config->init) {
                ret = ldev->config->init(ldev);
                if (ret)
                        return ret;
        }

        ldev->rgb = devm_kcalloc(&hdev->dev, ldev->config->num_leds,
                                 sizeof(struct hidled_rgb), GFP_KERNEL);
        if (!ldev->rgb)
                return -ENOMEM;

        ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
        if (ret)
                return ret;

        minor = ((struct hidraw *) hdev->hidraw)->minor;

        for (i = 0; i < ldev->config->num_leds; i++) {
                ldev->rgb[i].ldev = ldev;
                ldev->rgb[i].num = i;
                ret = hidled_init_rgb(&ldev->rgb[i], minor);
                if (ret) {
                        hid_hw_stop(hdev);
                        return ret;
                }
        }

        hid_info(hdev, "%s initialized\n", ldev->config->name);

        return 0;
}

static const struct hid_device_id hidled_table[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_RISO_KAGAKU,
          USB_DEVICE_ID_RI_KA_WEBMAIL), .driver_data = RISO_KAGAKU },
        { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY,
          USB_DEVICE_ID_DREAM_CHEEKY_WN), .driver_data = DREAM_CHEEKY },
        { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY,
          USB_DEVICE_ID_DREAM_CHEEKY_FA), .driver_data = DREAM_CHEEKY },
        { HID_USB_DEVICE(USB_VENDOR_ID_THINGM,
          USB_DEVICE_ID_BLINK1), .driver_data = THINGM },
        { HID_USB_DEVICE(USB_VENDOR_ID_DELCOM,
          USB_DEVICE_ID_DELCOM_VISUAL_IND), .driver_data = DELCOM },
        { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP,
          USB_DEVICE_ID_LUXAFOR), .driver_data = LUXAFOR },
        { }
};
MODULE_DEVICE_TABLE(hid, hidled_table);

static struct hid_driver hidled_driver = {
        .name = "hid-led",
        .probe = hidled_probe,
        .id_table = hidled_table,
};

module_hid_driver(hidled_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Heiner Kallweit <hkallweit1@gmail.com>");
MODULE_DESCRIPTION("Simple USB RGB LED driver");