// SPDX-License-Identifier: GPL-2.0-only
/***************************************************************************
 *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
 *                                                                         *
 *   Based on Logitech G13 driver (v0.4)                                   *
 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
 *                                                                         *
 ***************************************************************************/

#include <linux/hid.h>
#include <linux/hid-debug.h>

#include <linux/fb.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>

#include <linux/module.h>
#include <linux/uaccess.h>

#include "hid-picolcd.h"


static int picolcd_debug_reset_show(struct seq_file *f, void *p)
{
        if (picolcd_fbinfo((struct picolcd_data *)f->private))
                seq_printf(f, "all fb\n");
        else
                seq_printf(f, "all\n");
        return 0;
}

static int picolcd_debug_reset_open(struct inode *inode, struct file *f)
{
        return single_open(f, picolcd_debug_reset_show, inode->i_private);
}

static ssize_t picolcd_debug_reset_write(struct file *f, const char __user *user_buf,
                size_t count, loff_t *ppos)
{
        struct picolcd_data *data = ((struct seq_file *)f->private_data)->private;
        char buf[32];
        size_t cnt = min(count, sizeof(buf)-1);
        if (copy_from_user(buf, user_buf, cnt))
                return -EFAULT;

        while (cnt > 0 && (buf[cnt-1] == ' ' || buf[cnt-1] == '\n'))
                cnt--;
        buf[cnt] = '\0';
        if (strcmp(buf, "all") == 0) {
                picolcd_reset(data->hdev);
                picolcd_fb_reset(data, 1);
        } else if (strcmp(buf, "fb") == 0) {
                picolcd_fb_reset(data, 1);
        } else {
                return -EINVAL;
        }
        return count;
}

static const struct file_operations picolcd_debug_reset_fops = {
        .owner    = THIS_MODULE,
        .open     = picolcd_debug_reset_open,
        .read     = seq_read,
        .llseek   = seq_lseek,
        .write    = picolcd_debug_reset_write,
        .release  = single_release,
};

/*
 * The "eeprom" file
 */
static ssize_t picolcd_debug_eeprom_read(struct file *f, char __user *u,
                size_t s, loff_t *off)
{
        struct picolcd_data *data = f->private_data;
        struct picolcd_pending *resp;
        u8 raw_data[3];
        ssize_t ret = -EIO;

        if (s == 0)
                return -EINVAL;
        if (*off > 0x0ff)
                return 0;

        /* prepare buffer with info about what we want to read (addr & len) */
        raw_data[0] = *off & 0xff;
        raw_data[1] = (*off >> 8) & 0xff;
        raw_data[2] = s < 20 ? s : 20;
        if (*off + raw_data[2] > 0xff)
                raw_data[2] = 0x100 - *off;
        resp = picolcd_send_and_wait(data->hdev, REPORT_EE_READ, raw_data,
                        sizeof(raw_data));
        if (!resp)
                return -EIO;

        if (resp->in_report && resp->in_report->id == REPORT_EE_DATA) {
                /* successful read :) */
                ret = resp->raw_data[2];
                if (ret > s)
                        ret = s;
                if (copy_to_user(u, resp->raw_data+3, ret))
                        ret = -EFAULT;
                else
                        *off += ret;
        } /* anything else is some kind of IO error */

        kfree(resp);
        return ret;
}

static ssize_t picolcd_debug_eeprom_write(struct file *f, const char __user *u,
                size_t s, loff_t *off)
{
        struct picolcd_data *data = f->private_data;
        struct picolcd_pending *resp;
        ssize_t ret = -EIO;
        u8 raw_data[23];

        if (s == 0)
                return -EINVAL;
        if (*off > 0x0ff)
                return -ENOSPC;

        memset(raw_data, 0, sizeof(raw_data));
        raw_data[0] = *off & 0xff;
        raw_data[1] = (*off >> 8) & 0xff;
        raw_data[2] = min_t(size_t, 20, s);
        if (*off + raw_data[2] > 0xff)
                raw_data[2] = 0x100 - *off;

        if (copy_from_user(raw_data+3, u, min((u8)20, raw_data[2])))
                return -EFAULT;
        resp = picolcd_send_and_wait(data->hdev, REPORT_EE_WRITE, raw_data,
                        sizeof(raw_data));

        if (!resp)
                return -EIO;

        if (resp->in_report && resp->in_report->id == REPORT_EE_DATA) {
                /* check if written data matches */
                if (memcmp(raw_data, resp->raw_data, 3+raw_data[2]) == 0) {
                        *off += raw_data[2];
                        ret = raw_data[2];
                }
        }
        kfree(resp);
        return ret;
}

/*
 * Notes:
 * - read/write happens in chunks of at most 20 bytes, it's up to userspace
 *   to loop in order to get more data.
 * - on write errors on otherwise correct write request the bytes
 *   that should have been written are in undefined state.
 */
static const struct file_operations picolcd_debug_eeprom_fops = {
        .owner    = THIS_MODULE,
        .open     = simple_open,
        .read     = picolcd_debug_eeprom_read,
        .write    = picolcd_debug_eeprom_write,
        .llseek   = generic_file_llseek,
};

/*
 * The "flash" file
 */
/* record a flash address to buf (bounds check to be done by caller) */
static int _picolcd_flash_setaddr(struct picolcd_data *data, u8 *buf, long off)
{
        buf[0] = off & 0xff;
        buf[1] = (off >> 8) & 0xff;
        if (data->addr_sz == 3)
                buf[2] = (off >> 16) & 0xff;
        return data->addr_sz == 2 ? 2 : 3;
}

/* read a given size of data (bounds check to be done by caller) */
static ssize_t _picolcd_flash_read(struct picolcd_data *data, int report_id,
                char __user *u, size_t s, loff_t *off)
{
        struct picolcd_pending *resp;
        u8 raw_data[4];
        ssize_t ret = 0;
        int len_off, err = -EIO;

        while (s > 0) {
                err = -EIO;
                len_off = _picolcd_flash_setaddr(data, raw_data, *off);
                raw_data[len_off] = s > 32 ? 32 : s;
                resp = picolcd_send_and_wait(data->hdev, report_id, raw_data, len_off+1);
                if (!resp || !resp->in_report)
                        goto skip;
                if (resp->in_report->id == REPORT_MEMORY ||
                        resp->in_report->id == REPORT_BL_READ_MEMORY) {
                        if (memcmp(raw_data, resp->raw_data, len_off+1) != 0)
                                goto skip;
                        if (copy_to_user(u+ret, resp->raw_data+len_off+1, raw_data[len_off])) {
                                err = -EFAULT;
                                goto skip;
                        }
                        *off += raw_data[len_off];
                        s    -= raw_data[len_off];
                        ret  += raw_data[len_off];
                        err   = 0;
                }
skip:
                kfree(resp);
                if (err)
                        return ret > 0 ? ret : err;
        }
        return ret;
}

static ssize_t picolcd_debug_flash_read(struct file *f, char __user *u,
                size_t s, loff_t *off)
{
        struct picolcd_data *data = f->private_data;

        if (s == 0)
                return -EINVAL;
        if (*off > 0x05fff)
                return 0;
        if (*off + s > 0x05fff)
                s = 0x06000 - *off;

        if (data->status & PICOLCD_BOOTLOADER)
                return _picolcd_flash_read(data, REPORT_BL_READ_MEMORY, u, s, off);
        else
                return _picolcd_flash_read(data, REPORT_READ_MEMORY, u, s, off);
}

/* erase block aligned to 64bytes boundary */
static ssize_t _picolcd_flash_erase64(struct picolcd_data *data, int report_id,
                loff_t *off)
{
        struct picolcd_pending *resp;
        u8 raw_data[3];
        int len_off;
        ssize_t ret = -EIO;

        if (*off & 0x3f)
                return -EINVAL;

        len_off = _picolcd_flash_setaddr(data, raw_data, *off);
        resp = picolcd_send_and_wait(data->hdev, report_id, raw_data, len_off);
        if (!resp || !resp->in_report)
                goto skip;
        if (resp->in_report->id == REPORT_MEMORY ||
                resp->in_report->id == REPORT_BL_ERASE_MEMORY) {
                if (memcmp(raw_data, resp->raw_data, len_off) != 0)
                        goto skip;
                ret = 0;
        }
skip:
        kfree(resp);
        return ret;
}

/* write a given size of data (bounds check to be done by caller) */
static ssize_t _picolcd_flash_write(struct picolcd_data *data, int report_id,
                const char __user *u, size_t s, loff_t *off)
{
        struct picolcd_pending *resp;
        u8 raw_data[36];
        ssize_t ret = 0;
        int len_off, err = -EIO;

        while (s > 0) {
                err = -EIO;
                len_off = _picolcd_flash_setaddr(data, raw_data, *off);
                raw_data[len_off] = s > 32 ? 32 : s;
                if (copy_from_user(raw_data+len_off+1, u, raw_data[len_off])) {
                        err = -EFAULT;
                        break;
                }
                resp = picolcd_send_and_wait(data->hdev, report_id, raw_data,
                                len_off+1+raw_data[len_off]);
                if (!resp || !resp->in_report)
                        goto skip;
                if (resp->in_report->id == REPORT_MEMORY ||
                        resp->in_report->id == REPORT_BL_WRITE_MEMORY) {
                        if (memcmp(raw_data, resp->raw_data, len_off+1+raw_data[len_off]) != 0)
                                goto skip;
                        *off += raw_data[len_off];
                        s    -= raw_data[len_off];
                        ret  += raw_data[len_off];
                        err   = 0;
                }
skip:
                kfree(resp);
                if (err)
                        break;
        }
        return ret > 0 ? ret : err;
}

static ssize_t picolcd_debug_flash_write(struct file *f, const char __user *u,
                size_t s, loff_t *off)
{
        struct picolcd_data *data = f->private_data;
        ssize_t err, ret = 0;
        int report_erase, report_write;

        if (s == 0)
                return -EINVAL;
        if (*off > 0x5fff)
                return -ENOSPC;
        if (s & 0x3f)
                return -EINVAL;
        if (*off & 0x3f)
                return -EINVAL;

        if (data->status & PICOLCD_BOOTLOADER) {
                report_erase = REPORT_BL_ERASE_MEMORY;
                report_write = REPORT_BL_WRITE_MEMORY;
        } else {
                report_erase = REPORT_ERASE_MEMORY;
                report_write = REPORT_WRITE_MEMORY;
        }
        mutex_lock(&data->mutex_flash);
        while (s > 0) {
                err = _picolcd_flash_erase64(data, report_erase, off);
                if (err)
                        break;
                err = _picolcd_flash_write(data, report_write, u, 64, off);
                if (err < 0)
                        break;
                ret += err;
                *off += err;
                s -= err;
                if (err != 64)
                        break;
        }
        mutex_unlock(&data->mutex_flash);
        return ret > 0 ? ret : err;
}

/*
 * Notes:
 * - concurrent writing is prevented by mutex and all writes must be
 *   n*64 bytes and 64-byte aligned, each write being preceded by an
 *   ERASE which erases a 64byte block.
 *   If less than requested was written or an error is returned for an
 *   otherwise correct write request the next 64-byte block which should
 *   have been written is in undefined state (mostly: original, erased,
 *   (half-)written with write error)
 * - reading can happen without special restriction
 */
static const struct file_operations picolcd_debug_flash_fops = {
        .owner    = THIS_MODULE,
        .open     = simple_open,
        .read     = picolcd_debug_flash_read,
        .write    = picolcd_debug_flash_write,
        .llseek   = generic_file_llseek,
};


/*
 * Helper code for HID report level dumping/debugging
 */
static const char * const error_codes[] = {
        "success", "parameter missing", "data_missing", "block readonly",
        "block not erasable", "block too big", "section overflow",
        "invalid command length", "invalid data length",
};

static void dump_buff_as_hex(char *dst, size_t dst_sz, const u8 *data,
                const size_t data_len)
{
        int i, j;
        for (i = j = 0; i < data_len && j + 4 < dst_sz; i++) {
                dst[j++] = hex_asc[(data[i] >> 4) & 0x0f];
                dst[j++] = hex_asc[data[i] & 0x0f];
                dst[j++] = ' ';
        }
        dst[j]   = '\0';
        if (j > 0)
                dst[j-1] = '\n';
        if (i < data_len && j > 2)
                dst[j-2] = dst[j-3] = '.';
}

void picolcd_debug_out_report(struct picolcd_data *data,
                struct hid_device *hdev, struct hid_report *report)
{
        u8 *raw_data;
        int raw_size = (report->size >> 3) + 1;
        char *buff;
#define BUFF_SZ 256

        /* Avoid unnecessary overhead if debugfs is disabled */
        if (list_empty(&hdev->debug_list))
                return;

        buff = kmalloc(BUFF_SZ, GFP_ATOMIC);
        if (!buff)
                return;

        raw_data = hid_alloc_report_buf(report, GFP_ATOMIC);
        if (!raw_data) {
                kfree(buff);
                return;
        }

        snprintf(buff, BUFF_SZ, "\nout report %d (size %d) =  ",
                        report->id, raw_size);
        hid_debug_event(hdev, buff);
        raw_data[0] = report->id;
        hid_output_report(report, raw_data);
        dump_buff_as_hex(buff, BUFF_SZ, raw_data, raw_size);
        hid_debug_event(hdev, buff);

        switch (report->id) {
        case REPORT_LED_STATE:
                /* 1 data byte with GPO state */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_LED_STATE", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tGPO state: 0x%02x\n", raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_BRIGHTNESS:
                /* 1 data byte with brightness */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_BRIGHTNESS", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tBrightness: 0x%02x\n", raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_CONTRAST:
                /* 1 data byte with contrast */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_CONTRAST", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tContrast: 0x%02x\n", raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_RESET:
                /* 2 data bytes with reset duration in ms */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_RESET", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tDuration: 0x%02x%02x (%dms)\n",
                                raw_data[2], raw_data[1], raw_data[2] << 8 | raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_LCD_CMD:
                /* 63 data bytes with LCD commands */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_LCD_CMD", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                /* TODO: format decoding */
                break;
        case REPORT_LCD_DATA:
                /* 63 data bytes with LCD data */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_LCD_CMD", report->id, raw_size-1);
                /* TODO: format decoding */
                hid_debug_event(hdev, buff);
                break;
        case REPORT_LCD_CMD_DATA:
                /* 63 data bytes with LCD commands and data */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_LCD_CMD", report->id, raw_size-1);
                /* TODO: format decoding */
                hid_debug_event(hdev, buff);
                break;
        case REPORT_EE_READ:
                /* 3 data bytes with read area description */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_EE_READ", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_EE_WRITE:
                /* 3+1..20 data bytes with write area description */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_EE_WRITE", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                hid_debug_event(hdev, buff);
                if (raw_data[3] == 0) {
                        snprintf(buff, BUFF_SZ, "\tNo data\n");
                } else if (raw_data[3] + 4 <= raw_size) {
                        snprintf(buff, BUFF_SZ, "\tData: ");
                        hid_debug_event(hdev, buff);
                        dump_buff_as_hex(buff, BUFF_SZ, raw_data+4, raw_data[3]);
                } else {
                        snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                }
                hid_debug_event(hdev, buff);
                break;
        case REPORT_ERASE_MEMORY:
        case REPORT_BL_ERASE_MEMORY:
                /* 3 data bytes with pointer inside erase block */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_ERASE_MEMORY", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                switch (data->addr_sz) {
                case 2:
                        snprintf(buff, BUFF_SZ, "\tAddress inside 64 byte block: 0x%02x%02x\n",
                                        raw_data[2], raw_data[1]);
                        break;
                case 3:
                        snprintf(buff, BUFF_SZ, "\tAddress inside 64 byte block: 0x%02x%02x%02x\n",
                                        raw_data[3], raw_data[2], raw_data[1]);
                        break;
                default:
                        snprintf(buff, BUFF_SZ, "\tNot supported\n");
                }
                hid_debug_event(hdev, buff);
                break;
        case REPORT_READ_MEMORY:
        case REPORT_BL_READ_MEMORY:
                /* 4 data bytes with read area description */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_READ_MEMORY", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                switch (data->addr_sz) {
                case 2:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                        raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                        break;
                case 3:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x%02x\n",
                                        raw_data[3], raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[4]);
                        break;
                default:
                        snprintf(buff, BUFF_SZ, "\tNot supported\n");
                }
                hid_debug_event(hdev, buff);
                break;
        case REPORT_WRITE_MEMORY:
        case REPORT_BL_WRITE_MEMORY:
                /* 4+1..32 data bytes with write adrea description */
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_WRITE_MEMORY", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                switch (data->addr_sz) {
                case 2:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                        raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                        hid_debug_event(hdev, buff);
                        if (raw_data[3] == 0) {
                                snprintf(buff, BUFF_SZ, "\tNo data\n");
                        } else if (raw_data[3] + 4 <= raw_size) {
                                snprintf(buff, BUFF_SZ, "\tData: ");
                                hid_debug_event(hdev, buff);
                                dump_buff_as_hex(buff, BUFF_SZ, raw_data+4, raw_data[3]);
                        } else {
                                snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                        }
                        break;
                case 3:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x%02x\n",
                                        raw_data[3], raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[4]);
                        hid_debug_event(hdev, buff);
                        if (raw_data[4] == 0) {
                                snprintf(buff, BUFF_SZ, "\tNo data\n");
                        } else if (raw_data[4] + 5 <= raw_size) {
                                snprintf(buff, BUFF_SZ, "\tData: ");
                                hid_debug_event(hdev, buff);
                                dump_buff_as_hex(buff, BUFF_SZ, raw_data+5, raw_data[4]);
                        } else {
                                snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                        }
                        break;
                default:
                        snprintf(buff, BUFF_SZ, "\tNot supported\n");
                }
                hid_debug_event(hdev, buff);
                break;
        case REPORT_SPLASH_RESTART:
                /* TODO */
                break;
        case REPORT_EXIT_KEYBOARD:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_EXIT_KEYBOARD", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tRestart delay: %dms (0x%02x%02x)\n",
                                raw_data[1] | (raw_data[2] << 8),
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_VERSION:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_VERSION", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_DEVID:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_DEVID", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_SPLASH_SIZE:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_SPLASH_SIZE", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_HOOK_VERSION:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_HOOK_VERSION", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_EXIT_FLASHER:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "REPORT_VERSION", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tRestart delay: %dms (0x%02x%02x)\n",
                                raw_data[1] | (raw_data[2] << 8),
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        default:
                snprintf(buff, BUFF_SZ, "out report %s (%d, size=%d)\n",
                        "<unknown>", report->id, raw_size-1);
                hid_debug_event(hdev, buff);
                break;
        }
        wake_up_interruptible(&hdev->debug_wait);
        kfree(raw_data);
        kfree(buff);
}

void picolcd_debug_raw_event(struct picolcd_data *data,
                struct hid_device *hdev, struct hid_report *report,
                u8 *raw_data, int size)
{
        char *buff;

#define BUFF_SZ 256
        /* Avoid unnecessary overhead if debugfs is disabled */
        if (list_empty(&hdev->debug_list))
                return;

        buff = kmalloc(BUFF_SZ, GFP_ATOMIC);
        if (!buff)
                return;

        switch (report->id) {
        case REPORT_ERROR_CODE:
                /* 2 data bytes with affected report and error code */
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_ERROR_CODE", report->id, size-1);
                hid_debug_event(hdev, buff);
                if (raw_data[2] < ARRAY_SIZE(error_codes))
                        snprintf(buff, BUFF_SZ, "\tError code 0x%02x (%s) in reply to report 0x%02x\n",
                                        raw_data[2], error_codes[raw_data[2]], raw_data[1]);
                else
                        snprintf(buff, BUFF_SZ, "\tError code 0x%02x in reply to report 0x%02x\n",
                                        raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_KEY_STATE:
                /* 2 data bytes with key state */
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_KEY_STATE", report->id, size-1);
                hid_debug_event(hdev, buff);
                if (raw_data[1] == 0)
                        snprintf(buff, BUFF_SZ, "\tNo key pressed\n");
                else if (raw_data[2] == 0)
                        snprintf(buff, BUFF_SZ, "\tOne key pressed: 0x%02x (%d)\n",
                                        raw_data[1], raw_data[1]);
                else
                        snprintf(buff, BUFF_SZ, "\tTwo keys pressed: 0x%02x (%d), 0x%02x (%d)\n",
                                        raw_data[1], raw_data[1], raw_data[2], raw_data[2]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_IR_DATA:
                /* Up to 20 byes of IR scancode data */
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_IR_DATA", report->id, size-1);
                hid_debug_event(hdev, buff);
                if (raw_data[1] == 0) {
                        snprintf(buff, BUFF_SZ, "\tUnexpectedly 0 data length\n");
                        hid_debug_event(hdev, buff);
                } else if (raw_data[1] + 1 <= size) {
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n\tIR Data: ",
                                        raw_data[1]);
                        hid_debug_event(hdev, buff);
                        dump_buff_as_hex(buff, BUFF_SZ, raw_data+2, raw_data[1]);
                        hid_debug_event(hdev, buff);
                } else {
                        snprintf(buff, BUFF_SZ, "\tOverflowing data length: %d\n",
                                        raw_data[1]-1);
                        hid_debug_event(hdev, buff);
                }
                break;
        case REPORT_EE_DATA:
                /* Data buffer in response to REPORT_EE_READ or REPORT_EE_WRITE */
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_EE_DATA", report->id, size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                hid_debug_event(hdev, buff);
                if (raw_data[3] == 0) {
                        snprintf(buff, BUFF_SZ, "\tNo data\n");
                        hid_debug_event(hdev, buff);
                } else if (raw_data[3] + 4 <= size) {
                        snprintf(buff, BUFF_SZ, "\tData: ");
                        hid_debug_event(hdev, buff);
                        dump_buff_as_hex(buff, BUFF_SZ, raw_data+4, raw_data[3]);
                        hid_debug_event(hdev, buff);
                } else {
                        snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                        hid_debug_event(hdev, buff);
                }
                break;
        case REPORT_MEMORY:
                /* Data buffer in response to REPORT_READ_MEMORY or REPORT_WRITE_MEMORY */
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_MEMORY", report->id, size-1);
                hid_debug_event(hdev, buff);
                switch (data->addr_sz) {
                case 2:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x\n",
                                        raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[3]);
                        hid_debug_event(hdev, buff);
                        if (raw_data[3] == 0) {
                                snprintf(buff, BUFF_SZ, "\tNo data\n");
                        } else if (raw_data[3] + 4 <= size) {
                                snprintf(buff, BUFF_SZ, "\tData: ");
                                hid_debug_event(hdev, buff);
                                dump_buff_as_hex(buff, BUFF_SZ, raw_data+4, raw_data[3]);
                        } else {
                                snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                        }
                        break;
                case 3:
                        snprintf(buff, BUFF_SZ, "\tData address: 0x%02x%02x%02x\n",
                                        raw_data[3], raw_data[2], raw_data[1]);
                        hid_debug_event(hdev, buff);
                        snprintf(buff, BUFF_SZ, "\tData length: %d\n", raw_data[4]);
                        hid_debug_event(hdev, buff);
                        if (raw_data[4] == 0) {
                                snprintf(buff, BUFF_SZ, "\tNo data\n");
                        } else if (raw_data[4] + 5 <= size) {
                                snprintf(buff, BUFF_SZ, "\tData: ");
                                hid_debug_event(hdev, buff);
                                dump_buff_as_hex(buff, BUFF_SZ, raw_data+5, raw_data[4]);
                        } else {
                                snprintf(buff, BUFF_SZ, "\tData overflowed\n");
                        }
                        break;
                default:
                        snprintf(buff, BUFF_SZ, "\tNot supported\n");
                }
                hid_debug_event(hdev, buff);
                break;
        case REPORT_VERSION:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_VERSION", report->id, size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tFirmware version: %d.%d\n",
                                raw_data[2], raw_data[1]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_BL_ERASE_MEMORY:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_BL_ERASE_MEMORY", report->id, size-1);
                hid_debug_event(hdev, buff);
                /* TODO */
                break;
        case REPORT_BL_READ_MEMORY:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_BL_READ_MEMORY", report->id, size-1);
                hid_debug_event(hdev, buff);
                /* TODO */
                break;
        case REPORT_BL_WRITE_MEMORY:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_BL_WRITE_MEMORY", report->id, size-1);
                hid_debug_event(hdev, buff);
                /* TODO */
                break;
        case REPORT_DEVID:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_DEVID", report->id, size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tSerial: 0x%02x%02x%02x%02x\n",
                                raw_data[1], raw_data[2], raw_data[3], raw_data[4]);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tType: 0x%02x\n",
                                raw_data[5]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_SPLASH_SIZE:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_SPLASH_SIZE", report->id, size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tTotal splash space: %d\n",
                                (raw_data[2] << 8) | raw_data[1]);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tUsed splash space: %d\n",
                                (raw_data[4] << 8) | raw_data[3]);
                hid_debug_event(hdev, buff);
                break;
        case REPORT_HOOK_VERSION:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "REPORT_HOOK_VERSION", report->id, size-1);
                hid_debug_event(hdev, buff);
                snprintf(buff, BUFF_SZ, "\tFirmware version: %d.%d\n",
                                raw_data[1], raw_data[2]);
                hid_debug_event(hdev, buff);
                break;
        default:
                snprintf(buff, BUFF_SZ, "report %s (%d, size=%d)\n",
                        "<unknown>", report->id, size-1);
                hid_debug_event(hdev, buff);
                break;
        }
        wake_up_interruptible(&hdev->debug_wait);
        kfree(buff);
}

void picolcd_init_devfs(struct picolcd_data *data,
                struct hid_report *eeprom_r, struct hid_report *eeprom_w,
                struct hid_report *flash_r, struct hid_report *flash_w,
                struct hid_report *reset)
{
        struct hid_device *hdev = data->hdev;

        mutex_init(&data->mutex_flash);

        /* reset */
        if (reset)
                data->debug_reset = debugfs_create_file("reset", 0600,
                                hdev->debug_dir, data, &picolcd_debug_reset_fops);

        /* eeprom */
        if (eeprom_r || eeprom_w)
                data->debug_eeprom = debugfs_create_file("eeprom",
                        (eeprom_w ? S_IWUSR : 0) | (eeprom_r ? S_IRUSR : 0),
                        hdev->debug_dir, data, &picolcd_debug_eeprom_fops);

        /* flash */
        if (flash_r && flash_r->maxfield == 1 && flash_r->field[0]->report_size == 8)
                data->addr_sz = flash_r->field[0]->report_count - 1;
        else
                data->addr_sz = -1;
        if (data->addr_sz == 2 || data->addr_sz == 3) {
                data->debug_flash = debugfs_create_file("flash",
                        (flash_w ? S_IWUSR : 0) | (flash_r ? S_IRUSR : 0),
                        hdev->debug_dir, data, &picolcd_debug_flash_fops);
        } else if (flash_r || flash_w)
                hid_warn(hdev, "Unexpected FLASH access reports, please submit rdesc for review\n");
}

void picolcd_exit_devfs(struct picolcd_data *data)
{
        struct dentry *dent;

        dent = data->debug_reset;
        data->debug_reset = NULL;
        debugfs_remove(dent);
        dent = data->debug_eeprom;
        data->debug_eeprom = NULL;
        debugfs_remove(dent);
        dent = data->debug_flash;
        data->debug_flash = NULL;
        debugfs_remove(dent);
        mutex_destroy(&data->mutex_flash);
}