xref: /OK3568_Linux_fs/kernel/drivers/hid/hid-picolcd_debugfs.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)

// 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);
}