// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * kernel API
 *
 * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/pps_kernel.h>
#include <linux/slab.h>

#include "kc.h"

/*
 * Local functions
 */

static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
{
	ts->nsec += offset->nsec;
	while (ts->nsec >= NSEC_PER_SEC) {
		ts->nsec -= NSEC_PER_SEC;
		ts->sec++;
	}
	while (ts->nsec < 0) {
		ts->nsec += NSEC_PER_SEC;
		ts->sec--;
	}
	ts->sec += offset->sec;
}

static void pps_echo_client_default(struct pps_device *pps, int event,
		void *data)
{
	dev_info(pps->dev, "echo %s %s\n",
		event & PPS_CAPTUREASSERT ? "assert" : "",
		event & PPS_CAPTURECLEAR ? "clear" : "");
}

/*
 * Exported functions
 */

/* pps_register_source - add a PPS source in the system
 * @info: the PPS info struct
 * @default_params: the default PPS parameters of the new source
 *
 * This function is used to add a new PPS source in the system. The new
 * source is described by info's fields and it will have, as default PPS
 * parameters, the ones specified into default_params.
 *
 * The function returns, in case of success, the PPS device. Otherwise
 * ERR_PTR(errno).
 */

struct pps_device *pps_register_source(struct pps_source_info *info,
		int default_params)
{
	struct pps_device *pps;
	int err;

	/* Sanity checks */
	if ((info->mode & default_params) != default_params) {
		pr_err("%s: unsupported default parameters\n",
					info->name);
		err = -EINVAL;
		goto pps_register_source_exit;
	}
	if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
		pr_err("%s: unspecified time format\n",
					info->name);
		err = -EINVAL;
		goto pps_register_source_exit;
	}

	/* Allocate memory for the new PPS source struct */
	pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
	if (pps == NULL) {
		err = -ENOMEM;
		goto pps_register_source_exit;
	}

	/* These initializations must be done before calling idr_alloc()
	 * in order to avoid reces into pps_event().
	 */
	pps->params.api_version = PPS_API_VERS;
	pps->params.mode = default_params;
	pps->info = *info;

	/* check for default echo function */
	if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) &&
			pps->info.echo == NULL)
		pps->info.echo = pps_echo_client_default;

	init_waitqueue_head(&pps->queue);
	spin_lock_init(&pps->lock);

	/* Create the char device */
	err = pps_register_cdev(pps);
	if (err < 0) {
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/*
 * Character LCD driver for Linux
 *
 * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu>
 * Copyright (C) 2016-2017 Glider bvba
 *
 * 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/atomic.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>

#include <generated/utsrelease.h>

#include <misc/charlcd.h>

#define LCD_MINOR		156

#define DEFAULT_LCD_BWIDTH      40
#define DEFAULT_LCD_HWIDTH      64

/* Keep the backlight on this many seconds for each flash */
#define LCD_BL_TEMPO_PERIOD	4

#define LCD_FLAG_B		0x0004	/* Blink on */
#define LCD_FLAG_C		0x0008	/* Cursor on */
#define LCD_FLAG_D		0x0010	/* Display on */
#define LCD_FLAG_F		0x0020	/* Large font mode */
#define LCD_FLAG_N		0x0040	/* 2-rows mode */
#define LCD_FLAG_L		0x0080	/* Backlight enabled */

/* LCD commands */
#define LCD_CMD_DISPLAY_CLEAR	0x01	/* Clear entire display */

#define LCD_CMD_ENTRY_MODE	0x04	/* Set entry mode */
#define LCD_CMD_CURSOR_INC	0x02	/* Increment cursor */

#define LCD_CMD_DISPLAY_CTRL	0x08	/* Display control */
#define LCD_CMD_DISPLAY_ON	0x04	/* Set display on */
#define LCD_CMD_CURSOR_ON	0x02	/* Set cursor on */
#define LCD_CMD_BLINK_ON	0x01	/* Set blink on */

#define LCD_CMD_SHIFT		0x10	/* Shift cursor/display */
#define LCD_CMD_DISPLAY_SHIFT	0x08	/* Shift display instead of cursor */
#define LCD_CMD_SHIFT_RIGHT	0x04	/* Shift display/cursor to the right */

#define LCD_CMD_FUNCTION_SET	0x20	/* Set function */
#define LCD_CMD_DATA_LEN_8BITS	0x10	/* Set data length to 8 bits */
#define LCD_CMD_TWO_LINES	0x08	/* Set to two display lines */
#define LCD_CMD_FONT_5X10_DOTS	0x04	/* Set char font to 5x10 dots */

#define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */

#define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */

#define LCD_ESCAPE_LEN		24	/* Max chars for LCD escape command */
#define LCD_ESCAPE_CHAR		27	/* Use char 27 for escape command */

struct charlcd_priv {
	struct charlcd lcd;

	struct delayed_work bl_work;
	struct mutex bl_tempo_lock;	/* Protects access to bl_tempo */
	bool bl_tempo;

	bool must_clear;

	/* contains the LCD config state */
	unsigned long int flags;

	/* Contains the LCD X and Y offset */
	struct {
		unsigned long int x;
		unsigned long int y;
	} addr;

	/* Current escape sequence and it's length or -1 if outside */
	struct {
		char buf[LCD_ESCAPE_LEN + 1];
		int len;
	} esc_seq;

	unsigned long long drvdata[0];
};

#define to_priv(p)	container_of(p, struct charlcd_priv, lcd)

/* Device single-open policy control */
static atomic_t charlcd_available = ATOMIC_INIT(1);

/* sleeps that many milliseconds with a reschedule */
static void long_sleep(int ms)
{
	if (in_interrupt())
		mdelay(ms);
	else
		schedule_timeout_interruptible(msecs_to_jiffies(ms));
}

/* turn the backlight on or off */
static void charlcd_backlight(struct charlcd *lcd, int on)
{
	struct charlcd_priv *priv = to_priv(lcd);

	if (!lcd->ops->backlight)
		return;

	mutex_lock(&priv->bl_tempo_lock);
	if (!priv->bl_tempo)
		lcd->ops->backlight(lcd, on);
	mutex_unlock(&priv->bl_tempo_lock);
}

static void charlcd_bl_off(struct work_struct *work)
{
	struct delayed_work *dwork = to_delayed_work(work);
	struct charlcd_priv *priv =
		container_of(dwork, struct charlcd_priv, bl_work);

	mutex_lock(&priv->bl_tempo_lock);
	if (priv->bl_tempo) {
		priv->bl_tempo = false;
		if (!(priv->flags & LCD_FLAG_L))
			priv->lcd.ops->backlight(&priv->lcd, 0);
	}
	mutex_unlock(&priv->bl_tempo_lock);
}

/* turn the backlight on for a little while */
void charlcd_poke(struct charlcd *lcd)
{
	struct charlcd_priv *priv = to_priv(lcd);

	if (!lcd->ops->backlight)
		return;

	cancel_delayed_work_sync(&priv->bl_work);

	mutex_lock(&priv->bl_tempo_lock);
	if (!priv->bl_tempo && !(priv->flags & LCD_FLAG_L))
		lcd->ops->backlight(lcd, 1);
	priv->bl_tempo = true;
	schedule_delayed_work(&priv->bl_work, LCD_BL_TEMPO_PERIOD * HZ);
	mutex_unlock(&priv->bl_tempo_lock);
}
EXPORT_SYMBOL_GPL(charlcd_poke);

static void charlcd_gotoxy(struct charlcd *lcd)
{
	struct charlcd_priv *priv = to_priv(lcd);
	unsigned int addr;

	/*
	 * we force the cursor to stay at the end of the
	 * line if it wants to go farther
	 */
	addr = priv->addr.x < lcd->bwidth ? priv->addr.x & (lcd->hwidth - 1)
					  : lcd->bwidth - 1;
	if (priv->addr.y & 1)
		addr += lcd->hwidth;
	if (priv->addr.y & 2)
		addr += lcd->bwidth;
	lcd->ops->write_cmd(lcd, LCD_CMD_SET_DDRAM_ADDR | addr);
}

static void charlcd_home(struct charlcd *lcd)
{
	struct charlcd_priv *priv = to_priv(lcd);

	priv->addr.x = 0;
	priv->addr.y = 0;
	charlcd_gotoxy(lcd);
}

static void charlcd_print(struct charlcd *lcd, char c)
{
	struct charlcd_priv *priv = to_priv(lcd);

	if (priv->addr.x < lcd->bwidth) {
		if (lcd->char_conv)
			c = lcd->char_conv[(unsigned char)c];
		lcd->ops->write_data(lcd, c);
		priv->addr.x++;
	}
	/* prevents the cursor from wrapping onto the next line */
	if (priv->addr.x == lcd->bwidth)
		charlcd_gotoxy(lcd);
}

static void charlcd_clear_fast(struct charlcd *lcd)
{
	int pos;

	charlcd_home(lcd);

	if (lcd->ops->clear_fast)
		lcd->ops->clear_fast(lcd);
	else
		for (pos = 0; pos < min(2, lcd->height) * lcd