From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/auxdisplay/charlcd.c | 681 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 681 insertions(+) create mode 100644 drivers/auxdisplay/charlcd.c (limited to 'drivers/auxdisplay/charlcd.c') diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c new file mode 100644 index 0000000000..6d309e4971 --- /dev/null +++ b/drivers/auxdisplay/charlcd.c @@ -0,0 +1,681 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Character LCD driver for Linux + * + * Copyright (C) 2000-2008, Willy Tarreau + * Copyright (C) 2016-2017 Glider bvba + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "charlcd.h" + +/* Keep the backlight on this many seconds for each flash */ +#define LCD_BL_TEMPO_PERIOD 4 + +#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 flags; + + /* 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[]; +}; + +#define charlcd_to_priv(p) container_of(p, struct charlcd_priv, lcd) + +/* Device single-open policy control */ +static atomic_t charlcd_available = ATOMIC_INIT(1); + +/* turn the backlight on or off */ +void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on) +{ + struct charlcd_priv *priv = charlcd_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); +} +EXPORT_SYMBOL_GPL(charlcd_backlight); + +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, CHARLCD_OFF); + } + mutex_unlock(&priv->bl_tempo_lock); +} + +/* turn the backlight on for a little while */ +void charlcd_poke(struct charlcd *lcd) +{ + struct charlcd_priv *priv = charlcd_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, CHARLCD_ON); + 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_home(struct charlcd *lcd) +{ + lcd->addr.x = 0; + lcd->addr.y = 0; + lcd->ops->home(lcd); +} + +static void charlcd_print(struct charlcd *lcd, char c) +{ + if (lcd->addr.x >= lcd->width) + return; + + if (lcd->char_conv) + c = lcd->char_conv[(unsigned char)c]; + + if (!lcd->ops->print(lcd, c)) + lcd->addr.x++; + + /* prevents the cursor from wrapping onto the next line */ + if (lcd->addr.x == lcd->width) + lcd->ops->gotoxy(lcd, lcd->addr.x - 1, lcd->addr.y); +} + +static void charlcd_clear_display(struct charlcd *lcd) +{ + lcd->ops->clear_display(lcd); + lcd->addr.x = 0; + lcd->addr.y = 0; +} + +/* + * Parses a movement command of the form "(.*);", where the group can be + * any number of subcommands of the form "(x|y)[0-9]+". + * + * Returns whether the command is valid. The position arguments are + * only written if the parsing was successful. + * + * For instance: + * - ";" returns (, ). + * - "x1;" returns (1, ). + * - "y2x1;" returns (1, 2). + * - "x12y34x56;" returns (56, 34). + * - "" fails. + * - "x" fails. + * - "x;" fails. + * - "x1" fails. + * - "xy12;" fails. + * - "x12yy12;" fails. + * - "xx" fails. + */ +static bool parse_xy(const char *s, unsigned long *x, unsigned long *y) +{ + unsigned long new_x = *x; + unsigned long new_y = *y; + char *p; + + for (;;) { + if (!*s) + return false; + + if (*s == ';') + break; + + if (*s == 'x') { + new_x = simple_strtoul(s + 1, &p, 10); + if (p == s + 1) + return false; + s = p; + } else if (*s == 'y') { + new_y = simple_strtoul(s + 1, &p, 10); + if (p == s + 1) + return false; + s = p; + } else { + return false; + } + } + + *x = new_x; + *y = new_y; + return true; +} + +/* + * These are the file operation function for user access to /dev/lcd + * This function can also be called from inside the kernel, by + * setting file and ppos to NULL. + * + */ + +static inline int handle_lcd_special_code(struct charlcd *lcd) +{ + struct charlcd_priv *priv = charlcd_to_priv(lcd); + + /* LCD special codes */ + + int processed = 0; + + char *esc = priv->esc_seq.buf + 2; + int oldflags = priv->flags; + + /* check for display mode flags */ + switch (*esc) { + case 'D': /* Display ON */ + priv->flags |= LCD_FLAG_D; + if (priv->flags != oldflags) + lcd->ops->display(lcd, CHARLCD_ON); + + processed = 1; + break; + case 'd': /* Display OFF */ + priv->flags &= ~LCD_FLAG_D; + if (priv->flags != oldflags) + lcd->ops->display(lcd, CHARLCD_OFF); + + processed = 1; + break; + case 'C': /* Cursor ON */ + priv->flags |= LCD_FLAG_C; + if (priv->flags != oldflags) + lcd->ops->cursor(lcd, CHARLCD_ON); + + processed = 1; + break; + case 'c': /* Cursor OFF */ + priv->flags &= ~LCD_FLAG_C; + if (priv->flags != oldflags) + lcd->ops->cursor(lcd, CHARLCD_OFF); + + processed = 1; + break; + case 'B': /* Blink ON */ + priv->flags |= LCD_FLAG_B; + if (priv->flags != oldflags) + lcd->ops->blink(lcd, CHARLCD_ON); + + processed = 1; + break; + case 'b': /* Blink OFF */ + priv->flags &= ~LCD_FLAG_B; + if (priv->flags != oldflags) + lcd->ops->blink(lcd, CHARLCD_OFF); + + processed = 1; + break; + case '+': /* Back light ON */ + priv->flags |= LCD_FLAG_L; + if (priv->flags != oldflags) + charlcd_backlight(lcd, CHARLCD_ON); + + processed = 1; + break; + case '-': /* Back light OFF */ + priv->flags &= ~LCD_FLAG_L; + if (priv->flags != oldflags) + charlcd_backlight(lcd, CHARLCD_OFF); + + processed = 1; + break; + case '*': /* Flash back light */ + charlcd_poke(lcd); + processed = 1; + break; + case 'f': /* Small Font */ + priv->flags &= ~LCD_FLAG_F; + if (priv->flags != oldflags) + lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_SMALL); + + processed = 1; + break; + case 'F': /* Large Font */ + priv->flags |= LCD_FLAG_F; + if (priv->flags != oldflags) + lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_LARGE); + + processed = 1; + break; + case 'n': /* One Line */ + priv->flags &= ~LCD_FLAG_N; + if (priv->flags != oldflags) + lcd->ops->lines(lcd, CHARLCD_LINES_1); + + processed = 1; + break; + case 'N': /* Two Lines */ + priv->flags |= LCD_FLAG_N; + if (priv->flags != oldflags) + lcd->ops->lines(lcd, CHARLCD_LINES_2); + + processed = 1; + break; + case 'l': /* Shift Cursor Left */ + if (lcd->addr.x > 0) { + if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT)) + lcd->addr.x--; + } + + processed = 1; + break; + case 'r': /* shift cursor right */ + if (lcd->addr.x < lcd->width) { + if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_RIGHT)) + lcd->addr.x++; + } + + processed = 1; + break; + case 'L': /* shift display left */ + lcd->ops->shift_display(lcd, CHARLCD_SHIFT_LEFT); + processed = 1; + break; + case 'R': /* shift display right */ + lcd->ops->shift_display(lcd, CHARLCD_SHIFT_RIGHT); + processed = 1; + break; + case 'k': { /* kill end of line */ + int x, xs, ys; + + xs = lcd->addr.x; + ys = lcd->addr.y; + for (x = lcd->addr.x; x < lcd->width; x++) + lcd->ops->print(lcd, ' '); + + /* restore cursor position */ + lcd->addr.x = xs; + lcd->addr.y = ys; + lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y); + processed = 1; + break; + } + case 'I': /* reinitialize display */ + lcd->ops->init_display(lcd); + priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D | + LCD_FLAG_C | LCD_FLAG_B; + processed = 1; + break; + case 'G': + if (lcd->ops->redefine_char) + processed = lcd->ops->redefine_char(lcd, esc); + else + processed = 1; + break; + + case 'x': /* gotoxy : LxXXX[yYYY]; */ + case 'y': /* gotoxy : LyYYY[xXXX]; */ + if (priv->esc_seq.buf[priv->esc_seq.len - 1] != ';') + break; + + /* If the command is valid, move to the new address */ + if (parse_xy(esc, &lcd->addr.x, &lcd->addr.y)) + lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y); + + /* Regardless of its validity, mark as processed */ + processed = 1; + break; + } + + return processed; +} + +static void charlcd_write_char(struct charlcd *lcd, char c) +{ + struct charlcd_priv *priv = charlcd_to_priv(lcd); + + /* first, we'll test if we're in escape mode */ + if ((c != '\n') && priv->esc_seq.len >= 0) { + /* yes, let's add this char to the buffer */ + priv->esc_seq.buf[priv->esc_seq.len++] = c; + priv->esc_seq.buf[priv->esc_seq.len] = '\0'; + } else { + /* aborts any previous escape sequence */ + priv->esc_seq.len = -1; + + switch (c) { + case LCD_ESCAPE_CHAR: + /* start of an escape sequence */ + priv->esc_seq.len = 0; + priv->esc_seq.buf[priv->esc_seq.len] = '\0'; + break; + case '\b': + /* go back one char and clear it */ + if (lcd->addr.x > 0) { + /* back one char */ + if (!lcd->ops->shift_cursor(lcd, + CHARLCD_SHIFT_LEFT)) + lcd->addr.x--; + } + /* replace with a space */ + charlcd_print(lcd, ' '); + /* back one char again */ + if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT)) + lcd->addr.x--; + + break; + case '\f': + /* quickly clear the display */ + charlcd_clear_display(lcd); + break; + case '\n': + /* + * flush the remainder of the current line and + * go to the beginning of the next line + */ + for (; lcd->addr.x < lcd->width; lcd->addr.x++) + lcd->ops->print(lcd, ' '); + + lcd->addr.x = 0; + lcd->addr.y = (lcd->addr.y + 1) % lcd->height; + lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y); + break; + case '\r': + /* go to the beginning of the same line */ + lcd->addr.x = 0; + lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y); + break; + case '\t': + /* print a space instead of the tab */ + charlcd_print(lcd, ' '); + break; + default: + /* simply print this char */ + charlcd_print(lcd, c); + break; + } + } + + /* + * now we'll see if we're in an escape mode and if the current + * escape sequence can be understood. + */ + if (priv->esc_seq.len >= 2) { + int processed = 0; + + if (!strcmp(priv->esc_seq.buf, "[2J")) { + /* clear the display */ + charlcd_clear_display(lcd); + processed = 1; + } else if (!strcmp(priv->esc_seq.buf, "[H")) { + /* cursor to home */ + charlcd_home(lcd); + processed = 1; + } + /* codes starting with ^[[L */ + else if ((priv->esc_seq.len >= 3) && + (priv->esc_seq.buf[0] == '[') && + (priv->esc_seq.buf[1] == 'L')) { + processed = handle_lcd_special_code(lcd); + } + + /* LCD special escape codes */ + /* + * flush the escape sequence if it's been processed + * or if it is getting too long. + */ + if (processed || (priv->esc_seq.len >= LCD_ESCAPE_LEN)) + priv->esc_seq.len = -1; + } /* escape codes */ +} + +static struct charlcd *the_charlcd; + +static ssize_t charlcd_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + const char __user *tmp = buf; + char c; + + for (; count-- > 0; (*ppos)++, tmp++) { + if (((count + 1) & 0x1f) == 0) { + /* + * charlcd_write() is invoked as a VFS->write() callback + * and as such it is always invoked from preemptible + * context and may sleep. + */ + cond_resched(); + } + + if (get_user(c, tmp)) + return -EFAULT; + + charlcd_write_char(the_charlcd, c); + } + + return tmp - buf; +} + +static int charlcd_open(struct inode *inode, struct file *file) +{ + struct charlcd_priv *priv = charlcd_to_priv(the_charlcd); + int ret; + + ret = -EBUSY; + if (!atomic_dec_and_test(&charlcd_available)) + goto fail; /* open only once at a time */ + + ret = -EPERM; + if (file->f_mode & FMODE_READ) /* device is write-only */ + goto fail; + + if (priv->must_clear) { + priv->lcd.ops->clear_display(&priv->lcd); + priv->must_clear = false; + priv->lcd.addr.x = 0; + priv->lcd.addr.y = 0; + } + return nonseekable_open(inode, file); + + fail: + atomic_inc(&charlcd_available); + return ret; +} + +static int charlcd_release(struct inode *inode, struct file *file) +{ + atomic_inc(&charlcd_available); + return 0; +} + +static const struct file_operations charlcd_fops = { + .write = charlcd_write, + .open = charlcd_open, + .release = charlcd_release, + .llseek = no_llseek, +}; + +static struct miscdevice charlcd_dev = { + .minor = LCD_MINOR, + .name = "lcd", + .fops = &charlcd_fops, +}; + +static void charlcd_puts(struct charlcd *lcd, const char *s) +{ + const char *tmp = s; + int count = strlen(s); + + for (; count-- > 0; tmp++) { + if (((count + 1) & 0x1f) == 0) + cond_resched(); + + charlcd_write_char(lcd, *tmp); + } +} + +#ifdef CONFIG_PANEL_BOOT_MESSAGE +#define LCD_INIT_TEXT CONFIG_PANEL_BOOT_MESSAGE +#else +#define LCD_INIT_TEXT "Linux-" UTS_RELEASE "\n" +#endif + +#ifdef CONFIG_CHARLCD_BL_ON +#define LCD_INIT_BL "\x1b[L+" +#elif defined(CONFIG_CHARLCD_BL_FLASH) +#define LCD_INIT_BL "\x1b[L*" +#else +#define LCD_INIT_BL "\x1b[L-" +#endif + +/* initialize the LCD driver */ +static int charlcd_init(struct charlcd *lcd) +{ + struct charlcd_priv *priv = charlcd_to_priv(lcd); + int ret; + + priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D | + LCD_FLAG_C | LCD_FLAG_B; + if (lcd->ops->backlight) { + mutex_init(&priv->bl_tempo_lock); + INIT_DELAYED_WORK(&priv->bl_work, charlcd_bl_off); + } + + /* + * before this line, we must NOT send anything to the display. + * Since charlcd_init_display() needs to write data, we have to + * enable mark the LCD initialized just before. + */ + if (WARN_ON(!lcd->ops->init_display)) + return -EINVAL; + + ret = lcd->ops->init_display(lcd); + if (ret) + return ret; + + /* display a short message */ + charlcd_puts(lcd, "\x1b[Lc\x1b[Lb" LCD_INIT_BL LCD_INIT_TEXT); + + /* clear the display on the next device opening */ + priv->must_clear = true; + charlcd_home(lcd); + return 0; +} + +struct charlcd *charlcd_alloc(void) +{ + struct charlcd_priv *priv; + struct charlcd *lcd; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return NULL; + + priv->esc_seq.len = -1; + + lcd = &priv->lcd; + + return lcd; +} +EXPORT_SYMBOL_GPL(charlcd_alloc); + +void charlcd_free(struct charlcd *lcd) +{ + kfree(charlcd_to_priv(lcd)); +} +EXPORT_SYMBOL_GPL(charlcd_free); + +static int panel_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + struct charlcd *lcd = the_charlcd; + + switch (code) { + case SYS_DOWN: + charlcd_puts(lcd, + "\x0cReloading\nSystem...\x1b[Lc\x1b[Lb\x1b[L+"); + break; + case SYS_HALT: + charlcd_puts(lcd, "\x0cSystem Halted.\x1b[Lc\x1b[Lb\x1b[L+"); + break; + case SYS_POWER_OFF: + charlcd_puts(lcd, "\x0cPower off.\x1b[Lc\x1b[Lb\x1b[L+"); + break; + default: + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block panel_notifier = { + .notifier_call = panel_notify_sys, +}; + +int charlcd_register(struct charlcd *lcd) +{ + int ret; + + ret = charlcd_init(lcd); + if (ret) + return ret; + + ret = misc_register(&charlcd_dev); + if (ret) + return ret; + + the_charlcd = lcd; + register_reboot_notifier(&panel_notifier); + return 0; +} +EXPORT_SYMBOL_GPL(charlcd_register); + +int charlcd_unregister(struct charlcd *lcd) +{ + struct charlcd_priv *priv = charlcd_to_priv(lcd); + + unregister_reboot_notifier(&panel_notifier); + charlcd_puts(lcd, "\x0cLCD driver unloaded.\x1b[Lc\x1b[Lb\x1b[L-"); + misc_deregister(&charlcd_dev); + the_charlcd = NULL; + if (lcd->ops->backlight) { + cancel_delayed_work_sync(&priv->bl_work); + priv->lcd.ops->backlight(&priv->lcd, CHARLCD_OFF); + } + + return 0; +} +EXPORT_SYMBOL_GPL(charlcd_unregister); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3