Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Geert Uytterhoeven | 3434 | 90.49% | 3 | 17.65% |
Miguel Ojeda Sandonis | 220 | 5.80% | 2 | 11.76% |
Måns Rullgård | 64 | 1.69% | 3 | 17.65% |
Andy Shevchenko | 36 | 0.95% | 2 | 11.76% |
Willy Tarreau | 30 | 0.79% | 1 | 5.88% |
Robert ABEL | 9 | 0.24% | 4 | 23.53% |
Masahiro Yamada | 1 | 0.03% | 1 | 5.88% |
Sean Young | 1 | 0.03% | 1 | 5.88% |
Total | 3795 | 17 |
// SPDX-License-Identifier: GPL-2.0+ /* * Character LCD driver for Linux * * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu> * Copyright (C) 2016-2017 Glider bvba */ #include <linux/atomic.h> #include <linux/ctype.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 "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 charlcd_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) { 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 = 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); } 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 = 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, 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 = charlcd_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 = charlcd_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 = charlcd_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->hwidth; pos++) lcd->ops->write_data(lcd, ' '); charlcd_home(lcd); } /* clears the display and resets X/Y */ static void charlcd_clear_display(struct charlcd *lcd) { struct charlcd_priv *priv = charlcd_to_priv(lcd); lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CLEAR); priv->addr.x = 0; priv->addr.y = 0; /* we must wait a few milliseconds (15) */ long_sleep(15); } static int charlcd_init_display(struct charlcd *lcd) { void (*write_cmd_raw)(struct charlcd *lcd, int cmd); struct charlcd_priv *priv = charlcd_to_priv(lcd); u8 init; if (lcd->ifwidth != 4 && lcd->ifwidth != 8) return -EINVAL; priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D | LCD_FLAG_C | LCD_FLAG_B; long_sleep(20); /* wait 20 ms after power-up for the paranoid */ /* * 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure * the LCD is in 8-bit mode afterwards */ init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS; if (lcd->ifwidth == 4) { init >>= 4; write_cmd_raw = lcd->ops->write_cmd_raw4; } else { write_cmd_raw = lcd->ops->write_cmd; } write_cmd_raw(lcd, init); long_sleep(10); write_cmd_raw(lcd, init); long_sleep(10); write_cmd_raw(lcd, init); long_sleep(10); if (lcd->ifwidth == 4) { /* Switch to 4-bit mode, 1 line, small fonts */ lcd->ops->write_cmd_raw4(lcd, LCD_CMD_FUNCTION_SET >> 4); long_sleep(10); } /* set font height and lines number */ lcd->ops->write_cmd(lcd, LCD_CMD_FUNCTION_SET | ((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) | ((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) | ((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0)); long_sleep(10); /* display off, cursor off, blink off */ lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CTRL); long_sleep(10); lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CTRL | /* set display mode */ ((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) | ((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) | ((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0)); charlcd_backlight(lcd, (priv->flags & LCD_FLAG_L) ? 1 : 0); long_sleep(10); /* entry mode set : increment, cursor shifting */ lcd->ops->write_cmd(lcd, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC); charlcd_clear_display(lcd); return 0; } /* * Parses an unsigned integer from a string, until a non-digit character * is found. The empty string is not accepted. No overflow checks are done. * * Returns whether the parsing was successful. Only in that case * the output parameters are written to. * * TODO: If the kernel adds an inplace version of kstrtoul(), this function * could be easily replaced by that. */ static bool parse_n(const char *s, unsigned long *res, const char **next_s) { if (!isdigit(*s)) return false; *res = 0; while (isdigit(*s)) { *res = *res * 10 + (*s - '0'); ++s; } *next_s = s; return true; } /* * 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 (<original x>, <original y>). * - "x1;" returns (1, <original y>). * - "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; for (;;) { if (!*s) return false; if (*s == ';') break; if (*s == 'x') { if (!parse_n(s + 1, &new_x, &s)) return false; } else if (*s == 'y') { if (!parse_n(s + 1, &new_y, &s)) return false; } 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; processed = 1; break; case 'd': /* Display OFF */ priv->flags &= ~LCD_FLAG_D; processed = 1; break; case 'C': /* Cursor ON */ priv->flags |= LCD_FLAG_C; processed = 1; break; case 'c': /* Cursor OFF */ priv->flags &= ~LCD_FLAG_C; processed = 1; break; case 'B': /* Blink ON */ priv->flags |= LCD_FLAG_B; processed = 1; break; case 'b': /* Blink OFF */ priv->flags &= ~LCD_FLAG_B; processed = 1; break; case '+': /* Back light ON */ priv->flags |= LCD_FLAG_L; processed = 1; break; case '-': /* Back light OFF */ priv->flags &= ~LCD_FLAG_L; processed = 1; break; case '*': /* Flash back light */ charlcd_poke(lcd); processed = 1; break; case 'f': /* Small Font */ priv->flags &= ~LCD_FLAG_F; processed = 1; break; case 'F': /* Large Font */ priv->flags |= LCD_FLAG_F; processed = 1; break; case 'n': /* One Line */ priv->flags &= ~LCD_FLAG_N; processed = 1; break; case 'N': /* Two Lines */ priv->flags |= LCD_FLAG_N; processed = 1; break; case 'l': /* Shift Cursor Left */ if (priv->addr.x > 0) { /* back one char if not at end of line */ if (priv->addr.x < lcd->bwidth) lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); priv->addr.x--; } processed = 1; break; case 'r': /* shift cursor right */ if (priv->addr.x < lcd->width) { /* allow the cursor to pass the end of the line */ if (priv->addr.x < (lcd->bwidth - 1)) lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT); priv->addr.x++; } processed = 1; break; case 'L': /* shift display left */ lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT); processed = 1; break; case 'R': /* shift display right */ lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT | LCD_CMD_SHIFT_RIGHT); processed = 1; break; case 'k': { /* kill end of line */ int x; for (x = priv->addr.x; x < lcd->bwidth; x++) lcd->ops->write_data(lcd, ' '); /* restore cursor position */ charlcd_gotoxy(lcd); processed = 1; break; } case 'I': /* reinitialize display */ charlcd_init_display(lcd); processed = 1; break; case 'G': { /* Generator : LGcxxxxx...xx; must have <c> between '0' * and '7', representing the numerical ASCII code of the * redefined character, and <xx...xx> a sequence of 16 * hex digits representing 8 bytes for each character. * Most LCDs will only use 5 lower bits of the 7 first * bytes. */ unsigned char cgbytes[8]; unsigned char cgaddr; int cgoffset; int shift; char value; int addr; if (!strchr(esc, ';')) break; esc++; cgaddr = *(esc++) - '0'; if (cgaddr > 7) { processed = 1; break; } cgoffset = 0; shift = 0; value = 0; while (*esc && cgoffset < 8) { shift ^= 4; if (*esc >= '0' && *esc <= '9') { value |= (*esc - '0') << shift; } else if (*esc >= 'A' && *esc <= 'F') { value |= (*esc - 'A' + 10) << shift; } else if (*esc >= 'a' && *esc <= 'f') { value |= (*esc - 'a' + 10) << shift; } else { esc++; continue; } if (shift == 0) { cgbytes[cgoffset++] = value; value = 0; } esc++; } lcd->ops->write_cmd(lcd, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8)); for (addr = 0; addr < cgoffset; addr++) lcd->ops->write_data(lcd, cgbytes[addr]); /* ensures that we stop writing to CGRAM */ charlcd_gotoxy(lcd); 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, &priv->addr.x, &priv->addr.y)) charlcd_gotoxy(lcd); /* Regardless of its validity, mark as processed */ processed = 1; break; } /* TODO: This indent party here got ugly, clean it! */ /* Check whether one flag was changed */ if (oldflags == priv->flags) return processed; /* check whether one of B,C,D flags were changed */ if ((oldflags ^ priv->flags) & (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D)) /* set display mode */ lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CTRL | ((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) | ((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) | ((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0)); /* check whether one of F,N flags was changed */ else if ((oldflags ^ priv->flags) & (LCD_FLAG_F | LCD_FLAG_N)) lcd->ops->write_cmd(lcd, LCD_CMD_FUNCTION_SET | ((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) | ((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) | ((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0)); /* check whether L flag was changed */ else if ((oldflags ^ priv->flags) & LCD_FLAG_L) charlcd_backlight(lcd, !!(priv->flags & LCD_FLAG_L)); 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 (priv->addr.x > 0) { /* * check if we're not at the * end of the line */ if (priv->addr.x < lcd->bwidth) /* back one char */ lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); priv->addr.x--; } /* replace with a space */ lcd->ops->write_data(lcd, ' '); /* back one char again */ lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); break; case '\f': /* quickly clear the display */ charlcd_clear_fast(lcd); break; case '\n': /* * flush the remainder of the current line and * go to the beginning of the next line */ for (; priv->addr.x < lcd->bwidth; priv->addr.x++) lcd->ops->write_data(lcd, ' '); priv->addr.x = 0; priv->addr.y = (priv->addr.y + 1) % lcd->height; charlcd_gotoxy(lcd); break; case '\r': /* go to the beginning of the same line */ priv->addr.x = 0; charlcd_gotoxy(lcd); 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_fast(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 (!in_interrupt() && (((count + 1) & 0x1f) == 0)) /* * let's be a little nice with other processes * that need some CPU */ schedule(); 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) { charlcd_clear_display(&priv->lcd); priv->must_clear = false; } 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 (!in_interrupt() && (((count + 1) & 0x1f) == 0)) /* * let's be a little nice with other processes * that need some CPU */ schedule(); 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; 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. */ ret = charlcd_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(unsigned int drvdata_size) { struct charlcd_priv *priv; struct charlcd *lcd; priv = kzalloc(sizeof(*priv) + drvdata_size, GFP_KERNEL); if (!priv) return NULL; priv->esc_seq.len = -1; lcd = &priv->lcd; lcd->ifwidth = 8; lcd->bwidth = DEFAULT_LCD_BWIDTH; lcd->hwidth = DEFAULT_LCD_HWIDTH; lcd->drvdata = priv->drvdata; 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 = { panel_notify_sys, NULL, 0 }; 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, 0); } return 0; } EXPORT_SYMBOL_GPL(charlcd_unregister); MODULE_LICENSE("GPL");
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