diff options
Diffstat (limited to 'drivers/auxdisplay')
| -rw-r--r-- | drivers/auxdisplay/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/auxdisplay/Makefile | 1 | ||||
| -rw-r--r-- | drivers/auxdisplay/charlcd.c | 790 |
3 files changed, 794 insertions, 0 deletions
diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig index 8a8e403644d6..b4686380d4e3 100644 --- a/drivers/auxdisplay/Kconfig +++ b/drivers/auxdisplay/Kconfig @@ -13,6 +13,9 @@ menuconfig AUXDISPLAY If you say N, all options in this submenu will be skipped and disabled. +config CHARLCD + tristate "Character LCD core support" if COMPILE_TEST + if AUXDISPLAY config KS0108 diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile index cb3dd847713b..f56f45dcc78e 100644 --- a/drivers/auxdisplay/Makefile +++ b/drivers/auxdisplay/Makefile @@ -2,6 +2,7 @@ # Makefile for the kernel auxiliary displays device drivers. # +obj-$(CONFIG_CHARLCD) += charlcd.o obj-$(CONFIG_KS0108) += ks0108.o obj-$(CONFIG_CFAG12864B) += cfag12864b.o cfag12864bfb.o obj-$(CONFIG_IMG_ASCII_LCD) += img-ascii-lcd.o diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c new file mode 100644 index 000000000000..930ffb2fb317 --- /dev/null +++ b/drivers/auxdisplay/charlcd.c @@ -0,0 +1,790 @@ +/* + * 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); + + lcd->ops->write_cmd(lcd, + LCD_CMD_SET_DDRAM_ADDR | (priv->addr.y ? lcd->hwidth : 0) | + /* + * we force the cursor to stay at the end of the + * line if it wants to go farther + */ + ((priv->addr.x < lcd->bwidth) ? priv->addr.x & (lcd->hwidth - 1) + : lcd->bwidth - 1)); +} + +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 < 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 = 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) +{ + struct charlcd_priv *priv = to_priv(lcd); + + 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 */ + + /* 8bits, 1 line, small fonts; let's do it 3 times */ + lcd->ops->write_cmd(lcd, LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS); + long_sleep(10); + lcd->ops->write_cmd(lcd, LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS); + long_sleep(10); + lcd->ops->write_cmd(lcd, LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS); + long_sleep(10); + + /* set font height and lines number */ + lcd->ops->write_cmd(lcd, + LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS | + ((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; +} + +/* + * 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 = 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; + 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 <= 'Z') { + value |= (*esc - 'A' + 10) << shift; + } else if (*esc >= 'a' && *esc <= 'z') { + 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 (!strchr(esc, ';')) + break; + + while (*esc) { + if (*esc == 'x') { + esc++; + if (kstrtoul(esc, 10, &priv->addr.x) < 0) + break; + } else if (*esc == 'y') { + esc++; + if (kstrtoul(esc, 10, &priv->addr.y) < 0) + break; + } else { + break; + } + } + + charlcd_gotoxy(lcd); + 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_CMD_DATA_LEN_8BITS | + ((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 = 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 '\014': + /* 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 = to_priv(the_charlcd); + + if (!atomic_dec_and_test(&charlcd_available)) + return -EBUSY; /* open only once at a time */ + + if (file->f_mode & FMODE_READ) /* device is write-only */ + return -EPERM; + + if (priv->must_clear) { + charlcd_clear_display(&priv->lcd); + priv->must_clear = false; + } + return nonseekable_open(inode, file); +} + +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); + } +} + +/* initialize the LCD driver */ +static int charlcd_init(struct charlcd *lcd) +{ + struct charlcd_priv *priv = 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 */ +#ifdef CONFIG_PANEL_CHANGE_MESSAGE +#ifdef CONFIG_PANEL_BOOT_MESSAGE + charlcd_puts(lcd, "\x1b[Lc\x1b[Lb\x1b[L*" CONFIG_PANEL_BOOT_MESSAGE); +#endif +#else + charlcd_puts(lcd, "\x1b[Lc\x1b[Lb\x1b[L*Linux-" UTS_RELEASE "\n"); +#endif + /* 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->bwidth = DEFAULT_LCD_BWIDTH; + lcd->hwidth = DEFAULT_LCD_HWIDTH; + lcd->drvdata = priv->drvdata; + + return lcd; +} +EXPORT_SYMBOL_GPL(charlcd_alloc); + +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 = 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"); |