370 lines
9.4 KiB
C
370 lines
9.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include "charlcd.h"
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#include "hd44780_common.h"
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/* LCD commands */
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#define LCD_CMD_DISPLAY_CLEAR 0x01 /* Clear entire display */
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#define LCD_CMD_ENTRY_MODE 0x04 /* Set entry mode */
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#define LCD_CMD_CURSOR_INC 0x02 /* Increment cursor */
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#define LCD_CMD_DISPLAY_CTRL 0x08 /* Display control */
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#define LCD_CMD_DISPLAY_ON 0x04 /* Set display on */
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#define LCD_CMD_CURSOR_ON 0x02 /* Set cursor on */
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#define LCD_CMD_BLINK_ON 0x01 /* Set blink on */
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#define LCD_CMD_SHIFT 0x10 /* Shift cursor/display */
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#define LCD_CMD_DISPLAY_SHIFT 0x08 /* Shift display instead of cursor */
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#define LCD_CMD_SHIFT_RIGHT 0x04 /* Shift display/cursor to the right */
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#define LCD_CMD_FUNCTION_SET 0x20 /* Set function */
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#define LCD_CMD_DATA_LEN_8BITS 0x10 /* Set data length to 8 bits */
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#define LCD_CMD_TWO_LINES 0x08 /* Set to two display lines */
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#define LCD_CMD_FONT_5X10_DOTS 0x04 /* Set char font to 5x10 dots */
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#define LCD_CMD_SET_CGRAM_ADDR 0x40 /* Set char generator RAM address */
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#define LCD_CMD_SET_DDRAM_ADDR 0x80 /* Set display data RAM address */
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/* sleeps that many milliseconds with a reschedule */
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static void long_sleep(int ms)
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{
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schedule_timeout_interruptible(msecs_to_jiffies(ms));
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}
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int hd44780_common_print(struct charlcd *lcd, int c)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (lcd->addr.x < hdc->bwidth) {
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hdc->write_data(hdc, c);
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return 0;
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}
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return 1;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_print);
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int hd44780_common_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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unsigned int addr;
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/*
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* we force the cursor to stay at the end of the
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* line if it wants to go farther
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*/
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addr = x < hdc->bwidth ? x & (hdc->hwidth - 1) : hdc->bwidth - 1;
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if (y & 1)
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addr += hdc->hwidth;
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if (y & 2)
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addr += hdc->bwidth;
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hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
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int hd44780_common_home(struct charlcd *lcd)
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{
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return hd44780_common_gotoxy(lcd, 0, 0);
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}
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EXPORT_SYMBOL_GPL(hd44780_common_home);
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/* clears the display and resets X/Y */
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int hd44780_common_clear_display(struct charlcd *lcd)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
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/* datasheet says to wait 1,64 milliseconds */
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long_sleep(2);
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/*
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* The Hitachi HD44780 controller (and compatible ones) reset the DDRAM
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* address when executing the DISPLAY_CLEAR command, thus the
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* following call is not required. However, other controllers do not
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* (e.g. NewHaven NHD-0220DZW-AG5), thus move the cursor to home
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* unconditionally to support both.
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*/
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return hd44780_common_home(lcd);
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}
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EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
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int hd44780_common_init_display(struct charlcd *lcd)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
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u8 init;
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if (hdc->ifwidth != 4 && hdc->ifwidth != 8)
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return -EINVAL;
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hdc->hd44780_common_flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) |
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LCD_FLAG_D | LCD_FLAG_C | LCD_FLAG_B;
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long_sleep(20); /* wait 20 ms after power-up for the paranoid */
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/*
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* 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure
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* the LCD is in 8-bit mode afterwards
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*/
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init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS;
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if (hdc->ifwidth == 4) {
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init >>= 4;
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write_cmd_raw = hdc->write_cmd_raw4;
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} else {
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write_cmd_raw = hdc->write_cmd;
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}
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write_cmd_raw(hdc, init);
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long_sleep(10);
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write_cmd_raw(hdc, init);
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long_sleep(10);
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write_cmd_raw(hdc, init);
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long_sleep(10);
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if (hdc->ifwidth == 4) {
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/* Switch to 4-bit mode, 1 line, small fonts */
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hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4);
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long_sleep(10);
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}
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/* set font height and lines number */
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hdc->write_cmd(hdc,
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LCD_CMD_FUNCTION_SET |
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((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_F) ?
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LCD_CMD_FONT_5X10_DOTS : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_N) ?
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LCD_CMD_TWO_LINES : 0));
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long_sleep(10);
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/* display off, cursor off, blink off */
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hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL);
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long_sleep(10);
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hdc->write_cmd(hdc,
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LCD_CMD_DISPLAY_CTRL | /* set display mode */
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((hdc->hd44780_common_flags & LCD_FLAG_D) ?
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LCD_CMD_DISPLAY_ON : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_C) ?
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LCD_CMD_CURSOR_ON : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_B) ?
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LCD_CMD_BLINK_ON : 0));
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charlcd_backlight(lcd,
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(hdc->hd44780_common_flags & LCD_FLAG_L) ? 1 : 0);
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long_sleep(10);
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/* entry mode set : increment, cursor shifting */
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hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
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hd44780_common_clear_display(lcd);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_init_display);
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int hd44780_common_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (dir == CHARLCD_SHIFT_LEFT) {
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/* back one char if not at end of line */
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if (lcd->addr.x < hdc->bwidth)
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hdc->write_cmd(hdc, LCD_CMD_SHIFT);
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} else if (dir == CHARLCD_SHIFT_RIGHT) {
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/* allow the cursor to pass the end of the line */
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if (lcd->addr.x < (hdc->bwidth - 1))
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hdc->write_cmd(hdc,
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LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_shift_cursor);
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int hd44780_common_shift_display(struct charlcd *lcd,
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enum charlcd_shift_dir dir)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (dir == CHARLCD_SHIFT_LEFT)
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hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
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else if (dir == CHARLCD_SHIFT_RIGHT)
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hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
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LCD_CMD_SHIFT_RIGHT);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_shift_display);
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static void hd44780_common_set_mode(struct hd44780_common *hdc)
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{
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hdc->write_cmd(hdc,
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LCD_CMD_DISPLAY_CTRL |
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((hdc->hd44780_common_flags & LCD_FLAG_D) ?
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LCD_CMD_DISPLAY_ON : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_C) ?
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LCD_CMD_CURSOR_ON : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_B) ?
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LCD_CMD_BLINK_ON : 0));
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}
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int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (on == CHARLCD_ON)
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hdc->hd44780_common_flags |= LCD_FLAG_D;
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else
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hdc->hd44780_common_flags &= ~LCD_FLAG_D;
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hd44780_common_set_mode(hdc);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_display);
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int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (on == CHARLCD_ON)
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hdc->hd44780_common_flags |= LCD_FLAG_C;
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else
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hdc->hd44780_common_flags &= ~LCD_FLAG_C;
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hd44780_common_set_mode(hdc);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_cursor);
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int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (on == CHARLCD_ON)
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hdc->hd44780_common_flags |= LCD_FLAG_B;
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else
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hdc->hd44780_common_flags &= ~LCD_FLAG_B;
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hd44780_common_set_mode(hdc);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_blink);
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static void hd44780_common_set_function(struct hd44780_common *hdc)
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{
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hdc->write_cmd(hdc,
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LCD_CMD_FUNCTION_SET |
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((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_F) ?
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LCD_CMD_FONT_5X10_DOTS : 0) |
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((hdc->hd44780_common_flags & LCD_FLAG_N) ?
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LCD_CMD_TWO_LINES : 0));
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}
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int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (size == CHARLCD_FONTSIZE_LARGE)
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hdc->hd44780_common_flags |= LCD_FLAG_F;
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else
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hdc->hd44780_common_flags &= ~LCD_FLAG_F;
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hd44780_common_set_function(hdc);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_fontsize);
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int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines)
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{
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struct hd44780_common *hdc = lcd->drvdata;
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if (lines == CHARLCD_LINES_2)
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hdc->hd44780_common_flags |= LCD_FLAG_N;
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else
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hdc->hd44780_common_flags &= ~LCD_FLAG_N;
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hd44780_common_set_function(hdc);
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return 0;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_lines);
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int hd44780_common_redefine_char(struct charlcd *lcd, char *esc)
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{
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/* Generator : LGcxxxxx...xx; must have <c> between '0'
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* and '7', representing the numerical ASCII code of the
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* redefined character, and <xx...xx> a sequence of 16
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* hex digits representing 8 bytes for each character.
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* Most LCDs will only use 5 lower bits of the 7 first
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* bytes.
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*/
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struct hd44780_common *hdc = lcd->drvdata;
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unsigned char cgbytes[8];
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unsigned char cgaddr;
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int cgoffset;
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int shift;
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char value;
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int addr;
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if (!strchr(esc, ';'))
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return 0;
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esc++;
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cgaddr = *(esc++) - '0';
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if (cgaddr > 7)
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return 1;
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cgoffset = 0;
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shift = 0;
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value = 0;
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while (*esc && cgoffset < 8) {
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int half;
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shift ^= 4;
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half = hex_to_bin(*esc++);
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if (half < 0)
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continue;
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value |= half << shift;
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if (shift == 0) {
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cgbytes[cgoffset++] = value;
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value = 0;
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}
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}
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hdc->write_cmd(hdc, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
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for (addr = 0; addr < cgoffset; addr++)
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hdc->write_data(hdc, cgbytes[addr]);
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/* ensures that we stop writing to CGRAM */
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lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
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return 1;
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}
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EXPORT_SYMBOL_GPL(hd44780_common_redefine_char);
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struct hd44780_common *hd44780_common_alloc(void)
|
||
|
|
{
|
||
|
|
struct hd44780_common *hd;
|
||
|
|
|
||
|
|
hd = kzalloc(sizeof(*hd), GFP_KERNEL);
|
||
|
|
if (!hd)
|
||
|
|
return NULL;
|
||
|
|
|
||
|
|
hd->ifwidth = 8;
|
||
|
|
hd->bwidth = DEFAULT_LCD_BWIDTH;
|
||
|
|
hd->hwidth = DEFAULT_LCD_HWIDTH;
|
||
|
|
return hd;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(hd44780_common_alloc);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|