int hd44780_common_init_display()

in hd44780_common.c [89:161]

• 52 lines of code
• 13 McCabe index (conditional complexity)

int hd44780_common_init_display(struct charlcd *lcd)
{
	struct hd44780_common *hdc = lcd->drvdata;

	void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
	u8 init;

	if (hdc->ifwidth != 4 && hdc->ifwidth != 8)
		return -EINVAL;

	hdc->hd44780_common_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 (hdc->ifwidth == 4) {
		init >>= 4;
		write_cmd_raw = hdc->write_cmd_raw4;
	} else {
		write_cmd_raw = hdc->write_cmd;
	}
	write_cmd_raw(hdc, init);
	long_sleep(10);
	write_cmd_raw(hdc, init);
	long_sleep(10);
	write_cmd_raw(hdc, init);
	long_sleep(10);

	if (hdc->ifwidth == 4) {
		/* Switch to 4-bit mode, 1 line, small fonts */
		hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4);
		long_sleep(10);
	}

	/* set font height and lines number */
	hdc->write_cmd(hdc,
		LCD_CMD_FUNCTION_SET |
		((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
		((hdc->hd44780_common_flags & LCD_FLAG_F) ?
			LCD_CMD_FONT_5X10_DOTS : 0) |
		((hdc->hd44780_common_flags & LCD_FLAG_N) ?
			LCD_CMD_TWO_LINES : 0));
	long_sleep(10);

	/* display off, cursor off, blink off */
	hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL);
	long_sleep(10);

	hdc->write_cmd(hdc,
		LCD_CMD_DISPLAY_CTRL |	/* set display mode */
		((hdc->hd44780_common_flags & LCD_FLAG_D) ?
			LCD_CMD_DISPLAY_ON : 0) |
		((hdc->hd44780_common_flags & LCD_FLAG_C) ?
			LCD_CMD_CURSOR_ON : 0) |
		((hdc->hd44780_common_flags & LCD_FLAG_B) ?
			LCD_CMD_BLINK_ON : 0));

	charlcd_backlight(lcd,
			(hdc->hd44780_common_flags & LCD_FLAG_L) ? 1 : 0);

	long_sleep(10);

	/* entry mode set : increment, cursor shifting */
	hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);

	hd44780_common_clear_display(lcd);
	return 0;
}