static int lcd2s_redefine_char()

in lcd2s.c [217:261]

• 30 lines of code
• 7 McCabe index (conditional complexity)

static int lcd2s_redefine_char(struct charlcd *lcd, char *esc)
{
	/* 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.
	 */

	struct lcd2s_data *lcd2s = lcd->drvdata;
	u8 buf[LCD2S_CHARACTER_SIZE + 2] = { LCD2S_CMD_DEF_CUSTOM_CHAR };
	u8 value;
	int shift, i;

	if (!strchr(esc, ';'))
		return 0;

	esc++;

	buf[1] = *(esc++) - '0';
	if (buf[1] > 7)
		return 1;

	i = 0;
	shift = 0;
	value = 0;
	while (*esc && i < LCD2S_CHARACTER_SIZE + 2) {
		int half;

		shift ^= 4;
		half = hex_to_bin(*esc++);
		if (half < 0)
			continue;

		value |= half << shift;
		if (shift == 0) {
			buf[i++] = value;
			value = 0;
		}
	}

	lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
	return 1;
}