static int w1_f1C_write()

in slaves/w1_ds28e04.c [160:220]

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

static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data)
{
	u8 wrbuf[4];
	u8 rdbuf[W1_PAGE_SIZE + 3];
	u8 es = (addr + len - 1) & 0x1f;
	unsigned int tm = 10;
	int i;
	struct w1_f1C_data *f1C = sl->family_data;

	/* Write the data to the scratchpad */
	if (w1_reset_select_slave(sl))
		return -1;

	wrbuf[0] = W1_F1C_WRITE_SCRATCH;
	wrbuf[1] = addr & 0xff;
	wrbuf[2] = addr >> 8;

	w1_write_block(sl->master, wrbuf, 3);
	w1_write_block(sl->master, data, len);

	/* Read the scratchpad and verify */
	if (w1_reset_select_slave(sl))
		return -1;

	w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
	w1_read_block(sl->master, rdbuf, len + 3);

	/* Compare what was read against the data written */
	if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
	    (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
		return -1;

	/* Copy the scratchpad to EEPROM */
	if (w1_reset_select_slave(sl))
		return -1;

	wrbuf[0] = W1_F1C_COPY_SCRATCH;
	wrbuf[3] = es;

	for (i = 0; i < sizeof(wrbuf); ++i) {
		/* issue 10ms strong pullup (or delay) on the last byte
		   for writing the data from the scratchpad to EEPROM */
		if (w1_strong_pullup && i == sizeof(wrbuf)-1)
			w1_next_pullup(sl->master, tm);

		w1_write_8(sl->master, wrbuf[i]);
	}

	if (!w1_strong_pullup)
		msleep(tm);

	if (w1_enable_crccheck) {
		/* invalidate cached data */
		f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
	}

	/* Reset the bus to wake up the EEPROM (this may not be needed) */
	w1_reset_bus(sl->master);

	return 0;
}