static int quad8_count_write()

in 104-quad-8.c [161:201]

• 23 lines of code
• 4 McCabe index (conditional complexity)

static int quad8_count_write(struct counter_device *counter,
			     struct counter_count *count, u64 val)
{
	struct quad8 *const priv = counter_priv(counter);
	const int base_offset = priv->base + 2 * count->id;
	unsigned long irqflags;
	int i;

	/* Only 24-bit values are supported */
	if (val > 0xFFFFFF)
		return -ERANGE;

	spin_lock_irqsave(&priv->lock, irqflags);

	/* Reset Byte Pointer */
	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);

	/* Counter can only be set via Preset Register */
	for (i = 0; i < 3; i++)
		outb(val >> (8 * i), base_offset);

	/* Transfer Preset Register to Counter */
	outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);

	/* Reset Byte Pointer */
	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);

	/* Set Preset Register back to original value */
	val = priv->preset[count->id];
	for (i = 0; i < 3; i++)
		outb(val >> (8 * i), base_offset);

	/* Reset Borrow, Carry, Compare, and Sign flags */
	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
	/* Reset Error flag */
	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);

	spin_unlock_irqrestore(&priv->lock, irqflags);

	return 0;
}