static int stm32_bsec_read()

in stm32-romem.c [68:113]

• 38 lines of code
• 6 McCabe index (conditional complexity)

static int stm32_bsec_read(void *context, unsigned int offset, void *buf,
			   size_t bytes)
{
	struct stm32_romem_priv *priv = context;
	struct device *dev = priv->cfg.dev;
	u32 roffset, rbytes, val;
	u8 *buf8 = buf, *val8 = (u8 *)&val;
	int i, j = 0, ret, skip_bytes, size;

	/* Round unaligned access to 32-bits */
	roffset = rounddown(offset, 4);
	skip_bytes = offset & 0x3;
	rbytes = roundup(bytes + skip_bytes, 4);

	if (roffset + rbytes > priv->cfg.size)
		return -EINVAL;

	for (i = roffset; (i < roffset + rbytes); i += 4) {
		u32 otp = i >> 2;

		if (otp < STM32MP15_BSEC_NUM_LOWER) {
			/* read lower data from shadow registers */
			val = readl_relaxed(
				priv->base + STM32MP15_BSEC_DATA0 + i);
		} else {
			ret = stm32_bsec_smc(STM32_SMC_READ_SHADOW, otp, 0,
					     &val);
			if (ret) {
				dev_err(dev, "Can't read data%d (%d)\n", otp,
					ret);
				return ret;
			}
		}
		/* skip first bytes in case of unaligned read */
		if (skip_bytes)
			size = min(bytes, (size_t)(4 - skip_bytes));
		else
			size = min(bytes, (size_t)4);
		memcpy(&buf8[j], &val8[skip_bytes], size);
		bytes -= size;
		j += size;
		skip_bytes = 0;
	}

	return 0;
}