Re: [PATCH v4 2/2] mtd: mediatek: driver for MTK Smart Device Gen1 NAND

[Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>]

On 05/10/2016 08:13 AM, Boris Brezillon wrote:
>> +	if (config->codec == ECC_ENC) {
>> >+		/* configure ECC encoder (in bits) */
>> >+		enc_sz = config->enc_len << 3;
>> >+
>> >+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);
>> >+		reg |= (enc_sz << ECC_MS_SHIFT);
>> >+		writel(reg, ecc->regs + ECC_ENCCNFG);
>> >+
>> >+		if (config->ecc_mode != ECC_NFI_MODE)
>> >+			writel(lower_32_bits(config->addr),
>> >+				ecc->regs + ECC_ENCDIADDR);
>> >+
>> >+	} else {
>> >+		/* configure ECC decoder (in bits) */
>> >+		dec_sz = config->dec_len;
>> >+
>> >+		reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);
>> >+		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
>> >+		reg |= DEC_EMPTY_EN;
>> >+		writel(reg, ecc->regs + ECC_DECCNFG);
>> >+
>> >+		if (config->sec_mask)
>> >+			ecc->sec_mask = 1 << (config->sec_mask - 1);
>> >+	}
> I see that some of the logic could be shared between the ENC and DEC
> cases.

I guess you are referring to
reg = ecc_bit | (config->ecc_mode << ECC_MODE_SHIFT);

ok...

> BTW, why do you multiply enc_len by 8 (bits to byte conversion), but
> don't do that for dec_len?
>

just as needed by the hardware:
the config is in bits, the encoder register requires bytes, the decoder 
register requires bits.