Hi, On Wed, May 19, 2021 at 11:50:41AM +0200, Emmanuel Gil Peyrot wrote: > This OTP is read-only and contains various keys used by the console to > decrypt, encrypt or verify various pieces of storage. > > Its size depends on the console, it is 128 bytes on the Wii and > 1024 bytes on the Wii U (split into eight 128 bytes banks). > > It can be used directly by writing into one register and reading from > the other one, without any additional synchronisation. > > Signed-off-by: Emmanuel Gil Peyrot <linkmauve@xxxxxxxxxxxx> > --- A link to the (third-party) documentation would be nice, either in the commit message or in the code itself. (https://wiiubrew.org/wiki/Hardware/OTP i guess) [...] > +static int nintendo_otp_reg_read(void *context, > + unsigned int reg, void *_val, size_t bytes) > +{ > + struct nintendo_otp_priv *priv = context; > + u32 *val = _val; > + int words = bytes >> 2; > + u32 bank, addr; > + > + while (words--) { > + bank = (reg << 1) & ~0xff; This is a bit non-obvious, IMHO. As far as I understand it, the expanded formula is: bank = (reg / 128) << 8; I.e. first divide by bank size, then shift the parameter into the right place. > + addr = (reg >> 2) & 0x1f; Here, I think it's about the word size (4 bytes); I think / 4 would be clearer. I *think* (but haven't checked) that gcc should generate efficent shifts for the divisions above, so using the division operator shouldn't be problem. > + iowrite32be(OTP_READ | bank | addr, priv->regs + HW_OTPCMD); > + *val++ = ioread32be(priv->regs + HW_OTPDATA); > + reg += 4; > + } > + > + return 0; > +} > + [...] > + if (of_id->data) { > + const struct nintendo_otp_devtype_data *data = of_id->data; > + config.name = data->name; > + config.size = data->num_banks * 128; Given that 128 appears a few times, perhaps a #define would be good. > + } > + > + config.dev = dev; > + config.priv = priv; > + > + nvmem = devm_nvmem_register(dev, &config); > + > + return PTR_ERR_OR_ZERO(nvmem); > +} > + > +static struct platform_driver nintendo_otp_driver = { > + .probe = nintendo_otp_probe, > + .driver = { > + .name = "nintendo-otp", > + .of_match_table = nintendo_otp_of_table, > + }, > +}; > +module_platform_driver(nintendo_otp_driver); > +MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Nintendo Wii and Wii U OTP driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.31.1 > Tested-by: Jonathan Neuschäfer <j.ne@xxxxxxxxxx> # on Wii Thanks, Jonathan Neuschäfer
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