18c2ecf20Sopenharmony_ciMacronix NANDs Device Tree Bindings 28c2ecf20Sopenharmony_ci----------------------------------- 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ciMacronix NANDs support randomizer operation for scrambling user data, 58c2ecf20Sopenharmony_ciwhich can be enabled with a SET_FEATURE. The penalty when using the 68c2ecf20Sopenharmony_cirandomizer are subpage accesses prohibited and more time period needed 78c2ecf20Sopenharmony_cifor program operation, i.e., tPROG 300us to 340us (randomizer enabled). 88c2ecf20Sopenharmony_ciEnabling the randomizer is a one time persistent and non reversible 98c2ecf20Sopenharmony_cioperation. 108c2ecf20Sopenharmony_ci 118c2ecf20Sopenharmony_ciFor more high-reliability concern, if subpage write is not available 128c2ecf20Sopenharmony_ciwith hardware ECC and not enabled at UBI level, then enabling the 138c2ecf20Sopenharmony_cirandomizer is recommended by default by adding a new specific property 148c2ecf20Sopenharmony_ciin children nodes. 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ciRequired NAND chip properties in children mode: 178c2ecf20Sopenharmony_ci- randomizer enable: should be "mxic,enable-randomizer-otp" 188c2ecf20Sopenharmony_ci 198c2ecf20Sopenharmony_ciExample: 208c2ecf20Sopenharmony_ci 218c2ecf20Sopenharmony_ci nand: nand-controller@unit-address { 228c2ecf20Sopenharmony_ci 238c2ecf20Sopenharmony_ci nand@0 { 248c2ecf20Sopenharmony_ci reg = <0>; 258c2ecf20Sopenharmony_ci mxic,enable-randomizer-otp; 268c2ecf20Sopenharmony_ci }; 278c2ecf20Sopenharmony_ci }; 28