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    ARM: OMAP5: Enable support for AVS0 for OMAP5 production devices · 21d5cc02
    Nishanth Menon authored
    OMAP5432 did go into production with AVS class0 registers which were
    mutually exclusive from AVS Class 1.5 registers.
    
    Most OMAP5-uEVM boards use the pre-production Class1.5 which has
    production efuse registers set to 0. However on production devices,
    these are set to valid data.
    
    scale_vcore logic is already smart enough to detect this and use the
    "Nominal voltage" on devices that do not have efuse registers populated.
    
    On a test production device populated as follows:
    MPU OPP_NOM:
    => md.l 0x04A0021C4 1
    4a0021c4: 03a003e9                               ....
    (0x3e9 = 1.01v) vs nom voltage of 1.06v
    MPU OPP_HIGH:
    => md.l 0x04A0021C8 1
    4a0021c8: 03400485                               ..@.
    
    MM OPP_NOM:
    => md.l 0x04A0021A4 1
    4a0021a4: 038003d4                               ....
    (0x3d4 = 980mV) vs nom voltage of 1.025v
    MM OPP_OD:
    => md.l 0x04A0021A8 1
    4a0021a8: 03600403                               ..`.
    
    CORE OPP_NOM:
    => md.l 0x04A0021D8 1
    4a0021d8: 000003cf                               ....
    (0x3cf = 975mV) vs nom voltage of 1.040v
    
    Since the efuse values are'nt currently used, we do not regress on
    existing pre-production samples (they continue to use nominal voltage).
    
    But on boards that do have production samples populated, we can leverage
    the optimal voltages necessary for proper operation.
    
    Tested on:
    a) 720-2644-001 OMAP5UEVM with production sample.
    b) 750-2628-222(A) UEVM5432G-02 with pre-production sample.
    
    Data based on OMAP5432 Technical reference Manual SWPU282AF (May
    2012-Revised Aug 2016)
    
    NOTE: All collaterals on OMAP5432 silicon itself seems to have been
    removed from ti.com, though EVM details are still available:
    http://www.ti.com/tool/OMAP5432-EVM
    
    
    
    Signed-off-by: default avatarNishanth Menon <nm@ti.com>
    21d5cc02