[otp_ctrl/lint] Update range comparisons

This ensures we are not inserting range comparisons that can
never be false (which the linter complained about).

Signed-off-by: Michael Schaffner <[email protected]>

hw/ip/otp_ctrl/rtl/otp_ctrl.sv

@@ -231,8 +231,12 @@ module otp_ctrl
   for (genvar k = 0; k < NumPart; k++) begin : gen_part_sel
     localparam logic [OtpByteAddrWidth:0] PartEnd = (OtpByteAddrWidth+1)'(PartInfo[k].offset) +
                                                     (OtpByteAddrWidth+1)'(PartInfo[k].size);
-    assign tlul_part_sel_oh[k] = ({tlul_addr, 2'b00} >= PartInfo[k].offset) &
-                                 ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+    if (PartInfo[k].offset == 0) begin : gen_zero_offset
+      assign tlul_part_sel_oh[k] = ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+    end else begin : gen_nonzero_offset
+      assign tlul_part_sel_oh[k] = ({tlul_addr, 2'b00} >= PartInfo[k].offset) &
+                                   ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+    end
   end
 
   `ASSERT(PartSelMustBeOnehot_A, $onehot0(tlul_part_sel_oh))

hw/ip/otp_ctrl/rtl/otp_ctrl_dai.sv

@@ -702,8 +702,13 @@ module otp_ctrl_dai
     // between OtpAddrWidth and OtpByteAddrWidth, so we know that we can slice safely here.
     localparam bit [OtpAddrWidth-1:0] DigestAddrLut = DigestAddrLutInt[OtpAddrWidth-1:0];
 
-    assign part_sel_oh[k] = (dai_addr_i >= PartInfo[k].offset) &
-                            ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+    if (PartInfo[k].offset == 0) begin : gen_zero_offset
+      assign part_sel_oh[k] = ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+
+    end else begin : gen_nonzero_offset
+      assign part_sel_oh[k] = (dai_addr_i >= PartInfo[k].offset) &
+                              ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+    end
     assign digest_addr_lut[k] = DigestAddrLut;
   end
 

hw/ip/otp_ctrl/rtl/otp_ctrl_part_unbuf.sv

@@ -128,6 +128,7 @@ module otp_ctrl_part_unbuf
   logic digest_reg_en;
   logic ecc_err;
 
+  logic tlul_addr_in_range;
   logic [SwWindowAddrWidth-1:0] tlul_addr_d, tlul_addr_q;
 
   // This is only used to return bus errors when the FSM is in ErrorSt.
@@ -233,9 +234,7 @@ module otp_ctrl_part_unbuf
       ReadSt: begin
         init_done_o = 1'b1;
         // Double check the address range.
-        if ({tlul_addr_q, 2'b00} >= Info.offset &&
-            {1'b0, tlul_addr_q, 2'b00} < PartEnd &&
-             mubi8_test_false_strict(access_o.read_lock)) begin
+        if (tlul_addr_in_range && mubi8_test_false_strict(access_o.read_lock)) begin
           otp_req_o = 1'b1;
           otp_addr_sel = DataAddrSel;
           if (otp_gnt_i) begin
@@ -325,6 +324,14 @@ module otp_ctrl_part_unbuf
   // Do not forward data in case of an error.
   assign tlul_rdata_o = (tlul_rvalid_o && tlul_rerror_o == '0) ? otp_rdata_i[31:0] : '0;
 
+  if (Info.offset == 0) begin : gen_zero_offset
+    assign tlul_addr_in_range = {1'b0, tlul_addr_q, 2'b00} < PartEnd;
+
+  end else begin : gen_nonzero_offset
+    assign tlul_addr_in_range = {tlul_addr_q, 2'b00} >= Info.offset &&
+                                {1'b0, tlul_addr_q, 2'b00} < PartEnd;
+  end
+
   // Note that OTP works on halfword (16bit) addresses, hence need to
   // shift the addresses appropriately.
   logic [OtpByteAddrWidth-1:0] addr_calc;

hw/ip/otp_ctrl/rtl/otp_ctrl_scrmbl.sv

@@ -144,11 +144,12 @@ module otp_ctrl_scrmbl
     digest_iv_lut = '0;
 
     for (int k = 0; k < NumScrmblKeys; k++) begin
+      localparam logic [4:0] NumRounds = 5'(unsigned'(NumPresentRounds));
       otp_enc_key_lut[k] = rnd_cnst_key_anchor[k];
       // Due to the PRESENT key schedule, we have to step the key schedule function by
       // NumPresentRounds forwards to get the decryption key.
       otp_dec_key_lut[k] =
-          prim_cipher_pkg::present_get_dec_key128(rnd_cnst_key_anchor[k], 5'(NumPresentRounds));
+          prim_cipher_pkg::present_get_dec_key128(rnd_cnst_key_anchor[k], NumRounds);
     end
 
     for (int k = 0; k < NumDigestSets; k++) begin