25  *        primary bus width = spd byte8[2:0]
26  *        sdram width = spd byte7[2:0]
33  *	0011		2Gb		256MB
36  *	0110		16Gb		2GB
39  * 	bit[2:0]	primary bus width
46  * 	bit[2:0]	sdram device width
67 		nbit_sdram_width = (spd->organization & 0x7) + 2;  in compute_ranksize()
107 		return 2;  in ddr_compute_dimm_parameters()
130 	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);  in ddr_compute_dimm_parameters()
141 		for (i = 0; i < 16; i += 2) {  in ddr_compute_dimm_parameters()
142 			u8 rcw = spd->mod_section.registered.rcw[i/2];  in ddr_compute_dimm_parameters()
192 	 * The unit in the SPD spec is ns,  in ddr_compute_dimm_parameters()
194 	 * eg: MTB = 0.125ns (125ps)  in ddr_compute_dimm_parameters()
209 	 * we assume the MTB is 0.125ns  in ddr_compute_dimm_parameters()
211 	 * tck_min=15 MTB (1.875ns) ->DDR3-1066  in ddr_compute_dimm_parameters()
212 	 *        =12 MTB (1.5ns) ->DDR3-1333  in ddr_compute_dimm_parameters()
213 	 *        =10 MTB (1.25ns) ->DDR3-1600  in ddr_compute_dimm_parameters()
229 	 * DDR3-800D	100 MTB (12.5ns)  in ddr_compute_dimm_parameters()
230 	 * DDR3-1066F	105 MTB (13.125ns)  in ddr_compute_dimm_parameters()
231 	 * DDR3-1333H	108 MTB (13.5ns)  in ddr_compute_dimm_parameters()
232 	 * DDR3-1600H	90 MTB (11.25ns)  in ddr_compute_dimm_parameters()
240 	 * twr_min = 120 MTB (15ns) -> all speed grades.  in ddr_compute_dimm_parameters()
247 	 * DDR3-800	100 MTB (12.5ns)  in ddr_compute_dimm_parameters()
248 	 * DDR3-1066F	105 MTB (13.125ns)  in ddr_compute_dimm_parameters()
249 	 * DDR3-1333H	108 MTB (13.5ns)  in ddr_compute_dimm_parameters()
258 	 * DDR3-800(1KB page)	80 MTB (10ns)  in ddr_compute_dimm_parameters()
259 	 * DDR3-1333(1KB page)	48 MTB (6ns)  in ddr_compute_dimm_parameters()
266 	 * DDR3-800D	100 MTB (12.5ns)  in ddr_compute_dimm_parameters()
267 	 * DDR3-1066F	105 MTB (13.125ns)  in ddr_compute_dimm_parameters()
268 	 * DDR3-1333H	108 MTB (13.5ns)  in ddr_compute_dimm_parameters()
269 	 * DDR3-1600H	90 MTB (11.25ns)  in ddr_compute_dimm_parameters()
276 	 * DDR3-800D	300 MTB (37.5ns)  in ddr_compute_dimm_parameters()
277 	 * DDR3-1066F	300 MTB (37.5ns)  in ddr_compute_dimm_parameters()
278 	 * DDR3-1333H	288 MTB (36ns)  in ddr_compute_dimm_parameters()
279 	 * DDR3-1600H	280 MTB (35ns)  in ddr_compute_dimm_parameters()
286 	 * DDR3-800D	400 MTB (50ns)  in ddr_compute_dimm_parameters()
287 	 * DDR3-1066F	405 MTB (50.625ns)  in ddr_compute_dimm_parameters()
288 	 * DDR3-1333H	396 MTB (49.5ns)  in ddr_compute_dimm_parameters()
289 	 * DDR3-1600H	370 MTB (46.25ns)  in ddr_compute_dimm_parameters()
296 	 * 512Mb	720 MTB (90ns)  in ddr_compute_dimm_parameters()
297 	 * 1Gb		880 MTB (110ns)  in ddr_compute_dimm_parameters()
298 	 * 2Gb		1280 MTB (160ns)  in ddr_compute_dimm_parameters()
304 	 * eg: twtr_min = 40 MTB (7.5ns) - all speed bins.  in ddr_compute_dimm_parameters()
311 	 * eg: trtp_min = 40 MTB (7.5ns) - all speed bins.  in ddr_compute_dimm_parameters()
330 	 * DDR3-800(1KB page)	320 MTB (40ns)  in ddr_compute_dimm_parameters()
331 	 * DDR3-1066(1KB page)	300 MTB (37.5ns)  in ddr_compute_dimm_parameters()
332 	 * DDR3-1333(1KB page)	240 MTB (30ns)  in ddr_compute_dimm_parameters()
333 	 * DDR3-1600(1KB page)	240 MTB (30ns)  in ddr_compute_dimm_parameters()