1 /*
2  * Copyright 2008-2012 Freescale Semiconductor, Inc.
3  *	Dave Liu <daveliu@freescale.com>
4  *
5  * calculate the organization and timing parameter
6  * from ddr3 spd, please refer to the spec
7  * JEDEC standard No.21-C 4_01_02_11R18.pdf
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * Version 2 as published by the Free Software Foundation.
12  */
13 
14 #include <common.h>
15 #include <fsl_ddr_sdram.h>
16 
17 #include <fsl_ddr.h>
18 
19 /*
20  * Calculate the Density of each Physical Rank.
21  * Returned size is in bytes.
22  *
23  * each rank size =
24  * sdram capacity(bit) / 8 * primary bus width / sdram width
25  *
26  * where: sdram capacity  = spd byte4[3:0]
27  *        primary bus width = spd byte8[2:0]
28  *        sdram width = spd byte7[2:0]
29  *
30  * SPD byte4 - sdram density and banks
31  *	bit[3:0]	size(bit)	size(byte)
32  *	0000		256Mb		32MB
33  *	0001		512Mb		64MB
34  *	0010		1Gb		128MB
35  *	0011		2Gb		256MB
36  *	0100		4Gb		512MB
37  *	0101		8Gb		1GB
38  *	0110		16Gb		2GB
39  *
40  * SPD byte8 - module memory bus width
41  * 	bit[2:0]	primary bus width
42  *	000		8bits
43  * 	001		16bits
44  * 	010		32bits
45  * 	011		64bits
46  *
47  * SPD byte7 - module organiztion
48  * 	bit[2:0]	sdram device width
49  * 	000		4bits
50  * 	001		8bits
51  * 	010		16bits
52  * 	011		32bits
53  *
54  */
55 static unsigned long long
56 compute_ranksize(const ddr3_spd_eeprom_t *spd)
57 {
58 	unsigned long long bsize;
59 
60 	int nbit_sdram_cap_bsize = 0;
61 	int nbit_primary_bus_width = 0;
62 	int nbit_sdram_width = 0;
63 
64 	if ((spd->density_banks & 0xf) < 7)
65 		nbit_sdram_cap_bsize = (spd->density_banks & 0xf) + 28;
66 	if ((spd->bus_width & 0x7) < 4)
67 		nbit_primary_bus_width = (spd->bus_width & 0x7) + 3;
68 	if ((spd->organization & 0x7) < 4)
69 		nbit_sdram_width = (spd->organization & 0x7) + 2;
70 
71 	bsize = 1ULL << (nbit_sdram_cap_bsize - 3
72 		    + nbit_primary_bus_width - nbit_sdram_width);
73 
74 	debug("DDR: DDR III rank density = 0x%16llx\n", bsize);
75 
76 	return bsize;
77 }
78 
79 /*
80  * ddr_compute_dimm_parameters for DDR3 SPD
81  *
82  * Compute DIMM parameters based upon the SPD information in spd.
83  * Writes the results to the dimm_params_t structure pointed by pdimm.
84  *
85  */
86 unsigned int
87 ddr_compute_dimm_parameters(const ddr3_spd_eeprom_t *spd,
88 			     dimm_params_t *pdimm,
89 			     unsigned int dimm_number)
90 {
91 	unsigned int retval;
92 	unsigned int mtb_ps;
93 	int ftb_10th_ps;
94 	int i;
95 
96 	if (spd->mem_type) {
97 		if (spd->mem_type != SPD_MEMTYPE_DDR3) {
98 			printf("DIMM %u: is not a DDR3 SPD.\n", dimm_number);
99 			return 1;
100 		}
101 	} else {
102 		memset(pdimm, 0, sizeof(dimm_params_t));
103 		return 1;
104 	}
105 
106 	retval = ddr3_spd_check(spd);
107 	if (retval) {
108 		printf("DIMM %u: failed checksum\n", dimm_number);
109 		return 2;
110 	}
111 
112 	/*
113 	 * The part name in ASCII in the SPD EEPROM is not null terminated.
114 	 * Guarantee null termination here by presetting all bytes to 0
115 	 * and copying the part name in ASCII from the SPD onto it
116 	 */
117 	memset(pdimm->mpart, 0, sizeof(pdimm->mpart));
118 	if ((spd->info_size_crc & 0xF) > 1)
119 		memcpy(pdimm->mpart, spd->mpart, sizeof(pdimm->mpart) - 1);
120 
121 	/* DIMM organization parameters */
122 	pdimm->n_ranks = ((spd->organization >> 3) & 0x7) + 1;
123 	pdimm->rank_density = compute_ranksize(spd);
124 	pdimm->capacity = pdimm->n_ranks * pdimm->rank_density;
125 	pdimm->primary_sdram_width = 1 << (3 + (spd->bus_width & 0x7));
126 	if ((spd->bus_width >> 3) & 0x3)
127 		pdimm->ec_sdram_width = 8;
128 	else
129 		pdimm->ec_sdram_width = 0;
130 	pdimm->data_width = pdimm->primary_sdram_width
131 			  + pdimm->ec_sdram_width;
132 	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);
133 
134 	/* These are the types defined by the JEDEC DDR3 SPD spec */
135 	pdimm->mirrored_dimm = 0;
136 	pdimm->registered_dimm = 0;
137 	switch (spd->module_type & DDR3_SPD_MODULETYPE_MASK) {
138 	case DDR3_SPD_MODULETYPE_RDIMM:
139 	case DDR3_SPD_MODULETYPE_MINI_RDIMM:
140 	case DDR3_SPD_MODULETYPE_72B_SO_RDIMM:
141 		/* Registered/buffered DIMMs */
142 		pdimm->registered_dimm = 1;
143 		for (i = 0; i < 16; i += 2) {
144 			u8 rcw = spd->mod_section.registered.rcw[i/2];
145 			pdimm->rcw[i]   = (rcw >> 0) & 0x0F;
146 			pdimm->rcw[i+1] = (rcw >> 4) & 0x0F;
147 		}
148 		break;
149 
150 	case DDR3_SPD_MODULETYPE_UDIMM:
151 	case DDR3_SPD_MODULETYPE_SO_DIMM:
152 	case DDR3_SPD_MODULETYPE_MICRO_DIMM:
153 	case DDR3_SPD_MODULETYPE_MINI_UDIMM:
154 	case DDR3_SPD_MODULETYPE_MINI_CDIMM:
155 	case DDR3_SPD_MODULETYPE_72B_SO_UDIMM:
156 	case DDR3_SPD_MODULETYPE_72B_SO_CDIMM:
157 	case DDR3_SPD_MODULETYPE_LRDIMM:
158 	case DDR3_SPD_MODULETYPE_16B_SO_DIMM:
159 	case DDR3_SPD_MODULETYPE_32B_SO_DIMM:
160 		/* Unbuffered DIMMs */
161 		if (spd->mod_section.unbuffered.addr_mapping & 0x1)
162 			pdimm->mirrored_dimm = 1;
163 		break;
164 
165 	default:
166 		printf("unknown module_type 0x%02X\n", spd->module_type);
167 		return 1;
168 	}
169 
170 	/* SDRAM device parameters */
171 	pdimm->n_row_addr = ((spd->addressing >> 3) & 0x7) + 12;
172 	pdimm->n_col_addr = (spd->addressing & 0x7) + 9;
173 	pdimm->n_banks_per_sdram_device = 8 << ((spd->density_banks >> 4) & 0x7);
174 
175 	/*
176 	 * The SPD spec has not the ECC bit,
177 	 * We consider the DIMM as ECC capability
178 	 * when the extension bus exist
179 	 */
180 	if (pdimm->ec_sdram_width)
181 		pdimm->edc_config = 0x02;
182 	else
183 		pdimm->edc_config = 0x00;
184 
185 	/*
186 	 * The SPD spec has not the burst length byte
187 	 * but DDR3 spec has nature BL8 and BC4,
188 	 * BL8 -bit3, BC4 -bit2
189 	 */
190 	pdimm->burst_lengths_bitmask = 0x0c;
191 	pdimm->row_density = __ilog2(pdimm->rank_density);
192 
193 	/* MTB - medium timebase
194 	 * The unit in the SPD spec is ns,
195 	 * We convert it to ps.
196 	 * eg: MTB = 0.125ns (125ps)
197 	 */
198 	mtb_ps = (spd->mtb_dividend * 1000) /spd->mtb_divisor;
199 	pdimm->mtb_ps = mtb_ps;
200 
201 	/*
202 	 * FTB - fine timebase
203 	 * use 1/10th of ps as our unit to avoid floating point
204 	 * eg, 10 for 1ps, 25 for 2.5ps, 50 for 5ps
205 	 */
206 	ftb_10th_ps =
207 		((spd->ftb_div & 0xf0) >> 4) * 10 / (spd->ftb_div & 0x0f);
208 	pdimm->ftb_10th_ps = ftb_10th_ps;
209 	/*
210 	 * sdram minimum cycle time
211 	 * we assume the MTB is 0.125ns
212 	 * eg:
213 	 * tck_min=15 MTB (1.875ns) ->DDR3-1066
214 	 *        =12 MTB (1.5ns) ->DDR3-1333
215 	 *        =10 MTB (1.25ns) ->DDR3-1600
216 	 */
217 	pdimm->tckmin_x_ps = spd->tck_min * mtb_ps +
218 		(spd->fine_tck_min * ftb_10th_ps) / 10;
219 
220 	/*
221 	 * CAS latency supported
222 	 * bit4 - CL4
223 	 * bit5 - CL5
224 	 * bit18 - CL18
225 	 */
226 	pdimm->caslat_x  = ((spd->caslat_msb << 8) | spd->caslat_lsb) << 4;
227 
228 	/*
229 	 * min CAS latency time
230 	 * eg: taa_min =
231 	 * DDR3-800D	100 MTB (12.5ns)
232 	 * DDR3-1066F	105 MTB (13.125ns)
233 	 * DDR3-1333H	108 MTB (13.5ns)
234 	 * DDR3-1600H	90 MTB (11.25ns)
235 	 */
236 	pdimm->taa_ps = spd->taa_min * mtb_ps +
237 		(spd->fine_taa_min * ftb_10th_ps) / 10;
238 
239 	/*
240 	 * min write recovery time
241 	 * eg:
242 	 * twr_min = 120 MTB (15ns) -> all speed grades.
243 	 */
244 	pdimm->twr_ps = spd->twr_min * mtb_ps;
245 
246 	/*
247 	 * min RAS to CAS delay time
248 	 * eg: trcd_min =
249 	 * DDR3-800	100 MTB (12.5ns)
250 	 * DDR3-1066F	105 MTB (13.125ns)
251 	 * DDR3-1333H	108 MTB (13.5ns)
252 	 * DDR3-1600H	90 MTB (11.25)
253 	 */
254 	pdimm->trcd_ps = spd->trcd_min * mtb_ps +
255 		(spd->fine_trcd_min * ftb_10th_ps) / 10;
256 
257 	/*
258 	 * min row active to row active delay time
259 	 * eg: trrd_min =
260 	 * DDR3-800(1KB page)	80 MTB (10ns)
261 	 * DDR3-1333(1KB page)	48 MTB (6ns)
262 	 */
263 	pdimm->trrd_ps = spd->trrd_min * mtb_ps;
264 
265 	/*
266 	 * min row precharge delay time
267 	 * eg: trp_min =
268 	 * DDR3-800D	100 MTB (12.5ns)
269 	 * DDR3-1066F	105 MTB (13.125ns)
270 	 * DDR3-1333H	108 MTB (13.5ns)
271 	 * DDR3-1600H	90 MTB (11.25ns)
272 	 */
273 	pdimm->trp_ps = spd->trp_min * mtb_ps +
274 		(spd->fine_trp_min * ftb_10th_ps) / 10;
275 
276 	/* min active to precharge delay time
277 	 * eg: tRAS_min =
278 	 * DDR3-800D	300 MTB (37.5ns)
279 	 * DDR3-1066F	300 MTB (37.5ns)
280 	 * DDR3-1333H	288 MTB (36ns)
281 	 * DDR3-1600H	280 MTB (35ns)
282 	 */
283 	pdimm->tras_ps = (((spd->tras_trc_ext & 0xf) << 8) | spd->tras_min_lsb)
284 			* mtb_ps;
285 	/*
286 	 * min active to actice/refresh delay time
287 	 * eg: tRC_min =
288 	 * DDR3-800D	400 MTB (50ns)
289 	 * DDR3-1066F	405 MTB (50.625ns)
290 	 * DDR3-1333H	396 MTB (49.5ns)
291 	 * DDR3-1600H	370 MTB (46.25ns)
292 	 */
293 	pdimm->trc_ps = (((spd->tras_trc_ext & 0xf0) << 4) | spd->trc_min_lsb)
294 			* mtb_ps + (spd->fine_trc_min * ftb_10th_ps) / 10;
295 	/*
296 	 * min refresh recovery delay time
297 	 * eg: tRFC_min =
298 	 * 512Mb	720 MTB (90ns)
299 	 * 1Gb		880 MTB (110ns)
300 	 * 2Gb		1280 MTB (160ns)
301 	 */
302 	pdimm->trfc_ps = ((spd->trfc_min_msb << 8) | spd->trfc_min_lsb)
303 			* mtb_ps;
304 	/*
305 	 * min internal write to read command delay time
306 	 * eg: twtr_min = 40 MTB (7.5ns) - all speed bins.
307 	 * tWRT is at least 4 mclk independent of operating freq.
308 	 */
309 	pdimm->twtr_ps = spd->twtr_min * mtb_ps;
310 
311 	/*
312 	 * min internal read to precharge command delay time
313 	 * eg: trtp_min = 40 MTB (7.5ns) - all speed bins.
314 	 * tRTP is at least 4 mclk independent of operating freq.
315 	 */
316 	pdimm->trtp_ps = spd->trtp_min * mtb_ps;
317 
318 	/*
319 	 * Average periodic refresh interval
320 	 * tREFI = 7.8 us at normal temperature range
321 	 *       = 3.9 us at ext temperature range
322 	 */
323 	pdimm->refresh_rate_ps = 7800000;
324 	if ((spd->therm_ref_opt & 0x1) && !(spd->therm_ref_opt & 0x2)) {
325 		pdimm->refresh_rate_ps = 3900000;
326 		pdimm->extended_op_srt = 1;
327 	}
328 
329 	/*
330 	 * min four active window delay time
331 	 * eg: tfaw_min =
332 	 * DDR3-800(1KB page)	320 MTB (40ns)
333 	 * DDR3-1066(1KB page)	300 MTB (37.5ns)
334 	 * DDR3-1333(1KB page)	240 MTB (30ns)
335 	 * DDR3-1600(1KB page)	240 MTB (30ns)
336 	 */
337 	pdimm->tfaw_ps = (((spd->tfaw_msb & 0xf) << 8) | spd->tfaw_min)
338 			* mtb_ps;
339 
340 	return 0;
341 }
342