1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020 Marvell International Ltd.
4  */
5 
6 #include <i2c.h>
7 #include <ram.h>
8 
9 #include <mach/octeon_ddr.h>
10 
11 #define DEVICE_TYPE	DDR4_SPD_KEY_BYTE_DEVICE_TYPE // same for DDR3 and DDR4
12 #define MODULE_TYPE	DDR4_SPD_KEY_BYTE_MODULE_TYPE // same for DDR3 and DDR4
13 #define BUS_WIDTH(t)	(((t) == DDR4_DRAM) ?		    \
14 			 DDR4_SPD_MODULE_MEMORY_BUS_WIDTH : \
15 			 DDR3_SPD_MEMORY_BUS_WIDTH)
16 
17 /*
18  * Allow legacy code to encode bus number in the upper bits of the address
19  * These are only supported in read_spd()
20  */
21 #define OCTEON_TWSI_BUS_IN_ADDR_BIT       12
22 #define OCTEON_TWSI_BUS_IN_ADDR_MASK      (15 << OCTEON_TWSI_BUS_IN_ADDR_BIT)
23 #define OCTEON_TWSI_GET_BUS(addr)			\
24 	(((addr) >> OCTEON_TWSI_BUS_IN_ADDR_BIT) & 0xf)
25 
26 const char *ddr3_dimm_types[] = {
27 	/* 0000 */ "Undefined",
28 	/* 0001 */ "RDIMM",
29 	/* 0010 */ "UDIMM",
30 	/* 0011 */ "SO-DIMM",
31 	/* 0100 */ "Micro-DIMM",
32 	/* 0101 */ "Mini-RDIMM",
33 	/* 0110 */ "Mini-UDIMM",
34 	/* 0111 */ "Mini-CDIMM",
35 	/* 1000 */ "72b-SO-UDIMM",
36 	/* 1001 */ "72b-SO-RDIMM",
37 	/* 1010 */ "72b-SO-CDIMM"
38 	/* 1011 */ "LRDIMM",
39 	/* 1100 */ "16b-SO-DIMM",
40 	/* 1101 */ "32b-SO-DIMM",
41 	/* 1110 */ "Reserved",
42 	/* 1111 */ "Reserved"
43 };
44 
45 const char *ddr4_dimm_types[] = {
46 	/* 0000 */ "Extended",
47 	/* 0001 */ "RDIMM",
48 	/* 0010 */ "UDIMM",
49 	/* 0011 */ "SO-DIMM",
50 	/* 0100 */ "LRDIMM",
51 	/* 0101 */ "Mini-RDIMM",
52 	/* 0110 */ "Mini-UDIMM",
53 	/* 0111 */ "Reserved",
54 	/* 1000 */ "72b-SO-RDIMM",
55 	/* 1001 */ "72b-SO-UDIMM",
56 	/* 1010 */ "Reserved",
57 	/* 1011 */ "Reserved",
58 	/* 1100 */ "16b-SO-DIMM",
59 	/* 1101 */ "32b-SO-DIMM",
60 	/* 1110 */ "Reserved",
61 	/* 1111 */ "Reserved"
62 };
63 
ddr3_crc16(u8 * ptr,int count)64 static u16 ddr3_crc16(u8 *ptr, int count)
65 {
66 	/* From DDR3 SPD specification */
67 	int crc, i;
68 
69 	crc = 0;
70 	while (--count >= 0) {
71 		crc = crc ^ (int)*ptr++ << 8;
72 		for (i = 0; i < 8; ++i) {
73 			if (crc & 0x8000)
74 				crc = crc << 1 ^ 0x1021;
75 			else
76 				crc = crc << 1;
77 		}
78 	}
79 
80 	return (crc & 0xFFFF);
81 }
82 
validate_spd_checksum_ddr4(struct dimm_config * dimm_config,int dimm_index,int twsi_addr,int silent)83 static int validate_spd_checksum_ddr4(struct dimm_config *dimm_config,
84 				      int dimm_index, int twsi_addr, int silent)
85 {
86 	u8 *spd_data = dimm_config->spd_data[dimm_index];
87 	int crc_bytes = 126;
88 	u16 crc_comp;
89 
90 	/* Check byte 0 to see how many bytes checksum is over */
91 	if (spd_data[0] & 0x80)
92 		crc_bytes = 117;
93 
94 	crc_comp = ddr3_crc16(spd_data, crc_bytes);
95 
96 	if (spd_data[126] == (crc_comp & 0xff) &&
97 	    spd_data[127] == (crc_comp >> 8))
98 		return 1;
99 
100 	if (!silent) {
101 		printf("DDR4 SPD CRC error, spd addr: 0x%x, calculated crc: 0x%04x, read crc: 0x%02x%02x\n",
102 		       twsi_addr, crc_comp, spd_data[127], spd_data[126]);
103 	}
104 
105 	return 0;
106 }
107 
validate_spd_checksum(struct ddr_priv * priv,struct dimm_config * dimm_config,int dimm_index,int twsi_addr,int silent,u8 rv)108 static int validate_spd_checksum(struct ddr_priv *priv,
109 				 struct dimm_config *dimm_config,
110 				 int dimm_index, int twsi_addr,
111 				 int silent, u8 rv)
112 {
113 	if (ddr_verbose(priv))
114 		debug("Validating DIMM at address 0x%x\n", twsi_addr);
115 
116 	if (rv >= 0x8 && rv <= 0xA)
117 		printf("%s: Error: DDR2 support disabled\n", __func__);
118 
119 	if (rv == 0xB)
120 		printf("%s: Error: DDR3 support disabled\n", __func__);
121 
122 	if (rv == 0xC) {
123 		return validate_spd_checksum_ddr4(dimm_config, dimm_index,
124 						  twsi_addr, silent);
125 	}
126 
127 	if (!silent) {
128 		printf("Unrecognized DIMM type: 0x%x at spd address: 0x%x\n",
129 		       rv, twsi_addr);
130 	}
131 
132 	return 0;
133 }
134 
135 /*
136  * Read an DIMM SPD value, either using TWSI to read it from the DIMM, or
137  * from a provided array.
138  */
read_spd(struct dimm_config * dimm_config,int dimm_index,int spd_field)139 int read_spd(struct dimm_config *dimm_config, int dimm_index, int spd_field)
140 {
141 	dimm_index = !!dimm_index;
142 
143 	if (spd_field >= SPD_EEPROM_SIZE) {
144 		printf("ERROR: Trying to read unsupported SPD EEPROM value %d\n",
145 		       spd_field);
146 	}
147 
148 	/*
149 	 * If pointer to data is provided, use it, otherwise read from SPD
150 	 * over twsi
151 	 */
152 	if (dimm_config->spd_ptrs[dimm_index])
153 		return dimm_config->spd_ptrs[dimm_index][spd_field];
154 	else if (dimm_config->spd_addrs[dimm_index])
155 		return dimm_config->spd_data[dimm_index][spd_field];
156 
157 	return -1;
158 }
159 
read_spd_init(struct dimm_config * dimm_config,int dimm_index)160 int read_spd_init(struct dimm_config *dimm_config, int dimm_index)
161 {
162 	u8 busno = OCTEON_TWSI_GET_BUS(dimm_config->spd_addrs[dimm_index]);
163 	u8 cmdno = dimm_config->spd_addrs[dimm_index];
164 	struct udevice *dev_i2c;
165 	u8 *spd_data;
166 	int ret;
167 
168 	if (dimm_config->spd_cached[dimm_index])
169 		return 0;
170 
171 	dimm_config->spd_cached[dimm_index] = 1;
172 	spd_data = dimm_config->spd_data[dimm_index];
173 
174 	ret = i2c_get_chip_for_busnum(busno, cmdno, 2, &dev_i2c);
175 	if (ret) {
176 		debug("Cannot find SPL EEPROM: %d\n", ret);
177 		return -ENODEV;
178 	}
179 
180 	ret = dm_i2c_read(dev_i2c, 0, spd_data, SPD_EEPROM_SIZE);
181 
182 	return ret;
183 }
184 
validate_dimm(struct ddr_priv * priv,struct dimm_config * dimm_config,int dimm_index)185 int validate_dimm(struct ddr_priv *priv, struct dimm_config *dimm_config,
186 		  int dimm_index)
187 {
188 	int spd_addr;
189 
190 	dimm_index = !!dimm_index;  /* Normalize to 0/1 */
191 	spd_addr = dimm_config->spd_addrs[dimm_index];
192 
193 	debug("Validating dimm %d, spd addr: 0x%02x spd ptr: %p\n",
194 	      dimm_index,
195 	      dimm_config->spd_addrs[dimm_index],
196 	      dimm_config->spd_ptrs[dimm_index]);
197 
198 	/* Only validate 'real' dimms, assume compiled in values are OK */
199 	if (!dimm_config->spd_ptrs[dimm_index]) {
200 		int val0, val1;
201 		int dimm_type;
202 		int ret;
203 
204 		ret = read_spd_init(dimm_config, dimm_index);
205 		if (ret)
206 			return 0;
207 
208 		dimm_type = read_spd(dimm_config, dimm_index,
209 				     DDR2_SPD_MEM_TYPE) & 0xff;
210 		switch (dimm_type) {
211 		case 0x0B:              /* DDR3 */
212 			if (ddr_verbose(priv))
213 				printf("Validating DDR3 DIMM %d\n", dimm_index);
214 			val0 = read_spd(dimm_config, dimm_index,
215 					DDR3_SPD_DENSITY_BANKS);
216 			val1 = read_spd(dimm_config, dimm_index,
217 					DDR3_SPD_ADDRESSING_ROW_COL_BITS);
218 			if (val0 < 0 && val1 < 0) {
219 				if (ddr_verbose(priv))
220 					printf("Error reading SPD for DIMM %d\n",
221 					       dimm_index);
222 				return 0; /* Failed to read dimm */
223 			}
224 			if (val0 == 0xff && val1 == 0xff) {
225 				if (ddr_verbose(priv))
226 					printf("Blank or unreadable SPD for DIMM %d\n",
227 					       dimm_index);
228 				/* Blank SPD or otherwise unreadable device */
229 				return 0;
230 			}
231 
232 			/* Don't treat bad checksums as fatal */
233 			validate_spd_checksum(priv, dimm_config, dimm_index,
234 					      spd_addr, 0, dimm_type);
235 			break;
236 
237 		case 0x0C:              /* DDR4 */
238 			if (ddr_verbose(priv))
239 				printf("Validating DDR4 DIMM %d\n", dimm_index);
240 			val0 = read_spd(dimm_config, dimm_index,
241 					DDR4_SPD_DENSITY_BANKS);
242 			val1 = read_spd(dimm_config, dimm_index,
243 					DDR4_SPD_ADDRESSING_ROW_COL_BITS);
244 			if (val0 < 0 && val1 < 0) {
245 				if (ddr_verbose(priv))
246 					printf("Error reading SPD for DIMM %d\n",
247 					       dimm_index);
248 				return 0; /* Failed to read dimm */
249 			}
250 			if (val0 == 0xff && val1 == 0xff) {
251 				if (ddr_verbose(priv)) {
252 					printf("Blank or unreadable SPD for DIMM %d\n",
253 					       dimm_index);
254 				}
255 				/* Blank SPD or otherwise unreadable device */
256 				return 0;
257 			}
258 
259 			/* Don't treat bad checksums as fatal */
260 			validate_spd_checksum(priv, dimm_config, dimm_index,
261 					      spd_addr, 0, dimm_type);
262 			break;
263 
264 		case 0x00:
265 			/* Terminator detected. Fail silently. */
266 			return 0;
267 
268 		default:
269 			debug("Unknown DIMM type 0x%x for DIMM %d @ 0x%x\n",
270 			      dimm_type, dimm_index,
271 			      dimm_config->spd_addrs[dimm_index]);
272 			return 0;      /* Failed to read dimm */
273 		}
274 	}
275 
276 	return 1;
277 }
278 
get_ddr_type(struct dimm_config * dimm_config,int upper_dimm)279 int get_ddr_type(struct dimm_config *dimm_config, int upper_dimm)
280 {
281 	int spd_ddr_type;
282 
283 	spd_ddr_type = read_spd(dimm_config, upper_dimm, DEVICE_TYPE);
284 
285 	debug("%s:%d spd_ddr_type=0x%02x\n", __func__, __LINE__,
286 	      spd_ddr_type);
287 
288 	/* we return only DDR4 or DDR3 */
289 	return (spd_ddr_type == 0x0C) ? DDR4_DRAM : DDR3_DRAM;
290 }
291 
get_dimm_ecc(struct dimm_config * dimm_config,int upper_dimm,int ddr_type)292 static int get_dimm_ecc(struct dimm_config *dimm_config, int upper_dimm,
293 			int ddr_type)
294 {
295 	return !!(read_spd(dimm_config, upper_dimm, BUS_WIDTH(ddr_type)) & 8);
296 }
297 
get_dimm_module_type(struct dimm_config * dimm_config,int upper_dimm,int ddr_type)298 int get_dimm_module_type(struct dimm_config *dimm_config, int upper_dimm,
299 			 int ddr_type)
300 {
301 	return read_spd(dimm_config, upper_dimm, MODULE_TYPE) & 0x0f;
302 }
303 
printable_rank_spec(char * buffer,int num_ranks,int dram_width,int spd_package)304 char *printable_rank_spec(char *buffer, int num_ranks, int dram_width,
305 			  int spd_package)
306 {
307 	int die_count = ((spd_package >> 4) & 7) + 1;
308 
309 	if (spd_package & 0x80) { // non-monolithic
310 		if ((spd_package & 3) == 2) { // 3DS
311 			sprintf(buffer, "%dS%dRx%d", num_ranks, die_count,
312 				dram_width);
313 		} else { // MLS
314 			char hchar = (die_count == 2) ? 'D' : 'Q';
315 
316 			sprintf(buffer, "%d%cRx%d", num_ranks, hchar,
317 				dram_width);
318 		}
319 	} else {
320 		sprintf(buffer, "%dRx%d", num_ranks, dram_width);
321 	}
322 
323 	return buffer;
324 }
325 
report_common_dimm(struct dimm_config * dimm_config,int upper_dimm,int dimm,const char ** dimm_types,int ddr_type,char * volt_str,int if_num,int num_ranks,int dram_width,int spd_package)326 static void report_common_dimm(struct dimm_config *dimm_config, int upper_dimm,
327 			       int dimm, const char **dimm_types, int ddr_type,
328 			       char *volt_str, int if_num,
329 			       int num_ranks, int dram_width, int spd_package)
330 {
331 	unsigned int spd_module_type;
332 	char rank_spec[8];
333 	int spd_ecc;
334 
335 	spd_module_type = get_dimm_module_type(dimm_config, upper_dimm,
336 					       ddr_type);
337 	spd_ecc = get_dimm_ecc(dimm_config, upper_dimm, ddr_type);
338 
339 	printable_rank_spec(rank_spec, num_ranks, dram_width, spd_package);
340 	printf("LMC%d.DIMM%d: DDR%d %s %s %s, %s\n",
341 	       if_num, dimm, ddr_type, dimm_types[spd_module_type],
342 	       rank_spec, spd_ecc ? "ECC" : "non-ECC", volt_str);
343 }
344 
report_ddr3_dimm(struct dimm_config * dimm_config,int upper_dimm,int dimm,int if_num)345 static void report_ddr3_dimm(struct dimm_config *dimm_config, int upper_dimm,
346 			     int dimm, int if_num)
347 {
348 	int spd_voltage;
349 	char *volt_str;
350 	int spd_org = read_spd(dimm_config, upper_dimm,
351 			       DDR3_SPD_MODULE_ORGANIZATION);
352 	int num_ranks = 1 +  ((spd_org >> 3) & 0x7);
353 	int dram_width = 4 << ((spd_org >> 0) & 0x7);
354 
355 	spd_voltage = read_spd(dimm_config, upper_dimm,
356 			       DDR3_SPD_NOMINAL_VOLTAGE);
357 	if (spd_voltage == 0 || spd_voltage & 3)
358 		volt_str = "1.5V";
359 	if (spd_voltage & 2)
360 		volt_str = "1.35V";
361 	if (spd_voltage & 4)
362 		volt_str = "1.2xV";
363 
364 	report_common_dimm(dimm_config, upper_dimm, dimm, ddr3_dimm_types,
365 			   DDR3_DRAM, volt_str, if_num,
366 			   num_ranks, dram_width, /*spd_package*/0);
367 }
368 
report_ddr4_dimm(struct dimm_config * dimm_config,int upper_dimm,int dimm,int if_num)369 static void report_ddr4_dimm(struct dimm_config *dimm_config, int upper_dimm,
370 			     int dimm, int if_num)
371 {
372 	int spd_voltage;
373 	char *volt_str;
374 	int spd_package = 0xff & read_spd(dimm_config, upper_dimm,
375 					  DDR4_SPD_PACKAGE_TYPE);
376 	int spd_org     = 0xff & read_spd(dimm_config, upper_dimm,
377 					  DDR4_SPD_MODULE_ORGANIZATION);
378 	int num_ranks   = 1 +  ((spd_org >> 3) & 0x7);
379 	int dram_width  = 4 << ((spd_org >> 0) & 0x7);
380 
381 	spd_voltage = read_spd(dimm_config, upper_dimm,
382 			       DDR4_SPD_MODULE_NOMINAL_VOLTAGE);
383 	if (spd_voltage == 0x01 || spd_voltage & 0x02)
384 		volt_str = "1.2V";
385 	if (spd_voltage == 0x04 || spd_voltage & 0x08)
386 		volt_str = "TBD1 V";
387 	if (spd_voltage == 0x10 || spd_voltage & 0x20)
388 		volt_str = "TBD2 V";
389 
390 	report_common_dimm(dimm_config, upper_dimm, dimm, ddr4_dimm_types,
391 			   DDR4_DRAM, volt_str, if_num,
392 			   num_ranks, dram_width, spd_package);
393 }
394 
report_dimm(struct dimm_config * dimm_config,int upper_dimm,int dimm,int if_num)395 void report_dimm(struct dimm_config *dimm_config, int upper_dimm,
396 		 int dimm, int if_num)
397 {
398 	int ddr_type;
399 
400 	/* ddr_type only indicates DDR4 or DDR3 */
401 	ddr_type = get_ddr_type(dimm_config, upper_dimm);
402 
403 	if (ddr_type == DDR4_DRAM)
404 		report_ddr4_dimm(dimm_config, 0, dimm, if_num);
405 	else
406 		report_ddr3_dimm(dimm_config, 0, dimm, if_num);
407 }
408