device/dram/ddr2: Add common ddr2 spd decoder

Decode DDR2 SPD similar to DDR3 SPD decoder to ease
readability, reduce code complexity and reduce size of
maintainable code.

Rename dimm_is_registered to spd_dimm_is_registered_ddr3 to avoid
compilation errors.

Change-Id: I741f0e61ab23e3999ae9e31f57228ba034c2509e
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/18273
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins)

1 files changed, 218 insertions, 0 deletions

diff --git a/src/include/device/dram/ddr2.h b/src/include/device/dram/ddr2.h
new file mode 100644
index 000000000000..7f59a7a7c146
--- /dev/null
+++ b/src/include/device/dram/ddr2.h
@@ -0,0 +1,218 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2017 Patrick Rudolph <siro@das-labor.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * JEDEC Standard No. 21-C
+ * Annex J: Annex J: Serial Presence Detects for DDR2 SDRAM (Revision 1.3)
+ */
+
+#ifndef DEVICE_DRAM_DDR2L_H
+#define DEVICE_DRAM_DDR2L_H
+
+/**
+ * @file ddr2.h
+ *
+ * \brief Utilities for decoding DDR2 SPDs
+ */
+
+#include <stdint.h>
+#include <spd.h>
+
+/**
+ * \brief Convenience definitions for TCK values
+ *
+ * Different values for tCK, representing standard DDR2 frequencies.
+ * These values are in 1/256 ns units.
+ * @{
+ */
+#define TCK_800MHZ      320
+#define TCK_700MHZ      365
+#define TCK_666MHZ      384
+#define TCK_533MHZ      480
+#define TCK_400MHZ      640
+#define TCK_333MHZ      768
+#define TCK_266MHZ      960
+#define TCK_200MHZ      1280
+/** @} */
+
+/**
+ * \brief Convenience macro for enabling printk with CONFIG_DEBUG_RAM_SETUP
+ *
+ * Use this macro instead of printk(); for verbose RAM initialization messages.
+ * When CONFIG_DEBUG_RAM_SETUP is not selected, these messages are automatically
+ * disabled.
+ * @{
+ */
+#if IS_ENABLED(CONFIG_DEBUG_RAM_SETUP)
+#define printram(x, ...) printk(BIOS_DEBUG, x, ##__VA_ARGS__)
+#else
+#define printram(x, ...)
+#endif
+/** @} */
+
+/*
+ * Module type (byte 20, bits 5:0) of SPD
+ * This definition is specific to DDR2. DDR3 SPDs have a different structure.
+ */
+enum spd_dimm_type {
+	SPD_DIMM_TYPE_UNDEFINED			= 0x00,
+	SPD_DIMM_TYPE_RDIMM			= 0x01,
+	SPD_DIMM_TYPE_UDIMM			= 0x02,
+	SPD_DIMM_TYPE_SO_DIMM			= 0x04,
+	SPD_DIMM_TYPE_72B_SO_CDIMM		= 0x06,
+	SPD_DIMM_TYPE_72B_SO_RDIMM		= 0x07,
+	SPD_DIMM_TYPE_MICRO_DIMM		= 0x08,
+	SPD_DIMM_TYPE_MINI_DIMM			= 0x10,
+	SPD_DIMM_TYPE_MINI_UDIMM		= 0x20,
+	/* Masks to bits 5:0 to give the dimm type */
+	SPD_DIMM_TYPE_MASK			= 0x3f,
+};
+
+/**
+ * \brief DIMM flags
+ *
+ * Characteristic flags for the DIMM, as presented by the SPD
+ */
+union dimm_flags_st {
+	/* The whole point of the union/struct construct is to allow us to clear
+	 * all the bits with one line: flags.raw = 0.
+	 * We do not care how these bits are ordered */
+	struct {
+		/* Module can work at 5.00V */
+		unsigned operable_5_00V:1;
+		/* Module can work at 3.33V */
+		unsigned operable_3_33V:1;
+		/* Module can work at 2.50V */
+		unsigned operable_2_50V:1;
+		/* Module can work at 1.80V - All DIMMS must be 1.8V operable */
+		unsigned operable_1_80V:1;
+		/* Module can work at 1.50V */
+		unsigned operable_1_50V:1;
+		/* Module can work at 1.35V */
+		unsigned operable_1_35V:1;
+		/* Module can work at 1.20V */
+		unsigned operable_1_25V:1;
+		/* Has an 8-bit bus extension, meaning the DIMM supports ECC */
+		unsigned is_ecc:1;
+		/* Supports weak driver */
+		unsigned weak_driver:1;
+		/* Supports terminating at 50 Ohm */
+		unsigned terminate_50ohms:1;
+		/* Partial Array Self Refresh */
+		unsigned pasr:1;
+		/* Supports burst length 8 */
+		unsigned bl8:1;
+		/* Supports burst length 4 */
+		unsigned bl4:1;
+		/* DIMM Package is stack */
+		unsigned stacked:1;
+	};
+	unsigned int raw;
+};
+
+/**
+ * \brief DIMM characteristics
+ *
+ * The characteristics of each DIMM, as presented by the SPD
+ */
+struct dimm_attr_st {
+	enum spd_memory_type dram_type;
+	enum spd_dimm_type dimm_type;
+	/* BCD SPD revision */
+	u8 rev;
+	/* Supported CAS mask, bit 0 == CL0 .. bit7 == CL7 */
+	u8 cas_supported;
+	/* Maximum cloclk to data cycle times for various CAS.
+	 * Fields 0 and 1 are unused. */
+	u32 cycle_time[8];
+	/* Maximum data access times for various CAS.
+	 * Fields 0 and 1 are unused. */
+	u32 access_time[8];
+	/* Flags extracted from SPD */
+	union dimm_flags_st flags;
+	/* Number of banks */
+	u8 banks;
+	/* SDRAM width */
+	u8 width;
+	/* Module width */
+	u8 mod_width;
+	/* Number of ranks */
+	u8 ranks;
+	/* Number or row address bits */
+	u8 row_bits;
+	/* Number or column address bits */
+	u8 col_bits;
+	/* Number of PLLs on module */
+	u8 plls;
+	/* Size of module in MiB */
+	u16 size_mb;
+	/* Size of one rank in MiB */
+	u16 ranksize_mb;
+	/* Latencies are in units of 1/256 ns */
+	u32 tCK;
+	u32 tWR;
+	u32 tRCD;
+	u32 tRRD;
+	u32 tRP;
+	u32 tRAS;
+	u32 tIS;
+	u32 tIH;
+	u32 tDS;
+	u32 tDH;
+
+	u32 tRC;
+	u32 tRFC;
+	u32 tWTR;
+	u32 tRTP;
+	u32 tDQSQ;
+	u32 tQHS;
+
+	/* Latencies are in units of 1/256 us */
+	u32 tPLL;
+	u32 tRR;
+
+	/* Manufacturer ID */
+	u32 manufacturer_id;
+	/* ASCII part number - NULL terminated */
+	u8 part_number[17];
+	/* Year manufactured */
+	u16 year;
+	/* Week manufactured */
+	u8 weeks;
+	/* Unique serial number */
+	u32 serial;
+};
+
+/** Result of the SPD decoding process */
+enum spd_status {
+	SPD_STATUS_OK = 0,
+	SPD_STATUS_INVALID,
+	SPD_STATUS_CRC_ERROR,
+	SPD_STATUS_INVALID_FIELD,
+};
+
+/** Maximum SPD size supported */
+#define SPD_SIZE_MAX_DDR2 128
+
+int spd_dimm_is_registered_ddr2(enum spd_dimm_type type);
+u8 spd_ddr2_calc_checksum(u8 *spd, int len);
+u32 spd_decode_spd_size_ddr2(u8 byte0);
+u32 spd_decode_eeprom_size_ddr2(u8 byte1);
+int spd_decode_ddr2(struct dimm_attr_st *dimm, u8 spd[SPD_SIZE_MAX_DDR2]);
+void dram_print_spd_ddr2(const struct dimm_attr_st *dimm);
+
+
+#endif /* DEVICE_DRAM_DDR2L_H */