xref: /openbmc/u-boot/board/xes/xpedite520x/ddr.c (revision 4e3349b6)
1 /*
2  * Copyright 2008 Freescale Semiconductor, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * Version 2 as published by the Free Software Foundation.
7  */
8 
9 #include <common.h>
10 #include <i2c.h>
11 
12 #include <asm/fsl_ddr_sdram.h>
13 #include <asm/fsl_ddr_dimm_params.h>
14 
15 void get_spd(ddr2_spd_eeprom_t *spd, unsigned char i2c_address)
16 {
17 	i2c_read(i2c_address, 0, 1, (uchar *)spd, sizeof(ddr2_spd_eeprom_t));
18 
19 	/* We use soldered memory, but use an SPD EEPROM to describe it.
20 	 * The SPD has an unspecified dimm type, but the DDR2 initialization
21 	 * code requires a specific type to be specified. This sets the type
22 	 * as a standard unregistered SO-DIMM. */
23 	if (spd->dimm_type == 0) {
24 		spd->dimm_type = 0x4;
25 		((uchar *)spd)[63] += 0x4;
26 	}
27 }
28 
29 void fsl_ddr_board_options(memctl_options_t *popts,
30 				dimm_params_t *pdimm,
31 				unsigned int ctrl_num)
32 {
33 	/*
34 	 * Factors to consider for clock adjust:
35 	 *	- number of chips on bus
36 	 *	- position of slot
37 	 *	- DDR1 vs. DDR2?
38 	 *	- ???
39 	 *
40 	 * This needs to be determined on a board-by-board basis.
41 	 *	0110	3/4 cycle late
42 	 *	0111	7/8 cycle late
43 	 */
44 	popts->clk_adjust = 7;
45 
46 	/*
47 	 * Factors to consider for CPO:
48 	 *	- frequency
49 	 *	- ddr1 vs. ddr2
50 	 */
51 	popts->cpo_override = 9;
52 
53 	/*
54 	 * Factors to consider for write data delay:
55 	 *	- number of DIMMs
56 	 *
57 	 * 1 = 1/4 clock delay
58 	 * 2 = 1/2 clock delay
59 	 * 3 = 3/4 clock delay
60 	 * 4 = 1   clock delay
61 	 * 5 = 5/4 clock delay
62 	 * 6 = 3/2 clock delay
63 	 */
64 	popts->write_data_delay = 3;
65 
66 	/*
67 	 * Factors to consider for half-strength driver enable:
68 	 *	- number of DIMMs installed
69 	 */
70 	popts->half_strength_driver_enable = 0;
71 }
72