xref: /openbmc/u-boot/board/freescale/mpc8544ds/ddr.c (revision d984fed0)
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 static void
16 get_spd(ddr2_spd_eeprom_t *spd, unsigned char i2c_address)
17 {
18 	i2c_read(i2c_address, 0, 1, (uchar *)spd, sizeof(ddr2_spd_eeprom_t));
19 }
20 
21 unsigned int fsl_ddr_get_mem_data_rate(void)
22 {
23 	return get_ddr_freq(0);
24 }
25 
26 void fsl_ddr_get_spd(ddr2_spd_eeprom_t *ctrl_dimms_spd,
27 		      unsigned int ctrl_num)
28 {
29 	unsigned int i;
30 
31 	if (ctrl_num) {
32 		printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
33 		return;
34 	}
35 
36 	for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
37 		get_spd(&(ctrl_dimms_spd[i]), SPD_EEPROM_ADDRESS);
38 	}
39 }
40 
41 void fsl_ddr_board_options(memctl_options_t *popts,
42 				dimm_params_t *pdimm,
43 				unsigned int ctrl_num)
44 {
45 	/*
46 	 * Factors to consider for clock adjust:
47 	 *	- number of chips on bus
48 	 *	- position of slot
49 	 *	- DDR1 vs. DDR2?
50 	 *	- ???
51 	 *
52 	 * This needs to be determined on a board-by-board basis.
53 	 *	0110	3/4 cycle late
54 	 *	0111	7/8 cycle late
55 	 */
56 	popts->clk_adjust = 7;
57 
58 	/*
59 	 * Factors to consider for CPO:
60 	 *	- frequency
61 	 *	- ddr1 vs. ddr2
62 	 */
63 	popts->cpo_override = 10;
64 
65 	/*
66 	 * Factors to consider for write data delay:
67 	 *	- number of DIMMs
68 	 *
69 	 * 1 = 1/4 clock delay
70 	 * 2 = 1/2 clock delay
71 	 * 3 = 3/4 clock delay
72 	 * 4 = 1   clock delay
73 	 * 5 = 5/4 clock delay
74 	 * 6 = 3/2 clock delay
75 	 */
76 	popts->write_data_delay = 3;
77 
78 	/* 2T timing enable */
79 	popts->twoT_en = 1;
80 
81 	/*
82 	 * Factors to consider for half-strength driver enable:
83 	 *	- number of DIMMs installed
84 	 */
85 	popts->half_strength_driver_enable = 0;
86 }
87