xref: /openbmc/u-boot/board/freescale/mpc8544ds/ddr.c (revision 0cf4fd3c)
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 
14 static void
15 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 
20 unsigned int fsl_ddr_get_mem_data_rate(void)
21 {
22 	return get_ddr_freq(0);
23 }
24 
25 void fsl_ddr_get_spd(ddr2_spd_eeprom_t *ctrl_dimms_spd,
26 		      unsigned int ctrl_num)
27 {
28 	unsigned int i;
29 
30 	if (ctrl_num) {
31 		printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
32 		return;
33 	}
34 
35 	for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
36 		get_spd(&(ctrl_dimms_spd[i]), SPD_EEPROM_ADDRESS);
37 	}
38 }
39 
40 void fsl_ddr_board_options(memctl_options_t *popts, unsigned int ctrl_num)
41 {
42 	/*
43 	 * Factors to consider for clock adjust:
44 	 *	- number of chips on bus
45 	 *	- position of slot
46 	 *	- DDR1 vs. DDR2?
47 	 *	- ???
48 	 *
49 	 * This needs to be determined on a board-by-board basis.
50 	 *	0110	3/4 cycle late
51 	 *	0111	7/8 cycle late
52 	 */
53 	popts->clk_adjust = 7;
54 
55 	/*
56 	 * Factors to consider for CPO:
57 	 *	- frequency
58 	 *	- ddr1 vs. ddr2
59 	 */
60 	popts->cpo_override = 10;
61 
62 	/*
63 	 * Factors to consider for write data delay:
64 	 *	- number of DIMMs
65 	 *
66 	 * 1 = 1/4 clock delay
67 	 * 2 = 1/2 clock delay
68 	 * 3 = 3/4 clock delay
69 	 * 4 = 1   clock delay
70 	 * 5 = 5/4 clock delay
71 	 * 6 = 3/2 clock delay
72 	 */
73 	popts->write_data_delay = 3;
74 
75 	/*
76 	 * Factors to consider for half-strength driver enable:
77 	 *	- number of DIMMs installed
78 	 */
79 	popts->half_strength_driver_enable = 0;
80 }
81