xref: /openbmc/u-boot/board/freescale/mpc8555cds/ddr.c (revision 5df4b0ad0dff3cef1bd6660bcc8cba028c80adcb)
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(ddr1_spd_eeprom_t *spd, unsigned char i2c_address)
17 {
18 	i2c_read(i2c_address, 0, 1, (uchar *)spd, sizeof(ddr1_spd_eeprom_t));
19 }
20 
21 void fsl_ddr_get_spd(ddr1_spd_eeprom_t *ctrl_dimms_spd,
22 		      unsigned int ctrl_num)
23 {
24 	unsigned int i;
25 	unsigned int i2c_address = 0;
26 
27 	for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
28 		if (ctrl_num == 0 && i == 0) {
29 			i2c_address = SPD_EEPROM_ADDRESS;
30 		}
31 		get_spd(&(ctrl_dimms_spd[i]), i2c_address);
32 	}
33 }
34 
35 void fsl_ddr_board_options(memctl_options_t *popts,
36 				dimm_params_t *pdimm,
37 				unsigned int ctrl_num)
38 {
39 	/*
40 	 * Factors to consider for clock adjust:
41 	 *	- number of chips on bus
42 	 *	- position of slot
43 	 *	- DDR1 vs. DDR2?
44 	 *	- ???
45 	 *
46 	 * This needs to be determined on a board-by-board basis.
47 	 *	0110	3/4 cycle late
48 	 *	0111	7/8 cycle late
49 	 */
50 	popts->clk_adjust = 6;
51 
52 	/*
53 	 * Factors to consider for CPO:
54 	 *	- frequency
55 	 *	- ddr1 vs. ddr2
56 	 */
57 	popts->cpo_override = 0;
58 
59 	/*
60 	 * Factors to consider for write data delay:
61 	 *	- number of DIMMs
62 	 *
63 	 * 1 = 1/4 clock delay
64 	 * 2 = 1/2 clock delay
65 	 * 3 = 3/4 clock delay
66 	 * 4 = 1   clock delay
67 	 * 5 = 5/4 clock delay
68 	 * 6 = 3/2 clock delay
69 	 */
70 	popts->write_data_delay = 3;
71 
72 	/*
73 	 * Factors to consider for half-strength driver enable:
74 	 *	- number of DIMMs installed
75 	 */
76 	popts->half_strength_driver_enable = 0;
77 }
78