xref: /openbmc/u-boot/board/freescale/mpc8536ds/ddr.c (revision 24113a44)
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 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,
41 				dimm_params_t *pdimm,
42 				unsigned int ctrl_num)
43 {
44 	/*
45 	 * Factors to consider for clock adjust:
46 	 *	- number of chips on bus
47 	 *	- position of slot
48 	 *	- DDR1 vs. DDR2?
49 	 *	- ???
50 	 *
51 	 * This needs to be determined on a board-by-board basis.
52 	 *	0110	3/4 cycle late
53 	 *	0111	7/8 cycle late
54 	 */
55 	popts->clk_adjust = 7;
56 
57 	/*
58 	 * Factors to consider for CPO:
59 	 *	- frequency
60 	 *	- ddr1 vs. ddr2
61 	 */
62 	popts->cpo_override = 10;
63 
64 	/*
65 	 * Factors to consider for write data delay:
66 	 *	- number of DIMMs
67 	 *
68 	 * 1 = 1/4 clock delay
69 	 * 2 = 1/2 clock delay
70 	 * 3 = 3/4 clock delay
71 	 * 4 = 1   clock delay
72 	 * 5 = 5/4 clock delay
73 	 * 6 = 3/2 clock delay
74 	 */
75 	popts->write_data_delay = 3;
76 
77 	/*
78 	 * Factors to consider for half-strength driver enable:
79 	 *	- number of DIMMs installed
80 	 */
81 	popts->half_strength_driver_enable = 0;
82 }
83