xref: /openbmc/u-boot/board/xes/xpedite517x/ddr.c (revision 17dd883c)
1 /*
2  * Copyright 2009 Extreme Engineering Solutions, Inc.
3  * Copyright 2007-2008 Freescale Semiconductor, Inc.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 #include <i2c.h>
26 #include <asm/fsl_ddr_sdram.h>
27 #include <asm/fsl_ddr_dimm_params.h>
28 
29 static void get_spd(ddr2_spd_eeprom_t *spd, unsigned char i2c_address)
30 {
31 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
32 		sizeof(ddr2_spd_eeprom_t));
33 }
34 
35 unsigned int fsl_ddr_get_mem_data_rate(void)
36 {
37 	return get_bus_freq(0);
38 }
39 
40 void fsl_ddr_get_spd(ddr2_spd_eeprom_t *ctrl_dimms_spd,
41 			unsigned int ctrl_num)
42 {
43 	unsigned int i;
44 	unsigned int i2c_address = 0;
45 
46 	for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
47 		if (ctrl_num == 0) {
48 			i2c_address = SPD_EEPROM_ADDRESS1;
49 #ifdef SPD_EEPROM_ADDRESS2
50 		} else if (ctrl_num == 1) {
51 			i2c_address = SPD_EEPROM_ADDRESS2;
52 #endif
53 		} else {
54 			/* An inalid ctrl number was give, use default SPD */
55 			printf("ERROR: invalid DDR ctrl: %d\n", ctrl_num);
56 			i2c_address = SPD_EEPROM_ADDRESS1;
57 		}
58 
59 		get_spd(&(ctrl_dimms_spd[i]), i2c_address);
60 	}
61 }
62 
63 /*
64  * There are four board-specific SDRAM timing parameters which must be
65  * calculated based on the particular PCB artwork.  These are:
66  *   1.) CPO (Read Capture Delay)
67  *           - TIMING_CFG_2 register
68  *           Source: Calculation based on board trace lengths and
69  *                   chip-specific internal delays.
70  *   2.) WR_DATA_DELAY (Write Command to Data Strobe Delay)
71  *           - TIMING_CFG_2 register
72  *           Source: Calculation based on board trace lengths.
73  *                   Unless clock and DQ lanes are very different
74  *                   lengths (>2"), this should be set to the nominal value
75  *                   of 1/2 clock delay.
76  *   3.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
77  *           - DDR_SDRAM_CLK_CNTL register
78  *           Source: Signal Integrity Simulations
79  *   4.) 2T Timing on Addr/Ctl
80  *           - TIMING_CFG_2 register
81  *           Source: Signal Integrity Simulations
82  *           Usually only needed with heavy load/very high speed (>DDR2-800)
83  *
84  *     PCB routing on the XPedite5170 is nearly identical to the XPedite5370
85  *     so we use the XPedite5370 settings as a basis for the XPedite5170.
86  */
87 
88 typedef struct board_memctl_options {
89 	uint16_t datarate_mhz_low;
90 	uint16_t datarate_mhz_high;
91 	uint8_t clk_adjust;
92 	uint8_t cpo_override;
93 	uint8_t write_data_delay;
94 } board_memctl_options_t;
95 
96 static struct board_memctl_options bopts_ctrl[][2] = {
97 	{
98 		/* Controller 0 */
99 		{
100 			/* DDR2 600/667 */
101 			.datarate_mhz_low	= 500,
102 			.datarate_mhz_high	= 750,
103 			.clk_adjust		= 5,
104 			.cpo_override		= 8,
105 			.write_data_delay	= 2,
106 		},
107 		{
108 			/* DDR2 800 */
109 			.datarate_mhz_low	= 750,
110 			.datarate_mhz_high	= 850,
111 			.clk_adjust		= 5,
112 			.cpo_override		= 9,
113 			.write_data_delay	= 2,
114 		},
115 	},
116 	{
117 		/* Controller 1 */
118 		{
119 			/* DDR2 600/667 */
120 			.datarate_mhz_low	= 500,
121 			.datarate_mhz_high	= 750,
122 			.clk_adjust		= 5,
123 			.cpo_override		= 7,
124 			.write_data_delay	= 2,
125 		},
126 		{
127 			/* DDR2 800 */
128 			.datarate_mhz_low	= 750,
129 			.datarate_mhz_high	= 850,
130 			.clk_adjust		= 5,
131 			.cpo_override		= 8,
132 			.write_data_delay	= 2,
133 		},
134 	},
135 };
136 
137 void fsl_ddr_board_options(memctl_options_t *popts,
138 			dimm_params_t *pdimm,
139 			unsigned int ctrl_num)
140 {
141 	struct board_memctl_options *bopts = bopts_ctrl[ctrl_num];
142 	sys_info_t sysinfo;
143 	int i;
144 	unsigned int datarate;
145 
146 	get_sys_info(&sysinfo);
147 	datarate = fsl_ddr_get_mem_data_rate() / 1000000;
148 
149 	for (i = 0; i < ARRAY_SIZE(bopts_ctrl[ctrl_num]); i++) {
150 		if ((bopts[i].datarate_mhz_low <= datarate) &&
151 		    (bopts[i].datarate_mhz_high >= datarate)) {
152 			debug("controller %d:\n", ctrl_num);
153 			debug(" clk_adjust = %d\n", bopts[i].clk_adjust);
154 			debug(" cpo = %d\n", bopts[i].cpo_override);
155 			debug(" write_data_delay = %d\n",
156 				bopts[i].write_data_delay);
157 			popts->clk_adjust = bopts[i].clk_adjust;
158 			popts->cpo_override = bopts[i].cpo_override;
159 			popts->write_data_delay = bopts[i].write_data_delay;
160 		}
161 	}
162 
163 	/*
164 	 * Factors to consider for half-strength driver enable:
165 	 *	- number of DIMMs installed
166 	 */
167 	popts->half_strength_driver_enable = 0;
168 }
169