xref: /openbmc/u-boot/board/xes/xpedite550x/ddr.c (revision bfe18815)
1 /*
2  * Copyright 2010 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 
27 #include <asm/fsl_ddr_sdram.h>
28 #include <asm/fsl_ddr_dimm_params.h>
29 
30 static void get_spd(ddr3_spd_eeprom_t *spd, unsigned char i2c_address)
31 {
32 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
33 		 sizeof(ddr3_spd_eeprom_t));
34 }
35 
36 void fsl_ddr_get_spd(ddr3_spd_eeprom_t *ctrl_dimms_spd,
37 		      unsigned int ctrl_num)
38 {
39 	unsigned int i;
40 	unsigned int i2c_address = 0;
41 
42 	for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
43 		if (ctrl_num == 0 && i == 0)
44 			i2c_address = SPD_EEPROM_ADDRESS1;
45 		get_spd(&(ctrl_dimms_spd[i]), i2c_address);
46 	}
47 }
48 
49 unsigned int fsl_ddr_get_mem_data_rate(void)
50 {
51 	return get_ddr_freq(0);
52 }
53 
54 /*
55  *     There are traditionally three board-specific SDRAM timing parameters
56  *     which must be calculated based on the particular PCB artwork.  These are:
57  *     1.) CPO (Read Capture Delay)
58  *             - TIMING_CFG_2 register
59  *             Source: Calculation based on board trace lengths and
60  *                     chip-specific internal delays.
61  *     2.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
62  *             - DDR_SDRAM_CLK_CNTL register
63  *             Source: Signal Integrity Simulations
64  *     3.) 2T Timing on Addr/Ctl
65  *             - TIMING_CFG_2 register
66  *             Source: Signal Integrity Simulations
67  *             Usually only needed with heavy load/very high speed (>DDR2-800)
68  *
69  *     ====== XPedite550x DDR3-800 read delay calculations ======
70  *
71  *     The P2020 processor provides an autoleveling option. Setting CPO to
72  *     0x1f enables this auto configuration.
73  */
74 
75 typedef struct {
76 	unsigned short datarate_mhz_low;
77 	unsigned short datarate_mhz_high;
78 	unsigned char clk_adjust;
79 	unsigned char cpo;
80 } board_specific_parameters_t;
81 
82 const board_specific_parameters_t board_specific_parameters[][20] = {
83 	{
84 		/* Controller 0 */
85                 {
86 			/* DDR3-600/667 */
87 			.datarate_mhz_low	= 500,
88 			.datarate_mhz_high	= 750,
89 			.clk_adjust		= 5,
90 			.cpo			= 31,
91 		},
92                 {
93 			/* DDR3-800 */
94 			.datarate_mhz_low	= 750,
95 			.datarate_mhz_high	= 850,
96 			.clk_adjust		= 5,
97 			.cpo			= 31,
98 		},
99 	},
100 };
101 
102 void fsl_ddr_board_options(memctl_options_t *popts,
103 				dimm_params_t *pdimm,
104 				unsigned int ctrl_num)
105 {
106 	const board_specific_parameters_t *pbsp =
107 				&(board_specific_parameters[ctrl_num][0]);
108 	u32 num_params = sizeof(board_specific_parameters[ctrl_num]) /
109 				sizeof(board_specific_parameters[0][0]);
110 	u32 i;
111 	ulong ddr_freq;
112 
113 	/*
114 	 * Set odt_rd_cfg and odt_wr_cfg. If the there is only one dimm in
115 	 * that controller, set odt_wr_cfg to 4 for CS0, and 0 to CS1. If
116 	 * there are two dimms in the controller, set odt_rd_cfg to 3 and
117 	 * odt_wr_cfg to 3 for the even CS, 0 for the odd CS.
118 	 */
119 	for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
120 		if (i&1) {	/* odd CS */
121 			popts->cs_local_opts[i].odt_rd_cfg = 0;
122 			popts->cs_local_opts[i].odt_wr_cfg = 0;
123 		} else {	/* even CS */
124 			if (CONFIG_DIMM_SLOTS_PER_CTLR == 1) {
125 				popts->cs_local_opts[i].odt_rd_cfg = 0;
126 				popts->cs_local_opts[i].odt_wr_cfg = 4;
127 			} else if (CONFIG_DIMM_SLOTS_PER_CTLR == 2) {
128 				popts->cs_local_opts[i].odt_rd_cfg = 3;
129 				popts->cs_local_opts[i].odt_wr_cfg = 3;
130 			}
131 		}
132 	}
133 
134 	/*
135 	 * Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
136 	 * freqency and n_banks specified in board_specific_parameters table.
137 	 */
138 	ddr_freq = get_ddr_freq(0) / 1000000;
139 
140 	for (i = 0; i < num_params; i++) {
141 		if (ddr_freq >= pbsp->datarate_mhz_low &&
142 		    ddr_freq <= pbsp->datarate_mhz_high) {
143 			popts->clk_adjust = pbsp->clk_adjust;
144 			popts->cpo_override = pbsp->cpo;
145 			popts->twoT_en = 0;
146 		}
147 		pbsp++;
148 	}
149 
150 	/*
151 	 * Factors to consider for half-strength driver enable:
152 	 *	- number of DIMMs installed
153 	 */
154 	popts->half_strength_driver_enable = 0;
155 
156 	/*
157 	 * Enable on-die termination.
158 	 * From the Micron Technical Node TN-41-04, RTT_Nom should typically
159 	 * be 30 to 40 ohms, while RTT_WR should be 120 ohms.  Setting RTT_WR
160 	 * is handled in the Freescale DDR3 driver.  Set RTT_Nom here.
161 	 */
162 	popts->rtt_override = 1;
163 	popts->rtt_override_value = 3;
164 }
165 
166