xref: /openbmc/u-boot/board/xes/xpedite550x/ddr.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2010 Extreme Engineering Solutions, Inc.
4  * Copyright 2007-2008 Freescale Semiconductor, Inc.
5  */
6 
7 #include <common.h>
8 #include <i2c.h>
9 
10 #include <fsl_ddr_sdram.h>
11 #include <fsl_ddr_dimm_params.h>
12 
13 void get_spd(ddr3_spd_eeprom_t *spd, u8 i2c_address)
14 {
15 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
16 		 sizeof(ddr3_spd_eeprom_t));
17 }
18 
19 /*
20  *     There are traditionally three board-specific SDRAM timing parameters
21  *     which must be calculated based on the particular PCB artwork.  These are:
22  *     1.) CPO (Read Capture Delay)
23  *	       - TIMING_CFG_2 register
24  *	       Source: Calculation based on board trace lengths and
25  *		       chip-specific internal delays.
26  *     2.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
27  *	       - DDR_SDRAM_CLK_CNTL register
28  *	       Source: Signal Integrity Simulations
29  *     3.) 2T Timing on Addr/Ctl
30  *	       - TIMING_CFG_2 register
31  *	       Source: Signal Integrity Simulations
32  *	       Usually only needed with heavy load/very high speed (>DDR2-800)
33  *
34  *     ====== XPedite550x DDR3-800 read delay calculations ======
35  *
36  *     The P2020 processor provides an autoleveling option. Setting CPO to
37  *     0x1f enables this auto configuration.
38  */
39 
40 typedef struct {
41 	unsigned short datarate_mhz_low;
42 	unsigned short datarate_mhz_high;
43 	unsigned char clk_adjust;
44 	unsigned char cpo;
45 } board_specific_parameters_t;
46 
47 const board_specific_parameters_t board_specific_parameters[][20] = {
48 	{
49 		/* Controller 0 */
50 		{
51 			/* DDR3-600/667 */
52 			.datarate_mhz_low	= 500,
53 			.datarate_mhz_high	= 750,
54 			.clk_adjust		= 5,
55 			.cpo			= 31,
56 		},
57 		{
58 			/* DDR3-800 */
59 			.datarate_mhz_low	= 750,
60 			.datarate_mhz_high	= 850,
61 			.clk_adjust		= 5,
62 			.cpo			= 31,
63 		},
64 	},
65 };
66 
67 void fsl_ddr_board_options(memctl_options_t *popts,
68 				dimm_params_t *pdimm,
69 				unsigned int ctrl_num)
70 {
71 	const board_specific_parameters_t *pbsp =
72 				&(board_specific_parameters[ctrl_num][0]);
73 	u32 num_params = sizeof(board_specific_parameters[ctrl_num]) /
74 				sizeof(board_specific_parameters[0][0]);
75 	u32 i;
76 	ulong ddr_freq;
77 
78 	/*
79 	 * Set odt_rd_cfg and odt_wr_cfg. If the there is only one dimm in
80 	 * that controller, set odt_wr_cfg to 4 for CS0, and 0 to CS1. If
81 	 * there are two dimms in the controller, set odt_rd_cfg to 3 and
82 	 * odt_wr_cfg to 3 for the even CS, 0 for the odd CS.
83 	 */
84 	for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
85 		if (i&1) {	/* odd CS */
86 			popts->cs_local_opts[i].odt_rd_cfg = 0;
87 			popts->cs_local_opts[i].odt_wr_cfg = 0;
88 		} else {	/* even CS */
89 			if (CONFIG_DIMM_SLOTS_PER_CTLR == 1) {
90 				popts->cs_local_opts[i].odt_rd_cfg = 0;
91 				popts->cs_local_opts[i].odt_wr_cfg = 4;
92 			} else if (CONFIG_DIMM_SLOTS_PER_CTLR == 2) {
93 				popts->cs_local_opts[i].odt_rd_cfg = 3;
94 				popts->cs_local_opts[i].odt_wr_cfg = 3;
95 			}
96 		}
97 	}
98 
99 	/*
100 	 * Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
101 	 * freqency and n_banks specified in board_specific_parameters table.
102 	 */
103 	ddr_freq = get_ddr_freq(0) / 1000000;
104 
105 	for (i = 0; i < num_params; i++) {
106 		if (ddr_freq >= pbsp->datarate_mhz_low &&
107 		    ddr_freq <= pbsp->datarate_mhz_high) {
108 			popts->clk_adjust = pbsp->clk_adjust;
109 			popts->cpo_override = pbsp->cpo;
110 			popts->twot_en = 0;
111 			break;
112 		}
113 		pbsp++;
114 	}
115 
116 	if (i == num_params) {
117 		printf("Warning: board specific timing not found "
118 		"for data rate %lu MT/s!\n", ddr_freq);
119 	}
120 
121 	/*
122 	 * Factors to consider for half-strength driver enable:
123 	 *	- number of DIMMs installed
124 	 */
125 	popts->half_strength_driver_enable = 0;
126 
127 	/*
128 	 * Enable on-die termination.
129 	 * From the Micron Technical Node TN-41-04, RTT_Nom should typically
130 	 * be 30 to 40 ohms, while RTT_WR should be 120 ohms.  Setting RTT_WR
131 	 * is handled in the Freescale DDR3 driver.  Set RTT_Nom here.
132 	 */
133 	popts->rtt_override = 1;
134 	popts->rtt_override_value = 3;
135 }
136