xref: /openbmc/u-boot/board/xes/xpedite550x/ddr.c (revision 274bced8)
1 /*
2  * Copyright 2010 Extreme Engineering Solutions, Inc.
3  * Copyright 2007-2008 Freescale Semiconductor, Inc.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <i2c.h>
10 
11 #include <fsl_ddr_sdram.h>
12 #include <fsl_ddr_dimm_params.h>
13 
14 void get_spd(ddr3_spd_eeprom_t *spd, u8 i2c_address)
15 {
16 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
17 		 sizeof(ddr3_spd_eeprom_t));
18 }
19 
20 /*
21  *     There are traditionally three board-specific SDRAM timing parameters
22  *     which must be calculated based on the particular PCB artwork.  These are:
23  *     1.) CPO (Read Capture Delay)
24  *	       - TIMING_CFG_2 register
25  *	       Source: Calculation based on board trace lengths and
26  *		       chip-specific internal delays.
27  *     2.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
28  *	       - DDR_SDRAM_CLK_CNTL register
29  *	       Source: Signal Integrity Simulations
30  *     3.) 2T Timing on Addr/Ctl
31  *	       - TIMING_CFG_2 register
32  *	       Source: Signal Integrity Simulations
33  *	       Usually only needed with heavy load/very high speed (>DDR2-800)
34  *
35  *     ====== XPedite550x DDR3-800 read delay calculations ======
36  *
37  *     The P2020 processor provides an autoleveling option. Setting CPO to
38  *     0x1f enables this auto configuration.
39  */
40 
41 typedef struct {
42 	unsigned short datarate_mhz_low;
43 	unsigned short datarate_mhz_high;
44 	unsigned char clk_adjust;
45 	unsigned char cpo;
46 } board_specific_parameters_t;
47 
48 const board_specific_parameters_t board_specific_parameters[][20] = {
49 	{
50 		/* Controller 0 */
51 		{
52 			/* DDR3-600/667 */
53 			.datarate_mhz_low	= 500,
54 			.datarate_mhz_high	= 750,
55 			.clk_adjust		= 5,
56 			.cpo			= 31,
57 		},
58 		{
59 			/* DDR3-800 */
60 			.datarate_mhz_low	= 750,
61 			.datarate_mhz_high	= 850,
62 			.clk_adjust		= 5,
63 			.cpo			= 31,
64 		},
65 	},
66 };
67 
68 void fsl_ddr_board_options(memctl_options_t *popts,
69 				dimm_params_t *pdimm,
70 				unsigned int ctrl_num)
71 {
72 	const board_specific_parameters_t *pbsp =
73 				&(board_specific_parameters[ctrl_num][0]);
74 	u32 num_params = sizeof(board_specific_parameters[ctrl_num]) /
75 				sizeof(board_specific_parameters[0][0]);
76 	u32 i;
77 	ulong ddr_freq;
78 
79 	/*
80 	 * Set odt_rd_cfg and odt_wr_cfg. If the there is only one dimm in
81 	 * that controller, set odt_wr_cfg to 4 for CS0, and 0 to CS1. If
82 	 * there are two dimms in the controller, set odt_rd_cfg to 3 and
83 	 * odt_wr_cfg to 3 for the even CS, 0 for the odd CS.
84 	 */
85 	for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
86 		if (i&1) {	/* odd CS */
87 			popts->cs_local_opts[i].odt_rd_cfg = 0;
88 			popts->cs_local_opts[i].odt_wr_cfg = 0;
89 		} else {	/* even CS */
90 			if (CONFIG_DIMM_SLOTS_PER_CTLR == 1) {
91 				popts->cs_local_opts[i].odt_rd_cfg = 0;
92 				popts->cs_local_opts[i].odt_wr_cfg = 4;
93 			} else if (CONFIG_DIMM_SLOTS_PER_CTLR == 2) {
94 				popts->cs_local_opts[i].odt_rd_cfg = 3;
95 				popts->cs_local_opts[i].odt_wr_cfg = 3;
96 			}
97 		}
98 	}
99 
100 	/*
101 	 * Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
102 	 * freqency and n_banks specified in board_specific_parameters table.
103 	 */
104 	ddr_freq = get_ddr_freq(0) / 1000000;
105 
106 	for (i = 0; i < num_params; i++) {
107 		if (ddr_freq >= pbsp->datarate_mhz_low &&
108 		    ddr_freq <= pbsp->datarate_mhz_high) {
109 			popts->clk_adjust = pbsp->clk_adjust;
110 			popts->cpo_override = pbsp->cpo;
111 			popts->twot_en = 0;
112 			break;
113 		}
114 		pbsp++;
115 	}
116 
117 	if (i == num_params) {
118 		printf("Warning: board specific timing not found "
119 		"for data rate %lu MT/s!\n", ddr_freq);
120 	}
121 
122 	/*
123 	 * Factors to consider for half-strength driver enable:
124 	 *	- number of DIMMs installed
125 	 */
126 	popts->half_strength_driver_enable = 0;
127 
128 	/*
129 	 * Enable on-die termination.
130 	 * From the Micron Technical Node TN-41-04, RTT_Nom should typically
131 	 * be 30 to 40 ohms, while RTT_WR should be 120 ohms.  Setting RTT_WR
132 	 * is handled in the Freescale DDR3 driver.  Set RTT_Nom here.
133 	 */
134 	popts->rtt_override = 1;
135 	popts->rtt_override_value = 3;
136 }
137