xref: /openbmc/u-boot/board/xes/xpedite517x/ddr.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2009 Extreme Engineering Solutions, Inc.
4  * Copyright 2007-2008 Freescale Semiconductor, Inc.
5  */
6 
7 #include <common.h>
8 #include <i2c.h>
9 #include <fsl_ddr_sdram.h>
10 #include <fsl_ddr_dimm_params.h>
11 
12 void get_spd(ddr2_spd_eeprom_t *spd, u8 i2c_address)
13 {
14 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
15 		sizeof(ddr2_spd_eeprom_t));
16 }
17 
18 /*
19  * There are four board-specific SDRAM timing parameters which must be
20  * calculated based on the particular PCB artwork.  These are:
21  *   1.) CPO (Read Capture Delay)
22  *           - TIMING_CFG_2 register
23  *           Source: Calculation based on board trace lengths and
24  *                   chip-specific internal delays.
25  *   2.) WR_DATA_DELAY (Write Command to Data Strobe Delay)
26  *           - TIMING_CFG_2 register
27  *           Source: Calculation based on board trace lengths.
28  *                   Unless clock and DQ lanes are very different
29  *                   lengths (>2"), this should be set to the nominal value
30  *                   of 1/2 clock delay.
31  *   3.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
32  *           - DDR_SDRAM_CLK_CNTL register
33  *           Source: Signal Integrity Simulations
34  *   4.) 2T Timing on Addr/Ctl
35  *           - TIMING_CFG_2 register
36  *           Source: Signal Integrity Simulations
37  *           Usually only needed with heavy load/very high speed (>DDR2-800)
38  *
39  *     PCB routing on the XPedite5170 is nearly identical to the XPedite5370
40  *     so we use the XPedite5370 settings as a basis for the XPedite5170.
41  */
42 
43 typedef struct board_memctl_options {
44 	uint16_t datarate_mhz_low;
45 	uint16_t datarate_mhz_high;
46 	uint8_t clk_adjust;
47 	uint8_t cpo_override;
48 	uint8_t write_data_delay;
49 } board_memctl_options_t;
50 
51 static struct board_memctl_options bopts_ctrl[][2] = {
52 	{
53 		/* Controller 0 */
54 		{
55 			/* DDR2 600/667 */
56 			.datarate_mhz_low	= 500,
57 			.datarate_mhz_high	= 750,
58 			.clk_adjust		= 5,
59 			.cpo_override		= 8,
60 			.write_data_delay	= 2,
61 		},
62 		{
63 			/* DDR2 800 */
64 			.datarate_mhz_low	= 750,
65 			.datarate_mhz_high	= 850,
66 			.clk_adjust		= 5,
67 			.cpo_override		= 9,
68 			.write_data_delay	= 2,
69 		},
70 	},
71 	{
72 		/* Controller 1 */
73 		{
74 			/* DDR2 600/667 */
75 			.datarate_mhz_low	= 500,
76 			.datarate_mhz_high	= 750,
77 			.clk_adjust		= 5,
78 			.cpo_override		= 7,
79 			.write_data_delay	= 2,
80 		},
81 		{
82 			/* DDR2 800 */
83 			.datarate_mhz_low	= 750,
84 			.datarate_mhz_high	= 850,
85 			.clk_adjust		= 5,
86 			.cpo_override		= 8,
87 			.write_data_delay	= 2,
88 		},
89 	},
90 };
91 
92 void fsl_ddr_board_options(memctl_options_t *popts,
93 			dimm_params_t *pdimm,
94 			unsigned int ctrl_num)
95 {
96 	struct board_memctl_options *bopts = bopts_ctrl[ctrl_num];
97 	sys_info_t sysinfo;
98 	int i;
99 	unsigned int datarate;
100 
101 	get_sys_info(&sysinfo);
102 	datarate = get_ddr_freq(0) / 1000000;
103 
104 	for (i = 0; i < ARRAY_SIZE(bopts_ctrl[ctrl_num]); i++) {
105 		if ((bopts[i].datarate_mhz_low <= datarate) &&
106 		    (bopts[i].datarate_mhz_high >= datarate)) {
107 			debug("controller %d:\n", ctrl_num);
108 			debug(" clk_adjust = %d\n", bopts[i].clk_adjust);
109 			debug(" cpo = %d\n", bopts[i].cpo_override);
110 			debug(" write_data_delay = %d\n",
111 				bopts[i].write_data_delay);
112 			popts->clk_adjust = bopts[i].clk_adjust;
113 			popts->cpo_override = bopts[i].cpo_override;
114 			popts->write_data_delay = bopts[i].write_data_delay;
115 		}
116 	}
117 
118 	/*
119 	 * Factors to consider for half-strength driver enable:
120 	 *	- number of DIMMs installed
121 	 */
122 	popts->half_strength_driver_enable = 0;
123 }
124