xref: /openbmc/u-boot/board/xes/xpedite517x/ddr.c (revision e77e65df)
1 /*
2  * Copyright 2009 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 #include <fsl_ddr_sdram.h>
11 #include <fsl_ddr_dimm_params.h>
12 
13 void get_spd(ddr2_spd_eeprom_t *spd, u8 i2c_address)
14 {
15 	i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
16 		sizeof(ddr2_spd_eeprom_t));
17 }
18 
19 /*
20  * There are four board-specific SDRAM timing parameters which must be
21  * 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.) WR_DATA_DELAY (Write Command to Data Strobe Delay)
27  *           - TIMING_CFG_2 register
28  *           Source: Calculation based on board trace lengths.
29  *                   Unless clock and DQ lanes are very different
30  *                   lengths (>2"), this should be set to the nominal value
31  *                   of 1/2 clock delay.
32  *   3.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
33  *           - DDR_SDRAM_CLK_CNTL register
34  *           Source: Signal Integrity Simulations
35  *   4.) 2T Timing on Addr/Ctl
36  *           - TIMING_CFG_2 register
37  *           Source: Signal Integrity Simulations
38  *           Usually only needed with heavy load/very high speed (>DDR2-800)
39  *
40  *     PCB routing on the XPedite5170 is nearly identical to the XPedite5370
41  *     so we use the XPedite5370 settings as a basis for the XPedite5170.
42  */
43 
44 typedef struct board_memctl_options {
45 	uint16_t datarate_mhz_low;
46 	uint16_t datarate_mhz_high;
47 	uint8_t clk_adjust;
48 	uint8_t cpo_override;
49 	uint8_t write_data_delay;
50 } board_memctl_options_t;
51 
52 static struct board_memctl_options bopts_ctrl[][2] = {
53 	{
54 		/* Controller 0 */
55 		{
56 			/* DDR2 600/667 */
57 			.datarate_mhz_low	= 500,
58 			.datarate_mhz_high	= 750,
59 			.clk_adjust		= 5,
60 			.cpo_override		= 8,
61 			.write_data_delay	= 2,
62 		},
63 		{
64 			/* DDR2 800 */
65 			.datarate_mhz_low	= 750,
66 			.datarate_mhz_high	= 850,
67 			.clk_adjust		= 5,
68 			.cpo_override		= 9,
69 			.write_data_delay	= 2,
70 		},
71 	},
72 	{
73 		/* Controller 1 */
74 		{
75 			/* DDR2 600/667 */
76 			.datarate_mhz_low	= 500,
77 			.datarate_mhz_high	= 750,
78 			.clk_adjust		= 5,
79 			.cpo_override		= 7,
80 			.write_data_delay	= 2,
81 		},
82 		{
83 			/* DDR2 800 */
84 			.datarate_mhz_low	= 750,
85 			.datarate_mhz_high	= 850,
86 			.clk_adjust		= 5,
87 			.cpo_override		= 8,
88 			.write_data_delay	= 2,
89 		},
90 	},
91 };
92 
93 void fsl_ddr_board_options(memctl_options_t *popts,
94 			dimm_params_t *pdimm,
95 			unsigned int ctrl_num)
96 {
97 	struct board_memctl_options *bopts = bopts_ctrl[ctrl_num];
98 	sys_info_t sysinfo;
99 	int i;
100 	unsigned int datarate;
101 
102 	get_sys_info(&sysinfo);
103 	datarate = get_ddr_freq(0) / 1000000;
104 
105 	for (i = 0; i < ARRAY_SIZE(bopts_ctrl[ctrl_num]); i++) {
106 		if ((bopts[i].datarate_mhz_low <= datarate) &&
107 		    (bopts[i].datarate_mhz_high >= datarate)) {
108 			debug("controller %d:\n", ctrl_num);
109 			debug(" clk_adjust = %d\n", bopts[i].clk_adjust);
110 			debug(" cpo = %d\n", bopts[i].cpo_override);
111 			debug(" write_data_delay = %d\n",
112 				bopts[i].write_data_delay);
113 			popts->clk_adjust = bopts[i].clk_adjust;
114 			popts->cpo_override = bopts[i].cpo_override;
115 			popts->write_data_delay = bopts[i].write_data_delay;
116 		}
117 	}
118 
119 	/*
120 	 * Factors to consider for half-strength driver enable:
121 	 *	- number of DIMMs installed
122 	 */
123 	popts->half_strength_driver_enable = 0;
124 }
125