1 /**
2  * Copyright 2010 Freescale Semiconductor
3  * Author: Timur Tabi <timur@freescale.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License as published by the Free
7  * Software Foundation; either version 2 of the License, or (at your option)
8  * any later version.
9  *
10  * This file provides support for the ngPIXIS, a board-specific FPGA used on
11  * some Freescale reference boards.
12  *
13  * A "switch" is black rectangular block on the motherboard.  It contains
14  * eight "bits".  The ngPIXIS has a set of memory-mapped registers (SWx) that
15  * shadow the actual physical switches.  There is also another set of
16  * registers (ENx) that tell the ngPIXIS which bits of SWx should actually be
17  * used to override the values of the bits in the physical switches.
18  *
19  * The following macros need to be defined:
20  *
21  * PIXIS_BASE - The virtual address of the base of the PIXIS register map
22  *
23  * PIXIS_LBMAP_SWITCH - The switch number (i.e. the "x" in "SWx"). This value
24  *    is used in the PIXIS_SW() macro to determine which offset in
25  *    the PIXIS register map corresponds to the physical switch that controls
26  *    the boot bank.
27  *
28  * PIXIS_LBMAP_MASK - A bit mask the defines which bits in SWx to use.
29  *
30  * PIXIS_LBMAP_SHIFT - The shift value that corresponds to PIXIS_LBMAP_MASK.
31  *
32  * PIXIS_LBMAP_ALTBANK - The value to program into SWx to tell the ngPIXIS to
33  *    boot from the alternate bank.
34  */
35 
36 #include <common.h>
37 #include <command.h>
38 #include <watchdog.h>
39 #include <asm/cache.h>
40 #include <asm/io.h>
41 
42 #include "ngpixis.h"
43 
44 /*
45  * Reset the board. This ignores the ENx registers.
46  */
47 void pixis_reset(void)
48 {
49 	out_8(&pixis->rst, 0);
50 
51 	while (1);
52 }
53 
54 /*
55  * Reset the board.  Like pixis_reset(), but it honors the ENx registers.
56  */
57 void pixis_bank_reset(void)
58 {
59 	out_8(&pixis->vctl, 0);
60 	out_8(&pixis->vctl, 1);
61 
62 	while (1);
63 }
64 
65 /**
66  * Set the boot bank to the power-on default bank
67  */
68 void clear_altbank(void)
69 {
70 	/* Tell the ngPIXIS to use this the bits in the physical switch for the
71 	 * boot bank value, instead of the SWx register.  We need to be careful
72 	 * only to set the bits in SWx that correspond to the boot bank.
73 	 */
74 	clrbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
75 }
76 
77 /**
78  * Set the boot bank to the alternate bank
79  */
80 void set_altbank(void)
81 {
82 	/* Program the alternate bank number into the SWx register.
83 	 */
84 	clrsetbits_8(&PIXIS_SW(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK,
85 		     PIXIS_LBMAP_ALTBANK);
86 
87 	/* Tell the ngPIXIS to use this the bits in the SWx register for the
88 	 * boot bank value, instead of the physical switch.  We need to be
89 	 * careful only to set the bits in SWx that correspond to the boot bank.
90 	 */
91 	setbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
92 }
93 
94 
95 int pixis_reset_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
96 {
97 	unsigned int i;
98 	char *p_altbank = NULL;
99 	char *unknown_param = NULL;
100 
101 	/* No args is a simple reset request.
102 	 */
103 	if (argc <= 1)
104 		pixis_reset();
105 
106 	for (i = 1; i < argc; i++) {
107 		if (strcmp(argv[i], "altbank") == 0) {
108 			p_altbank = argv[i];
109 			continue;
110 		}
111 
112 		unknown_param = argv[i];
113 	}
114 
115 	if (unknown_param) {
116 		printf("Invalid option: %s\n", unknown_param);
117 		return 1;
118 	}
119 
120 	if (p_altbank)
121 		set_altbank();
122 	else
123 		clear_altbank();
124 
125 	pixis_bank_reset();
126 
127 	/* Shouldn't be reached. */
128 	return 0;
129 }
130 
131 U_BOOT_CMD(
132 	pixis_reset, CONFIG_SYS_MAXARGS, 1, pixis_reset_cmd,
133 	"Reset the board using the FPGA sequencer",
134 	"- hard reset to default bank\n"
135 	"pixis_reset altbank - reset to alternate bank\n"
136 	);
137