1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
/*
* Copyright (c) 2011 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* This file contains convenience functions for decoding useful and
* enlightening information from FDTs. It is intended to be used by device
* drivers and board-specific code within U-Boot. It aims to reduce the
* amount of FDT munging required within U-Boot itself, so that driver code
* changes to support FDT are minimized.
*/
/* A typedef for a physical address. We should move it to a generic place */
#ifdef CONFIG_PHYS_64BIT
typedef u64 addr_t;
#define ADDR_T_NONE (-1ULL)
#define addr_to_cpu(reg) be64_to_cpu(reg)
#else
typedef u32 addr_t;
#define ADDR_T_NONE (-1U)
#define addr_to_cpu(reg) be32_to_cpu(reg)
#endif
/**
* Compat types that we know about and for which we might have drivers.
* Each is named COMPAT_<dir>_<filename> where <dir> is the directory
* within drivers.
*/
enum fdt_compat_id {
COMPAT_UNKNOWN,
COMPAT_COUNT,
};
/** compat items that we know about and might have drivers for */
struct fdt_compat {
enum fdt_compat_id id;
const char *name;
};
/* Information obtained about a UART from the FDT */
struct fdt_uart {
addr_t reg; /* address of registers in physical memory */
int id; /* id or port number (numbered from 0, default -1) */
int reg_shift; /* each register is (1 << reg_shift) apart */
int baudrate; /* baud rate, will be gd->baudrate if not defined */
int clock_freq; /* clock frequency, -1 if not provided */
int multiplier; /* divisor multiplier, default 16 */
int divisor; /* baud rate divisor, default calculated */
int enabled; /* 1 to enable, 0 to disable */
int interrupt; /* interrupt line */
int silent; /* 1 for silent UART (supresses output by default) */
enum fdt_compat_id compat; /* our selected driver */
};
/**
* Return information from the FDT about the console UART. This looks for
* an alias node called 'console' which must point to a UART. It then reads
* out the following attributes:
*
* reg
* port
* clock-frequency
* reg-shift (default 2)
* baudrate (default 115200)
* multiplier (default 16)
* divisor (calculated by default)
* enabled (default 1)
* interrupts (returns first in interrupt list, -1 if none)
* silent (default 0)
*
* The divisor calculation is performed by calling
* fdt_decode_uart_calc_divisor() automatically once the information is
* available. Therefore callers should be able to simply use the ->divisor
* field as their baud rate divisor.
*
* @param blob FDT blob to use
* @param uart struct to use to return information
* @param default_baudrate Baud rate to use if none defined in FDT
* @return 0 on success, -ve on error, in which case uart is unchanged
*/
int fdt_decode_uart_console(const void *blob, struct fdt_uart *uart,
int default_baudrate);
/**
* Calculate the divisor to use for the uart. This is done based on the
* formula (uart clock / (baudrate * multiplier). The divisor is updated
* in the uart structure ready for use.
*
* @param uart uart structure to examine and update
*/
void fdt_decode_uart_calc_divisor(struct fdt_uart *uart);
/**
* Find the compat id for a node. This looks at the 'compat' property of
* the node and looks up the corresponding ftp_compat_id. This is used for
* determining which driver will implement the decide described by the node.
*/
enum fdt_compat_id fdt_decode_lookup(const void *blob, int node);
|
