]>
Commit | Line | Data |
---|---|---|
ad1696f6 AM |
1 | /* |
2 | * Copyright (c) 2012, Intel Corporation | |
3 | * Copyright (c) 2015, Red Hat, Inc. | |
4 | * Copyright (c) 2015, 2016 Linaro Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | ||
12 | #define pr_fmt(fmt) "ACPI: SPCR: " fmt | |
13 | ||
14 | #include <linux/acpi.h> | |
15 | #include <linux/console.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/serial_core.h> | |
18 | ||
19 | /** | |
20 | * parse_spcr() - parse ACPI SPCR table and add preferred console | |
21 | * | |
22 | * @earlycon: set up earlycon for the console specified by the table | |
23 | * | |
24 | * For the architectures with support for ACPI, CONFIG_ACPI_SPCR_TABLE may be | |
25 | * defined to parse ACPI SPCR table. As a result of the parsing preferred | |
26 | * console is registered and if @earlycon is true, earlycon is set up. | |
27 | * | |
28 | * When CONFIG_ACPI_SPCR_TABLE is defined, this function should be called | |
29 | * from arch inintialization code as soon as the DT/ACPI decision is made. | |
30 | * | |
31 | */ | |
32 | int __init parse_spcr(bool earlycon) | |
33 | { | |
34 | static char opts[64]; | |
35 | struct acpi_table_spcr *table; | |
36 | acpi_size table_size; | |
37 | acpi_status status; | |
38 | char *uart; | |
39 | char *iotype; | |
40 | int baud_rate; | |
41 | int err; | |
42 | ||
43 | if (acpi_disabled) | |
44 | return -ENODEV; | |
45 | ||
46 | status = acpi_get_table_with_size(ACPI_SIG_SPCR, 0, | |
47 | (struct acpi_table_header **)&table, | |
48 | &table_size); | |
49 | ||
50 | if (ACPI_FAILURE(status)) | |
51 | return -ENOENT; | |
52 | ||
53 | if (table->header.revision < 2) { | |
54 | err = -ENOENT; | |
55 | pr_err("wrong table version\n"); | |
56 | goto done; | |
57 | } | |
58 | ||
59 | iotype = table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY ? | |
60 | "mmio" : "io"; | |
61 | ||
62 | switch (table->interface_type) { | |
63 | case ACPI_DBG2_ARM_SBSA_32BIT: | |
64 | iotype = "mmio32"; | |
65 | /* fall through */ | |
66 | case ACPI_DBG2_ARM_PL011: | |
67 | case ACPI_DBG2_ARM_SBSA_GENERIC: | |
68 | case ACPI_DBG2_BCM2835: | |
69 | uart = "pl011"; | |
70 | break; | |
71 | case ACPI_DBG2_16550_COMPATIBLE: | |
72 | case ACPI_DBG2_16550_SUBSET: | |
73 | uart = "uart"; | |
74 | break; | |
75 | default: | |
76 | err = -ENOENT; | |
77 | goto done; | |
78 | } | |
79 | ||
80 | switch (table->baud_rate) { | |
81 | case 3: | |
82 | baud_rate = 9600; | |
83 | break; | |
84 | case 4: | |
85 | baud_rate = 19200; | |
86 | break; | |
87 | case 6: | |
88 | baud_rate = 57600; | |
89 | break; | |
90 | case 7: | |
91 | baud_rate = 115200; | |
92 | break; | |
93 | default: | |
94 | err = -ENOENT; | |
95 | goto done; | |
96 | } | |
97 | ||
98 | snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, | |
99 | table->serial_port.address, baud_rate); | |
100 | ||
101 | pr_info("console: %s\n", opts); | |
102 | ||
103 | if (earlycon) | |
104 | setup_earlycon(opts); | |
105 | ||
106 | err = add_preferred_console(uart, 0, opts + strlen(uart) + 1); | |
107 | ||
108 | done: | |
109 | early_acpi_os_unmap_memory((void __iomem *)table, table_size); | |
110 | return err; | |
111 | } |