Commit | Line | Data |
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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 | ||
37ef38f3 TT |
19 | /* |
20 | * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as | |
21 | * occasionally getting stuck as 1. To avoid the potential for a hang, check | |
22 | * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART | |
23 | * implementations, so only do so if an affected platform is detected in | |
0231d000 | 24 | * acpi_parse_spcr(). |
37ef38f3 TT |
25 | */ |
26 | bool qdf2400_e44_present; | |
27 | EXPORT_SYMBOL(qdf2400_e44_present); | |
28 | ||
d8a4995b CC |
29 | /* |
30 | * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. | |
31 | * Detect them by examining the OEM fields in the SPCR header, similiar to PCI | |
32 | * quirk detection in pci_mcfg.c. | |
33 | */ | |
34 | static bool qdf2400_erratum_44_present(struct acpi_table_header *h) | |
35 | { | |
36 | if (memcmp(h->oem_id, "QCOM ", ACPI_OEM_ID_SIZE)) | |
37 | return false; | |
38 | ||
39 | if (!memcmp(h->oem_table_id, "QDF2432 ", ACPI_OEM_TABLE_ID_SIZE)) | |
40 | return true; | |
41 | ||
42 | if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) && | |
542ed784 | 43 | h->oem_revision == 1) |
d8a4995b CC |
44 | return true; |
45 | ||
46 | return false; | |
47 | } | |
48 | ||
79a64832 LH |
49 | /* |
50 | * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its | |
51 | * register aligned to 32-bit. In addition, the BIOS also encoded the | |
52 | * access width to be 8 bits. This function detects this errata condition. | |
53 | */ | |
54 | static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) | |
55 | { | |
dee82bc1 GG |
56 | bool xgene_8250 = false; |
57 | ||
79a64832 LH |
58 | if (tb->interface_type != ACPI_DBG2_16550_COMPATIBLE) |
59 | return false; | |
60 | ||
dee82bc1 GG |
61 | if (memcmp(tb->header.oem_id, "APMC0D", ACPI_OEM_ID_SIZE) && |
62 | memcmp(tb->header.oem_id, "HPE ", ACPI_OEM_ID_SIZE)) | |
79a64832 LH |
63 | return false; |
64 | ||
65 | if (!memcmp(tb->header.oem_table_id, "XGENESPC", | |
66 | ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 0) | |
dee82bc1 | 67 | xgene_8250 = true; |
79a64832 | 68 | |
dee82bc1 GG |
69 | if (!memcmp(tb->header.oem_table_id, "ProLiant", |
70 | ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 1) | |
71 | xgene_8250 = true; | |
72 | ||
73 | return xgene_8250; | |
79a64832 LH |
74 | } |
75 | ||
ad1696f6 | 76 | /** |
0231d000 | 77 | * acpi_parse_spcr() - parse ACPI SPCR table and add preferred console |
ad1696f6 | 78 | * |
0231d000 PB |
79 | * @enable_earlycon: set up earlycon for the console specified by the table |
80 | * @enable_console: setup the console specified by the table. | |
ad1696f6 AM |
81 | * |
82 | * For the architectures with support for ACPI, CONFIG_ACPI_SPCR_TABLE may be | |
83 | * defined to parse ACPI SPCR table. As a result of the parsing preferred | |
0231d000 PB |
84 | * console is registered and if @enable_earlycon is true, earlycon is set up. |
85 | * If @enable_console is true the system console is also configured. | |
ad1696f6 AM |
86 | * |
87 | * When CONFIG_ACPI_SPCR_TABLE is defined, this function should be called | |
183b8021 | 88 | * from arch initialization code as soon as the DT/ACPI decision is made. |
ad1696f6 AM |
89 | * |
90 | */ | |
0231d000 | 91 | int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console) |
ad1696f6 AM |
92 | { |
93 | static char opts[64]; | |
94 | struct acpi_table_spcr *table; | |
ad1696f6 AM |
95 | acpi_status status; |
96 | char *uart; | |
97 | char *iotype; | |
98 | int baud_rate; | |
99 | int err; | |
100 | ||
101 | if (acpi_disabled) | |
102 | return -ENODEV; | |
103 | ||
6b11d1d6 LZ |
104 | status = acpi_get_table(ACPI_SIG_SPCR, 0, |
105 | (struct acpi_table_header **)&table); | |
ad1696f6 AM |
106 | |
107 | if (ACPI_FAILURE(status)) | |
108 | return -ENOENT; | |
109 | ||
0231d000 PB |
110 | if (table->header.revision < 2) |
111 | pr_info("SPCR table version %d\n", table->header.revision); | |
ad1696f6 | 112 | |
2bece493 | 113 | if (table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { |
4eebedd8 LZ |
114 | switch (ACPI_ACCESS_BIT_WIDTH(( |
115 | table->serial_port.access_width))) { | |
2bece493 LH |
116 | default: |
117 | pr_err("Unexpected SPCR Access Width. Defaulting to byte size\n"); | |
5a9e59e8 | 118 | /* fall through */ |
4eebedd8 | 119 | case 8: |
2bece493 LH |
120 | iotype = "mmio"; |
121 | break; | |
4eebedd8 | 122 | case 16: |
2bece493 LH |
123 | iotype = "mmio16"; |
124 | break; | |
4eebedd8 | 125 | case 32: |
2bece493 LH |
126 | iotype = "mmio32"; |
127 | break; | |
128 | } | |
129 | } else | |
130 | iotype = "io"; | |
ad1696f6 AM |
131 | |
132 | switch (table->interface_type) { | |
133 | case ACPI_DBG2_ARM_SBSA_32BIT: | |
134 | iotype = "mmio32"; | |
135 | /* fall through */ | |
136 | case ACPI_DBG2_ARM_PL011: | |
137 | case ACPI_DBG2_ARM_SBSA_GENERIC: | |
138 | case ACPI_DBG2_BCM2835: | |
139 | uart = "pl011"; | |
140 | break; | |
141 | case ACPI_DBG2_16550_COMPATIBLE: | |
142 | case ACPI_DBG2_16550_SUBSET: | |
143 | uart = "uart"; | |
144 | break; | |
145 | default: | |
146 | err = -ENOENT; | |
147 | goto done; | |
148 | } | |
149 | ||
150 | switch (table->baud_rate) { | |
151 | case 3: | |
152 | baud_rate = 9600; | |
153 | break; | |
154 | case 4: | |
155 | baud_rate = 19200; | |
156 | break; | |
157 | case 6: | |
158 | baud_rate = 57600; | |
159 | break; | |
160 | case 7: | |
161 | baud_rate = 115200; | |
162 | break; | |
163 | default: | |
164 | err = -ENOENT; | |
165 | goto done; | |
166 | } | |
167 | ||
37ef38f3 TT |
168 | /* |
169 | * If the E44 erratum is required, then we need to tell the pl011 | |
170 | * driver to implement the work-around. | |
171 | * | |
172 | * The global variable is used by the probe function when it | |
173 | * creates the UARTs, whether or not they're used as a console. | |
174 | * | |
175 | * If the user specifies "traditional" earlycon, the qdf2400_e44 | |
176 | * console name matches the EARLYCON_DECLARE() statement, and | |
177 | * SPCR is not used. Parameter "earlycon" is false. | |
178 | * | |
179 | * If the user specifies "SPCR" earlycon, then we need to update | |
180 | * the console name so that it also says "qdf2400_e44". Parameter | |
181 | * "earlycon" is true. | |
182 | * | |
183 | * For consistency, if we change the console name, then we do it | |
184 | * for everyone, not just earlycon. | |
185 | */ | |
186 | if (qdf2400_erratum_44_present(&table->header)) { | |
187 | qdf2400_e44_present = true; | |
0231d000 | 188 | if (enable_earlycon) |
37ef38f3 TT |
189 | uart = "qdf2400_e44"; |
190 | } | |
191 | ||
03c3876f | 192 | if (xgene_8250_erratum_present(table)) { |
79a64832 | 193 | iotype = "mmio32"; |
d8a4995b | 194 | |
03c3876f GG |
195 | /* for xgene v1 and v2 we don't know the clock rate of the |
196 | * UART so don't attempt to change to the baud rate state | |
197 | * in the table because driver cannot calculate the dividers | |
198 | */ | |
199 | snprintf(opts, sizeof(opts), "%s,%s,0x%llx", uart, iotype, | |
200 | table->serial_port.address); | |
201 | } else { | |
202 | snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, | |
203 | table->serial_port.address, baud_rate); | |
204 | } | |
ad1696f6 AM |
205 | |
206 | pr_info("console: %s\n", opts); | |
207 | ||
0231d000 | 208 | if (enable_earlycon) |
ad1696f6 AM |
209 | setup_earlycon(opts); |
210 | ||
0231d000 PB |
211 | if (enable_console) |
212 | err = add_preferred_console(uart, 0, opts + strlen(uart) + 1); | |
213 | else | |
214 | err = 0; | |
ad1696f6 | 215 | done: |
6b11d1d6 | 216 | acpi_put_table((struct acpi_table_header *)table); |
ad1696f6 AM |
217 | return err; |
218 | } |