xref: /freebsd/sys/dev/uart/uart_cpu_acpi.c (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2016 The FreeBSD Foundation
5  * Copyright (c) 2019 Colin Percival
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 
37 #include <machine/bus.h>
38 
39 #include <dev/uart/uart.h>
40 #include <dev/uart/uart_bus.h>
41 #include <dev/uart/uart_cpu.h>
42 #include <dev/uart/uart_cpu_acpi.h>
43 
44 #include <contrib/dev/acpica/include/acpi.h>
45 #include <contrib/dev/acpica/include/accommon.h>
46 #include <contrib/dev/acpica/include/actables.h>
47 
48 static struct acpi_uart_compat_data *
49 uart_cpu_acpi_scan(uint8_t interface_type)
50 {
51 	struct acpi_uart_compat_data **cd, *curcd;
52 	int i;
53 
54 	SET_FOREACH(cd, uart_acpi_class_and_device_set) {
55 		curcd = *cd;
56 		for (i = 0; curcd[i].cd_hid != NULL; i++) {
57 			if (curcd[i].cd_port_subtype == interface_type)
58 				return (&curcd[i]);
59 		}
60 	}
61 
62 	SET_FOREACH(cd, uart_acpi_class_set) {
63 		curcd = *cd;
64 		for (i = 0; curcd[i].cd_hid != NULL; i++) {
65 			if (curcd[i].cd_port_subtype == interface_type)
66 				return (&curcd[i]);
67 		}
68 	}
69 
70 	return (NULL);
71 }
72 
73 int
74 uart_cpu_acpi_spcr(int devtype, struct uart_devinfo *di)
75 {
76 	vm_paddr_t spcr_physaddr;
77 	ACPI_TABLE_SPCR *spcr;
78 	struct acpi_uart_compat_data *cd;
79 	struct uart_class *class;
80 	int error = ENXIO;
81 
82 	/* SPCR only tells us about consoles. */
83 	if (devtype != UART_DEV_CONSOLE)
84 		return (error);
85 
86 	/* Look for the SPCR table. */
87 	spcr_physaddr = acpi_find_table(ACPI_SIG_SPCR);
88 	if (spcr_physaddr == 0)
89 		return (error);
90 	spcr = acpi_map_table(spcr_physaddr, ACPI_SIG_SPCR);
91 	if (spcr == NULL) {
92 		printf("Unable to map the SPCR table!\n");
93 		return (error);
94 	}
95 
96 	/* Search for information about this SPCR interface type. */
97 	cd = uart_cpu_acpi_scan(spcr->InterfaceType);
98 	if (cd == NULL)
99 		goto out;
100 	class = cd->cd_class;
101 
102 	/* Fill in some fixed details. */
103 	di->bas.chan = 0;
104 	di->bas.rclk = 0;
105 	di->databits = 8;
106 	di->stopbits = 1;
107 	di->parity = UART_PARITY_NONE;
108 	di->ops = uart_getops(class);
109 
110 	/* Fill in details from SPCR table. */
111 	switch (spcr->SerialPort.SpaceId) {
112 	case 0:
113 		di->bas.bst = uart_bus_space_mem;
114 		break;
115 	case 1:
116 		di->bas.bst = uart_bus_space_io;
117 		break;
118 	default:
119 		printf("UART in unrecognized address space: %d!\n",
120 		    (int)spcr->SerialPort.SpaceId);
121 		goto out;
122 	}
123 	if (spcr->SerialPort.AccessWidth == 0)
124 		di->bas.regshft = 0;
125 	else
126 		di->bas.regshft = spcr->SerialPort.AccessWidth - 1;
127 	di->bas.regiowidth = spcr->SerialPort.BitWidth / 8;
128 	switch (spcr->BaudRate) {
129 	case 0:
130 		/* Special value; means "keep current value unchanged". */
131 		di->baudrate = 0;
132 		break;
133 	case 3:
134 		di->baudrate = 9600;
135 		break;
136 	case 4:
137 		di->baudrate = 19200;
138 		break;
139 	case 6:
140 		di->baudrate = 57600;
141 		break;
142 	case 7:
143 		di->baudrate = 115200;
144 		break;
145 	default:
146 		printf("SPCR has reserved BaudRate value: %d!\n",
147 		    (int)spcr->BaudRate);
148 		goto out;
149 	}
150 
151 	/* Apply device tweaks. */
152 	if ((cd->cd_quirks & UART_F_IGNORE_SPCR_REGSHFT) ==
153 	    UART_F_IGNORE_SPCR_REGSHFT) {
154 		di->bas.regshft = cd->cd_regshft;
155 	}
156 
157 	/* Create a bus space handle. */
158 	error = bus_space_map(di->bas.bst, spcr->SerialPort.Address,
159 	    uart_getrange(class), 0, &di->bas.bsh);
160 
161 out:
162 	acpi_unmap_table(spcr);
163 	return (error);
164 }
165