xref: /freebsd/sys/dev/uart/uart_cpu_acpi.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <machine/bus.h>
35 
36 #include <dev/pci/pcireg.h>
37 
38 #include <dev/uart/uart.h>
39 #include <dev/uart/uart_bus.h>
40 #include <dev/uart/uart_cpu.h>
41 #include <dev/uart/uart_cpu_acpi.h>
42 
43 #include <contrib/dev/acpica/include/acpi.h>
44 #include <contrib/dev/acpica/include/accommon.h>
45 #include <contrib/dev/acpica/include/actables.h>
46 
47 static struct acpi_uart_compat_data *
48 uart_cpu_acpi_scan(uint8_t interface_type)
49 {
50 	struct acpi_uart_compat_data **cd, *curcd;
51 	int i;
52 
53 	SET_FOREACH(cd, uart_acpi_class_and_device_set) {
54 		curcd = *cd;
55 		for (i = 0; curcd[i].cd_hid != NULL; i++) {
56 			if (curcd[i].cd_port_subtype == interface_type)
57 				return (&curcd[i]);
58 		}
59 	}
60 
61 	SET_FOREACH(cd, uart_acpi_class_set) {
62 		curcd = *cd;
63 		for (i = 0; curcd[i].cd_hid != NULL; i++) {
64 			if (curcd[i].cd_port_subtype == interface_type)
65 				return (&curcd[i]);
66 		}
67 	}
68 
69 	return (NULL);
70 }
71 
72 int
73 uart_cpu_acpi_spcr(int devtype, struct uart_devinfo *di)
74 {
75 	vm_paddr_t spcr_physaddr;
76 	ACPI_TABLE_SPCR *spcr;
77 	struct acpi_uart_compat_data *cd;
78 	struct uart_class *class;
79 	int error = ENXIO;
80 
81 	/* SPCR only tells us about consoles. */
82 	if (devtype != UART_DEV_CONSOLE)
83 		return (error);
84 
85 	/* Look for the SPCR table. */
86 	spcr_physaddr = acpi_find_table(ACPI_SIG_SPCR);
87 	if (spcr_physaddr == 0)
88 		return (error);
89 	spcr = acpi_map_table(spcr_physaddr, ACPI_SIG_SPCR);
90 	if (spcr == NULL) {
91 		printf("Unable to map the SPCR table!\n");
92 		return (error);
93 	}
94 
95 	/* Search for information about this SPCR interface type. */
96 	cd = uart_cpu_acpi_scan(spcr->InterfaceType);
97 	if (cd == NULL)
98 		goto out;
99 	class = cd->cd_class;
100 
101 	/* Fill in some fixed details. */
102 	di->bas.chan = 0;
103 	di->bas.rclk = 0;
104 	di->databits = 8;
105 	di->stopbits = 1;
106 	di->parity = UART_PARITY_NONE;
107 	di->ops = uart_getops(class);
108 
109 	/* Fill in details from SPCR table. */
110 	switch (spcr->SerialPort.SpaceId) {
111 	case 0:
112 		di->bas.bst = uart_bus_space_mem;
113 		break;
114 	case 1:
115 		di->bas.bst = uart_bus_space_io;
116 		break;
117 	default:
118 		printf("UART in unrecognized address space: %d!\n",
119 		    (int)spcr->SerialPort.SpaceId);
120 		goto out;
121 	}
122 	switch (spcr->SerialPort.AccessWidth) {
123 	case 0: /* EFI_ACPI_6_0_UNDEFINED */
124 		/* FALLTHROUGH */
125 	case 1: /* EFI_ACPI_6_0_BYTE */
126 		di->bas.regiowidth = 1;
127 		break;
128 	case 2: /* EFI_ACPI_6_0_WORD */
129 		di->bas.regiowidth = 2;
130 		break;
131 	case 3: /* EFI_ACPI_6_0_DWORD */
132 		di->bas.regiowidth = 4;
133 		break;
134 	case 4: /* EFI_ACPI_6_0_QWORD */
135 		di->bas.regiowidth = 8;
136 		break;
137 	default:
138 		printf("UART unsupported access width: %d!\n",
139 		    (int)spcr->SerialPort.AccessWidth);
140 		goto out;
141 	}
142 	switch (spcr->SerialPort.BitWidth) {
143 	case 0:
144 		/* FALLTHROUGH */
145 	case 8:
146 		di->bas.regshft = 0;
147 		break;
148 	case 16:
149 		di->bas.regshft = 1;
150 		break;
151 	case 32:
152 		di->bas.regshft = 2;
153 		break;
154 	case 64:
155 		di->bas.regshft = 3;
156 		break;
157 	default:
158 		printf("UART unsupported bit width: %d!\n",
159 		    (int)spcr->SerialPort.BitWidth);
160 		goto out;
161 	}
162 	switch (spcr->BaudRate) {
163 	case 0:
164 		/* Special value; means "keep current value unchanged". */
165 		di->baudrate = 0;
166 		break;
167 	case 3:
168 		di->baudrate = 9600;
169 		break;
170 	case 4:
171 		di->baudrate = 19200;
172 		break;
173 	case 6:
174 		di->baudrate = 57600;
175 		break;
176 	case 7:
177 		di->baudrate = 115200;
178 		break;
179 	default:
180 		printf("SPCR has reserved BaudRate value: %d!\n",
181 		    (int)spcr->BaudRate);
182 		goto out;
183 	}
184 	if (spcr->PciVendorId != PCIV_INVALID &&
185 	    spcr->PciDeviceId != PCIV_INVALID) {
186 		di->pci_info.vendor = spcr->PciVendorId;
187 		di->pci_info.device = spcr->PciDeviceId;
188 	}
189 
190 	/* Apply device tweaks. */
191 	if ((cd->cd_quirks & UART_F_IGNORE_SPCR_REGSHFT) ==
192 	    UART_F_IGNORE_SPCR_REGSHFT) {
193 		di->bas.regshft = cd->cd_regshft;
194 	}
195 
196 	/* Create a bus space handle. */
197 	error = bus_space_map(di->bas.bst, spcr->SerialPort.Address,
198 	    uart_getrange(class), 0, &di->bas.bsh);
199 
200 out:
201 	acpi_unmap_table(spcr);
202 	return (error);
203 }
204