xref: /openbmc/linux/drivers/dio/dio.c (revision d5771670)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Code to support devices on the DIO and DIO-II bus
3  * Copyright (C) 05/1998 Peter Maydell <pmaydell@chiark.greenend.org.uk>
4  * Copyright (C) 2004 Jochen Friedrich <jochen@scram.de>
5  *
6  * This code has basically these routines at the moment:
7  * int dio_find(u_int deviceid)
8  *    Search the list of DIO devices and return the select code
9  *    of the next unconfigured device found that matches the given device ID.
10  *    Note that the deviceid parameter should be the encoded ID.
11  *    This means that framebuffers should pass it as
12  *    DIO_ENCODE_ID(DIO_ID_FBUFFER,DIO_ID2_TOPCAT)
13  *    (or whatever); everybody else just uses DIO_ID_FOOBAR.
14  * unsigned long dio_scodetophysaddr(int scode)
15  *    Return the physical address corresponding to the given select code.
16  * int dio_scodetoipl(int scode)
17  *    Every DIO card has a fixed interrupt priority level. This function
18  *    returns it, whatever it is.
19  * const char *dio_scodetoname(int scode)
20  *    Return a character string describing this board [might be "" if
21  *    not CONFIG_DIO_CONSTANTS]
22  * void dio_config_board(int scode)     mark board as configured in the list
23  * void dio_unconfig_board(int scode)   mark board as no longer configured
24  *
25  * This file is based on the way the Amiga port handles Zorro II cards,
26  * although we aren't so complicated...
27  */
28 #include <linux/module.h>
29 #include <linux/string.h>
30 #include <linux/types.h>
31 #include <linux/kernel.h>
32 #include <linux/init.h>
33 #include <linux/dio.h>
34 #include <linux/slab.h>                         /* kmalloc() */
35 #include <linux/uaccess.h>
36 #include <linux/io.h>                           /* readb() */
37 
38 struct dio_bus dio_bus = {
39 	.resources = {
40 		/* DIO range */
41 		{ .name = "DIO mem", .start = 0x00600000, .end = 0x007fffff },
42 		/* DIO-II range */
43 		{ .name = "DIO-II mem", .start = 0x01000000, .end = 0x1fffffff }
44 	},
45 	.name = "DIO bus"
46 };
47 
48 /* not a real config option yet! */
49 #define CONFIG_DIO_CONSTANTS
50 
51 #ifdef CONFIG_DIO_CONSTANTS
52 /* We associate each numeric ID with an appropriate descriptive string
53  * using a constant array of these structs.
54  * FIXME: we should be able to arrange to throw away most of the strings
55  * using the initdata stuff. Then we wouldn't need to worry about
56  * carrying them around...
57  * I think we do this by copying them into newly kmalloc()ed memory and
58  * marking the names[] array as .initdata ?
59  */
60 struct dioname {
61 	int id;
62 	const char *name;
63 };
64 
65 /* useful macro */
66 #define DIONAME(x) { DIO_ID_##x, DIO_DESC_##x }
67 #define DIOFBNAME(x) { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_##x), DIO_DESC2_##x }
68 
69 static struct dioname names[] = {
70 	DIONAME(DCA0), DIONAME(DCA0REM), DIONAME(DCA1), DIONAME(DCA1REM),
71 	DIONAME(DCM), DIONAME(DCMREM),
72 	DIONAME(LAN),
73 	DIONAME(FHPIB), DIONAME(NHPIB),
74 	DIONAME(SCSI0), DIONAME(SCSI1), DIONAME(SCSI2), DIONAME(SCSI3),
75 	DIONAME(FBUFFER),
76 	DIONAME(PARALLEL), DIONAME(VME), DIONAME(DCL), DIONAME(DCLREM),
77 	DIONAME(MISC0), DIONAME(MISC1), DIONAME(MISC2), DIONAME(MISC3),
78 	DIONAME(MISC4), DIONAME(MISC5), DIONAME(MISC6), DIONAME(MISC7),
79 	DIONAME(MISC8), DIONAME(MISC9), DIONAME(MISC10), DIONAME(MISC11),
80 	DIONAME(MISC12), DIONAME(MISC13),
81 	DIOFBNAME(GATORBOX), DIOFBNAME(TOPCAT), DIOFBNAME(RENAISSANCE),
82 	DIOFBNAME(LRCATSEYE), DIOFBNAME(HRCCATSEYE), DIOFBNAME(HRMCATSEYE),
83 	DIOFBNAME(DAVINCI), DIOFBNAME(XXXCATSEYE), DIOFBNAME(HYPERION),
84 	DIOFBNAME(XGENESIS), DIOFBNAME(TIGER), DIOFBNAME(YGENESIS)
85 };
86 
87 #undef DIONAME
88 #undef DIOFBNAME
89 
90 static const char unknowndioname[]
91 	= "unknown DIO board, please email linux-m68k@lists.linux-m68k.org";
92 
93 static const char *dio_getname(int id)
94 {
95 	/* return pointer to a constant string describing the board with given ID */
96 	unsigned int i;
97 
98 	for (i = 0; i < ARRAY_SIZE(names); i++)
99 		if (names[i].id == id)
100 			return names[i].name;
101 
102 	return unknowndioname;
103 }
104 
105 #else
106 
107 static char dio_no_name[] = { 0 };
108 #define dio_getname(_id)	(dio_no_name)
109 
110 #endif /* CONFIG_DIO_CONSTANTS */
111 
112 int __init dio_find(int deviceid)
113 {
114 	/* Called to find a DIO device before the full bus scan has run.
115 	 * Only used by the console driver.
116 	 */
117 	int scode, id;
118 	u_char prid, secid, i;
119 
120 	for (scode = 0; scode < DIO_SCMAX; scode++) {
121 		void *va;
122 		unsigned long pa;
123 
124 		if (DIO_SCINHOLE(scode))
125 			continue;
126 
127 		pa = dio_scodetophysaddr(scode);
128 
129 		if (!pa)
130 			continue;
131 
132 		if (scode < DIOII_SCBASE)
133 			va = (void *)(pa + DIO_VIRADDRBASE);
134 		else
135 			va = ioremap(pa, PAGE_SIZE);
136 
137 		if (copy_from_kernel_nofault(&i,
138 				(unsigned char *)va + DIO_IDOFF, 1)) {
139 			if (scode >= DIOII_SCBASE)
140 				iounmap(va);
141 			continue;	     /* no board present at that select code */
142 		}
143 
144 		prid = DIO_ID(va);
145 
146 		if (DIO_NEEDSSECID(prid)) {
147 			secid = DIO_SECID(va);
148 			id = DIO_ENCODE_ID(prid, secid);
149 		} else
150 			id = prid;
151 
152 		if (id == deviceid) {
153 			if (scode >= DIOII_SCBASE)
154 				iounmap(va);
155 			return scode;
156 		}
157 	}
158 
159 	return -1;
160 }
161 
162 /* This is the function that scans the DIO space and works out what
163  * hardware is actually present.
164  */
165 static int __init dio_init(void)
166 {
167 	int scode;
168 	int i;
169 	struct dio_dev *dev;
170 	int error;
171 
172 	if (!MACH_IS_HP300)
173 		return 0;
174 
175         printk(KERN_INFO "Scanning for DIO devices...\n");
176 
177 	/* Initialize the DIO bus */
178 	INIT_LIST_HEAD(&dio_bus.devices);
179 	dev_set_name(&dio_bus.dev, "dio");
180 	error = device_register(&dio_bus.dev);
181 	if (error) {
182 		pr_err("DIO: Error registering dio_bus\n");
183 		return error;
184 	}
185 
186 	/* Request all resources */
187 	dio_bus.num_resources = (hp300_model == HP_320 ? 1 : 2);
188 	for (i = 0; i < dio_bus.num_resources; i++)
189 		request_resource(&iomem_resource, &dio_bus.resources[i]);
190 
191 	/* Register all devices */
192 	for (scode = 0; scode < DIO_SCMAX; ++scode) {
193 		u_char prid, secid = 0;	/* primary, secondary ID bytes */
194 		u_char *va;
195 		unsigned long pa;
196 
197 		if (DIO_SCINHOLE(scode))
198 			continue;
199 
200 		pa = dio_scodetophysaddr(scode);
201 
202 		if (!pa)
203 			continue;
204 
205 		if (scode < DIOII_SCBASE)
206 			va = (void *)(pa + DIO_VIRADDRBASE);
207 		else
208 			va = ioremap(pa, PAGE_SIZE);
209 
210 		if (copy_from_kernel_nofault(&i,
211 				(unsigned char *)va + DIO_IDOFF, 1)) {
212 			if (scode >= DIOII_SCBASE)
213 				iounmap(va);
214 			continue;	      /* no board present at that select code */
215 		}
216 
217 		/* Found a board, allocate it an entry in the list */
218 		dev = kzalloc(sizeof(struct dio_dev), GFP_KERNEL);
219 		if (!dev)
220 			return -ENOMEM;
221 
222 		dev->bus = &dio_bus;
223 		dev->dev.parent = &dio_bus.dev;
224 		dev->dev.bus = &dio_bus_type;
225 		dev->scode = scode;
226 		dev->resource.start = pa;
227 		dev->resource.end = pa + DIO_SIZE(scode, va);
228 		dev_set_name(&dev->dev, "%02x", scode);
229 
230 		/* read the ID byte(s) and encode if necessary. */
231 		prid = DIO_ID(va);
232 
233 		if (DIO_NEEDSSECID(prid)) {
234 			secid = DIO_SECID(va);
235 			dev->id = DIO_ENCODE_ID(prid, secid);
236 		} else
237 			dev->id = prid;
238 
239 		dev->ipl = DIO_IPL(va);
240 		strcpy(dev->name, dio_getname(dev->id));
241                 printk(KERN_INFO "select code %3d: ipl %d: ID %02X", dev->scode, dev->ipl, prid);
242 		if (DIO_NEEDSSECID(prid))
243                         printk(":%02X", secid);
244                 printk(": %s\n", dev->name);
245 
246 		if (scode >= DIOII_SCBASE)
247 			iounmap(va);
248 		error = device_register(&dev->dev);
249 		if (error) {
250 			pr_err("DIO: Error registering device %s\n",
251 			       dev->name);
252 			continue;
253 		}
254 		error = dio_create_sysfs_dev_files(dev);
255 		if (error)
256 			dev_err(&dev->dev, "Error creating sysfs files\n");
257 	}
258 	return 0;
259 }
260 
261 subsys_initcall(dio_init);
262 
263 /* Bear in mind that this is called in the very early stages of initialisation
264  * in order to get the address of the serial port for the console...
265  */
266 unsigned long dio_scodetophysaddr(int scode)
267 {
268 	if (scode >= DIOII_SCBASE)
269 		return (DIOII_BASE + (scode - 132) * DIOII_DEVSIZE);
270 	else if (scode > DIO_SCMAX || scode < 0)
271 		return 0;
272 	else if (DIO_SCINHOLE(scode))
273 		return 0;
274 
275 	return (DIO_BASE + scode * DIO_DEVSIZE);
276 }
277