xref: /openbmc/linux/drivers/dio/dio.c (revision be709d48)
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 <asm/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 {
62         int id;
63         const char *name;
64 };
65 
66 /* useful macro */
67 #define DIONAME(x) { DIO_ID_##x, DIO_DESC_##x }
68 #define DIOFBNAME(x) { DIO_ENCODE_ID( DIO_ID_FBUFFER, DIO_ID2_##x), DIO_DESC2_##x }
69 
70 static struct dioname names[] =
71 {
72         DIONAME(DCA0), DIONAME(DCA0REM), DIONAME(DCA1), DIONAME(DCA1REM),
73         DIONAME(DCM), DIONAME(DCMREM),
74         DIONAME(LAN),
75         DIONAME(FHPIB), DIONAME(NHPIB),
76         DIONAME(SCSI0), DIONAME(SCSI1), DIONAME(SCSI2), DIONAME(SCSI3),
77         DIONAME(FBUFFER),
78         DIONAME(PARALLEL), DIONAME(VME), DIONAME(DCL), DIONAME(DCLREM),
79         DIONAME(MISC0), DIONAME(MISC1), DIONAME(MISC2), DIONAME(MISC3),
80         DIONAME(MISC4), DIONAME(MISC5), DIONAME(MISC6), DIONAME(MISC7),
81         DIONAME(MISC8), DIONAME(MISC9), DIONAME(MISC10), DIONAME(MISC11),
82         DIONAME(MISC12), DIONAME(MISC13),
83         DIOFBNAME(GATORBOX), DIOFBNAME(TOPCAT), DIOFBNAME(RENAISSANCE),
84         DIOFBNAME(LRCATSEYE), DIOFBNAME(HRCCATSEYE), DIOFBNAME(HRMCATSEYE),
85         DIOFBNAME(DAVINCI), DIOFBNAME(XXXCATSEYE), DIOFBNAME(HYPERION),
86         DIOFBNAME(XGENESIS), DIOFBNAME(TIGER), DIOFBNAME(YGENESIS)
87 };
88 
89 #undef DIONAME
90 #undef DIOFBNAME
91 
92 static const char unknowndioname[]
93 	= "unknown DIO board, please email linux-m68k@lists.linux-m68k.org";
94 
95 static const char *dio_getname(int id)
96 {
97         /* return pointer to a constant string describing the board with given ID */
98 	unsigned int i;
99 	for (i = 0; i < ARRAY_SIZE(names); i++)
100                 if (names[i].id == id)
101                         return names[i].name;
102 
103         return unknowndioname;
104 }
105 
106 #else
107 
108 static char dio_no_name[] = { 0 };
109 #define dio_getname(_id)	(dio_no_name)
110 
111 #endif /* CONFIG_DIO_CONSTANTS */
112 
113 int __init dio_find(int deviceid)
114 {
115 	/* Called to find a DIO device before the full bus scan has run.
116 	 * Only used by the console driver.
117 	 */
118 	int scode, id;
119 	u_char prid, secid, i;
120 
121 	for (scode = 0; scode < DIO_SCMAX; scode++) {
122 		void *va;
123 		unsigned long pa;
124 
125                 if (DIO_SCINHOLE(scode))
126                         continue;
127 
128                 pa = dio_scodetophysaddr(scode);
129 
130 		if (!pa)
131 			continue;
132 
133 		if (scode < DIOII_SCBASE)
134 			va = (void *)(pa + DIO_VIRADDRBASE);
135 		else
136 			va = ioremap(pa, PAGE_SIZE);
137 
138                 if (probe_kernel_read(&i, (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         {
194                 u_char prid, secid = 0;        /* primary, secondary ID bytes */
195                 u_char *va;
196 		unsigned long pa;
197 
198                 if (DIO_SCINHOLE(scode))
199                         continue;
200 
201 		pa = dio_scodetophysaddr(scode);
202 
203 		if (!pa)
204 			continue;
205 
206 		if (scode < DIOII_SCBASE)
207 			va = (void *)(pa + DIO_VIRADDRBASE);
208 		else
209 			va = ioremap(pa, PAGE_SIZE);
210 
211                 if (probe_kernel_read(&i, (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 0;
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