xref: /openbmc/linux/drivers/dio/dio.c (revision aac5987a)
1 /* Code to support devices on the DIO and DIO-II bus
2  * Copyright (C) 05/1998 Peter Maydell <pmaydell@chiark.greenend.org.uk>
3  * Copyright (C) 2004 Jochen Friedrich <jochen@scram.de>
4  *
5  * This code has basically these routines at the moment:
6  * int dio_find(u_int deviceid)
7  *    Search the list of DIO devices and return the select code
8  *    of the next unconfigured device found that matches the given device ID.
9  *    Note that the deviceid parameter should be the encoded ID.
10  *    This means that framebuffers should pass it as
11  *    DIO_ENCODE_ID(DIO_ID_FBUFFER,DIO_ID2_TOPCAT)
12  *    (or whatever); everybody else just uses DIO_ID_FOOBAR.
13  * unsigned long dio_scodetophysaddr(int scode)
14  *    Return the physical address corresponding to the given select code.
15  * int dio_scodetoipl(int scode)
16  *    Every DIO card has a fixed interrupt priority level. This function
17  *    returns it, whatever it is.
18  * const char *dio_scodetoname(int scode)
19  *    Return a character string describing this board [might be "" if
20  *    not CONFIG_DIO_CONSTANTS]
21  * void dio_config_board(int scode)     mark board as configured in the list
22  * void dio_unconfig_board(int scode)   mark board as no longer configured
23  *
24  * This file is based on the way the Amiga port handles Zorro II cards,
25  * although we aren't so complicated...
26  */
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/types.h>
30 #include <linux/kernel.h>
31 #include <linux/init.h>
32 #include <linux/dio.h>
33 #include <linux/slab.h>                         /* kmalloc() */
34 #include <linux/uaccess.h>
35 #include <asm/io.h>                             /* readb() */
36 
37 struct dio_bus dio_bus = {
38 	.resources = {
39 		/* DIO range */
40 		{ .name = "DIO mem", .start = 0x00600000, .end = 0x007fffff },
41 		/* DIO-II range */
42 		{ .name = "DIO-II mem", .start = 0x01000000, .end = 0x1fffffff }
43 	},
44 	.name = "DIO bus"
45 };
46 
47 /* not a real config option yet! */
48 #define CONFIG_DIO_CONSTANTS
49 
50 #ifdef CONFIG_DIO_CONSTANTS
51 /* We associate each numeric ID with an appropriate descriptive string
52  * using a constant array of these structs.
53  * FIXME: we should be able to arrange to throw away most of the strings
54  * using the initdata stuff. Then we wouldn't need to worry about
55  * carrying them around...
56  * I think we do this by copying them into newly kmalloc()ed memory and
57  * marking the names[] array as .initdata ?
58  */
59 struct dioname
60 {
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 {
71         DIONAME(DCA0), DIONAME(DCA0REM), DIONAME(DCA1), DIONAME(DCA1REM),
72         DIONAME(DCM), DIONAME(DCMREM),
73         DIONAME(LAN),
74         DIONAME(FHPIB), DIONAME(NHPIB),
75         DIONAME(SCSI0), DIONAME(SCSI1), DIONAME(SCSI2), DIONAME(SCSI3),
76         DIONAME(FBUFFER),
77         DIONAME(PARALLEL), DIONAME(VME), DIONAME(DCL), DIONAME(DCLREM),
78         DIONAME(MISC0), DIONAME(MISC1), DIONAME(MISC2), DIONAME(MISC3),
79         DIONAME(MISC4), DIONAME(MISC5), DIONAME(MISC6), DIONAME(MISC7),
80         DIONAME(MISC8), DIONAME(MISC9), DIONAME(MISC10), DIONAME(MISC11),
81         DIONAME(MISC12), DIONAME(MISC13),
82         DIOFBNAME(GATORBOX), DIOFBNAME(TOPCAT), DIOFBNAME(RENAISSANCE),
83         DIOFBNAME(LRCATSEYE), DIOFBNAME(HRCCATSEYE), DIOFBNAME(HRMCATSEYE),
84         DIOFBNAME(DAVINCI), DIOFBNAME(XXXCATSEYE), DIOFBNAME(HYPERION),
85         DIOFBNAME(XGENESIS), DIOFBNAME(TIGER), DIOFBNAME(YGENESIS)
86 };
87 
88 #undef DIONAME
89 #undef DIOFBNAME
90 
91 static const char *unknowndioname
92         = "unknown DIO board -- please email <linux-m68k@lists.linux-m68k.org>!";
93 
94 static const char *dio_getname(int id)
95 {
96         /* return pointer to a constant string describing the board with given ID */
97 	unsigned int i;
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 	mm_segment_t fs;
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 		fs = get_fs();
139 		set_fs(KERNEL_DS);
140 
141                 if (get_user(i, (unsigned char *)va + DIO_IDOFF)) {
142 			set_fs(fs);
143 			if (scode >= DIOII_SCBASE)
144 				iounmap(va);
145                         continue;             /* no board present at that select code */
146 		}
147 
148 		set_fs(fs);
149 		prid = DIO_ID(va);
150 
151                 if (DIO_NEEDSSECID(prid)) {
152                         secid = DIO_SECID(va);
153                         id = DIO_ENCODE_ID(prid, secid);
154                 } else
155 			id = prid;
156 
157 		if (id == deviceid) {
158 			if (scode >= DIOII_SCBASE)
159 				iounmap(va);
160 			return scode;
161 		}
162 	}
163 
164 	return -1;
165 }
166 
167 /* This is the function that scans the DIO space and works out what
168  * hardware is actually present.
169  */
170 static int __init dio_init(void)
171 {
172 	int scode;
173 	mm_segment_t fs;
174 	int i;
175 	struct dio_dev *dev;
176 	int error;
177 
178 	if (!MACH_IS_HP300)
179 		return 0;
180 
181         printk(KERN_INFO "Scanning for DIO devices...\n");
182 
183 	/* Initialize the DIO bus */
184 	INIT_LIST_HEAD(&dio_bus.devices);
185 	dev_set_name(&dio_bus.dev, "dio");
186 	error = device_register(&dio_bus.dev);
187 	if (error) {
188 		pr_err("DIO: Error registering dio_bus\n");
189 		return error;
190 	}
191 
192 	/* Request all resources */
193 	dio_bus.num_resources = (hp300_model == HP_320 ? 1 : 2);
194 	for (i = 0; i < dio_bus.num_resources; i++)
195 		request_resource(&iomem_resource, &dio_bus.resources[i]);
196 
197 	/* Register all devices */
198         for (scode = 0; scode < DIO_SCMAX; ++scode)
199         {
200                 u_char prid, secid = 0;        /* primary, secondary ID bytes */
201                 u_char *va;
202 		unsigned long pa;
203 
204                 if (DIO_SCINHOLE(scode))
205                         continue;
206 
207 		pa = dio_scodetophysaddr(scode);
208 
209 		if (!pa)
210 			continue;
211 
212 		if (scode < DIOII_SCBASE)
213 			va = (void *)(pa + DIO_VIRADDRBASE);
214 		else
215 			va = ioremap(pa, PAGE_SIZE);
216 
217 		fs = get_fs();
218 		set_fs(KERNEL_DS);
219 
220                 if (get_user(i, (unsigned char *)va + DIO_IDOFF)) {
221 			set_fs(fs);
222 			if (scode >= DIOII_SCBASE)
223 				iounmap(va);
224                         continue;              /* no board present at that select code */
225 		}
226 
227 		set_fs(fs);
228 
229                 /* Found a board, allocate it an entry in the list */
230 		dev = kzalloc(sizeof(struct dio_dev), GFP_KERNEL);
231 		if (!dev)
232 			return 0;
233 
234 		dev->bus = &dio_bus;
235 		dev->dev.parent = &dio_bus.dev;
236 		dev->dev.bus = &dio_bus_type;
237 		dev->scode = scode;
238 		dev->resource.start = pa;
239 		dev->resource.end = pa + DIO_SIZE(scode, va);
240 		dev_set_name(&dev->dev, "%02x", scode);
241 
242                 /* read the ID byte(s) and encode if necessary. */
243 		prid = DIO_ID(va);
244 
245                 if (DIO_NEEDSSECID(prid)) {
246                         secid = DIO_SECID(va);
247                         dev->id = DIO_ENCODE_ID(prid, secid);
248                 } else
249                         dev->id = prid;
250 
251                 dev->ipl = DIO_IPL(va);
252                 strcpy(dev->name,dio_getname(dev->id));
253                 printk(KERN_INFO "select code %3d: ipl %d: ID %02X", dev->scode, dev->ipl, prid);
254                 if (DIO_NEEDSSECID(prid))
255                         printk(":%02X", secid);
256                 printk(": %s\n", dev->name);
257 
258 		if (scode >= DIOII_SCBASE)
259 			iounmap(va);
260 		error = device_register(&dev->dev);
261 		if (error) {
262 			pr_err("DIO: Error registering device %s\n",
263 			       dev->name);
264 			continue;
265 		}
266 		error = dio_create_sysfs_dev_files(dev);
267 		if (error)
268 			dev_err(&dev->dev, "Error creating sysfs files\n");
269         }
270 	return 0;
271 }
272 
273 subsys_initcall(dio_init);
274 
275 /* Bear in mind that this is called in the very early stages of initialisation
276  * in order to get the address of the serial port for the console...
277  */
278 unsigned long dio_scodetophysaddr(int scode)
279 {
280         if (scode >= DIOII_SCBASE) {
281                 return (DIOII_BASE + (scode - 132) * DIOII_DEVSIZE);
282         } else if (scode > DIO_SCMAX || scode < 0)
283                 return 0;
284         else if (DIO_SCINHOLE(scode))
285                 return 0;
286 
287         return (DIO_BASE + scode * DIO_DEVSIZE);
288 }
289