xref: /linux/drivers/dio/dio.c (revision f949cb759051b24aa6cacda73964327608c08a89)
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 static void dio_dev_release(struct device *dev)
113 {
114 	struct dio_dev *ddev = container_of(dev, typeof(struct dio_dev), dev);
115 	kfree(ddev);
116 }
117 
118 int __init dio_find(int deviceid)
119 {
120 	/* Called to find a DIO device before the full bus scan has run.
121 	 * Only used by the console driver.
122 	 */
123 	int scode, id;
124 	u_char prid, secid, i;
125 
126 	for (scode = 0; scode < DIO_SCMAX; scode++) {
127 		void *va;
128 		unsigned long pa;
129 
130 		if (DIO_SCINHOLE(scode))
131 			continue;
132 
133 		pa = dio_scodetophysaddr(scode);
134 
135 		if (!pa)
136 			continue;
137 
138 		if (scode < DIOII_SCBASE)
139 			va = (void *)(pa + DIO_VIRADDRBASE);
140 		else
141 			va = ioremap(pa, PAGE_SIZE);
142 
143 		if (copy_from_kernel_nofault(&i,
144 				(unsigned char *)va + DIO_IDOFF, 1)) {
145 			if (scode >= DIOII_SCBASE)
146 				iounmap(va);
147 			continue;	     /* no board present at that select code */
148 		}
149 
150 		prid = DIO_ID(va);
151 
152 		if (DIO_NEEDSSECID(prid)) {
153 			secid = DIO_SECID(va);
154 			id = DIO_ENCODE_ID(prid, secid);
155 		} else
156 			id = prid;
157 
158 		if (id == deviceid) {
159 			if (scode >= DIOII_SCBASE)
160 				iounmap(va);
161 			return scode;
162 		}
163 	}
164 
165 	return -1;
166 }
167 
168 /* This is the function that scans the DIO space and works out what
169  * hardware is actually present.
170  */
171 static int __init dio_init(void)
172 {
173 	int scode;
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 		u_char prid, secid = 0;	/* primary, secondary ID bytes */
200 		u_char *va;
201 		unsigned long pa;
202 
203 		if (DIO_SCINHOLE(scode))
204 			continue;
205 
206 		pa = dio_scodetophysaddr(scode);
207 
208 		if (!pa)
209 			continue;
210 
211 		if (scode < DIOII_SCBASE)
212 			va = (void *)(pa + DIO_VIRADDRBASE);
213 		else
214 			va = ioremap(pa, PAGE_SIZE);
215 
216 		if (copy_from_kernel_nofault(&i,
217 				(unsigned char *)va + DIO_IDOFF, 1)) {
218 			if (scode >= DIOII_SCBASE)
219 				iounmap(va);
220 			continue;	      /* no board present at that select code */
221 		}
222 
223 		/* Found a board, allocate it an entry in the list */
224 		dev = kzalloc(sizeof(struct dio_dev), GFP_KERNEL);
225 		if (!dev) {
226 			if (scode >= DIOII_SCBASE)
227 				iounmap(va);
228 			return -ENOMEM;
229 		}
230 
231 		dev->bus = &dio_bus;
232 		dev->dev.parent = &dio_bus.dev;
233 		dev->dev.bus = &dio_bus_type;
234 		dev->dev.release = dio_dev_release;
235 		dev->scode = scode;
236 		dev->resource.start = pa;
237 		dev->resource.end = pa + DIO_SIZE(scode, va);
238 		dev_set_name(&dev->dev, "%02x", scode);
239 
240 		/* read the ID byte(s) and encode if necessary. */
241 		prid = DIO_ID(va);
242 
243 		if (DIO_NEEDSSECID(prid)) {
244 			secid = DIO_SECID(va);
245 			dev->id = DIO_ENCODE_ID(prid, secid);
246 		} else
247 			dev->id = prid;
248 
249 		dev->ipl = DIO_IPL(va);
250 		strcpy(dev->name, dio_getname(dev->id));
251                 printk(KERN_INFO "select code %3d: ipl %d: ID %02X", dev->scode, dev->ipl, prid);
252 		if (DIO_NEEDSSECID(prid))
253                         printk(":%02X", secid);
254                 printk(": %s\n", dev->name);
255 
256 		if (scode >= DIOII_SCBASE)
257 			iounmap(va);
258 		error = device_register(&dev->dev);
259 		if (error) {
260 			pr_err("DIO: Error registering device %s\n",
261 			       dev->name);
262 			put_device(&dev->dev);
263 			continue;
264 		}
265 		error = dio_create_sysfs_dev_files(dev);
266 		if (error)
267 			dev_err(&dev->dev, "Error creating sysfs files\n");
268 	}
269 	return 0;
270 }
271 
272 subsys_initcall(dio_init);
273 
274 /* Bear in mind that this is called in the very early stages of initialisation
275  * in order to get the address of the serial port for the console...
276  */
277 unsigned long dio_scodetophysaddr(int scode)
278 {
279 	if (scode >= DIOII_SCBASE)
280 		return (DIOII_BASE + (scode - 132) * DIOII_DEVSIZE);
281 	else if (scode > DIO_SCMAX || scode < 0)
282 		return 0;
283 	else if (DIO_SCINHOLE(scode))
284 		return 0;
285 
286 	return (DIO_BASE + scode * DIO_DEVSIZE);
287 }
288