xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-gio.c (revision 9b93eb47)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/export.h>
3 #include <linux/kernel.h>
4 #include <linux/init.h>
5 #include <linux/slab.h>
6 
7 #include <asm/addrspace.h>
8 #include <asm/paccess.h>
9 #include <asm/gio_device.h>
10 #include <asm/sgi/gio.h>
11 #include <asm/sgi/hpc3.h>
12 #include <asm/sgi/mc.h>
13 #include <asm/sgi/ip22.h>
14 
15 static struct bus_type gio_bus_type;
16 
17 static struct {
18 	const char *name;
19 	__u8	   id;
20 } gio_name_table[] = {
21 	{ .name = "SGI Impact", .id = 0x10 },
22 	{ .name = "Phobos G160", .id = 0x35 },
23 	{ .name = "Phobos G130", .id = 0x36 },
24 	{ .name = "Phobos G100", .id = 0x37 },
25 	{ .name = "Set Engineering GFE", .id = 0x38 },
26 	/* fake IDs */
27 	{ .name = "SGI Newport", .id = 0x7e },
28 	{ .name = "SGI GR2/GR3", .id = 0x7f },
29 };
30 
31 static void gio_bus_release(struct device *dev)
32 {
33 	kfree(dev);
34 }
35 
36 static struct device gio_bus = {
37 	.init_name = "gio",
38 	.release = &gio_bus_release,
39 };
40 
41 /**
42  * gio_match_device - Tell if an of_device structure has a matching
43  * gio_match structure
44  * @ids: array of of device match structures to search in
45  * @dev: the of device structure to match against
46  *
47  * Used by a driver to check whether an of_device present in the
48  * system is in its list of supported devices.
49  */
50 const struct gio_device_id *gio_match_device(const struct gio_device_id *match,
51 		     const struct gio_device *dev)
52 {
53 	const struct gio_device_id *ids;
54 
55 	for (ids = match; ids->id != 0xff; ids++)
56 		if (ids->id == dev->id.id)
57 			return ids;
58 
59 	return NULL;
60 }
61 EXPORT_SYMBOL_GPL(gio_match_device);
62 
63 struct gio_device *gio_dev_get(struct gio_device *dev)
64 {
65 	struct device *tmp;
66 
67 	if (!dev)
68 		return NULL;
69 	tmp = get_device(&dev->dev);
70 	if (tmp)
71 		return to_gio_device(tmp);
72 	else
73 		return NULL;
74 }
75 EXPORT_SYMBOL_GPL(gio_dev_get);
76 
77 void gio_dev_put(struct gio_device *dev)
78 {
79 	if (dev)
80 		put_device(&dev->dev);
81 }
82 EXPORT_SYMBOL_GPL(gio_dev_put);
83 
84 /**
85  * gio_release_dev - free an gio device structure when all users of it are finished.
86  * @dev: device that's been disconnected
87  *
88  * Will be called only by the device core when all users of this gio device are
89  * done.
90  */
91 void gio_release_dev(struct device *dev)
92 {
93 	struct gio_device *giodev;
94 
95 	giodev = to_gio_device(dev);
96 	kfree(giodev);
97 }
98 EXPORT_SYMBOL_GPL(gio_release_dev);
99 
100 int gio_device_register(struct gio_device *giodev)
101 {
102 	giodev->dev.bus = &gio_bus_type;
103 	giodev->dev.parent = &gio_bus;
104 	return device_register(&giodev->dev);
105 }
106 EXPORT_SYMBOL_GPL(gio_device_register);
107 
108 void gio_device_unregister(struct gio_device *giodev)
109 {
110 	device_unregister(&giodev->dev);
111 }
112 EXPORT_SYMBOL_GPL(gio_device_unregister);
113 
114 static int gio_bus_match(struct device *dev, struct device_driver *drv)
115 {
116 	struct gio_device *gio_dev = to_gio_device(dev);
117 	struct gio_driver *gio_drv = to_gio_driver(drv);
118 
119 	return gio_match_device(gio_drv->id_table, gio_dev) != NULL;
120 }
121 
122 static int gio_device_probe(struct device *dev)
123 {
124 	int error = -ENODEV;
125 	struct gio_driver *drv;
126 	struct gio_device *gio_dev;
127 	const struct gio_device_id *match;
128 
129 	drv = to_gio_driver(dev->driver);
130 	gio_dev = to_gio_device(dev);
131 
132 	if (!drv->probe)
133 		return error;
134 
135 	gio_dev_get(gio_dev);
136 
137 	match = gio_match_device(drv->id_table, gio_dev);
138 	if (match)
139 		error = drv->probe(gio_dev, match);
140 	if (error)
141 		gio_dev_put(gio_dev);
142 
143 	return error;
144 }
145 
146 static int gio_device_remove(struct device *dev)
147 {
148 	struct gio_device *gio_dev = to_gio_device(dev);
149 	struct gio_driver *drv = to_gio_driver(dev->driver);
150 
151 	if (dev->driver && drv->remove)
152 		drv->remove(gio_dev);
153 	return 0;
154 }
155 
156 static void gio_device_shutdown(struct device *dev)
157 {
158 	struct gio_device *gio_dev = to_gio_device(dev);
159 	struct gio_driver *drv = to_gio_driver(dev->driver);
160 
161 	if (dev->driver && drv->shutdown)
162 		drv->shutdown(gio_dev);
163 }
164 
165 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
166 			     char *buf)
167 {
168 	struct gio_device *gio_dev = to_gio_device(dev);
169 	int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);
170 
171 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
172 }
173 static DEVICE_ATTR_RO(modalias);
174 
175 static ssize_t name_show(struct device *dev,
176 			 struct device_attribute *attr, char *buf)
177 {
178 	struct gio_device *giodev;
179 
180 	giodev = to_gio_device(dev);
181 	return sprintf(buf, "%s", giodev->name);
182 }
183 static DEVICE_ATTR_RO(name);
184 
185 static ssize_t id_show(struct device *dev,
186 		       struct device_attribute *attr, char *buf)
187 {
188 	struct gio_device *giodev;
189 
190 	giodev = to_gio_device(dev);
191 	return sprintf(buf, "%x", giodev->id.id);
192 }
193 static DEVICE_ATTR_RO(id);
194 
195 static struct attribute *gio_dev_attrs[] = {
196 	&dev_attr_modalias.attr,
197 	&dev_attr_name.attr,
198 	&dev_attr_id.attr,
199 	NULL,
200 };
201 ATTRIBUTE_GROUPS(gio_dev);
202 
203 static int gio_device_uevent(struct device *dev, struct kobj_uevent_env *env)
204 {
205 	struct gio_device *gio_dev = to_gio_device(dev);
206 
207 	add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
208 	return 0;
209 }
210 
211 int gio_register_driver(struct gio_driver *drv)
212 {
213 	/* initialize common driver fields */
214 	if (!drv->driver.name)
215 		drv->driver.name = drv->name;
216 	if (!drv->driver.owner)
217 		drv->driver.owner = drv->owner;
218 	drv->driver.bus = &gio_bus_type;
219 
220 	/* register with core */
221 	return driver_register(&drv->driver);
222 }
223 EXPORT_SYMBOL_GPL(gio_register_driver);
224 
225 void gio_unregister_driver(struct gio_driver *drv)
226 {
227 	driver_unregister(&drv->driver);
228 }
229 EXPORT_SYMBOL_GPL(gio_unregister_driver);
230 
231 void gio_set_master(struct gio_device *dev)
232 {
233 	u32 tmp = sgimc->giopar;
234 
235 	switch (dev->slotno) {
236 	case 0:
237 		tmp |= SGIMC_GIOPAR_MASTERGFX;
238 		break;
239 	case 1:
240 		tmp |= SGIMC_GIOPAR_MASTEREXP0;
241 		break;
242 	case 2:
243 		tmp |= SGIMC_GIOPAR_MASTEREXP1;
244 		break;
245 	}
246 	sgimc->giopar = tmp;
247 }
248 EXPORT_SYMBOL_GPL(gio_set_master);
249 
250 void ip22_gio_set_64bit(int slotno)
251 {
252 	u32 tmp = sgimc->giopar;
253 
254 	switch (slotno) {
255 	case 0:
256 		tmp |= SGIMC_GIOPAR_GFX64;
257 		break;
258 	case 1:
259 		tmp |= SGIMC_GIOPAR_EXP064;
260 		break;
261 	case 2:
262 		tmp |= SGIMC_GIOPAR_EXP164;
263 		break;
264 	}
265 	sgimc->giopar = tmp;
266 }
267 
268 static int ip22_gio_id(unsigned long addr, u32 *res)
269 {
270 	u8 tmp8;
271 	u8 tmp16;
272 	u32 tmp32;
273 	u8 *ptr8;
274 	u16 *ptr16;
275 	u32 *ptr32;
276 
277 	ptr32 = (void *)CKSEG1ADDR(addr);
278 	if (!get_dbe(tmp32, ptr32)) {
279 		/*
280 		 * We got no DBE, but this doesn't mean anything.
281 		 * If GIO is pipelined (which can't be disabled
282 		 * for GFX slot) we don't get a DBE, but we see
283 		 * the transfer size as data. So we do an 8bit
284 		 * and a 16bit access and check whether the common
285 		 * data matches
286 		 */
287 		ptr8 = (void *)CKSEG1ADDR(addr + 3);
288 		if (get_dbe(tmp8, ptr8)) {
289 			/*
290 			 * 32bit access worked, but 8bit doesn't
291 			 * so we don't see phantom reads on
292 			 * a pipelined bus, but a real card which
293 			 * doesn't support 8 bit reads
294 			 */
295 			*res = tmp32;
296 			return 1;
297 		}
298 		ptr16 = (void *)CKSEG1ADDR(addr + 2);
299 		get_dbe(tmp16, ptr16);
300 		if (tmp8 == (tmp16 & 0xff) &&
301 		    tmp8 == (tmp32 & 0xff) &&
302 		    tmp16 == (tmp32 & 0xffff)) {
303 			*res = tmp32;
304 			return 1;
305 		}
306 	}
307 	return 0; /* nothing here */
308 }
309 
310 #define HQ2_MYSTERY_OFFS       0x6A07C
311 #define NEWPORT_USTATUS_OFFS   0xF133C
312 
313 static int ip22_is_gr2(unsigned long addr)
314 {
315 	u32 tmp;
316 	u32 *ptr;
317 
318 	/* HQ2 only allows 32bit accesses */
319 	ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
320 	if (!get_dbe(tmp, ptr)) {
321 		if (tmp == 0xdeadbeef)
322 			return 1;
323 	}
324 	return 0;
325 }
326 
327 
328 static void ip22_check_gio(int slotno, unsigned long addr, int irq)
329 {
330 	const char *name = "Unknown";
331 	struct gio_device *gio_dev;
332 	u32 tmp;
333 	__u8 id;
334 	int i;
335 
336 	/* first look for GR2/GR3 by checking mystery register */
337 	if (ip22_is_gr2(addr))
338 		tmp = 0x7f;
339 	else {
340 		if (!ip22_gio_id(addr, &tmp)) {
341 			/*
342 			 * no GIO signature at start address of slot
343 			 * since Newport doesn't have one, we check if
344 			 * user status register is readable
345 			 */
346 			if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
347 				tmp = 0x7e;
348 			else
349 				tmp = 0;
350 		}
351 	}
352 	if (tmp) {
353 		id = GIO_ID(tmp);
354 		if (tmp & GIO_32BIT_ID) {
355 			if (tmp & GIO_64BIT_IFACE)
356 				ip22_gio_set_64bit(slotno);
357 		}
358 		for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
359 			if (id == gio_name_table[i].id) {
360 				name = gio_name_table[i].name;
361 				break;
362 			}
363 		}
364 		printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
365 		       slotno, name, id);
366 		gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
367 		gio_dev->name = name;
368 		gio_dev->slotno = slotno;
369 		gio_dev->id.id = id;
370 		gio_dev->resource.start = addr;
371 		gio_dev->resource.end = addr + 0x3fffff;
372 		gio_dev->resource.flags = IORESOURCE_MEM;
373 		gio_dev->irq = irq;
374 		dev_set_name(&gio_dev->dev, "%d", slotno);
375 		gio_device_register(gio_dev);
376 	} else
377 		printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
378 }
379 
380 static struct bus_type gio_bus_type = {
381 	.name	   = "gio",
382 	.dev_groups = gio_dev_groups,
383 	.match	   = gio_bus_match,
384 	.probe	   = gio_device_probe,
385 	.remove	   = gio_device_remove,
386 	.shutdown  = gio_device_shutdown,
387 	.uevent	   = gio_device_uevent,
388 };
389 
390 static struct resource gio_bus_resource = {
391 	.start = GIO_SLOT_GFX_BASE,
392 	.end   = GIO_SLOT_GFX_BASE + 0x9fffff,
393 	.name  = "GIO Bus",
394 	.flags = IORESOURCE_MEM,
395 };
396 
397 int __init ip22_gio_init(void)
398 {
399 	unsigned int pbdma __maybe_unused;
400 	int ret;
401 
402 	ret = device_register(&gio_bus);
403 	if (ret) {
404 		put_device(&gio_bus);
405 		return ret;
406 	}
407 
408 	ret = bus_register(&gio_bus_type);
409 	if (!ret) {
410 		request_resource(&iomem_resource, &gio_bus_resource);
411 		printk(KERN_INFO "GIO: Probing bus...\n");
412 
413 		if (ip22_is_fullhouse()) {
414 			/* Indigo2 */
415 			ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
416 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
417 		} else {
418 			/* Indy/Challenge S */
419 			if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
420 				ip22_check_gio(0, GIO_SLOT_GFX_BASE,
421 					       SGI_GIO_0_IRQ);
422 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
423 			ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
424 		}
425 	} else
426 		device_unregister(&gio_bus);
427 
428 	return ret;
429 }
430 
431 subsys_initcall(ip22_gio_init);
432