xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-gio.c (revision a93fbb00)
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 static const struct gio_device_id *
51 gio_match_device(const struct gio_device_id *match,
52 		 const struct gio_device *dev)
53 {
54 	const struct gio_device_id *ids;
55 
56 	for (ids = match; ids->id != 0xff; ids++)
57 		if (ids->id == dev->id.id)
58 			return ids;
59 
60 	return NULL;
61 }
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 void 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 }
154 
155 static void gio_device_shutdown(struct device *dev)
156 {
157 	struct gio_device *gio_dev = to_gio_device(dev);
158 	struct gio_driver *drv = to_gio_driver(dev->driver);
159 
160 	if (dev->driver && drv->shutdown)
161 		drv->shutdown(gio_dev);
162 }
163 
164 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
165 			     char *buf)
166 {
167 	struct gio_device *gio_dev = to_gio_device(dev);
168 	int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);
169 
170 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
171 }
172 static DEVICE_ATTR_RO(modalias);
173 
174 static ssize_t name_show(struct device *dev,
175 			 struct device_attribute *attr, char *buf)
176 {
177 	struct gio_device *giodev;
178 
179 	giodev = to_gio_device(dev);
180 	return sprintf(buf, "%s", giodev->name);
181 }
182 static DEVICE_ATTR_RO(name);
183 
184 static ssize_t id_show(struct device *dev,
185 		       struct device_attribute *attr, char *buf)
186 {
187 	struct gio_device *giodev;
188 
189 	giodev = to_gio_device(dev);
190 	return sprintf(buf, "%x", giodev->id.id);
191 }
192 static DEVICE_ATTR_RO(id);
193 
194 static struct attribute *gio_dev_attrs[] = {
195 	&dev_attr_modalias.attr,
196 	&dev_attr_name.attr,
197 	&dev_attr_id.attr,
198 	NULL,
199 };
200 ATTRIBUTE_GROUPS(gio_dev);
201 
202 static int gio_device_uevent(struct device *dev, struct kobj_uevent_env *env)
203 {
204 	struct gio_device *gio_dev = to_gio_device(dev);
205 
206 	add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
207 	return 0;
208 }
209 
210 int gio_register_driver(struct gio_driver *drv)
211 {
212 	/* initialize common driver fields */
213 	if (!drv->driver.name)
214 		drv->driver.name = drv->name;
215 	if (!drv->driver.owner)
216 		drv->driver.owner = drv->owner;
217 	drv->driver.bus = &gio_bus_type;
218 
219 	/* register with core */
220 	return driver_register(&drv->driver);
221 }
222 EXPORT_SYMBOL_GPL(gio_register_driver);
223 
224 void gio_unregister_driver(struct gio_driver *drv)
225 {
226 	driver_unregister(&drv->driver);
227 }
228 EXPORT_SYMBOL_GPL(gio_unregister_driver);
229 
230 void gio_set_master(struct gio_device *dev)
231 {
232 	u32 tmp = sgimc->giopar;
233 
234 	switch (dev->slotno) {
235 	case 0:
236 		tmp |= SGIMC_GIOPAR_MASTERGFX;
237 		break;
238 	case 1:
239 		tmp |= SGIMC_GIOPAR_MASTEREXP0;
240 		break;
241 	case 2:
242 		tmp |= SGIMC_GIOPAR_MASTEREXP1;
243 		break;
244 	}
245 	sgimc->giopar = tmp;
246 }
247 EXPORT_SYMBOL_GPL(gio_set_master);
248 
249 void ip22_gio_set_64bit(int slotno)
250 {
251 	u32 tmp = sgimc->giopar;
252 
253 	switch (slotno) {
254 	case 0:
255 		tmp |= SGIMC_GIOPAR_GFX64;
256 		break;
257 	case 1:
258 		tmp |= SGIMC_GIOPAR_EXP064;
259 		break;
260 	case 2:
261 		tmp |= SGIMC_GIOPAR_EXP164;
262 		break;
263 	}
264 	sgimc->giopar = tmp;
265 }
266 
267 static int ip22_gio_id(unsigned long addr, u32 *res)
268 {
269 	u8 tmp8;
270 	u8 tmp16;
271 	u32 tmp32;
272 	u8 *ptr8;
273 	u16 *ptr16;
274 	u32 *ptr32;
275 
276 	ptr32 = (void *)CKSEG1ADDR(addr);
277 	if (!get_dbe(tmp32, ptr32)) {
278 		/*
279 		 * We got no DBE, but this doesn't mean anything.
280 		 * If GIO is pipelined (which can't be disabled
281 		 * for GFX slot) we don't get a DBE, but we see
282 		 * the transfer size as data. So we do an 8bit
283 		 * and a 16bit access and check whether the common
284 		 * data matches
285 		 */
286 		ptr8 = (void *)CKSEG1ADDR(addr + 3);
287 		if (get_dbe(tmp8, ptr8)) {
288 			/*
289 			 * 32bit access worked, but 8bit doesn't
290 			 * so we don't see phantom reads on
291 			 * a pipelined bus, but a real card which
292 			 * doesn't support 8 bit reads
293 			 */
294 			*res = tmp32;
295 			return 1;
296 		}
297 		ptr16 = (void *)CKSEG1ADDR(addr + 2);
298 		get_dbe(tmp16, ptr16);
299 		if (tmp8 == (tmp16 & 0xff) &&
300 		    tmp8 == (tmp32 & 0xff) &&
301 		    tmp16 == (tmp32 & 0xffff)) {
302 			*res = tmp32;
303 			return 1;
304 		}
305 	}
306 	return 0; /* nothing here */
307 }
308 
309 #define HQ2_MYSTERY_OFFS       0x6A07C
310 #define NEWPORT_USTATUS_OFFS   0xF133C
311 
312 static int ip22_is_gr2(unsigned long addr)
313 {
314 	u32 tmp;
315 	u32 *ptr;
316 
317 	/* HQ2 only allows 32bit accesses */
318 	ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
319 	if (!get_dbe(tmp, ptr)) {
320 		if (tmp == 0xdeadbeef)
321 			return 1;
322 	}
323 	return 0;
324 }
325 
326 
327 static void ip22_check_gio(int slotno, unsigned long addr, int irq)
328 {
329 	const char *name = "Unknown";
330 	struct gio_device *gio_dev;
331 	u32 tmp;
332 	__u8 id;
333 	int i;
334 
335 	/* first look for GR2/GR3 by checking mystery register */
336 	if (ip22_is_gr2(addr))
337 		tmp = 0x7f;
338 	else {
339 		if (!ip22_gio_id(addr, &tmp)) {
340 			/*
341 			 * no GIO signature at start address of slot
342 			 * since Newport doesn't have one, we check if
343 			 * user status register is readable
344 			 */
345 			if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
346 				tmp = 0x7e;
347 			else
348 				tmp = 0;
349 		}
350 	}
351 	if (tmp) {
352 		id = GIO_ID(tmp);
353 		if (tmp & GIO_32BIT_ID) {
354 			if (tmp & GIO_64BIT_IFACE)
355 				ip22_gio_set_64bit(slotno);
356 		}
357 		for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
358 			if (id == gio_name_table[i].id) {
359 				name = gio_name_table[i].name;
360 				break;
361 			}
362 		}
363 		printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
364 		       slotno, name, id);
365 		gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
366 		if (!gio_dev)
367 			return;
368 		gio_dev->name = name;
369 		gio_dev->slotno = slotno;
370 		gio_dev->id.id = id;
371 		gio_dev->resource.start = addr;
372 		gio_dev->resource.end = addr + 0x3fffff;
373 		gio_dev->resource.flags = IORESOURCE_MEM;
374 		gio_dev->irq = irq;
375 		dev_set_name(&gio_dev->dev, "%d", slotno);
376 		gio_device_register(gio_dev);
377 	} else
378 		printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
379 }
380 
381 static struct bus_type gio_bus_type = {
382 	.name	   = "gio",
383 	.dev_groups = gio_dev_groups,
384 	.match	   = gio_bus_match,
385 	.probe	   = gio_device_probe,
386 	.remove	   = gio_device_remove,
387 	.shutdown  = gio_device_shutdown,
388 	.uevent	   = gio_device_uevent,
389 };
390 
391 static struct resource gio_bus_resource = {
392 	.start = GIO_SLOT_GFX_BASE,
393 	.end   = GIO_SLOT_GFX_BASE + 0x9fffff,
394 	.name  = "GIO Bus",
395 	.flags = IORESOURCE_MEM,
396 };
397 
398 int __init ip22_gio_init(void)
399 {
400 	unsigned int pbdma __maybe_unused;
401 	int ret;
402 
403 	ret = device_register(&gio_bus);
404 	if (ret) {
405 		put_device(&gio_bus);
406 		return ret;
407 	}
408 
409 	ret = bus_register(&gio_bus_type);
410 	if (!ret) {
411 		request_resource(&iomem_resource, &gio_bus_resource);
412 		printk(KERN_INFO "GIO: Probing bus...\n");
413 
414 		if (ip22_is_fullhouse()) {
415 			/* Indigo2 */
416 			ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
417 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
418 		} else {
419 			/* Indy/Challenge S */
420 			if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
421 				ip22_check_gio(0, GIO_SLOT_GFX_BASE,
422 					       SGI_GIO_0_IRQ);
423 			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
424 			ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
425 		}
426 	} else
427 		device_unregister(&gio_bus);
428 
429 	return ret;
430 }
431 
432 subsys_initcall(ip22_gio_init);
433