xref: /openbmc/linux/arch/mips/pci/ops-bcm63xx.c (revision 745b7908)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/io.h>
14 
15 #include "pci-bcm63xx.h"
16 
17 /*
18  * swizzle 32bits data to return only the needed part
19  */
20 static int postprocess_read(u32 data, int where, unsigned int size)
21 {
22 	u32 ret;
23 
24 	ret = 0;
25 	switch (size) {
26 	case 1:
27 		ret = (data >> ((where & 3) << 3)) & 0xff;
28 		break;
29 	case 2:
30 		ret = (data >> ((where & 3) << 3)) & 0xffff;
31 		break;
32 	case 4:
33 		ret = data;
34 		break;
35 	}
36 	return ret;
37 }
38 
39 static int preprocess_write(u32 orig_data, u32 val, int where,
40 			    unsigned int size)
41 {
42 	u32 ret;
43 
44 	ret = 0;
45 	switch (size) {
46 	case 1:
47 		ret = (orig_data & ~(0xff << ((where & 3) << 3))) |
48 			(val << ((where & 3) << 3));
49 		break;
50 	case 2:
51 		ret = (orig_data & ~(0xffff << ((where & 3) << 3))) |
52 			(val << ((where & 3) << 3));
53 		break;
54 	case 4:
55 		ret = val;
56 		break;
57 	}
58 	return ret;
59 }
60 
61 /*
62  * setup hardware for a configuration cycle with given parameters
63  */
64 static int bcm63xx_setup_cfg_access(int type, unsigned int busn,
65 				    unsigned int devfn, int where)
66 {
67 	unsigned int slot, func, reg;
68 	u32 val;
69 
70 	slot = PCI_SLOT(devfn);
71 	func = PCI_FUNC(devfn);
72 	reg = where >> 2;
73 
74 	/* sanity check */
75 	if (slot > (MPI_L2PCFG_DEVNUM_MASK >> MPI_L2PCFG_DEVNUM_SHIFT))
76 		return 1;
77 
78 	if (func > (MPI_L2PCFG_FUNC_MASK >> MPI_L2PCFG_FUNC_SHIFT))
79 		return 1;
80 
81 	if (reg > (MPI_L2PCFG_REG_MASK >> MPI_L2PCFG_REG_SHIFT))
82 		return 1;
83 
84 	/* ok, setup config access */
85 	val = (reg << MPI_L2PCFG_REG_SHIFT);
86 	val |= (func << MPI_L2PCFG_FUNC_SHIFT);
87 	val |= (slot << MPI_L2PCFG_DEVNUM_SHIFT);
88 	val |= MPI_L2PCFG_CFG_USEREG_MASK;
89 	val |= MPI_L2PCFG_CFG_SEL_MASK;
90 	/* type 0 cycle for local bus, type 1 cycle for anything else */
91 	if (type != 0) {
92 		/* FIXME: how to specify bus ??? */
93 		val |= (1 << MPI_L2PCFG_CFG_TYPE_SHIFT);
94 	}
95 	bcm_mpi_writel(val, MPI_L2PCFG_REG);
96 
97 	return 0;
98 }
99 
100 static int bcm63xx_do_cfg_read(int type, unsigned int busn,
101 				unsigned int devfn, int where, int size,
102 				u32 *val)
103 {
104 	u32 data;
105 
106 	/* two phase cycle, first we write address, then read data at
107 	 * another location, caller already has a spinlock so no need
108 	 * to add one here  */
109 	if (bcm63xx_setup_cfg_access(type, busn, devfn, where))
110 		return PCIBIOS_DEVICE_NOT_FOUND;
111 	iob();
112 	data = le32_to_cpu(__raw_readl(pci_iospace_start));
113 	/* restore IO space normal behaviour */
114 	bcm_mpi_writel(0, MPI_L2PCFG_REG);
115 
116 	*val = postprocess_read(data, where, size);
117 
118 	return PCIBIOS_SUCCESSFUL;
119 }
120 
121 static int bcm63xx_do_cfg_write(int type, unsigned int busn,
122 				 unsigned int devfn, int where, int size,
123 				 u32 val)
124 {
125 	u32 data;
126 
127 	/* two phase cycle, first we write address, then write data to
128 	 * another location, caller already has a spinlock so no need
129 	 * to add one here  */
130 	if (bcm63xx_setup_cfg_access(type, busn, devfn, where))
131 		return PCIBIOS_DEVICE_NOT_FOUND;
132 	iob();
133 
134 	data = le32_to_cpu(__raw_readl(pci_iospace_start));
135 	data = preprocess_write(data, val, where, size);
136 
137 	__raw_writel(cpu_to_le32(data), pci_iospace_start);
138 	wmb();
139 	/* no way to know the access is done, we have to wait */
140 	udelay(500);
141 	/* restore IO space normal behaviour */
142 	bcm_mpi_writel(0, MPI_L2PCFG_REG);
143 
144 	return PCIBIOS_SUCCESSFUL;
145 }
146 
147 static int bcm63xx_pci_read(struct pci_bus *bus, unsigned int devfn,
148 			     int where, int size, u32 *val)
149 {
150 	int type;
151 
152 	type = bus->parent ? 1 : 0;
153 
154 	if (type == 0 && PCI_SLOT(devfn) == CARDBUS_PCI_IDSEL)
155 		return PCIBIOS_DEVICE_NOT_FOUND;
156 
157 	return bcm63xx_do_cfg_read(type, bus->number, devfn,
158 				    where, size, val);
159 }
160 
161 static int bcm63xx_pci_write(struct pci_bus *bus, unsigned int devfn,
162 			      int where, int size, u32 val)
163 {
164 	int type;
165 
166 	type = bus->parent ? 1 : 0;
167 
168 	if (type == 0 && PCI_SLOT(devfn) == CARDBUS_PCI_IDSEL)
169 		return PCIBIOS_DEVICE_NOT_FOUND;
170 
171 	return bcm63xx_do_cfg_write(type, bus->number, devfn,
172 				     where, size, val);
173 }
174 
175 struct pci_ops bcm63xx_pci_ops = {
176 	.read	= bcm63xx_pci_read,
177 	.write	= bcm63xx_pci_write
178 };
179 
180 #ifdef CONFIG_CARDBUS
181 /*
182  * emulate configuration read access on a cardbus bridge
183  */
184 #define FAKE_CB_BRIDGE_SLOT	0x1e
185 
186 static int fake_cb_bridge_bus_number = -1;
187 
188 static struct {
189 	u16 pci_command;
190 	u8 cb_latency;
191 	u8 subordinate_busn;
192 	u8 cardbus_busn;
193 	u8 pci_busn;
194 	int bus_assigned;
195 	u16 bridge_control;
196 
197 	u32 mem_base0;
198 	u32 mem_limit0;
199 	u32 mem_base1;
200 	u32 mem_limit1;
201 
202 	u32 io_base0;
203 	u32 io_limit0;
204 	u32 io_base1;
205 	u32 io_limit1;
206 } fake_cb_bridge_regs;
207 
208 static int fake_cb_bridge_read(int where, int size, u32 *val)
209 {
210 	unsigned int reg;
211 	u32 data;
212 
213 	data = 0;
214 	reg = where >> 2;
215 	switch (reg) {
216 	case (PCI_VENDOR_ID >> 2):
217 	case (PCI_CB_SUBSYSTEM_VENDOR_ID >> 2):
218 		/* create dummy vendor/device id from our cpu id */
219 		data = (bcm63xx_get_cpu_id() << 16) | PCI_VENDOR_ID_BROADCOM;
220 		break;
221 
222 	case (PCI_COMMAND >> 2):
223 		data = (PCI_STATUS_DEVSEL_SLOW << 16);
224 		data |= fake_cb_bridge_regs.pci_command;
225 		break;
226 
227 	case (PCI_CLASS_REVISION >> 2):
228 		data = (PCI_CLASS_BRIDGE_CARDBUS << 16);
229 		break;
230 
231 	case (PCI_CACHE_LINE_SIZE >> 2):
232 		data = (PCI_HEADER_TYPE_CARDBUS << 16);
233 		break;
234 
235 	case (PCI_INTERRUPT_LINE >> 2):
236 		/* bridge control */
237 		data = (fake_cb_bridge_regs.bridge_control << 16);
238 		/* pin:intA line:0xff */
239 		data |= (0x1 << 8) | 0xff;
240 		break;
241 
242 	case (PCI_CB_PRIMARY_BUS >> 2):
243 		data = (fake_cb_bridge_regs.cb_latency << 24);
244 		data |= (fake_cb_bridge_regs.subordinate_busn << 16);
245 		data |= (fake_cb_bridge_regs.cardbus_busn << 8);
246 		data |= fake_cb_bridge_regs.pci_busn;
247 		break;
248 
249 	case (PCI_CB_MEMORY_BASE_0 >> 2):
250 		data = fake_cb_bridge_regs.mem_base0;
251 		break;
252 
253 	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
254 		data = fake_cb_bridge_regs.mem_limit0;
255 		break;
256 
257 	case (PCI_CB_MEMORY_BASE_1 >> 2):
258 		data = fake_cb_bridge_regs.mem_base1;
259 		break;
260 
261 	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
262 		data = fake_cb_bridge_regs.mem_limit1;
263 		break;
264 
265 	case (PCI_CB_IO_BASE_0 >> 2):
266 		/* | 1 for 32bits io support */
267 		data = fake_cb_bridge_regs.io_base0 | 0x1;
268 		break;
269 
270 	case (PCI_CB_IO_LIMIT_0 >> 2):
271 		data = fake_cb_bridge_regs.io_limit0;
272 		break;
273 
274 	case (PCI_CB_IO_BASE_1 >> 2):
275 		/* | 1 for 32bits io support */
276 		data = fake_cb_bridge_regs.io_base1 | 0x1;
277 		break;
278 
279 	case (PCI_CB_IO_LIMIT_1 >> 2):
280 		data = fake_cb_bridge_regs.io_limit1;
281 		break;
282 	}
283 
284 	*val = postprocess_read(data, where, size);
285 	return PCIBIOS_SUCCESSFUL;
286 }
287 
288 /*
289  * emulate configuration write access on a cardbus bridge
290  */
291 static int fake_cb_bridge_write(int where, int size, u32 val)
292 {
293 	unsigned int reg;
294 	u32 data, tmp;
295 	int ret;
296 
297 	ret = fake_cb_bridge_read((where & ~0x3), 4, &data);
298 	if (ret != PCIBIOS_SUCCESSFUL)
299 		return ret;
300 
301 	data = preprocess_write(data, val, where, size);
302 
303 	reg = where >> 2;
304 	switch (reg) {
305 	case (PCI_COMMAND >> 2):
306 		fake_cb_bridge_regs.pci_command = (data & 0xffff);
307 		break;
308 
309 	case (PCI_CB_PRIMARY_BUS >> 2):
310 		fake_cb_bridge_regs.cb_latency = (data >> 24) & 0xff;
311 		fake_cb_bridge_regs.subordinate_busn = (data >> 16) & 0xff;
312 		fake_cb_bridge_regs.cardbus_busn = (data >> 8) & 0xff;
313 		fake_cb_bridge_regs.pci_busn = data & 0xff;
314 		if (fake_cb_bridge_regs.cardbus_busn)
315 			fake_cb_bridge_regs.bus_assigned = 1;
316 		break;
317 
318 	case (PCI_INTERRUPT_LINE >> 2):
319 		tmp = (data >> 16) & 0xffff;
320 		/* disable memory prefetch support */
321 		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
322 		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
323 		fake_cb_bridge_regs.bridge_control = tmp;
324 		break;
325 
326 	case (PCI_CB_MEMORY_BASE_0 >> 2):
327 		fake_cb_bridge_regs.mem_base0 = data;
328 		break;
329 
330 	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
331 		fake_cb_bridge_regs.mem_limit0 = data;
332 		break;
333 
334 	case (PCI_CB_MEMORY_BASE_1 >> 2):
335 		fake_cb_bridge_regs.mem_base1 = data;
336 		break;
337 
338 	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
339 		fake_cb_bridge_regs.mem_limit1 = data;
340 		break;
341 
342 	case (PCI_CB_IO_BASE_0 >> 2):
343 		fake_cb_bridge_regs.io_base0 = data;
344 		break;
345 
346 	case (PCI_CB_IO_LIMIT_0 >> 2):
347 		fake_cb_bridge_regs.io_limit0 = data;
348 		break;
349 
350 	case (PCI_CB_IO_BASE_1 >> 2):
351 		fake_cb_bridge_regs.io_base1 = data;
352 		break;
353 
354 	case (PCI_CB_IO_LIMIT_1 >> 2):
355 		fake_cb_bridge_regs.io_limit1 = data;
356 		break;
357 	}
358 
359 	return PCIBIOS_SUCCESSFUL;
360 }
361 
362 static int bcm63xx_cb_read(struct pci_bus *bus, unsigned int devfn,
363 			   int where, int size, u32 *val)
364 {
365 	/* snoop access to slot 0x1e on root bus, we fake a cardbus
366 	 * bridge at this location */
367 	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
368 		fake_cb_bridge_bus_number = bus->number;
369 		return fake_cb_bridge_read(where, size, val);
370 	}
371 
372 	/* a  configuration  cycle for	the  device  behind the	 cardbus
373 	 * bridge is  actually done as a  type 0 cycle	on the primary
374 	 * bus. This means that only  one device can be on the cardbus
375 	 * bus */
376 	if (fake_cb_bridge_regs.bus_assigned &&
377 	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
378 	    PCI_SLOT(devfn) == 0)
379 		return bcm63xx_do_cfg_read(0, 0,
380 					   PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
381 					   where, size, val);
382 
383 	return PCIBIOS_DEVICE_NOT_FOUND;
384 }
385 
386 static int bcm63xx_cb_write(struct pci_bus *bus, unsigned int devfn,
387 			    int where, int size, u32 val)
388 {
389 	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
390 		fake_cb_bridge_bus_number = bus->number;
391 		return fake_cb_bridge_write(where, size, val);
392 	}
393 
394 	if (fake_cb_bridge_regs.bus_assigned &&
395 	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
396 	    PCI_SLOT(devfn) == 0)
397 		return bcm63xx_do_cfg_write(0, 0,
398 					    PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
399 					    where, size, val);
400 
401 	return PCIBIOS_DEVICE_NOT_FOUND;
402 }
403 
404 struct pci_ops bcm63xx_cb_ops = {
405 	.read	= bcm63xx_cb_read,
406 	.write	 = bcm63xx_cb_write,
407 };
408 
409 /*
410  * only one IO window, so it  cannot be shared by PCI and cardbus, use
411  * fixup to choose and detect unhandled configuration
412  */
413 static void bcm63xx_fixup(struct pci_dev *dev)
414 {
415 	static int io_window = -1;
416 	int found, new_io_window;
417 	struct resource *r;
418 	u32 val;
419 
420 	/* look for any io resource */
421 	found = 0;
422 	pci_dev_for_each_resource(dev, r) {
423 		if (resource_type(r) == IORESOURCE_IO) {
424 			found = 1;
425 			break;
426 		}
427 	}
428 	if (!found)
429 		return;
430 
431 	/* skip our fake bus with only cardbus bridge on it */
432 	if (dev->bus->number == fake_cb_bridge_bus_number)
433 		return;
434 
435 	/* find on which bus the device is */
436 	if (fake_cb_bridge_regs.bus_assigned &&
437 	    dev->bus->number == fake_cb_bridge_regs.cardbus_busn &&
438 	    PCI_SLOT(dev->devfn) == 0)
439 		new_io_window = 1;
440 	else
441 		new_io_window = 0;
442 
443 	if (new_io_window == io_window)
444 		return;
445 
446 	if (io_window != -1) {
447 		printk(KERN_ERR "bcm63xx: both PCI and cardbus devices "
448 		       "need IO, which hardware cannot do\n");
449 		return;
450 	}
451 
452 	printk(KERN_INFO "bcm63xx: PCI IO window assigned to %s\n",
453 	       (new_io_window == 0) ? "PCI" : "cardbus");
454 
455 	val = bcm_mpi_readl(MPI_L2PIOREMAP_REG);
456 	if (io_window)
457 		val |= MPI_L2PREMAP_IS_CARDBUS_MASK;
458 	else
459 		val &= ~MPI_L2PREMAP_IS_CARDBUS_MASK;
460 	bcm_mpi_writel(val, MPI_L2PIOREMAP_REG);
461 
462 	io_window = new_io_window;
463 }
464 
465 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, bcm63xx_fixup);
466 #endif
467 
468 static int bcm63xx_pcie_can_access(struct pci_bus *bus, int devfn)
469 {
470 	switch (bus->number) {
471 	case PCIE_BUS_BRIDGE:
472 		return PCI_SLOT(devfn) == 0;
473 	case PCIE_BUS_DEVICE:
474 		if (PCI_SLOT(devfn) == 0)
475 			return bcm_pcie_readl(PCIE_DLSTATUS_REG)
476 					& DLSTATUS_PHYLINKUP;
477 		fallthrough;
478 	default:
479 		return false;
480 	}
481 }
482 
483 static int bcm63xx_pcie_read(struct pci_bus *bus, unsigned int devfn,
484 			     int where, int size, u32 *val)
485 {
486 	u32 data;
487 	u32 reg = where & ~3;
488 
489 	if (!bcm63xx_pcie_can_access(bus, devfn))
490 		return PCIBIOS_DEVICE_NOT_FOUND;
491 
492 	if (bus->number == PCIE_BUS_DEVICE)
493 		reg += PCIE_DEVICE_OFFSET;
494 
495 	data = bcm_pcie_readl(reg);
496 
497 	*val = postprocess_read(data, where, size);
498 
499 	return PCIBIOS_SUCCESSFUL;
500 
501 }
502 
503 static int bcm63xx_pcie_write(struct pci_bus *bus, unsigned int devfn,
504 			      int where, int size, u32 val)
505 {
506 	u32 data;
507 	u32 reg = where & ~3;
508 
509 	if (!bcm63xx_pcie_can_access(bus, devfn))
510 		return PCIBIOS_DEVICE_NOT_FOUND;
511 
512 	if (bus->number == PCIE_BUS_DEVICE)
513 		reg += PCIE_DEVICE_OFFSET;
514 
515 
516 	data = bcm_pcie_readl(reg);
517 
518 	data = preprocess_write(data, val, where, size);
519 	bcm_pcie_writel(data, reg);
520 
521 	return PCIBIOS_SUCCESSFUL;
522 }
523 
524 
525 struct pci_ops bcm63xx_pcie_ops = {
526 	.read	= bcm63xx_pcie_read,
527 	.write	= bcm63xx_pcie_write
528 };
529