xref: /openbmc/linux/arch/mips/pci/ops-bcm63xx.c (revision e8e0929d)
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/init.h>
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 
16 #include "pci-bcm63xx.h"
17 
18 /*
19  * swizzle 32bits data to return only the needed part
20  */
21 static int postprocess_read(u32 data, int where, unsigned int size)
22 {
23 	u32 ret;
24 
25 	ret = 0;
26 	switch (size) {
27 	case 1:
28 		ret = (data >> ((where & 3) << 3)) & 0xff;
29 		break;
30 	case 2:
31 		ret = (data >> ((where & 3) << 3)) & 0xffff;
32 		break;
33 	case 4:
34 		ret = data;
35 		break;
36 	}
37 	return ret;
38 }
39 
40 static int preprocess_write(u32 orig_data, u32 val, int where,
41 			    unsigned int size)
42 {
43 	u32 ret;
44 
45 	ret = 0;
46 	switch (size) {
47 	case 1:
48 		ret = (orig_data & ~(0xff << ((where & 3) << 3))) |
49 			(val << ((where & 3) << 3));
50 		break;
51 	case 2:
52 		ret = (orig_data & ~(0xffff << ((where & 3) << 3))) |
53 			(val << ((where & 3) << 3));
54 		break;
55 	case 4:
56 		ret = val;
57 		break;
58 	}
59 	return ret;
60 }
61 
62 /*
63  * setup hardware for a configuration cycle with given parameters
64  */
65 static int bcm63xx_setup_cfg_access(int type, unsigned int busn,
66 				    unsigned int devfn, int where)
67 {
68 	unsigned int slot, func, reg;
69 	u32 val;
70 
71 	slot = PCI_SLOT(devfn);
72 	func = PCI_FUNC(devfn);
73 	reg = where >> 2;
74 
75 	/* sanity check */
76 	if (slot > (MPI_L2PCFG_DEVNUM_MASK >> MPI_L2PCFG_DEVNUM_SHIFT))
77 		return 1;
78 
79 	if (func > (MPI_L2PCFG_FUNC_MASK >> MPI_L2PCFG_FUNC_SHIFT))
80 		return 1;
81 
82 	if (reg > (MPI_L2PCFG_REG_MASK >> MPI_L2PCFG_REG_SHIFT))
83 		return 1;
84 
85 	/* ok, setup config access */
86 	val = (reg << MPI_L2PCFG_REG_SHIFT);
87 	val |= (func << MPI_L2PCFG_FUNC_SHIFT);
88 	val |= (slot << MPI_L2PCFG_DEVNUM_SHIFT);
89 	val |= MPI_L2PCFG_CFG_USEREG_MASK;
90 	val |= MPI_L2PCFG_CFG_SEL_MASK;
91 	/* type 0 cycle for local bus, type 1 cycle for anything else */
92 	if (type != 0) {
93 		/* FIXME: how to specify bus ??? */
94 		val |= (1 << MPI_L2PCFG_CFG_TYPE_SHIFT);
95 	}
96 	bcm_mpi_writel(val, MPI_L2PCFG_REG);
97 
98 	return 0;
99 }
100 
101 static int bcm63xx_do_cfg_read(int type, unsigned int busn,
102 				unsigned int devfn, int where, int size,
103 				u32 *val)
104 {
105 	u32 data;
106 
107 	/* two phase cycle, first we write address, then read data at
108 	 * another location, caller already has a spinlock so no need
109 	 * to add one here  */
110 	if (bcm63xx_setup_cfg_access(type, busn, devfn, where))
111 		return PCIBIOS_DEVICE_NOT_FOUND;
112 	iob();
113 	data = le32_to_cpu(__raw_readl(pci_iospace_start));
114 	/* restore IO space normal behaviour */
115 	bcm_mpi_writel(0, MPI_L2PCFG_REG);
116 
117 	*val = postprocess_read(data, where, size);
118 
119 	return PCIBIOS_SUCCESSFUL;
120 }
121 
122 static int bcm63xx_do_cfg_write(int type, unsigned int busn,
123 				 unsigned int devfn, int where, int size,
124 				 u32 val)
125 {
126 	u32 data;
127 
128 	/* two phase cycle, first we write address, then write data to
129 	 * another location, caller already has a spinlock so no need
130 	 * to add one here  */
131 	if (bcm63xx_setup_cfg_access(type, busn, devfn, where))
132 		return PCIBIOS_DEVICE_NOT_FOUND;
133 	iob();
134 
135 	data = le32_to_cpu(__raw_readl(pci_iospace_start));
136 	data = preprocess_write(data, val, where, size);
137 
138 	__raw_writel(cpu_to_le32(data), pci_iospace_start);
139 	wmb();
140 	/* no way to know the access is done, we have to wait */
141 	udelay(500);
142 	/* restore IO space normal behaviour */
143 	bcm_mpi_writel(0, MPI_L2PCFG_REG);
144 
145 	return PCIBIOS_SUCCESSFUL;
146 }
147 
148 static int bcm63xx_pci_read(struct pci_bus *bus, unsigned int devfn,
149 			     int where, int size, u32 *val)
150 {
151 	int type;
152 
153 	type = bus->parent ? 1 : 0;
154 
155 	if (type == 0 && PCI_SLOT(devfn) == CARDBUS_PCI_IDSEL)
156 		return PCIBIOS_DEVICE_NOT_FOUND;
157 
158 	return bcm63xx_do_cfg_read(type, bus->number, devfn,
159 				    where, size, val);
160 }
161 
162 static int bcm63xx_pci_write(struct pci_bus *bus, unsigned int devfn,
163 			      int where, int size, u32 val)
164 {
165 	int type;
166 
167 	type = bus->parent ? 1 : 0;
168 
169 	if (type == 0 && PCI_SLOT(devfn) == CARDBUS_PCI_IDSEL)
170 		return PCIBIOS_DEVICE_NOT_FOUND;
171 
172 	return bcm63xx_do_cfg_write(type, bus->number, devfn,
173 				     where, size, val);
174 }
175 
176 struct pci_ops bcm63xx_pci_ops = {
177 	.read   = bcm63xx_pci_read,
178 	.write  = bcm63xx_pci_write
179 };
180 
181 #ifdef CONFIG_CARDBUS
182 /*
183  * emulate configuration read access on a cardbus bridge
184  */
185 #define FAKE_CB_BRIDGE_SLOT	0x1e
186 
187 static int fake_cb_bridge_bus_number = -1;
188 
189 static struct {
190 	u16 pci_command;
191 	u8 cb_latency;
192 	u8 subordinate_busn;
193 	u8 cardbus_busn;
194 	u8 pci_busn;
195 	int bus_assigned;
196 	u16 bridge_control;
197 
198 	u32 mem_base0;
199 	u32 mem_limit0;
200 	u32 mem_base1;
201 	u32 mem_limit1;
202 
203 	u32 io_base0;
204 	u32 io_limit0;
205 	u32 io_base1;
206 	u32 io_limit1;
207 } fake_cb_bridge_regs;
208 
209 static int fake_cb_bridge_read(int where, int size, u32 *val)
210 {
211 	unsigned int reg;
212 	u32 data;
213 
214 	data = 0;
215 	reg = where >> 2;
216 	switch (reg) {
217 	case (PCI_VENDOR_ID >> 2):
218 	case (PCI_CB_SUBSYSTEM_VENDOR_ID >> 2):
219 		/* create dummy vendor/device id from our cpu id */
220 		data = (bcm63xx_get_cpu_id() << 16) | PCI_VENDOR_ID_BROADCOM;
221 		break;
222 
223 	case (PCI_COMMAND >> 2):
224 		data = (PCI_STATUS_DEVSEL_SLOW << 16);
225 		data |= fake_cb_bridge_regs.pci_command;
226 		break;
227 
228 	case (PCI_CLASS_REVISION >> 2):
229 		data = (PCI_CLASS_BRIDGE_CARDBUS << 16);
230 		break;
231 
232 	case (PCI_CACHE_LINE_SIZE >> 2):
233 		data = (PCI_HEADER_TYPE_CARDBUS << 16);
234 		break;
235 
236 	case (PCI_INTERRUPT_LINE >> 2):
237 		/* bridge control */
238 		data = (fake_cb_bridge_regs.bridge_control << 16);
239 		/* pin:intA line:0xff */
240 		data |= (0x1 << 8) | 0xff;
241 		break;
242 
243 	case (PCI_CB_PRIMARY_BUS >> 2):
244 		data = (fake_cb_bridge_regs.cb_latency << 24);
245 		data |= (fake_cb_bridge_regs.subordinate_busn << 16);
246 		data |= (fake_cb_bridge_regs.cardbus_busn << 8);
247 		data |= fake_cb_bridge_regs.pci_busn;
248 		break;
249 
250 	case (PCI_CB_MEMORY_BASE_0 >> 2):
251 		data = fake_cb_bridge_regs.mem_base0;
252 		break;
253 
254 	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
255 		data = fake_cb_bridge_regs.mem_limit0;
256 		break;
257 
258 	case (PCI_CB_MEMORY_BASE_1 >> 2):
259 		data = fake_cb_bridge_regs.mem_base1;
260 		break;
261 
262 	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
263 		data = fake_cb_bridge_regs.mem_limit1;
264 		break;
265 
266 	case (PCI_CB_IO_BASE_0 >> 2):
267 		/* | 1 for 32bits io support */
268 		data = fake_cb_bridge_regs.io_base0 | 0x1;
269 		break;
270 
271 	case (PCI_CB_IO_LIMIT_0 >> 2):
272 		data = fake_cb_bridge_regs.io_limit0;
273 		break;
274 
275 	case (PCI_CB_IO_BASE_1 >> 2):
276 		/* | 1 for 32bits io support */
277 		data = fake_cb_bridge_regs.io_base1 | 0x1;
278 		break;
279 
280 	case (PCI_CB_IO_LIMIT_1 >> 2):
281 		data = fake_cb_bridge_regs.io_limit1;
282 		break;
283 	}
284 
285 	*val = postprocess_read(data, where, size);
286 	return PCIBIOS_SUCCESSFUL;
287 }
288 
289 /*
290  * emulate configuration write access on a cardbus bridge
291  */
292 static int fake_cb_bridge_write(int where, int size, u32 val)
293 {
294 	unsigned int reg;
295 	u32 data, tmp;
296 	int ret;
297 
298 	ret = fake_cb_bridge_read((where & ~0x3), 4, &data);
299 	if (ret != PCIBIOS_SUCCESSFUL)
300 		return ret;
301 
302 	data = preprocess_write(data, val, where, size);
303 
304 	reg = where >> 2;
305 	switch (reg) {
306 	case (PCI_COMMAND >> 2):
307 		fake_cb_bridge_regs.pci_command = (data & 0xffff);
308 		break;
309 
310 	case (PCI_CB_PRIMARY_BUS >> 2):
311 		fake_cb_bridge_regs.cb_latency = (data >> 24) & 0xff;
312 		fake_cb_bridge_regs.subordinate_busn = (data >> 16) & 0xff;
313 		fake_cb_bridge_regs.cardbus_busn = (data >> 8) & 0xff;
314 		fake_cb_bridge_regs.pci_busn = data & 0xff;
315 		if (fake_cb_bridge_regs.cardbus_busn)
316 			fake_cb_bridge_regs.bus_assigned = 1;
317 		break;
318 
319 	case (PCI_INTERRUPT_LINE >> 2):
320 		tmp = (data >> 16) & 0xffff;
321 		/* disable memory prefetch support */
322 		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
323 		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
324 		fake_cb_bridge_regs.bridge_control = tmp;
325 		break;
326 
327 	case (PCI_CB_MEMORY_BASE_0 >> 2):
328 		fake_cb_bridge_regs.mem_base0 = data;
329 		break;
330 
331 	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
332 		fake_cb_bridge_regs.mem_limit0 = data;
333 		break;
334 
335 	case (PCI_CB_MEMORY_BASE_1 >> 2):
336 		fake_cb_bridge_regs.mem_base1 = data;
337 		break;
338 
339 	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
340 		fake_cb_bridge_regs.mem_limit1 = data;
341 		break;
342 
343 	case (PCI_CB_IO_BASE_0 >> 2):
344 		fake_cb_bridge_regs.io_base0 = data;
345 		break;
346 
347 	case (PCI_CB_IO_LIMIT_0 >> 2):
348 		fake_cb_bridge_regs.io_limit0 = data;
349 		break;
350 
351 	case (PCI_CB_IO_BASE_1 >> 2):
352 		fake_cb_bridge_regs.io_base1 = data;
353 		break;
354 
355 	case (PCI_CB_IO_LIMIT_1 >> 2):
356 		fake_cb_bridge_regs.io_limit1 = data;
357 		break;
358 	}
359 
360 	return PCIBIOS_SUCCESSFUL;
361 }
362 
363 static int bcm63xx_cb_read(struct pci_bus *bus, unsigned int devfn,
364 			   int where, int size, u32 *val)
365 {
366 	/* snoop access to slot 0x1e on root bus, we fake a cardbus
367 	 * bridge at this location */
368 	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
369 		fake_cb_bridge_bus_number = bus->number;
370 		return fake_cb_bridge_read(where, size, val);
371 	}
372 
373 	/* a  configuration  cycle for  the  device  behind the  cardbus
374 	 * bridge is  actually done as a  type 0 cycle  on the primary
375 	 * bus. This means that only  one device can be on the cardbus
376 	 * bus */
377 	if (fake_cb_bridge_regs.bus_assigned &&
378 	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
379 	    PCI_SLOT(devfn) == 0)
380 		return bcm63xx_do_cfg_read(0, 0,
381 					   PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
382 					   where, size, val);
383 
384 	return PCIBIOS_DEVICE_NOT_FOUND;
385 }
386 
387 static int bcm63xx_cb_write(struct pci_bus *bus, unsigned int devfn,
388 			    int where, int size, u32 val)
389 {
390 	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
391 		fake_cb_bridge_bus_number = bus->number;
392 		return fake_cb_bridge_write(where, size, val);
393 	}
394 
395 	if (fake_cb_bridge_regs.bus_assigned &&
396 	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
397 	    PCI_SLOT(devfn) == 0)
398 		return bcm63xx_do_cfg_write(0, 0,
399 					    PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
400 					    where, size, val);
401 
402 	return PCIBIOS_DEVICE_NOT_FOUND;
403 }
404 
405 struct pci_ops bcm63xx_cb_ops = {
406 	.read   = bcm63xx_cb_read,
407 	.write   = bcm63xx_cb_write,
408 };
409 
410 /*
411  * only one IO window, so it  cannot be shared by PCI and cardbus, use
412  * fixup to choose and detect unhandled configuration
413  */
414 static void bcm63xx_fixup(struct pci_dev *dev)
415 {
416 	static int io_window = -1;
417 	int i, found, new_io_window;
418 	u32 val;
419 
420 	/* look for any io resource */
421 	found = 0;
422 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
423 		if (pci_resource_flags(dev, i) & IORESOURCE_IO) {
424 			found = 1;
425 			break;
426 		}
427 	}
428 
429 	if (!found)
430 		return;
431 
432 	/* skip our fake bus with only cardbus bridge on it */
433 	if (dev->bus->number == fake_cb_bridge_bus_number)
434 		return;
435 
436 	/* find on which bus the device is */
437 	if (fake_cb_bridge_regs.bus_assigned &&
438 	    dev->bus->number == fake_cb_bridge_regs.cardbus_busn &&
439 	    PCI_SLOT(dev->devfn) == 0)
440 		new_io_window = 1;
441 	else
442 		new_io_window = 0;
443 
444 	if (new_io_window == io_window)
445 		return;
446 
447 	if (io_window != -1) {
448 		printk(KERN_ERR "bcm63xx: both PCI and cardbus devices "
449 		       "need IO, which hardware cannot do\n");
450 		return;
451 	}
452 
453 	printk(KERN_INFO "bcm63xx: PCI IO window assigned to %s\n",
454 	       (new_io_window == 0) ? "PCI" : "cardbus");
455 
456 	val = bcm_mpi_readl(MPI_L2PIOREMAP_REG);
457 	if (io_window)
458 		val |= MPI_L2PREMAP_IS_CARDBUS_MASK;
459 	else
460 		val &= ~MPI_L2PREMAP_IS_CARDBUS_MASK;
461 	bcm_mpi_writel(val, MPI_L2PIOREMAP_REG);
462 
463 	io_window = new_io_window;
464 }
465 
466 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, bcm63xx_fixup);
467 #endif
468