1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Support for Intel IXP4xx PCI host controller
4 *
5 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
6 *
7 * Based on the IXP4xx arch/arm/mach-ixp4xx/common-pci.c driver
8 * Copyright (C) 2002 Intel Corporation
9 * Copyright (C) 2003 Greg Ungerer <gerg@linux-m68k.org>
10 * Copyright (C) 2003-2004 MontaVista Software, Inc.
11 * Copyright (C) 2005 Deepak Saxena <dsaxena@plexity.net>
12 * Copyright (C) 2005 Alessandro Zummo <a.zummo@towertech.it>
13 *
14 * TODO:
15 * - Test IO-space access
16 * - DMA support
17 */
18
19 #include <linux/init.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/of_address.h>
23 #include <linux/of_device.h>
24 #include <linux/of_pci.h>
25 #include <linux/pci.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/bits.h>
29
30 /* Register offsets */
31 #define IXP4XX_PCI_NP_AD 0x00
32 #define IXP4XX_PCI_NP_CBE 0x04
33 #define IXP4XX_PCI_NP_WDATA 0x08
34 #define IXP4XX_PCI_NP_RDATA 0x0c
35 #define IXP4XX_PCI_CRP_AD_CBE 0x10
36 #define IXP4XX_PCI_CRP_WDATA 0x14
37 #define IXP4XX_PCI_CRP_RDATA 0x18
38 #define IXP4XX_PCI_CSR 0x1c
39 #define IXP4XX_PCI_ISR 0x20
40 #define IXP4XX_PCI_INTEN 0x24
41 #define IXP4XX_PCI_DMACTRL 0x28
42 #define IXP4XX_PCI_AHBMEMBASE 0x2c
43 #define IXP4XX_PCI_AHBIOBASE 0x30
44 #define IXP4XX_PCI_PCIMEMBASE 0x34
45 #define IXP4XX_PCI_AHBDOORBELL 0x38
46 #define IXP4XX_PCI_PCIDOORBELL 0x3c
47 #define IXP4XX_PCI_ATPDMA0_AHBADDR 0x40
48 #define IXP4XX_PCI_ATPDMA0_PCIADDR 0x44
49 #define IXP4XX_PCI_ATPDMA0_LENADDR 0x48
50 #define IXP4XX_PCI_ATPDMA1_AHBADDR 0x4c
51 #define IXP4XX_PCI_ATPDMA1_PCIADDR 0x50
52 #define IXP4XX_PCI_ATPDMA1_LENADDR 0x54
53
54 /* CSR bit definitions */
55 #define IXP4XX_PCI_CSR_HOST BIT(0)
56 #define IXP4XX_PCI_CSR_ARBEN BIT(1)
57 #define IXP4XX_PCI_CSR_ADS BIT(2)
58 #define IXP4XX_PCI_CSR_PDS BIT(3)
59 #define IXP4XX_PCI_CSR_ABE BIT(4)
60 #define IXP4XX_PCI_CSR_DBT BIT(5)
61 #define IXP4XX_PCI_CSR_ASE BIT(8)
62 #define IXP4XX_PCI_CSR_IC BIT(15)
63 #define IXP4XX_PCI_CSR_PRST BIT(16)
64
65 /* ISR (Interrupt status) Register bit definitions */
66 #define IXP4XX_PCI_ISR_PSE BIT(0)
67 #define IXP4XX_PCI_ISR_PFE BIT(1)
68 #define IXP4XX_PCI_ISR_PPE BIT(2)
69 #define IXP4XX_PCI_ISR_AHBE BIT(3)
70 #define IXP4XX_PCI_ISR_APDC BIT(4)
71 #define IXP4XX_PCI_ISR_PADC BIT(5)
72 #define IXP4XX_PCI_ISR_ADB BIT(6)
73 #define IXP4XX_PCI_ISR_PDB BIT(7)
74
75 /* INTEN (Interrupt Enable) Register bit definitions */
76 #define IXP4XX_PCI_INTEN_PSE BIT(0)
77 #define IXP4XX_PCI_INTEN_PFE BIT(1)
78 #define IXP4XX_PCI_INTEN_PPE BIT(2)
79 #define IXP4XX_PCI_INTEN_AHBE BIT(3)
80 #define IXP4XX_PCI_INTEN_APDC BIT(4)
81 #define IXP4XX_PCI_INTEN_PADC BIT(5)
82 #define IXP4XX_PCI_INTEN_ADB BIT(6)
83 #define IXP4XX_PCI_INTEN_PDB BIT(7)
84
85 /* Shift value for byte enable on NP cmd/byte enable register */
86 #define IXP4XX_PCI_NP_CBE_BESL 4
87
88 /* PCI commands supported by NP access unit */
89 #define NP_CMD_IOREAD 0x2
90 #define NP_CMD_IOWRITE 0x3
91 #define NP_CMD_CONFIGREAD 0xa
92 #define NP_CMD_CONFIGWRITE 0xb
93 #define NP_CMD_MEMREAD 0x6
94 #define NP_CMD_MEMWRITE 0x7
95
96 /* Constants for CRP access into local config space */
97 #define CRP_AD_CBE_BESL 20
98 #define CRP_AD_CBE_WRITE 0x00010000
99
100 /* Special PCI configuration space registers for this controller */
101 #define IXP4XX_PCI_RTOTTO 0x40
102
103 struct ixp4xx_pci {
104 struct device *dev;
105 void __iomem *base;
106 bool errata_hammer;
107 bool host_mode;
108 };
109
110 /*
111 * The IXP4xx has a peculiar address bus that will change the
112 * byte order on SoC peripherals depending on whether the device
113 * operates in big-endian or little-endian mode. That means that
114 * readl() and writel() that always use little-endian access
115 * will not work for SoC peripherals such as the PCI controller
116 * when used in big-endian mode. The accesses to the individual
117 * PCI devices on the other hand, are always little-endian and
118 * can use readl() and writel().
119 *
120 * For local AHB bus access we need to use __raw_[readl|writel]()
121 * to make sure that we access the SoC devices in the CPU native
122 * endianness.
123 */
ixp4xx_readl(struct ixp4xx_pci * p,u32 reg)124 static inline u32 ixp4xx_readl(struct ixp4xx_pci *p, u32 reg)
125 {
126 return __raw_readl(p->base + reg);
127 }
128
ixp4xx_writel(struct ixp4xx_pci * p,u32 reg,u32 val)129 static inline void ixp4xx_writel(struct ixp4xx_pci *p, u32 reg, u32 val)
130 {
131 __raw_writel(val, p->base + reg);
132 }
133
ixp4xx_pci_check_master_abort(struct ixp4xx_pci * p)134 static int ixp4xx_pci_check_master_abort(struct ixp4xx_pci *p)
135 {
136 u32 isr = ixp4xx_readl(p, IXP4XX_PCI_ISR);
137
138 if (isr & IXP4XX_PCI_ISR_PFE) {
139 /* Make sure the master abort bit is reset */
140 ixp4xx_writel(p, IXP4XX_PCI_ISR, IXP4XX_PCI_ISR_PFE);
141 dev_dbg(p->dev, "master abort detected\n");
142 return -EINVAL;
143 }
144
145 return 0;
146 }
147
ixp4xx_pci_read_indirect(struct ixp4xx_pci * p,u32 addr,u32 cmd,u32 * data)148 static int ixp4xx_pci_read_indirect(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 *data)
149 {
150 ixp4xx_writel(p, IXP4XX_PCI_NP_AD, addr);
151
152 if (p->errata_hammer) {
153 int i;
154
155 /*
156 * PCI workaround - only works if NP PCI space reads have
157 * no side effects. Hammer the register and read twice 8
158 * times. last one will be good.
159 */
160 for (i = 0; i < 8; i++) {
161 ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd);
162 *data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA);
163 *data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA);
164 }
165 } else {
166 ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd);
167 *data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA);
168 }
169
170 return ixp4xx_pci_check_master_abort(p);
171 }
172
ixp4xx_pci_write_indirect(struct ixp4xx_pci * p,u32 addr,u32 cmd,u32 data)173 static int ixp4xx_pci_write_indirect(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 data)
174 {
175 ixp4xx_writel(p, IXP4XX_PCI_NP_AD, addr);
176
177 /* Set up the write */
178 ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd);
179
180 /* Execute the write by writing to NP_WDATA */
181 ixp4xx_writel(p, IXP4XX_PCI_NP_WDATA, data);
182
183 return ixp4xx_pci_check_master_abort(p);
184 }
185
ixp4xx_config_addr(u8 bus_num,u16 devfn,int where)186 static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
187 {
188 /* Root bus is always 0 in this hardware */
189 if (bus_num == 0) {
190 /* type 0 */
191 return BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) |
192 (where & ~3);
193 } else {
194 /* type 1 */
195 return (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) |
196 ((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
197 }
198 }
199
200 /*
201 * CRP functions are "Controller Configuration Port" accesses
202 * initiated from within this driver itself to read/write PCI
203 * control information in the config space.
204 */
ixp4xx_crp_byte_lane_enable_bits(u32 n,int size)205 static u32 ixp4xx_crp_byte_lane_enable_bits(u32 n, int size)
206 {
207 if (size == 1)
208 return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
209 if (size == 2)
210 return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
211 if (size == 4)
212 return 0;
213 return 0xffffffff;
214 }
215
ixp4xx_crp_read_config(struct ixp4xx_pci * p,int where,int size,u32 * value)216 static int ixp4xx_crp_read_config(struct ixp4xx_pci *p, int where, int size,
217 u32 *value)
218 {
219 u32 n, cmd, val;
220
221 n = where % 4;
222 cmd = where & ~3;
223
224 dev_dbg(p->dev, "%s from %d size %d cmd %08x\n",
225 __func__, where, size, cmd);
226
227 ixp4xx_writel(p, IXP4XX_PCI_CRP_AD_CBE, cmd);
228 val = ixp4xx_readl(p, IXP4XX_PCI_CRP_RDATA);
229
230 val >>= (8*n);
231 switch (size) {
232 case 1:
233 val &= U8_MAX;
234 dev_dbg(p->dev, "%s read byte %02x\n", __func__, val);
235 break;
236 case 2:
237 val &= U16_MAX;
238 dev_dbg(p->dev, "%s read word %04x\n", __func__, val);
239 break;
240 case 4:
241 val &= U32_MAX;
242 dev_dbg(p->dev, "%s read long %08x\n", __func__, val);
243 break;
244 default:
245 /* Should not happen */
246 dev_err(p->dev, "%s illegal size\n", __func__);
247 return PCIBIOS_DEVICE_NOT_FOUND;
248 }
249 *value = val;
250
251 return PCIBIOS_SUCCESSFUL;
252 }
253
ixp4xx_crp_write_config(struct ixp4xx_pci * p,int where,int size,u32 value)254 static int ixp4xx_crp_write_config(struct ixp4xx_pci *p, int where, int size,
255 u32 value)
256 {
257 u32 n, cmd, val;
258
259 n = where % 4;
260 cmd = ixp4xx_crp_byte_lane_enable_bits(n, size);
261 if (cmd == 0xffffffff)
262 return PCIBIOS_BAD_REGISTER_NUMBER;
263 cmd |= where & ~3;
264 cmd |= CRP_AD_CBE_WRITE;
265
266 val = value << (8*n);
267
268 dev_dbg(p->dev, "%s to %d size %d cmd %08x val %08x\n",
269 __func__, where, size, cmd, val);
270
271 ixp4xx_writel(p, IXP4XX_PCI_CRP_AD_CBE, cmd);
272 ixp4xx_writel(p, IXP4XX_PCI_CRP_WDATA, val);
273
274 return PCIBIOS_SUCCESSFUL;
275 }
276
277 /*
278 * Then follows the functions that read and write from the common PCI
279 * configuration space.
280 */
ixp4xx_byte_lane_enable_bits(u32 n,int size)281 static u32 ixp4xx_byte_lane_enable_bits(u32 n, int size)
282 {
283 if (size == 1)
284 return (0xf & ~BIT(n)) << 4;
285 if (size == 2)
286 return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
287 if (size == 4)
288 return 0;
289 return 0xffffffff;
290 }
291
ixp4xx_pci_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)292 static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
293 int where, int size, u32 *value)
294 {
295 struct ixp4xx_pci *p = bus->sysdata;
296 u32 n, addr, val, cmd;
297 u8 bus_num = bus->number;
298 int ret;
299
300 *value = 0xffffffff;
301 n = where % 4;
302 cmd = ixp4xx_byte_lane_enable_bits(n, size);
303 if (cmd == 0xffffffff)
304 return PCIBIOS_BAD_REGISTER_NUMBER;
305
306 addr = ixp4xx_config_addr(bus_num, devfn, where);
307 cmd |= NP_CMD_CONFIGREAD;
308 dev_dbg(p->dev, "read_config from %d size %d dev %d:%d:%d address: %08x cmd: %08x\n",
309 where, size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn), addr, cmd);
310
311 ret = ixp4xx_pci_read_indirect(p, addr, cmd, &val);
312 if (ret)
313 return PCIBIOS_DEVICE_NOT_FOUND;
314
315 val >>= (8*n);
316 switch (size) {
317 case 1:
318 val &= U8_MAX;
319 dev_dbg(p->dev, "%s read byte %02x\n", __func__, val);
320 break;
321 case 2:
322 val &= U16_MAX;
323 dev_dbg(p->dev, "%s read word %04x\n", __func__, val);
324 break;
325 case 4:
326 val &= U32_MAX;
327 dev_dbg(p->dev, "%s read long %08x\n", __func__, val);
328 break;
329 default:
330 /* Should not happen */
331 dev_err(p->dev, "%s illegal size\n", __func__);
332 return PCIBIOS_DEVICE_NOT_FOUND;
333 }
334 *value = val;
335
336 return PCIBIOS_SUCCESSFUL;
337 }
338
ixp4xx_pci_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)339 static int ixp4xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
340 int where, int size, u32 value)
341 {
342 struct ixp4xx_pci *p = bus->sysdata;
343 u32 n, addr, val, cmd;
344 u8 bus_num = bus->number;
345 int ret;
346
347 n = where % 4;
348 cmd = ixp4xx_byte_lane_enable_bits(n, size);
349 if (cmd == 0xffffffff)
350 return PCIBIOS_BAD_REGISTER_NUMBER;
351
352 addr = ixp4xx_config_addr(bus_num, devfn, where);
353 cmd |= NP_CMD_CONFIGWRITE;
354 val = value << (8*n);
355
356 dev_dbg(p->dev, "write_config_byte %#x to %d size %d dev %d:%d:%d addr: %08x cmd %08x\n",
357 value, where, size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn), addr, cmd);
358
359 ret = ixp4xx_pci_write_indirect(p, addr, cmd, val);
360 if (ret)
361 return PCIBIOS_DEVICE_NOT_FOUND;
362
363 return PCIBIOS_SUCCESSFUL;
364 }
365
366 static struct pci_ops ixp4xx_pci_ops = {
367 .read = ixp4xx_pci_read_config,
368 .write = ixp4xx_pci_write_config,
369 };
370
ixp4xx_pci_addr_to_64mconf(phys_addr_t addr)371 static u32 ixp4xx_pci_addr_to_64mconf(phys_addr_t addr)
372 {
373 u8 base;
374
375 base = ((addr & 0xff000000) >> 24);
376 return (base << 24) | ((base + 1) << 16)
377 | ((base + 2) << 8) | (base + 3);
378 }
379
ixp4xx_pci_parse_map_ranges(struct ixp4xx_pci * p)380 static int ixp4xx_pci_parse_map_ranges(struct ixp4xx_pci *p)
381 {
382 struct device *dev = p->dev;
383 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(p);
384 struct resource_entry *win;
385 struct resource *res;
386 phys_addr_t addr;
387
388 win = resource_list_first_type(&bridge->windows, IORESOURCE_MEM);
389 if (win) {
390 u32 pcimembase;
391
392 res = win->res;
393 addr = res->start - win->offset;
394
395 if (res->flags & IORESOURCE_PREFETCH)
396 res->name = "IXP4xx PCI PRE-MEM";
397 else
398 res->name = "IXP4xx PCI NON-PRE-MEM";
399
400 dev_dbg(dev, "%s window %pR, bus addr %pa\n",
401 res->name, res, &addr);
402 if (resource_size(res) != SZ_64M) {
403 dev_err(dev, "memory range is not 64MB\n");
404 return -EINVAL;
405 }
406
407 pcimembase = ixp4xx_pci_addr_to_64mconf(addr);
408 /* Commit configuration */
409 ixp4xx_writel(p, IXP4XX_PCI_PCIMEMBASE, pcimembase);
410 } else {
411 dev_err(dev, "no AHB memory mapping defined\n");
412 }
413
414 win = resource_list_first_type(&bridge->windows, IORESOURCE_IO);
415 if (win) {
416 res = win->res;
417
418 addr = pci_pio_to_address(res->start);
419 if (addr & 0xff) {
420 dev_err(dev, "IO mem at uneven address: %pa\n", &addr);
421 return -EINVAL;
422 }
423
424 res->name = "IXP4xx PCI IO MEM";
425 /*
426 * Setup I/O space location for PCI->AHB access, the
427 * upper 24 bits of the address goes into the lower
428 * 24 bits of this register.
429 */
430 ixp4xx_writel(p, IXP4XX_PCI_AHBIOBASE, (addr >> 8));
431 } else {
432 dev_info(dev, "no IO space AHB memory mapping defined\n");
433 }
434
435 return 0;
436 }
437
ixp4xx_pci_parse_map_dma_ranges(struct ixp4xx_pci * p)438 static int ixp4xx_pci_parse_map_dma_ranges(struct ixp4xx_pci *p)
439 {
440 struct device *dev = p->dev;
441 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(p);
442 struct resource_entry *win;
443 struct resource *res;
444 phys_addr_t addr;
445 u32 ahbmembase;
446
447 win = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
448 if (win) {
449 res = win->res;
450 addr = res->start - win->offset;
451
452 if (resource_size(res) != SZ_64M) {
453 dev_err(dev, "DMA memory range is not 64MB\n");
454 return -EINVAL;
455 }
456
457 dev_dbg(dev, "DMA MEM BASE: %pa\n", &addr);
458 /*
459 * 4 PCI-to-AHB windows of 16 MB each, write the 8 high bits
460 * into each byte of the PCI_AHBMEMBASE register.
461 */
462 ahbmembase = ixp4xx_pci_addr_to_64mconf(addr);
463 /* Commit AHB membase */
464 ixp4xx_writel(p, IXP4XX_PCI_AHBMEMBASE, ahbmembase);
465 } else {
466 dev_err(dev, "no DMA memory range defined\n");
467 }
468
469 return 0;
470 }
471
472 /* Only used to get context for abort handling */
473 static struct ixp4xx_pci *ixp4xx_pci_abort_singleton;
474
ixp4xx_pci_abort_handler(unsigned long addr,unsigned int fsr,struct pt_regs * regs)475 static int ixp4xx_pci_abort_handler(unsigned long addr, unsigned int fsr,
476 struct pt_regs *regs)
477 {
478 struct ixp4xx_pci *p = ixp4xx_pci_abort_singleton;
479 u32 isr, status;
480 int ret;
481
482 isr = ixp4xx_readl(p, IXP4XX_PCI_ISR);
483 ret = ixp4xx_crp_read_config(p, PCI_STATUS, 2, &status);
484 if (ret) {
485 dev_err(p->dev, "unable to read abort status\n");
486 return -EINVAL;
487 }
488
489 dev_err(p->dev,
490 "PCI: abort_handler addr = %#lx, isr = %#x, status = %#x\n",
491 addr, isr, status);
492
493 /* Make sure the Master Abort bit is reset */
494 ixp4xx_writel(p, IXP4XX_PCI_ISR, IXP4XX_PCI_ISR_PFE);
495 status |= PCI_STATUS_REC_MASTER_ABORT;
496 ret = ixp4xx_crp_write_config(p, PCI_STATUS, 2, status);
497 if (ret)
498 dev_err(p->dev, "unable to clear abort status bit\n");
499
500 /*
501 * If it was an imprecise abort, then we need to correct the
502 * return address to be _after_ the instruction.
503 */
504 if (fsr & (1 << 10)) {
505 dev_err(p->dev, "imprecise abort\n");
506 regs->ARM_pc += 4;
507 }
508
509 return 0;
510 }
511
ixp4xx_pci_probe(struct platform_device * pdev)512 static int __init ixp4xx_pci_probe(struct platform_device *pdev)
513 {
514 struct device *dev = &pdev->dev;
515 struct device_node *np = dev->of_node;
516 struct ixp4xx_pci *p;
517 struct pci_host_bridge *host;
518 int ret;
519 u32 val;
520 phys_addr_t addr;
521 u32 basereg[4] = {
522 PCI_BASE_ADDRESS_0,
523 PCI_BASE_ADDRESS_1,
524 PCI_BASE_ADDRESS_2,
525 PCI_BASE_ADDRESS_3,
526 };
527 int i;
528
529 host = devm_pci_alloc_host_bridge(dev, sizeof(*p));
530 if (!host)
531 return -ENOMEM;
532
533 host->ops = &ixp4xx_pci_ops;
534 p = pci_host_bridge_priv(host);
535 host->sysdata = p;
536 p->dev = dev;
537 dev_set_drvdata(dev, p);
538
539 /*
540 * Set up quirk for erratic behaviour in the 42x variant
541 * when accessing config space.
542 */
543 if (of_device_is_compatible(np, "intel,ixp42x-pci")) {
544 p->errata_hammer = true;
545 dev_info(dev, "activate hammering errata\n");
546 }
547
548 p->base = devm_platform_ioremap_resource(pdev, 0);
549 if (IS_ERR(p->base))
550 return PTR_ERR(p->base);
551
552 val = ixp4xx_readl(p, IXP4XX_PCI_CSR);
553 p->host_mode = !!(val & IXP4XX_PCI_CSR_HOST);
554 dev_info(dev, "controller is in %s mode\n",
555 p->host_mode ? "host" : "option");
556
557 /* Hook in our fault handler for PCI errors */
558 ixp4xx_pci_abort_singleton = p;
559 hook_fault_code(16+6, ixp4xx_pci_abort_handler, SIGBUS, 0,
560 "imprecise external abort");
561
562 ret = ixp4xx_pci_parse_map_ranges(p);
563 if (ret)
564 return ret;
565
566 ret = ixp4xx_pci_parse_map_dma_ranges(p);
567 if (ret)
568 return ret;
569
570 /* This is only configured in host mode */
571 if (p->host_mode) {
572 addr = __pa(PAGE_OFFSET);
573 /* This is a noop (0x00) but explains what is going on */
574 addr |= PCI_BASE_ADDRESS_SPACE_MEMORY;
575
576 for (i = 0; i < 4; i++) {
577 /* Write this directly into the config space */
578 ret = ixp4xx_crp_write_config(p, basereg[i], 4, addr);
579 if (ret)
580 dev_err(dev, "failed to set up PCI_BASE_ADDRESS_%d\n", i);
581 else
582 dev_info(dev, "set PCI_BASE_ADDR_%d to %pa\n", i, &addr);
583 addr += SZ_16M;
584 }
585
586 /*
587 * Enable CSR window at 64 MiB to allow PCI masters to continue
588 * prefetching past the 64 MiB boundary, if all AHB to PCI
589 * windows are consecutive.
590 */
591 ret = ixp4xx_crp_write_config(p, PCI_BASE_ADDRESS_4, 4, addr);
592 if (ret)
593 dev_err(dev, "failed to set up PCI_BASE_ADDRESS_4\n");
594 else
595 dev_info(dev, "set PCI_BASE_ADDR_4 to %pa\n", &addr);
596
597 /*
598 * Put the IO memory window at the very end of physical memory
599 * at 0xfffffc00. This is when the system is trying to access IO
600 * memory over AHB.
601 */
602 addr = 0xfffffc00;
603 addr |= PCI_BASE_ADDRESS_SPACE_IO;
604 ret = ixp4xx_crp_write_config(p, PCI_BASE_ADDRESS_5, 4, addr);
605 if (ret)
606 dev_err(dev, "failed to set up PCI_BASE_ADDRESS_5\n");
607 else
608 dev_info(dev, "set PCI_BASE_ADDR_5 to %pa\n", &addr);
609
610 /*
611 * Retry timeout to 0x80
612 * Transfer ready timeout to 0xff
613 */
614 ret = ixp4xx_crp_write_config(p, IXP4XX_PCI_RTOTTO, 4,
615 0x000080ff);
616 if (ret)
617 dev_err(dev, "failed to set up TRDY limit\n");
618 else
619 dev_info(dev, "set TRDY limit to 0x80ff\n");
620 }
621
622 /* Clear interrupts */
623 val = IXP4XX_PCI_ISR_PSE | IXP4XX_PCI_ISR_PFE | IXP4XX_PCI_ISR_PPE | IXP4XX_PCI_ISR_AHBE;
624 ixp4xx_writel(p, IXP4XX_PCI_ISR, val);
625
626 /*
627 * Set Initialize Complete in PCI Control Register: allow IXP4XX to
628 * generate PCI configuration cycles. Specify that the AHB bus is
629 * operating in big-endian mode. Set up byte lane swapping between
630 * little-endian PCI and the big-endian AHB bus.
631 */
632 val = IXP4XX_PCI_CSR_IC | IXP4XX_PCI_CSR_ABE;
633 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
634 val |= (IXP4XX_PCI_CSR_PDS | IXP4XX_PCI_CSR_ADS);
635 ixp4xx_writel(p, IXP4XX_PCI_CSR, val);
636
637 ret = ixp4xx_crp_write_config(p, PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
638 if (ret)
639 dev_err(dev, "unable to initialize master and command memory\n");
640 else
641 dev_info(dev, "initialized as master\n");
642
643 pci_host_probe(host);
644
645 return 0;
646 }
647
648 static const struct of_device_id ixp4xx_pci_of_match[] = {
649 {
650 .compatible = "intel,ixp42x-pci",
651 },
652 {
653 .compatible = "intel,ixp43x-pci",
654 },
655 {},
656 };
657
658 /*
659 * This driver needs to be a builtin module with suppressed bind
660 * attributes since the probe() is initializing a hard exception
661 * handler and this can only be done from __init-tagged code
662 * sections. This module cannot be removed and inserted at all.
663 */
664 static struct platform_driver ixp4xx_pci_driver = {
665 .driver = {
666 .name = "ixp4xx-pci",
667 .suppress_bind_attrs = true,
668 .of_match_table = ixp4xx_pci_of_match,
669 },
670 };
671 builtin_platform_driver_probe(ixp4xx_pci_driver, ixp4xx_pci_probe);
672
