1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Alchemy PCI host mode support.
4 *
5 * Copyright 2001-2003, 2007-2008 MontaVista Software Inc.
6 * Author: MontaVista Software, Inc. <source@mvista.com>
7 *
8 * Support for all devices (greater than 16) added by David Gathright.
9 */
10
11#include <linux/clk.h>
12#include <linux/export.h>
13#include <linux/types.h>
14#include <linux/pci.h>
15#include <linux/platform_device.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/syscore_ops.h>
19#include <linux/vmalloc.h>
20#include <linux/dma-map-ops.h> /* for dma_default_coherent */
21
22#include <asm/mach-au1x00/au1000.h>
23#include <asm/tlbmisc.h>
24
25#ifdef CONFIG_PCI_DEBUG
26#define DBG(x...) printk(KERN_DEBUG x)
27#else
28#define DBG(x...) do {} while (0)
29#endif
30
31#define PCI_ACCESS_READ 0
32#define PCI_ACCESS_WRITE 1
33
34struct alchemy_pci_context {
35 struct pci_controller alchemy_pci_ctrl; /* leave as first member! */
36 void __iomem *regs; /* ctrl base */
37 /* tools for wired entry for config space access */
38 unsigned long last_elo0;
39 unsigned long last_elo1;
40 int wired_entry;
41 struct vm_struct *pci_cfg_vm;
42
43 unsigned long pm[12];
44
45 int (*board_map_irq)(const struct pci_dev *d, u8 slot, u8 pin);
46 int (*board_pci_idsel)(unsigned int devsel, int assert);
47};
48
49/* for syscore_ops. There's only one PCI controller on Alchemy chips, so this
50 * should suffice for now.
51 */
52static struct alchemy_pci_context *__alchemy_pci_ctx;
53
54
55/* IO/MEM resources for PCI. Keep the memres in sync with fixup_bigphys_addr
56 * in arch/mips/alchemy/common/setup.c
57 */
58static struct resource alchemy_pci_def_memres = {
59 .start = ALCHEMY_PCI_MEMWIN_START,
60 .end = ALCHEMY_PCI_MEMWIN_END,
61 .name = "PCI memory space",
62 .flags = IORESOURCE_MEM
63};
64
65static struct resource alchemy_pci_def_iores = {
66 .start = ALCHEMY_PCI_IOWIN_START,
67 .end = ALCHEMY_PCI_IOWIN_END,
68 .name = "PCI IO space",
69 .flags = IORESOURCE_IO
70};
71
72static void mod_wired_entry(int entry, unsigned long entrylo0,
73 unsigned long entrylo1, unsigned long entryhi,
74 unsigned long pagemask)
75{
76 unsigned long old_pagemask;
77 unsigned long old_ctx;
78
79 /* Save old context and create impossible VPN2 value */
80 old_ctx = read_c0_entryhi() & MIPS_ENTRYHI_ASID;
81 old_pagemask = read_c0_pagemask();
82 write_c0_index(entry);
83 write_c0_pagemask(pagemask);
84 write_c0_entryhi(entryhi);
85 write_c0_entrylo0(entrylo0);
86 write_c0_entrylo1(entrylo1);
87 tlb_write_indexed();
88 write_c0_entryhi(old_ctx);
89 write_c0_pagemask(old_pagemask);
90}
91
92static void alchemy_pci_wired_entry(struct alchemy_pci_context *ctx)
93{
94 ctx->wired_entry = read_c0_wired();
95 add_wired_entry(0, 0, (unsigned long)ctx->pci_cfg_vm->addr, PM_4K);
96 ctx->last_elo0 = ctx->last_elo1 = ~0;
97}
98
99static int config_access(unsigned char access_type, struct pci_bus *bus,
100 unsigned int dev_fn, unsigned char where, u32 *data)
101{
102 struct alchemy_pci_context *ctx = bus->sysdata;
103 unsigned int device = PCI_SLOT(dev_fn);
104 unsigned int function = PCI_FUNC(dev_fn);
105 unsigned long offset, status, cfg_base, flags, entryLo0, entryLo1, r;
106 int error = PCIBIOS_SUCCESSFUL;
107
108 if (device > 19) {
109 *data = 0xffffffff;
110 return -1;
111 }
112
113 local_irq_save(flags);
114 r = __raw_readl(addr: ctx->regs + PCI_REG_STATCMD) & 0x0000ffff;
115 r |= PCI_STATCMD_STATUS(0x2000);
116 __raw_writel(val: r, addr: ctx->regs + PCI_REG_STATCMD);
117 wmb();
118
119 /* Allow board vendors to implement their own off-chip IDSEL.
120 * If it doesn't succeed, may as well bail out at this point.
121 */
122 if (ctx->board_pci_idsel(device, 1) == 0) {
123 *data = 0xffffffff;
124 local_irq_restore(flags);
125 return -1;
126 }
127
128 /* Setup the config window */
129 if (bus->number == 0)
130 cfg_base = (1 << device) << 11;
131 else
132 cfg_base = 0x80000000 | (bus->number << 16) | (device << 11);
133
134 /* Setup the lower bits of the 36-bit address */
135 offset = (function << 8) | (where & ~0x3);
136 /* Pick up any address that falls below the page mask */
137 offset |= cfg_base & ~PAGE_MASK;
138
139 /* Page boundary */
140 cfg_base = cfg_base & PAGE_MASK;
141
142 /* To improve performance, if the current device is the same as
143 * the last device accessed, we don't touch the TLB.
144 */
145 entryLo0 = (6 << 26) | (cfg_base >> 6) | (2 << 3) | 7;
146 entryLo1 = (6 << 26) | (cfg_base >> 6) | (0x1000 >> 6) | (2 << 3) | 7;
147 if ((entryLo0 != ctx->last_elo0) || (entryLo1 != ctx->last_elo1)) {
148 mod_wired_entry(entry: ctx->wired_entry, entrylo0: entryLo0, entrylo1: entryLo1,
149 entryhi: (unsigned long)ctx->pci_cfg_vm->addr, pagemask: PM_4K);
150 ctx->last_elo0 = entryLo0;
151 ctx->last_elo1 = entryLo1;
152 }
153
154 if (access_type == PCI_ACCESS_WRITE)
155 __raw_writel(val: *data, addr: ctx->pci_cfg_vm->addr + offset);
156 else
157 *data = __raw_readl(addr: ctx->pci_cfg_vm->addr + offset);
158 wmb();
159
160 DBG("alchemy-pci: cfg access %d bus %u dev %u at %x dat %x conf %lx\n",
161 access_type, bus->number, device, where, *data, offset);
162
163 /* check for errors, master abort */
164 status = __raw_readl(addr: ctx->regs + PCI_REG_STATCMD);
165 if (status & (1 << 29)) {
166 *data = 0xffffffff;
167 error = -1;
168 DBG("alchemy-pci: master abort on cfg access %d bus %d dev %d\n",
169 access_type, bus->number, device);
170 } else if ((status >> 28) & 0xf) {
171 DBG("alchemy-pci: PCI ERR detected: dev %d, status %lx\n",
172 device, (status >> 28) & 0xf);
173
174 /* clear errors */
175 __raw_writel(val: status & 0xf000ffff, addr: ctx->regs + PCI_REG_STATCMD);
176
177 *data = 0xffffffff;
178 error = -1;
179 }
180
181 /* Take away the IDSEL. */
182 (void)ctx->board_pci_idsel(device, 0);
183
184 local_irq_restore(flags);
185 return error;
186}
187
188static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
189 int where, u8 *val)
190{
191 u32 data;
192 int ret = config_access(PCI_ACCESS_READ, bus, dev_fn: devfn, where, data: &data);
193
194 if (where & 1)
195 data >>= 8;
196 if (where & 2)
197 data >>= 16;
198 *val = data & 0xff;
199 return ret;
200}
201
202static int read_config_word(struct pci_bus *bus, unsigned int devfn,
203 int where, u16 *val)
204{
205 u32 data;
206 int ret = config_access(PCI_ACCESS_READ, bus, dev_fn: devfn, where, data: &data);
207
208 if (where & 2)
209 data >>= 16;
210 *val = data & 0xffff;
211 return ret;
212}
213
214static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
215 int where, u32 *val)
216{
217 return config_access(PCI_ACCESS_READ, bus, dev_fn: devfn, where, data: val);
218}
219
220static int write_config_byte(struct pci_bus *bus, unsigned int devfn,
221 int where, u8 val)
222{
223 u32 data = 0;
224
225 if (config_access(PCI_ACCESS_READ, bus, dev_fn: devfn, where, data: &data))
226 return -1;
227
228 data = (data & ~(0xff << ((where & 3) << 3))) |
229 (val << ((where & 3) << 3));
230
231 if (config_access(PCI_ACCESS_WRITE, bus, dev_fn: devfn, where, data: &data))
232 return -1;
233
234 return PCIBIOS_SUCCESSFUL;
235}
236
237static int write_config_word(struct pci_bus *bus, unsigned int devfn,
238 int where, u16 val)
239{
240 u32 data = 0;
241
242 if (config_access(PCI_ACCESS_READ, bus, dev_fn: devfn, where, data: &data))
243 return -1;
244
245 data = (data & ~(0xffff << ((where & 3) << 3))) |
246 (val << ((where & 3) << 3));
247
248 if (config_access(PCI_ACCESS_WRITE, bus, dev_fn: devfn, where, data: &data))
249 return -1;
250
251 return PCIBIOS_SUCCESSFUL;
252}
253
254static int write_config_dword(struct pci_bus *bus, unsigned int devfn,
255 int where, u32 val)
256{
257 return config_access(PCI_ACCESS_WRITE, bus, dev_fn: devfn, where, data: &val);
258}
259
260static int alchemy_pci_read(struct pci_bus *bus, unsigned int devfn,
261 int where, int size, u32 *val)
262{
263 switch (size) {
264 case 1: {
265 u8 _val;
266 int rc = read_config_byte(bus, devfn, where, val: &_val);
267
268 *val = _val;
269 return rc;
270 }
271 case 2: {
272 u16 _val;
273 int rc = read_config_word(bus, devfn, where, val: &_val);
274
275 *val = _val;
276 return rc;
277 }
278 default:
279 return read_config_dword(bus, devfn, where, val);
280 }
281}
282
283static int alchemy_pci_write(struct pci_bus *bus, unsigned int devfn,
284 int where, int size, u32 val)
285{
286 switch (size) {
287 case 1:
288 return write_config_byte(bus, devfn, where, val: (u8) val);
289 case 2:
290 return write_config_word(bus, devfn, where, val: (u16) val);
291 default:
292 return write_config_dword(bus, devfn, where, val);
293 }
294}
295
296static struct pci_ops alchemy_pci_ops = {
297 .read = alchemy_pci_read,
298 .write = alchemy_pci_write,
299};
300
301static int alchemy_pci_def_idsel(unsigned int devsel, int assert)
302{
303 return 1; /* success */
304}
305
306/* save PCI controller register contents. */
307static int alchemy_pci_suspend(void)
308{
309 struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
310 if (!ctx)
311 return 0;
312
313 ctx->pm[0] = __raw_readl(addr: ctx->regs + PCI_REG_CMEM);
314 ctx->pm[1] = __raw_readl(addr: ctx->regs + PCI_REG_CONFIG) & 0x0009ffff;
315 ctx->pm[2] = __raw_readl(addr: ctx->regs + PCI_REG_B2BMASK_CCH);
316 ctx->pm[3] = __raw_readl(addr: ctx->regs + PCI_REG_B2BBASE0_VID);
317 ctx->pm[4] = __raw_readl(addr: ctx->regs + PCI_REG_B2BBASE1_SID);
318 ctx->pm[5] = __raw_readl(addr: ctx->regs + PCI_REG_MWMASK_DEV);
319 ctx->pm[6] = __raw_readl(addr: ctx->regs + PCI_REG_MWBASE_REV_CCL);
320 ctx->pm[7] = __raw_readl(addr: ctx->regs + PCI_REG_ID);
321 ctx->pm[8] = __raw_readl(addr: ctx->regs + PCI_REG_CLASSREV);
322 ctx->pm[9] = __raw_readl(addr: ctx->regs + PCI_REG_PARAM);
323 ctx->pm[10] = __raw_readl(addr: ctx->regs + PCI_REG_MBAR);
324 ctx->pm[11] = __raw_readl(addr: ctx->regs + PCI_REG_TIMEOUT);
325
326 return 0;
327}
328
329static void alchemy_pci_resume(void)
330{
331 struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
332 if (!ctx)
333 return;
334
335 __raw_writel(val: ctx->pm[0], addr: ctx->regs + PCI_REG_CMEM);
336 __raw_writel(val: ctx->pm[2], addr: ctx->regs + PCI_REG_B2BMASK_CCH);
337 __raw_writel(val: ctx->pm[3], addr: ctx->regs + PCI_REG_B2BBASE0_VID);
338 __raw_writel(val: ctx->pm[4], addr: ctx->regs + PCI_REG_B2BBASE1_SID);
339 __raw_writel(val: ctx->pm[5], addr: ctx->regs + PCI_REG_MWMASK_DEV);
340 __raw_writel(val: ctx->pm[6], addr: ctx->regs + PCI_REG_MWBASE_REV_CCL);
341 __raw_writel(val: ctx->pm[7], addr: ctx->regs + PCI_REG_ID);
342 __raw_writel(val: ctx->pm[8], addr: ctx->regs + PCI_REG_CLASSREV);
343 __raw_writel(val: ctx->pm[9], addr: ctx->regs + PCI_REG_PARAM);
344 __raw_writel(val: ctx->pm[10], addr: ctx->regs + PCI_REG_MBAR);
345 __raw_writel(ctx->pm[11], ctx->regs + PCI_REG_TIMEOUT);
346 wmb();
347 __raw_writel(ctx->pm[1], ctx->regs + PCI_REG_CONFIG);
348 wmb();
349
350 /* YAMON on all db1xxx boards wipes the TLB and writes zero to C0_wired
351 * on resume, making it necessary to recreate it as soon as possible.
352 */
353 ctx->wired_entry = 8191; /* impossibly high value */
354 alchemy_pci_wired_entry(ctx); /* install it */
355}
356
357static struct syscore_ops alchemy_pci_pmops = {
358 .suspend = alchemy_pci_suspend,
359 .resume = alchemy_pci_resume,
360};
361
362static int alchemy_pci_probe(struct platform_device *pdev)
363{
364 struct alchemy_pci_platdata *pd = pdev->dev.platform_data;
365 struct alchemy_pci_context *ctx;
366 void __iomem *virt_io;
367 unsigned long val;
368 struct resource *r;
369 struct clk *c;
370 int ret;
371
372 /* need at least PCI IRQ mapping table */
373 if (!pd) {
374 dev_err(&pdev->dev, "need platform data for PCI setup\n");
375 ret = -ENODEV;
376 goto out;
377 }
378
379 ctx = kzalloc(size: sizeof(*ctx), GFP_KERNEL);
380 if (!ctx) {
381 dev_err(&pdev->dev, "no memory for pcictl context\n");
382 ret = -ENOMEM;
383 goto out;
384 }
385
386 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
387 if (!r) {
388 dev_err(&pdev->dev, "no pcictl ctrl regs resource\n");
389 ret = -ENODEV;
390 goto out1;
391 }
392
393 if (!request_mem_region(r->start, resource_size(r), pdev->name)) {
394 dev_err(&pdev->dev, "cannot claim pci regs\n");
395 ret = -ENODEV;
396 goto out1;
397 }
398
399 c = clk_get(dev: &pdev->dev, id: "pci_clko");
400 if (IS_ERR(ptr: c)) {
401 dev_err(&pdev->dev, "unable to find PCI clock\n");
402 ret = PTR_ERR(ptr: c);
403 goto out2;
404 }
405
406 ret = clk_prepare_enable(clk: c);
407 if (ret) {
408 dev_err(&pdev->dev, "cannot enable PCI clock\n");
409 goto out6;
410 }
411
412 ctx->regs = ioremap(offset: r->start, size: resource_size(res: r));
413 if (!ctx->regs) {
414 dev_err(&pdev->dev, "cannot map pci regs\n");
415 ret = -ENODEV;
416 goto out5;
417 }
418
419 /* map parts of the PCI IO area */
420 /* REVISIT: if this changes with a newer variant (doubt it) make this
421 * a platform resource.
422 */
423 virt_io = ioremap(AU1500_PCI_IO_PHYS_ADDR, 0x00100000);
424 if (!virt_io) {
425 dev_err(&pdev->dev, "cannot remap pci io space\n");
426 ret = -ENODEV;
427 goto out3;
428 }
429 ctx->alchemy_pci_ctrl.io_map_base = (unsigned long)virt_io;
430
431 /* Au1500 revisions older than AD have borked coherent PCI */
432 if (alchemy_get_cputype() == ALCHEMY_CPU_AU1500 &&
433 read_c0_prid() < 0x01030202 && !dma_default_coherent) {
434 val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
435 val |= PCI_CONFIG_NC;
436 __raw_writel(val, ctx->regs + PCI_REG_CONFIG);
437 wmb();
438 dev_info(&pdev->dev, "non-coherent PCI on Au1500 AA/AB/AC\n");
439 }
440
441 if (pd->board_map_irq)
442 ctx->board_map_irq = pd->board_map_irq;
443
444 if (pd->board_pci_idsel)
445 ctx->board_pci_idsel = pd->board_pci_idsel;
446 else
447 ctx->board_pci_idsel = alchemy_pci_def_idsel;
448
449 /* fill in relevant pci_controller members */
450 ctx->alchemy_pci_ctrl.pci_ops = &alchemy_pci_ops;
451 ctx->alchemy_pci_ctrl.mem_resource = &alchemy_pci_def_memres;
452 ctx->alchemy_pci_ctrl.io_resource = &alchemy_pci_def_iores;
453
454 /* we can't ioremap the entire pci config space because it's too large,
455 * nor can we dynamically ioremap it because some drivers use the
456 * PCI config routines from within atomic context and that becomes a
457 * problem in get_vm_area(). Instead we use one wired TLB entry to
458 * handle all config accesses for all busses.
459 */
460 ctx->pci_cfg_vm = get_vm_area(size: 0x2000, VM_IOREMAP);
461 if (!ctx->pci_cfg_vm) {
462 dev_err(&pdev->dev, "unable to get vm area\n");
463 ret = -ENOMEM;
464 goto out4;
465 }
466 ctx->wired_entry = 8191; /* impossibly high value */
467 alchemy_pci_wired_entry(ctx); /* install it */
468
469 set_io_port_base((unsigned long)ctx->alchemy_pci_ctrl.io_map_base);
470
471 /* board may want to modify bits in the config register, do it now */
472 val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
473 val &= ~pd->pci_cfg_clr;
474 val |= pd->pci_cfg_set;
475 val &= ~PCI_CONFIG_PD; /* clear disable bit */
476 __raw_writel(val, ctx->regs + PCI_REG_CONFIG);
477 wmb();
478
479 __alchemy_pci_ctx = ctx;
480 platform_set_drvdata(pdev, data: ctx);
481 register_syscore_ops(ops: &alchemy_pci_pmops);
482 register_pci_controller(&ctx->alchemy_pci_ctrl);
483
484 dev_info(&pdev->dev, "PCI controller at %ld MHz\n",
485 clk_get_rate(c) / 1000000);
486
487 return 0;
488
489out4:
490 iounmap(addr: virt_io);
491out3:
492 iounmap(addr: ctx->regs);
493out5:
494 clk_disable_unprepare(clk: c);
495out6:
496 clk_put(clk: c);
497out2:
498 release_mem_region(r->start, resource_size(r));
499out1:
500 kfree(objp: ctx);
501out:
502 return ret;
503}
504
505static struct platform_driver alchemy_pcictl_driver = {
506 .probe = alchemy_pci_probe,
507 .driver = {
508 .name = "alchemy-pci",
509 },
510};
511
512static int __init alchemy_pci_init(void)
513{
514 /* Au1500/Au1550 have PCI */
515 switch (alchemy_get_cputype()) {
516 case ALCHEMY_CPU_AU1500:
517 case ALCHEMY_CPU_AU1550:
518 return platform_driver_register(&alchemy_pcictl_driver);
519 }
520 return 0;
521}
522arch_initcall(alchemy_pci_init);
523
524
525int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
526{
527 struct alchemy_pci_context *ctx = dev->sysdata;
528 if (ctx && ctx->board_map_irq)
529 return ctx->board_map_irq(dev, slot, pin);
530 return -1;
531}
532
533int pcibios_plat_dev_init(struct pci_dev *dev)
534{
535 return 0;
536}
537

source code of linux/arch/mips/pci/pci-alchemy.c