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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Support for Faraday Technology FTPC100 PCI Controller
4 *
5 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
6 *
7 * Based on the out-of-tree OpenWRT patch for Cortina Gemini:
8 * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
9 * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
10 * Based on SL2312 PCI controller code
11 * Storlink (C) 2003
12 */
13
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/of_address.h>
19#include <linux/of_device.h>
20#include <linux/of_irq.h>
21#include <linux/of_pci.h>
22#include <linux/pci.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25#include <linux/irqdomain.h>
26#include <linux/irqchip/chained_irq.h>
27#include <linux/bitops.h>
28#include <linux/irq.h>
29#include <linux/clk.h>
30
31#include "../pci.h"
32
33/*
34 * Special configuration registers directly in the first few words
35 * in I/O space.
36 */
37#define PCI_IOSIZE 0x00
38#define PCI_PROT 0x04 /* AHB protection */
39#define PCI_CTRL 0x08 /* PCI control signal */
40#define PCI_SOFTRST 0x10 /* Soft reset counter and response error enable */
41#define PCI_CONFIG 0x28 /* PCI configuration command register */
42#define PCI_DATA 0x2C
43
44#define FARADAY_PCI_STATUS_CMD 0x04 /* Status and command */
45#define FARADAY_PCI_PMC 0x40 /* Power management control */
46#define FARADAY_PCI_PMCSR 0x44 /* Power management status */
47#define FARADAY_PCI_CTRL1 0x48 /* Control register 1 */
48#define FARADAY_PCI_CTRL2 0x4C /* Control register 2 */
49#define FARADAY_PCI_MEM1_BASE_SIZE 0x50 /* Memory base and size #1 */
50#define FARADAY_PCI_MEM2_BASE_SIZE 0x54 /* Memory base and size #2 */
51#define FARADAY_PCI_MEM3_BASE_SIZE 0x58 /* Memory base and size #3 */
52
53#define PCI_STATUS_66MHZ_CAPABLE BIT(21)
54
55/* Bits 31..28 gives INTD..INTA status */
56#define PCI_CTRL2_INTSTS_SHIFT 28
57#define PCI_CTRL2_INTMASK_CMDERR BIT(27)
58#define PCI_CTRL2_INTMASK_PARERR BIT(26)
59/* Bits 25..22 masks INTD..INTA */
60#define PCI_CTRL2_INTMASK_SHIFT 22
61#define PCI_CTRL2_INTMASK_MABRT_RX BIT(21)
62#define PCI_CTRL2_INTMASK_TABRT_RX BIT(20)
63#define PCI_CTRL2_INTMASK_TABRT_TX BIT(19)
64#define PCI_CTRL2_INTMASK_RETRY4 BIT(18)
65#define PCI_CTRL2_INTMASK_SERR_RX BIT(17)
66#define PCI_CTRL2_INTMASK_PERR_RX BIT(16)
67/* Bit 15 reserved */
68#define PCI_CTRL2_MSTPRI_REQ6 BIT(14)
69#define PCI_CTRL2_MSTPRI_REQ5 BIT(13)
70#define PCI_CTRL2_MSTPRI_REQ4 BIT(12)
71#define PCI_CTRL2_MSTPRI_REQ3 BIT(11)
72#define PCI_CTRL2_MSTPRI_REQ2 BIT(10)
73#define PCI_CTRL2_MSTPRI_REQ1 BIT(9)
74#define PCI_CTRL2_MSTPRI_REQ0 BIT(8)
75/* Bits 7..4 reserved */
76/* Bits 3..0 TRDYW */
77
78/*
79 * Memory configs:
80 * Bit 31..20 defines the PCI side memory base
81 * Bit 19..16 (4 bits) defines the size per below
82 */
83#define FARADAY_PCI_MEMBASE_MASK 0xfff00000
84#define FARADAY_PCI_MEMSIZE_1MB 0x0
85#define FARADAY_PCI_MEMSIZE_2MB 0x1
86#define FARADAY_PCI_MEMSIZE_4MB 0x2
87#define FARADAY_PCI_MEMSIZE_8MB 0x3
88#define FARADAY_PCI_MEMSIZE_16MB 0x4
89#define FARADAY_PCI_MEMSIZE_32MB 0x5
90#define FARADAY_PCI_MEMSIZE_64MB 0x6
91#define FARADAY_PCI_MEMSIZE_128MB 0x7
92#define FARADAY_PCI_MEMSIZE_256MB 0x8
93#define FARADAY_PCI_MEMSIZE_512MB 0x9
94#define FARADAY_PCI_MEMSIZE_1GB 0xa
95#define FARADAY_PCI_MEMSIZE_2GB 0xb
96#define FARADAY_PCI_MEMSIZE_SHIFT 16
97
98/*
99 * The DMA base is set to 0x0 for all memory segments, it reflects the
100 * fact that the memory of the host system starts at 0x0.
101 */
102#define FARADAY_PCI_DMA_MEM1_BASE 0x00000000
103#define FARADAY_PCI_DMA_MEM2_BASE 0x00000000
104#define FARADAY_PCI_DMA_MEM3_BASE 0x00000000
105
106/* Defines for PCI configuration command register */
107#define PCI_CONF_ENABLE BIT(31)
108#define PCI_CONF_WHERE(r) ((r) & 0xFC)
109#define PCI_CONF_BUS(b) (((b) & 0xFF) << 16)
110#define PCI_CONF_DEVICE(d) (((d) & 0x1F) << 11)
111#define PCI_CONF_FUNCTION(f) (((f) & 0x07) << 8)
112
113/**
114 * struct faraday_pci_variant - encodes IP block differences
115 * @cascaded_irq: this host has cascaded IRQs from an interrupt controller
116 * embedded in the host bridge.
117 */
118struct faraday_pci_variant {
119 bool cascaded_irq;
120};
121
122struct faraday_pci {
123 struct device *dev;
124 void __iomem *base;
125 struct irq_domain *irqdomain;
126 struct pci_bus *bus;
127 struct clk *bus_clk;
128};
129
130static int faraday_res_to_memcfg(resource_size_t mem_base,
131 resource_size_t mem_size, u32 *val)
132{
133 u32 outval;
134
135 switch (mem_size) {
136 case SZ_1M:
137 outval = FARADAY_PCI_MEMSIZE_1MB;
138 break;
139 case SZ_2M:
140 outval = FARADAY_PCI_MEMSIZE_2MB;
141 break;
142 case SZ_4M:
143 outval = FARADAY_PCI_MEMSIZE_4MB;
144 break;
145 case SZ_8M:
146 outval = FARADAY_PCI_MEMSIZE_8MB;
147 break;
148 case SZ_16M:
149 outval = FARADAY_PCI_MEMSIZE_16MB;
150 break;
151 case SZ_32M:
152 outval = FARADAY_PCI_MEMSIZE_32MB;
153 break;
154 case SZ_64M:
155 outval = FARADAY_PCI_MEMSIZE_64MB;
156 break;
157 case SZ_128M:
158 outval = FARADAY_PCI_MEMSIZE_128MB;
159 break;
160 case SZ_256M:
161 outval = FARADAY_PCI_MEMSIZE_256MB;
162 break;
163 case SZ_512M:
164 outval = FARADAY_PCI_MEMSIZE_512MB;
165 break;
166 case SZ_1G:
167 outval = FARADAY_PCI_MEMSIZE_1GB;
168 break;
169 case SZ_2G:
170 outval = FARADAY_PCI_MEMSIZE_2GB;
171 break;
172 default:
173 return -EINVAL;
174 }
175 outval <<= FARADAY_PCI_MEMSIZE_SHIFT;
176
177 /* This is probably not good */
178 if (mem_base & ~(FARADAY_PCI_MEMBASE_MASK))
179 pr_warn("truncated PCI memory base\n");
180 /* Translate to bridge side address space */
181 outval |= (mem_base & FARADAY_PCI_MEMBASE_MASK);
182 pr_debug("Translated pci base @%pap, size %pap to config %08x\n",
183 &mem_base, &mem_size, outval);
184
185 *val = outval;
186 return 0;
187}
188
189static int faraday_raw_pci_read_config(struct faraday_pci *p, int bus_number,
190 unsigned int fn, int config, int size,
191 u32 *value)
192{
193 writel(PCI_CONF_BUS(bus_number) |
194 PCI_CONF_DEVICE(PCI_SLOT(fn)) |
195 PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
196 PCI_CONF_WHERE(config) |
197 PCI_CONF_ENABLE,
198 p->base + PCI_CONFIG);
199
200 *value = readl(p->base + PCI_DATA);
201
202 if (size == 1)
203 *value = (*value >> (8 * (config & 3))) & 0xFF;
204 else if (size == 2)
205 *value = (*value >> (8 * (config & 3))) & 0xFFFF;
206
207 return PCIBIOS_SUCCESSFUL;
208}
209
210static int faraday_pci_read_config(struct pci_bus *bus, unsigned int fn,
211 int config, int size, u32 *value)
212{
213 struct faraday_pci *p = bus->sysdata;
214
215 dev_dbg(&bus->dev,
216 "[read] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
217 PCI_SLOT(fn), PCI_FUNC(fn), config, size, *value);
218
219 return faraday_raw_pci_read_config(p, bus->number, fn, config, size, value);
220}
221
222static int faraday_raw_pci_write_config(struct faraday_pci *p, int bus_number,
223 unsigned int fn, int config, int size,
224 u32 value)
225{
226 int ret = PCIBIOS_SUCCESSFUL;
227
228 writel(PCI_CONF_BUS(bus_number) |
229 PCI_CONF_DEVICE(PCI_SLOT(fn)) |
230 PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
231 PCI_CONF_WHERE(config) |
232 PCI_CONF_ENABLE,
233 p->base + PCI_CONFIG);
234
235 switch (size) {
236 case 4:
237 writel(value, p->base + PCI_DATA);
238 break;
239 case 2:
240 writew(value, p->base + PCI_DATA + (config & 3));
241 break;
242 case 1:
243 writeb(value, p->base + PCI_DATA + (config & 3));
244 break;
245 default:
246 ret = PCIBIOS_BAD_REGISTER_NUMBER;
247 }
248
249 return ret;
250}
251
252static int faraday_pci_write_config(struct pci_bus *bus, unsigned int fn,
253 int config, int size, u32 value)
254{
255 struct faraday_pci *p = bus->sysdata;
256
257 dev_dbg(&bus->dev,
258 "[write] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
259 PCI_SLOT(fn), PCI_FUNC(fn), config, size, value);
260
261 return faraday_raw_pci_write_config(p, bus->number, fn, config, size,
262 value);
263}
264
265static struct pci_ops faraday_pci_ops = {
266 .read = faraday_pci_read_config,
267 .write = faraday_pci_write_config,
268};
269
270static void faraday_pci_ack_irq(struct irq_data *d)
271{
272 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
273 unsigned int reg;
274
275 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
276 reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
277 reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTSTS_SHIFT);
278 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
279}
280
281static void faraday_pci_mask_irq(struct irq_data *d)
282{
283 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
284 unsigned int reg;
285
286 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
287 reg &= ~((0xF << PCI_CTRL2_INTSTS_SHIFT)
288 | BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT));
289 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
290}
291
292static void faraday_pci_unmask_irq(struct irq_data *d)
293{
294 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
295 unsigned int reg;
296
297 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
298 reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
299 reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT);
300 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
301}
302
303static void faraday_pci_irq_handler(struct irq_desc *desc)
304{
305 struct faraday_pci *p = irq_desc_get_handler_data(desc);
306 struct irq_chip *irqchip = irq_desc_get_chip(desc);
307 unsigned int irq_stat, reg, i;
308
309 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
310 irq_stat = reg >> PCI_CTRL2_INTSTS_SHIFT;
311
312 chained_irq_enter(irqchip, desc);
313
314 for (i = 0; i < 4; i++) {
315 if ((irq_stat & BIT(i)) == 0)
316 continue;
317 generic_handle_irq(irq_find_mapping(p->irqdomain, i));
318 }
319
320 chained_irq_exit(irqchip, desc);
321}
322
323static struct irq_chip faraday_pci_irq_chip = {
324 .name = "PCI",
325 .irq_ack = faraday_pci_ack_irq,
326 .irq_mask = faraday_pci_mask_irq,
327 .irq_unmask = faraday_pci_unmask_irq,
328};
329
330static int faraday_pci_irq_map(struct irq_domain *domain, unsigned int irq,
331 irq_hw_number_t hwirq)
332{
333 irq_set_chip_and_handler(irq, &faraday_pci_irq_chip, handle_level_irq);
334 irq_set_chip_data(irq, domain->host_data);
335
336 return 0;
337}
338
339static const struct irq_domain_ops faraday_pci_irqdomain_ops = {
340 .map = faraday_pci_irq_map,
341};
342
343static int faraday_pci_setup_cascaded_irq(struct faraday_pci *p)
344{
345 struct device_node *intc = of_get_next_child(p->dev->of_node, NULL);
346 int irq;
347 int i;
348
349 if (!intc) {
350 dev_err(p->dev, "missing child interrupt-controller node\n");
351 return -EINVAL;
352 }
353
354 /* All PCI IRQs cascade off this one */
355 irq = of_irq_get(intc, 0);
356 if (irq <= 0) {
357 dev_err(p->dev, "failed to get parent IRQ\n");
358 of_node_put(intc);
359 return irq ?: -EINVAL;
360 }
361
362 p->irqdomain = irq_domain_add_linear(intc, PCI_NUM_INTX,
363 &faraday_pci_irqdomain_ops, p);
364 of_node_put(intc);
365 if (!p->irqdomain) {
366 dev_err(p->dev, "failed to create Gemini PCI IRQ domain\n");
367 return -EINVAL;
368 }
369
370 irq_set_chained_handler_and_data(irq, faraday_pci_irq_handler, p);
371
372 for (i = 0; i < 4; i++)
373 irq_create_mapping(p->irqdomain, i);
374
375 return 0;
376}
377
378static int faraday_pci_parse_map_dma_ranges(struct faraday_pci *p,
379 struct device_node *np)
380{
381 struct of_pci_range range;
382 struct of_pci_range_parser parser;
383 struct device *dev = p->dev;
384 u32 confreg[3] = {
385 FARADAY_PCI_MEM1_BASE_SIZE,
386 FARADAY_PCI_MEM2_BASE_SIZE,
387 FARADAY_PCI_MEM3_BASE_SIZE,
388 };
389 int i = 0;
390 u32 val;
391
392 if (of_pci_dma_range_parser_init(&parser, np)) {
393 dev_err(dev, "missing dma-ranges property\n");
394 return -EINVAL;
395 }
396
397 /*
398 * Get the dma-ranges from the device tree
399 */
400 for_each_of_pci_range(&parser, &range) {
401 u64 end = range.pci_addr + range.size - 1;
402 int ret;
403
404 ret = faraday_res_to_memcfg(range.pci_addr, range.size, &val);
405 if (ret) {
406 dev_err(dev,
407 "DMA range %d: illegal MEM resource size\n", i);
408 return -EINVAL;
409 }
410
411 dev_info(dev, "DMA MEM%d BASE: 0x%016llx -> 0x%016llx config %08x\n",
412 i + 1, range.pci_addr, end, val);
413 if (i <= 2) {
414 faraday_raw_pci_write_config(p, 0, 0, confreg[i],
415 4, val);
416 } else {
417 dev_err(dev, "ignore extraneous dma-range %d\n", i);
418 break;
419 }
420
421 i++;
422 }
423
424 return 0;
425}
426
427static int faraday_pci_probe(struct platform_device *pdev)
428{
429 struct device *dev = &pdev->dev;
430 const struct faraday_pci_variant *variant =
431 of_device_get_match_data(dev);
432 struct resource *regs;
433 resource_size_t io_base;
434 struct resource_entry *win;
435 struct faraday_pci *p;
436 struct resource *mem;
437 struct resource *io;
438 struct pci_host_bridge *host;
439 struct clk *clk;
440 unsigned char max_bus_speed = PCI_SPEED_33MHz;
441 unsigned char cur_bus_speed = PCI_SPEED_33MHz;
442 int ret;
443 u32 val;
444 LIST_HEAD(res);
445
446 host = devm_pci_alloc_host_bridge(dev, sizeof(*p));
447 if (!host)
448 return -ENOMEM;
449
450 host->dev.parent = dev;
451 host->ops = &faraday_pci_ops;
452 host->busnr = 0;
453 host->msi = NULL;
454 host->map_irq = of_irq_parse_and_map_pci;
455 host->swizzle_irq = pci_common_swizzle;
456 p = pci_host_bridge_priv(host);
457 host->sysdata = p;
458 p->dev = dev;
459
460 /* Retrieve and enable optional clocks */
461 clk = devm_clk_get(dev, "PCLK");
462 if (IS_ERR(clk))
463 return PTR_ERR(clk);
464 ret = clk_prepare_enable(clk);
465 if (ret) {
466 dev_err(dev, "could not prepare PCLK\n");
467 return ret;
468 }
469 p->bus_clk = devm_clk_get(dev, "PCICLK");
470 if (IS_ERR(p->bus_clk))
471 return PTR_ERR(p->bus_clk);
472 ret = clk_prepare_enable(p->bus_clk);
473 if (ret) {
474 dev_err(dev, "could not prepare PCICLK\n");
475 return ret;
476 }
477
478 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
479 p->base = devm_ioremap_resource(dev, regs);
480 if (IS_ERR(p->base))
481 return PTR_ERR(p->base);
482
483 ret = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
484 &res, &io_base);
485 if (ret)
486 return ret;
487
488 ret = devm_request_pci_bus_resources(dev, &res);
489 if (ret)
490 return ret;
491
492 /* Get the I/O and memory ranges from DT */
493 resource_list_for_each_entry(win, &res) {
494 switch (resource_type(win->res)) {
495 case IORESOURCE_IO:
496 io = win->res;
497 io->name = "Gemini PCI I/O";
498 if (!faraday_res_to_memcfg(io->start - win->offset,
499 resource_size(io), &val)) {
500 /* setup I/O space size */
501 writel(val, p->base + PCI_IOSIZE);
502 } else {
503 dev_err(dev, "illegal IO mem size\n");
504 return -EINVAL;
505 }
506 ret = devm_pci_remap_iospace(dev, io, io_base);
507 if (ret) {
508 dev_warn(dev, "error %d: failed to map resource %pR\n",
509 ret, io);
510 continue;
511 }
512 break;
513 case IORESOURCE_MEM:
514 mem = win->res;
515 mem->name = "Gemini PCI MEM";
516 break;
517 case IORESOURCE_BUS:
518 break;
519 default:
520 break;
521 }
522 }
523
524 /* Setup hostbridge */
525 val = readl(p->base + PCI_CTRL);
526 val |= PCI_COMMAND_IO;
527 val |= PCI_COMMAND_MEMORY;
528 val |= PCI_COMMAND_MASTER;
529 writel(val, p->base + PCI_CTRL);
530 /* Mask and clear all interrupts */
531 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2 + 2, 2, 0xF000);
532 if (variant->cascaded_irq) {
533 ret = faraday_pci_setup_cascaded_irq(p);
534 if (ret) {
535 dev_err(dev, "failed to setup cascaded IRQ\n");
536 return ret;
537 }
538 }
539
540 /* Check bus clock if we can gear up to 66 MHz */
541 if (!IS_ERR(p->bus_clk)) {
542 unsigned long rate;
543 u32 val;
544
545 faraday_raw_pci_read_config(p, 0, 0,
546 FARADAY_PCI_STATUS_CMD, 4, &val);
547 rate = clk_get_rate(p->bus_clk);
548
549 if ((rate == 33000000) && (val & PCI_STATUS_66MHZ_CAPABLE)) {
550 dev_info(dev, "33MHz bus is 66MHz capable\n");
551 max_bus_speed = PCI_SPEED_66MHz;
552 ret = clk_set_rate(p->bus_clk, 66000000);
553 if (ret)
554 dev_err(dev, "failed to set bus clock\n");
555 } else {
556 dev_info(dev, "33MHz only bus\n");
557 max_bus_speed = PCI_SPEED_33MHz;
558 }
559
560 /* Bumping the clock may fail so read back the rate */
561 rate = clk_get_rate(p->bus_clk);
562 if (rate == 33000000)
563 cur_bus_speed = PCI_SPEED_33MHz;
564 if (rate == 66000000)
565 cur_bus_speed = PCI_SPEED_66MHz;
566 }
567
568 ret = faraday_pci_parse_map_dma_ranges(p, dev->of_node);
569 if (ret)
570 return ret;
571
572 list_splice_init(&res, &host->windows);
573 ret = pci_scan_root_bus_bridge(host);
574 if (ret) {
575 dev_err(dev, "failed to scan host: %d\n", ret);
576 return ret;
577 }
578 p->bus = host->bus;
579 p->bus->max_bus_speed = max_bus_speed;
580 p->bus->cur_bus_speed = cur_bus_speed;
581
582 pci_bus_assign_resources(p->bus);
583 pci_bus_add_devices(p->bus);
584 pci_free_resource_list(&res);
585
586 return 0;
587}
588
589/*
590 * We encode bridge variants here, we have at least two so it doesn't
591 * hurt to have infrastructure to encompass future variants as well.
592 */
593static const struct faraday_pci_variant faraday_regular = {
594 .cascaded_irq = true,
595};
596
597static const struct faraday_pci_variant faraday_dual = {
598 .cascaded_irq = false,
599};
600
601static const struct of_device_id faraday_pci_of_match[] = {
602 {
603 .compatible = "faraday,ftpci100",
604 .data = &faraday_regular,
605 },
606 {
607 .compatible = "faraday,ftpci100-dual",
608 .data = &faraday_dual,
609 },
610 {},
611};
612
613static struct platform_driver faraday_pci_driver = {
614 .driver = {
615 .name = "ftpci100",
616 .of_match_table = of_match_ptr(faraday_pci_of_match),
617 .suppress_bind_attrs = true,
618 },
619 .probe = faraday_pci_probe,
620};
621builtin_platform_driver(faraday_pci_driver);