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.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_pci.h>
21 #include <linux/pci.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 #include <linux/irqdomain.h>
25 #include <linux/irqchip/chained_irq.h>
26 #include <linux/bitops.h>
27 #include <linux/irq.h>
28 #include <linux/clk.h>
29
30 #include "../pci.h"
31
32 /*
33 * Special configuration registers directly in the first few words
34 * in I/O space.
35 */
36 #define FTPCI_IOSIZE 0x00
37 #define FTPCI_PROT 0x04 /* AHB protection */
38 #define FTPCI_CTRL 0x08 /* PCI control signal */
39 #define FTPCI_SOFTRST 0x10 /* Soft reset counter and response error enable */
40 #define FTPCI_CONFIG 0x28 /* PCI configuration command register */
41 #define FTPCI_DATA 0x2C
42
43 #define FARADAY_PCI_STATUS_CMD 0x04 /* Status and command */
44 #define FARADAY_PCI_PMC 0x40 /* Power management control */
45 #define FARADAY_PCI_PMCSR 0x44 /* Power management status */
46 #define FARADAY_PCI_CTRL1 0x48 /* Control register 1 */
47 #define FARADAY_PCI_CTRL2 0x4C /* Control register 2 */
48 #define FARADAY_PCI_MEM1_BASE_SIZE 0x50 /* Memory base and size #1 */
49 #define FARADAY_PCI_MEM2_BASE_SIZE 0x54 /* Memory base and size #2 */
50 #define FARADAY_PCI_MEM3_BASE_SIZE 0x58 /* Memory base and size #3 */
51
52 #define PCI_STATUS_66MHZ_CAPABLE BIT(21)
53
54 /* Bits 31..28 gives INTD..INTA status */
55 #define PCI_CTRL2_INTSTS_SHIFT 28
56 #define PCI_CTRL2_INTMASK_CMDERR BIT(27)
57 #define PCI_CTRL2_INTMASK_PARERR BIT(26)
58 /* Bits 25..22 masks INTD..INTA */
59 #define PCI_CTRL2_INTMASK_SHIFT 22
60 #define PCI_CTRL2_INTMASK_MABRT_RX BIT(21)
61 #define PCI_CTRL2_INTMASK_TABRT_RX BIT(20)
62 #define PCI_CTRL2_INTMASK_TABRT_TX BIT(19)
63 #define PCI_CTRL2_INTMASK_RETRY4 BIT(18)
64 #define PCI_CTRL2_INTMASK_SERR_RX BIT(17)
65 #define PCI_CTRL2_INTMASK_PERR_RX BIT(16)
66 /* Bit 15 reserved */
67 #define PCI_CTRL2_MSTPRI_REQ6 BIT(14)
68 #define PCI_CTRL2_MSTPRI_REQ5 BIT(13)
69 #define PCI_CTRL2_MSTPRI_REQ4 BIT(12)
70 #define PCI_CTRL2_MSTPRI_REQ3 BIT(11)
71 #define PCI_CTRL2_MSTPRI_REQ2 BIT(10)
72 #define PCI_CTRL2_MSTPRI_REQ1 BIT(9)
73 #define PCI_CTRL2_MSTPRI_REQ0 BIT(8)
74 /* Bits 7..4 reserved */
75 /* Bits 3..0 TRDYW */
76
77 /*
78 * Memory configs:
79 * Bit 31..20 defines the PCI side memory base
80 * Bit 19..16 (4 bits) defines the size per below
81 */
82 #define FARADAY_PCI_MEMBASE_MASK 0xfff00000
83 #define FARADAY_PCI_MEMSIZE_1MB 0x0
84 #define FARADAY_PCI_MEMSIZE_2MB 0x1
85 #define FARADAY_PCI_MEMSIZE_4MB 0x2
86 #define FARADAY_PCI_MEMSIZE_8MB 0x3
87 #define FARADAY_PCI_MEMSIZE_16MB 0x4
88 #define FARADAY_PCI_MEMSIZE_32MB 0x5
89 #define FARADAY_PCI_MEMSIZE_64MB 0x6
90 #define FARADAY_PCI_MEMSIZE_128MB 0x7
91 #define FARADAY_PCI_MEMSIZE_256MB 0x8
92 #define FARADAY_PCI_MEMSIZE_512MB 0x9
93 #define FARADAY_PCI_MEMSIZE_1GB 0xa
94 #define FARADAY_PCI_MEMSIZE_2GB 0xb
95 #define FARADAY_PCI_MEMSIZE_SHIFT 16
96
97 /*
98 * The DMA base is set to 0x0 for all memory segments, it reflects the
99 * fact that the memory of the host system starts at 0x0.
100 */
101 #define FARADAY_PCI_DMA_MEM1_BASE 0x00000000
102 #define FARADAY_PCI_DMA_MEM2_BASE 0x00000000
103 #define FARADAY_PCI_DMA_MEM3_BASE 0x00000000
104
105 /**
106 * struct faraday_pci_variant - encodes IP block differences
107 * @cascaded_irq: this host has cascaded IRQs from an interrupt controller
108 * embedded in the host bridge.
109 */
110 struct faraday_pci_variant {
111 bool cascaded_irq;
112 };
113
114 struct faraday_pci {
115 struct device *dev;
116 void __iomem *base;
117 struct irq_domain *irqdomain;
118 struct pci_bus *bus;
119 struct clk *bus_clk;
120 };
121
faraday_res_to_memcfg(resource_size_t mem_base,resource_size_t mem_size,u32 * val)122 static int faraday_res_to_memcfg(resource_size_t mem_base,
123 resource_size_t mem_size, u32 *val)
124 {
125 u32 outval;
126
127 switch (mem_size) {
128 case SZ_1M:
129 outval = FARADAY_PCI_MEMSIZE_1MB;
130 break;
131 case SZ_2M:
132 outval = FARADAY_PCI_MEMSIZE_2MB;
133 break;
134 case SZ_4M:
135 outval = FARADAY_PCI_MEMSIZE_4MB;
136 break;
137 case SZ_8M:
138 outval = FARADAY_PCI_MEMSIZE_8MB;
139 break;
140 case SZ_16M:
141 outval = FARADAY_PCI_MEMSIZE_16MB;
142 break;
143 case SZ_32M:
144 outval = FARADAY_PCI_MEMSIZE_32MB;
145 break;
146 case SZ_64M:
147 outval = FARADAY_PCI_MEMSIZE_64MB;
148 break;
149 case SZ_128M:
150 outval = FARADAY_PCI_MEMSIZE_128MB;
151 break;
152 case SZ_256M:
153 outval = FARADAY_PCI_MEMSIZE_256MB;
154 break;
155 case SZ_512M:
156 outval = FARADAY_PCI_MEMSIZE_512MB;
157 break;
158 case SZ_1G:
159 outval = FARADAY_PCI_MEMSIZE_1GB;
160 break;
161 case SZ_2G:
162 outval = FARADAY_PCI_MEMSIZE_2GB;
163 break;
164 default:
165 return -EINVAL;
166 }
167 outval <<= FARADAY_PCI_MEMSIZE_SHIFT;
168
169 /* This is probably not good */
170 if (mem_base & ~(FARADAY_PCI_MEMBASE_MASK))
171 pr_warn("truncated PCI memory base\n");
172 /* Translate to bridge side address space */
173 outval |= (mem_base & FARADAY_PCI_MEMBASE_MASK);
174 pr_debug("Translated pci base @%pap, size %pap to config %08x\n",
175 &mem_base, &mem_size, outval);
176
177 *val = outval;
178 return 0;
179 }
180
faraday_raw_pci_read_config(struct faraday_pci * p,int bus_number,unsigned int fn,int config,int size,u32 * value)181 static int faraday_raw_pci_read_config(struct faraday_pci *p, int bus_number,
182 unsigned int fn, int config, int size,
183 u32 *value)
184 {
185 writel(PCI_CONF1_ADDRESS(bus_number, PCI_SLOT(fn),
186 PCI_FUNC(fn), config),
187 p->base + FTPCI_CONFIG);
188
189 *value = readl(p->base + FTPCI_DATA);
190
191 if (size == 1)
192 *value = (*value >> (8 * (config & 3))) & 0xFF;
193 else if (size == 2)
194 *value = (*value >> (8 * (config & 3))) & 0xFFFF;
195
196 return PCIBIOS_SUCCESSFUL;
197 }
198
faraday_pci_read_config(struct pci_bus * bus,unsigned int fn,int config,int size,u32 * value)199 static int faraday_pci_read_config(struct pci_bus *bus, unsigned int fn,
200 int config, int size, u32 *value)
201 {
202 struct faraday_pci *p = bus->sysdata;
203
204 dev_dbg(&bus->dev,
205 "[read] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
206 PCI_SLOT(fn), PCI_FUNC(fn), config, size, *value);
207
208 return faraday_raw_pci_read_config(p, bus->number, fn, config, size, value);
209 }
210
faraday_raw_pci_write_config(struct faraday_pci * p,int bus_number,unsigned int fn,int config,int size,u32 value)211 static int faraday_raw_pci_write_config(struct faraday_pci *p, int bus_number,
212 unsigned int fn, int config, int size,
213 u32 value)
214 {
215 int ret = PCIBIOS_SUCCESSFUL;
216
217 writel(PCI_CONF1_ADDRESS(bus_number, PCI_SLOT(fn),
218 PCI_FUNC(fn), config),
219 p->base + FTPCI_CONFIG);
220
221 switch (size) {
222 case 4:
223 writel(value, p->base + FTPCI_DATA);
224 break;
225 case 2:
226 writew(value, p->base + FTPCI_DATA + (config & 3));
227 break;
228 case 1:
229 writeb(value, p->base + FTPCI_DATA + (config & 3));
230 break;
231 default:
232 ret = PCIBIOS_BAD_REGISTER_NUMBER;
233 }
234
235 return ret;
236 }
237
faraday_pci_write_config(struct pci_bus * bus,unsigned int fn,int config,int size,u32 value)238 static int faraday_pci_write_config(struct pci_bus *bus, unsigned int fn,
239 int config, int size, u32 value)
240 {
241 struct faraday_pci *p = bus->sysdata;
242
243 dev_dbg(&bus->dev,
244 "[write] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
245 PCI_SLOT(fn), PCI_FUNC(fn), config, size, value);
246
247 return faraday_raw_pci_write_config(p, bus->number, fn, config, size,
248 value);
249 }
250
251 static struct pci_ops faraday_pci_ops = {
252 .read = faraday_pci_read_config,
253 .write = faraday_pci_write_config,
254 };
255
faraday_pci_ack_irq(struct irq_data * d)256 static void faraday_pci_ack_irq(struct irq_data *d)
257 {
258 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
259 unsigned int reg;
260
261 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
262 reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
263 reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTSTS_SHIFT);
264 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
265 }
266
faraday_pci_mask_irq(struct irq_data * d)267 static void faraday_pci_mask_irq(struct irq_data *d)
268 {
269 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
270 unsigned int reg;
271
272 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
273 reg &= ~((0xF << PCI_CTRL2_INTSTS_SHIFT)
274 | BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT));
275 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
276 }
277
faraday_pci_unmask_irq(struct irq_data * d)278 static void faraday_pci_unmask_irq(struct irq_data *d)
279 {
280 struct faraday_pci *p = irq_data_get_irq_chip_data(d);
281 unsigned int reg;
282
283 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
284 reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
285 reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT);
286 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, reg);
287 }
288
faraday_pci_irq_handler(struct irq_desc * desc)289 static void faraday_pci_irq_handler(struct irq_desc *desc)
290 {
291 struct faraday_pci *p = irq_desc_get_handler_data(desc);
292 struct irq_chip *irqchip = irq_desc_get_chip(desc);
293 unsigned int irq_stat, reg, i;
294
295 faraday_raw_pci_read_config(p, 0, 0, FARADAY_PCI_CTRL2, 4, ®);
296 irq_stat = reg >> PCI_CTRL2_INTSTS_SHIFT;
297
298 chained_irq_enter(irqchip, desc);
299
300 for (i = 0; i < 4; i++) {
301 if ((irq_stat & BIT(i)) == 0)
302 continue;
303 generic_handle_domain_irq(p->irqdomain, i);
304 }
305
306 chained_irq_exit(irqchip, desc);
307 }
308
309 static struct irq_chip faraday_pci_irq_chip = {
310 .name = "PCI",
311 .irq_ack = faraday_pci_ack_irq,
312 .irq_mask = faraday_pci_mask_irq,
313 .irq_unmask = faraday_pci_unmask_irq,
314 };
315
faraday_pci_irq_map(struct irq_domain * domain,unsigned int irq,irq_hw_number_t hwirq)316 static int faraday_pci_irq_map(struct irq_domain *domain, unsigned int irq,
317 irq_hw_number_t hwirq)
318 {
319 irq_set_chip_and_handler(irq, &faraday_pci_irq_chip, handle_level_irq);
320 irq_set_chip_data(irq, domain->host_data);
321
322 return 0;
323 }
324
325 static const struct irq_domain_ops faraday_pci_irqdomain_ops = {
326 .map = faraday_pci_irq_map,
327 };
328
faraday_pci_setup_cascaded_irq(struct faraday_pci * p)329 static int faraday_pci_setup_cascaded_irq(struct faraday_pci *p)
330 {
331 struct device_node *intc = of_get_next_child(p->dev->of_node, NULL);
332 int irq;
333 int i;
334
335 if (!intc) {
336 dev_err(p->dev, "missing child interrupt-controller node\n");
337 return -EINVAL;
338 }
339
340 /* All PCI IRQs cascade off this one */
341 irq = of_irq_get(intc, 0);
342 if (irq <= 0) {
343 dev_err(p->dev, "failed to get parent IRQ\n");
344 of_node_put(intc);
345 return irq ?: -EINVAL;
346 }
347
348 p->irqdomain = irq_domain_add_linear(intc, PCI_NUM_INTX,
349 &faraday_pci_irqdomain_ops, p);
350 of_node_put(intc);
351 if (!p->irqdomain) {
352 dev_err(p->dev, "failed to create Gemini PCI IRQ domain\n");
353 return -EINVAL;
354 }
355
356 irq_set_chained_handler_and_data(irq, faraday_pci_irq_handler, p);
357
358 for (i = 0; i < 4; i++)
359 irq_create_mapping(p->irqdomain, i);
360
361 return 0;
362 }
363
faraday_pci_parse_map_dma_ranges(struct faraday_pci * p)364 static int faraday_pci_parse_map_dma_ranges(struct faraday_pci *p)
365 {
366 struct device *dev = p->dev;
367 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(p);
368 struct resource_entry *entry;
369 u32 confreg[3] = {
370 FARADAY_PCI_MEM1_BASE_SIZE,
371 FARADAY_PCI_MEM2_BASE_SIZE,
372 FARADAY_PCI_MEM3_BASE_SIZE,
373 };
374 int i = 0;
375 u32 val;
376
377 resource_list_for_each_entry(entry, &bridge->dma_ranges) {
378 u64 pci_addr = entry->res->start - entry->offset;
379 u64 end = entry->res->end - entry->offset;
380 int ret;
381
382 ret = faraday_res_to_memcfg(pci_addr,
383 resource_size(entry->res), &val);
384 if (ret) {
385 dev_err(dev,
386 "DMA range %d: illegal MEM resource size\n", i);
387 return -EINVAL;
388 }
389
390 dev_info(dev, "DMA MEM%d BASE: 0x%016llx -> 0x%016llx config %08x\n",
391 i + 1, pci_addr, end, val);
392 if (i <= 2) {
393 faraday_raw_pci_write_config(p, 0, 0, confreg[i],
394 4, val);
395 } else {
396 dev_err(dev, "ignore extraneous dma-range %d\n", i);
397 break;
398 }
399
400 i++;
401 }
402
403 return 0;
404 }
405
faraday_pci_probe(struct platform_device * pdev)406 static int faraday_pci_probe(struct platform_device *pdev)
407 {
408 struct device *dev = &pdev->dev;
409 const struct faraday_pci_variant *variant =
410 of_device_get_match_data(dev);
411 struct resource_entry *win;
412 struct faraday_pci *p;
413 struct resource *io;
414 struct pci_host_bridge *host;
415 struct clk *clk;
416 unsigned char max_bus_speed = PCI_SPEED_33MHz;
417 unsigned char cur_bus_speed = PCI_SPEED_33MHz;
418 int ret;
419 u32 val;
420
421 host = devm_pci_alloc_host_bridge(dev, sizeof(*p));
422 if (!host)
423 return -ENOMEM;
424
425 host->ops = &faraday_pci_ops;
426 p = pci_host_bridge_priv(host);
427 host->sysdata = p;
428 p->dev = dev;
429
430 /* Retrieve and enable optional clocks */
431 clk = devm_clk_get_enabled(dev, "PCLK");
432 if (IS_ERR(clk))
433 return PTR_ERR(clk);
434 p->bus_clk = devm_clk_get_enabled(dev, "PCICLK");
435 if (IS_ERR(p->bus_clk))
436 return PTR_ERR(p->bus_clk);
437
438 p->base = devm_platform_ioremap_resource(pdev, 0);
439 if (IS_ERR(p->base))
440 return PTR_ERR(p->base);
441
442 win = resource_list_first_type(&host->windows, IORESOURCE_IO);
443 if (win) {
444 io = win->res;
445 if (!faraday_res_to_memcfg(io->start - win->offset,
446 resource_size(io), &val)) {
447 /* setup I/O space size */
448 writel(val, p->base + FTPCI_IOSIZE);
449 } else {
450 dev_err(dev, "illegal IO mem size\n");
451 return -EINVAL;
452 }
453 }
454
455 /* Setup hostbridge */
456 val = readl(p->base + FTPCI_CTRL);
457 val |= PCI_COMMAND_IO;
458 val |= PCI_COMMAND_MEMORY;
459 val |= PCI_COMMAND_MASTER;
460 writel(val, p->base + FTPCI_CTRL);
461 /* Mask and clear all interrupts */
462 faraday_raw_pci_write_config(p, 0, 0, FARADAY_PCI_CTRL2 + 2, 2, 0xF000);
463 if (variant->cascaded_irq) {
464 ret = faraday_pci_setup_cascaded_irq(p);
465 if (ret) {
466 dev_err(dev, "failed to setup cascaded IRQ\n");
467 return ret;
468 }
469 }
470
471 /* Check bus clock if we can gear up to 66 MHz */
472 if (!IS_ERR(p->bus_clk)) {
473 unsigned long rate;
474 u32 val;
475
476 faraday_raw_pci_read_config(p, 0, 0,
477 FARADAY_PCI_STATUS_CMD, 4, &val);
478 rate = clk_get_rate(p->bus_clk);
479
480 if ((rate == 33000000) && (val & PCI_STATUS_66MHZ_CAPABLE)) {
481 dev_info(dev, "33MHz bus is 66MHz capable\n");
482 max_bus_speed = PCI_SPEED_66MHz;
483 ret = clk_set_rate(p->bus_clk, 66000000);
484 if (ret)
485 dev_err(dev, "failed to set bus clock\n");
486 } else {
487 dev_info(dev, "33MHz only bus\n");
488 max_bus_speed = PCI_SPEED_33MHz;
489 }
490
491 /* Bumping the clock may fail so read back the rate */
492 rate = clk_get_rate(p->bus_clk);
493 if (rate == 33000000)
494 cur_bus_speed = PCI_SPEED_33MHz;
495 if (rate == 66000000)
496 cur_bus_speed = PCI_SPEED_66MHz;
497 }
498
499 ret = faraday_pci_parse_map_dma_ranges(p);
500 if (ret)
501 return ret;
502
503 ret = pci_scan_root_bus_bridge(host);
504 if (ret) {
505 dev_err(dev, "failed to scan host: %d\n", ret);
506 return ret;
507 }
508 p->bus = host->bus;
509 p->bus->max_bus_speed = max_bus_speed;
510 p->bus->cur_bus_speed = cur_bus_speed;
511
512 pci_bus_assign_resources(p->bus);
513 pci_bus_add_devices(p->bus);
514
515 return 0;
516 }
517
518 /*
519 * We encode bridge variants here, we have at least two so it doesn't
520 * hurt to have infrastructure to encompass future variants as well.
521 */
522 static const struct faraday_pci_variant faraday_regular = {
523 .cascaded_irq = true,
524 };
525
526 static const struct faraday_pci_variant faraday_dual = {
527 .cascaded_irq = false,
528 };
529
530 static const struct of_device_id faraday_pci_of_match[] = {
531 {
532 .compatible = "faraday,ftpci100",
533 .data = &faraday_regular,
534 },
535 {
536 .compatible = "faraday,ftpci100-dual",
537 .data = &faraday_dual,
538 },
539 {},
540 };
541
542 static struct platform_driver faraday_pci_driver = {
543 .driver = {
544 .name = "ftpci100",
545 .of_match_table = faraday_pci_of_match,
546 .suppress_bind_attrs = true,
547 },
548 .probe = faraday_pci_probe,
549 };
550 builtin_platform_driver(faraday_pci_driver);
551