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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * pci-j721e - PCIe controller driver for TI's J721E SoCs
4 *
5 * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
7 */
8
9#include <linux/clk.h>
10#include <linux/clk-provider.h>
11#include <linux/container_of.h>
12#include <linux/delay.h>
13#include <linux/gpio/consumer.h>
14#include <linux/io.h>
15#include <linux/irqchip/chained_irq.h>
16#include <linux/irqdomain.h>
17#include <linux/mfd/syscon.h>
18#include <linux/of.h>
19#include <linux/pci.h>
20#include <linux/platform_device.h>
21#include <linux/pm_runtime.h>
22#include <linux/regmap.h>
23
24#include "../../pci.h"
25#include "pcie-cadence.h"
26
27#define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
28
29#define ENABLE_REG_SYS_2 0x108
30#define STATUS_REG_SYS_2 0x508
31#define STATUS_CLR_REG_SYS_2 0x708
32#define LINK_DOWN BIT(1)
33#define J7200_LINK_DOWN BIT(10)
34
35#define J721E_PCIE_USER_CMD_STATUS 0x4
36#define LINK_TRAINING_ENABLE BIT(0)
37
38#define J721E_PCIE_USER_LINKSTATUS 0x14
39#define LINK_STATUS GENMASK(1, 0)
40
41enum link_status {
42 NO_RECEIVERS_DETECTED,
43 LINK_TRAINING_IN_PROGRESS,
44 LINK_UP_DL_IN_PROGRESS,
45 LINK_UP_DL_COMPLETED,
46};
47
48#define J721E_MODE_RC BIT(7)
49#define LANE_COUNT(n) ((n) << 8)
50
51#define ACSPCIE_PAD_DISABLE_MASK GENMASK(1, 0)
52#define GENERATION_SEL_MASK GENMASK(1, 0)
53
54struct j721e_pcie {
55 struct cdns_pcie *cdns_pcie;
56 struct clk *refclk;
57 u32 mode;
58 u32 num_lanes;
59 u32 max_lanes;
60 struct gpio_desc *reset_gpio;
61 void __iomem *user_cfg_base;
62 void __iomem *intd_cfg_base;
63 u32 linkdown_irq_regfield;
64};
65
66enum j721e_pcie_mode {
67 PCI_MODE_RC,
68 PCI_MODE_EP,
69};
70
71struct j721e_pcie_data {
72 enum j721e_pcie_mode mode;
73 unsigned int quirk_retrain_flag:1;
74 unsigned int quirk_detect_quiet_flag:1;
75 unsigned int quirk_disable_flr:1;
76 u32 linkdown_irq_regfield;
77 unsigned int byte_access_allowed:1;
78 unsigned int max_lanes;
79};
80
81static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
82{
83 return readl(pcie->user_cfg_base + offset);
84}
85
86static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
87 u32 value)
88{
89 writel(value, pcie->user_cfg_base + offset);
90}
91
92static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
93{
94 return readl(pcie->intd_cfg_base + offset);
95}
96
97static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
98 u32 value)
99{
100 writel(value, pcie->intd_cfg_base + offset);
101}
102
103static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
104{
105 struct j721e_pcie *pcie = priv;
106 struct device *dev = pcie->cdns_pcie->dev;
107 u32 reg;
108
109 reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
110 if (!(reg & pcie->linkdown_irq_regfield))
111 return IRQ_NONE;
112
113 dev_err(dev, "LINK DOWN!\n");
114
115 j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
116 return IRQ_HANDLED;
117}
118
119static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
120{
121 u32 reg;
122
123 reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
124 reg |= pcie->linkdown_irq_regfield;
125 j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
126}
127
128static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
129{
130 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
131 u32 reg;
132
133 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
134 reg |= LINK_TRAINING_ENABLE;
135 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
136
137 return 0;
138}
139
140static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
141{
142 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
143 u32 reg;
144
145 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
146 reg &= ~LINK_TRAINING_ENABLE;
147 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
148}
149
150static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
151{
152 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
153 u32 reg;
154
155 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
156 reg &= LINK_STATUS;
157 if (reg == LINK_UP_DL_COMPLETED)
158 return true;
159
160 return false;
161}
162
163static const struct cdns_pcie_ops j721e_pcie_ops = {
164 .start_link = j721e_pcie_start_link,
165 .stop_link = j721e_pcie_stop_link,
166 .link_up = j721e_pcie_link_up,
167};
168
169static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
170 unsigned int offset)
171{
172 struct device *dev = pcie->cdns_pcie->dev;
173 u32 mask = J721E_MODE_RC;
174 u32 mode = pcie->mode;
175 u32 val = 0;
176 int ret = 0;
177
178 if (mode == PCI_MODE_RC)
179 val = J721E_MODE_RC;
180
181 ret = regmap_update_bits(syscon, offset, mask, val);
182 if (ret)
183 dev_err(dev, "failed to set pcie mode\n");
184
185 return ret;
186}
187
188static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
189 struct regmap *syscon, unsigned int offset)
190{
191 struct device *dev = pcie->cdns_pcie->dev;
192 struct device_node *np = dev->of_node;
193 int link_speed;
194 u32 val = 0;
195 int ret;
196
197 link_speed = of_pci_get_max_link_speed(np);
198 if (link_speed < 2)
199 link_speed = 2;
200
201 val = link_speed - 1;
202 ret = regmap_update_bits(syscon, offset, GENERATION_SEL_MASK, val);
203 if (ret)
204 dev_err(dev, "failed to set link speed\n");
205
206 return ret;
207}
208
209static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
210 struct regmap *syscon, unsigned int offset)
211{
212 struct device *dev = pcie->cdns_pcie->dev;
213 u32 lanes = pcie->num_lanes;
214 u32 mask = BIT(8);
215 u32 val = 0;
216 int ret;
217
218 if (pcie->max_lanes == 4)
219 mask = GENMASK(9, 8);
220
221 val = LANE_COUNT(lanes - 1);
222 ret = regmap_update_bits(syscon, offset, mask, val);
223 if (ret)
224 dev_err(dev, "failed to set link count\n");
225
226 return ret;
227}
228
229static int j721e_enable_acspcie_refclk(struct j721e_pcie *pcie,
230 struct regmap *syscon)
231{
232 struct device *dev = pcie->cdns_pcie->dev;
233 struct device_node *node = dev->of_node;
234 u32 mask = ACSPCIE_PAD_DISABLE_MASK;
235 struct of_phandle_args args;
236 u32 val;
237 int ret;
238
239 ret = of_parse_phandle_with_fixed_args(node,
240 "ti,syscon-acspcie-proxy-ctrl",
241 1, 0, &args);
242 if (ret) {
243 dev_err(dev,
244 "ti,syscon-acspcie-proxy-ctrl has invalid arguments\n");
245 return ret;
246 }
247
248 /* Clear PAD IO disable bits to enable refclk output */
249 val = ~(args.args[0]);
250 ret = regmap_update_bits(syscon, 0, mask, val);
251 if (ret) {
252 dev_err(dev, "failed to enable ACSPCIE refclk: %d\n", ret);
253 return ret;
254 }
255
256 return 0;
257}
258
259static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
260{
261 struct device *dev = pcie->cdns_pcie->dev;
262 struct device_node *node = dev->of_node;
263 struct of_phandle_args args;
264 unsigned int offset = 0;
265 struct regmap *syscon;
266 int ret;
267
268 syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
269 if (IS_ERR(syscon)) {
270 dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
271 return PTR_ERR(syscon);
272 }
273
274 /* Do not error out to maintain old DT compatibility */
275 ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-pcie-ctrl", 1,
276 0, &args);
277 if (!ret)
278 offset = args.args[0];
279
280 ret = j721e_pcie_set_mode(pcie, syscon, offset);
281 if (ret < 0) {
282 dev_err(dev, "Failed to set pci mode\n");
283 return ret;
284 }
285
286 ret = j721e_pcie_set_link_speed(pcie, syscon, offset);
287 if (ret < 0) {
288 dev_err(dev, "Failed to set link speed\n");
289 return ret;
290 }
291
292 ret = j721e_pcie_set_lane_count(pcie, syscon, offset);
293 if (ret < 0) {
294 dev_err(dev, "Failed to set num-lanes\n");
295 return ret;
296 }
297
298 /* Enable ACSPCIE refclk output if the optional property exists */
299 syscon = syscon_regmap_lookup_by_phandle_optional(node,
300 "ti,syscon-acspcie-proxy-ctrl");
301 if (!syscon)
302 return 0;
303
304 return j721e_enable_acspcie_refclk(pcie, syscon);
305}
306
307static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
308 int where, int size, u32 *value)
309{
310 if (pci_is_root_bus(bus))
311 return pci_generic_config_read32(bus, devfn, where, size,
312 value);
313
314 return pci_generic_config_read(bus, devfn, where, size, value);
315}
316
317static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
318 int where, int size, u32 value)
319{
320 if (pci_is_root_bus(bus))
321 return pci_generic_config_write32(bus, devfn, where, size,
322 value);
323
324 return pci_generic_config_write(bus, devfn, where, size, value);
325}
326
327static struct pci_ops cdns_ti_pcie_host_ops = {
328 .map_bus = cdns_pci_map_bus,
329 .read = cdns_ti_pcie_config_read,
330 .write = cdns_ti_pcie_config_write,
331};
332
333static const struct j721e_pcie_data j721e_pcie_rc_data = {
334 .mode = PCI_MODE_RC,
335 .quirk_retrain_flag = true,
336 .byte_access_allowed = false,
337 .linkdown_irq_regfield = LINK_DOWN,
338 .max_lanes = 2,
339};
340
341static const struct j721e_pcie_data j721e_pcie_ep_data = {
342 .mode = PCI_MODE_EP,
343 .linkdown_irq_regfield = LINK_DOWN,
344 .max_lanes = 2,
345};
346
347static const struct j721e_pcie_data j7200_pcie_rc_data = {
348 .mode = PCI_MODE_RC,
349 .quirk_detect_quiet_flag = true,
350 .linkdown_irq_regfield = J7200_LINK_DOWN,
351 .byte_access_allowed = true,
352 .max_lanes = 2,
353};
354
355static const struct j721e_pcie_data j7200_pcie_ep_data = {
356 .mode = PCI_MODE_EP,
357 .quirk_detect_quiet_flag = true,
358 .quirk_disable_flr = true,
359 .max_lanes = 2,
360};
361
362static const struct j721e_pcie_data am64_pcie_rc_data = {
363 .mode = PCI_MODE_RC,
364 .linkdown_irq_regfield = J7200_LINK_DOWN,
365 .byte_access_allowed = true,
366 .max_lanes = 1,
367};
368
369static const struct j721e_pcie_data am64_pcie_ep_data = {
370 .mode = PCI_MODE_EP,
371 .linkdown_irq_regfield = J7200_LINK_DOWN,
372 .max_lanes = 1,
373};
374
375static const struct j721e_pcie_data j784s4_pcie_rc_data = {
376 .mode = PCI_MODE_RC,
377 .quirk_retrain_flag = true,
378 .byte_access_allowed = false,
379 .linkdown_irq_regfield = LINK_DOWN,
380 .max_lanes = 4,
381};
382
383static const struct j721e_pcie_data j784s4_pcie_ep_data = {
384 .mode = PCI_MODE_EP,
385 .linkdown_irq_regfield = LINK_DOWN,
386 .max_lanes = 4,
387};
388
389static const struct j721e_pcie_data j722s_pcie_rc_data = {
390 .mode = PCI_MODE_RC,
391 .linkdown_irq_regfield = J7200_LINK_DOWN,
392 .byte_access_allowed = true,
393 .max_lanes = 1,
394};
395
396static const struct of_device_id of_j721e_pcie_match[] = {
397 {
398 .compatible = "ti,j721e-pcie-host",
399 .data = &j721e_pcie_rc_data,
400 },
401 {
402 .compatible = "ti,j721e-pcie-ep",
403 .data = &j721e_pcie_ep_data,
404 },
405 {
406 .compatible = "ti,j7200-pcie-host",
407 .data = &j7200_pcie_rc_data,
408 },
409 {
410 .compatible = "ti,j7200-pcie-ep",
411 .data = &j7200_pcie_ep_data,
412 },
413 {
414 .compatible = "ti,am64-pcie-host",
415 .data = &am64_pcie_rc_data,
416 },
417 {
418 .compatible = "ti,am64-pcie-ep",
419 .data = &am64_pcie_ep_data,
420 },
421 {
422 .compatible = "ti,j784s4-pcie-host",
423 .data = &j784s4_pcie_rc_data,
424 },
425 {
426 .compatible = "ti,j784s4-pcie-ep",
427 .data = &j784s4_pcie_ep_data,
428 },
429 {
430 .compatible = "ti,j722s-pcie-host",
431 .data = &j722s_pcie_rc_data,
432 },
433 {},
434};
435
436static int j721e_pcie_probe(struct platform_device *pdev)
437{
438 struct device *dev = &pdev->dev;
439 struct device_node *node = dev->of_node;
440 struct pci_host_bridge *bridge;
441 const struct j721e_pcie_data *data;
442 struct cdns_pcie *cdns_pcie;
443 struct j721e_pcie *pcie;
444 struct cdns_pcie_rc *rc = NULL;
445 struct cdns_pcie_ep *ep = NULL;
446 struct gpio_desc *gpiod;
447 void __iomem *base;
448 struct clk *clk;
449 u32 num_lanes;
450 u32 mode;
451 int ret;
452 int irq;
453
454 data = of_device_get_match_data(dev);
455 if (!data)
456 return -EINVAL;
457
458 mode = (u32)data->mode;
459
460 pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
461 if (!pcie)
462 return -ENOMEM;
463
464 switch (mode) {
465 case PCI_MODE_RC:
466 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST))
467 return -ENODEV;
468
469 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
470 if (!bridge)
471 return -ENOMEM;
472
473 if (!data->byte_access_allowed)
474 bridge->ops = &cdns_ti_pcie_host_ops;
475 rc = pci_host_bridge_priv(bridge);
476 rc->quirk_retrain_flag = data->quirk_retrain_flag;
477 rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
478
479 cdns_pcie = &rc->pcie;
480 cdns_pcie->dev = dev;
481 cdns_pcie->ops = &j721e_pcie_ops;
482 pcie->cdns_pcie = cdns_pcie;
483 break;
484 case PCI_MODE_EP:
485 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP))
486 return -ENODEV;
487
488 ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
489 if (!ep)
490 return -ENOMEM;
491
492 ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
493 ep->quirk_disable_flr = data->quirk_disable_flr;
494
495 cdns_pcie = &ep->pcie;
496 cdns_pcie->dev = dev;
497 cdns_pcie->ops = &j721e_pcie_ops;
498 pcie->cdns_pcie = cdns_pcie;
499 break;
500 default:
501 dev_err(dev, "INVALID device type %d\n", mode);
502 return 0;
503 }
504
505 pcie->mode = mode;
506 pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;
507
508 base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
509 if (IS_ERR(base))
510 return PTR_ERR(base);
511 pcie->intd_cfg_base = base;
512
513 base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
514 if (IS_ERR(base))
515 return PTR_ERR(base);
516 pcie->user_cfg_base = base;
517
518 ret = of_property_read_u32(node, "num-lanes", &num_lanes);
519 if (ret || num_lanes > data->max_lanes) {
520 dev_warn(dev, "num-lanes property not provided or invalid, setting num-lanes to 1\n");
521 num_lanes = 1;
522 }
523
524 pcie->num_lanes = num_lanes;
525 pcie->max_lanes = data->max_lanes;
526
527 if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
528 return -EINVAL;
529
530 irq = platform_get_irq_byname(pdev, "link_state");
531 if (irq < 0)
532 return irq;
533
534 dev_set_drvdata(dev, pcie);
535 pm_runtime_enable(dev);
536 ret = pm_runtime_get_sync(dev);
537 if (ret < 0) {
538 dev_err_probe(dev, ret, "pm_runtime_get_sync failed\n");
539 goto err_get_sync;
540 }
541
542 ret = j721e_pcie_ctrl_init(pcie);
543 if (ret < 0) {
544 dev_err_probe(dev, ret, "pm_runtime_get_sync failed\n");
545 goto err_get_sync;
546 }
547
548 ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
549 "j721e-pcie-link-down-irq", pcie);
550 if (ret < 0) {
551 dev_err_probe(dev, ret, "failed to request link state IRQ %d\n", irq);
552 goto err_get_sync;
553 }
554
555 j721e_pcie_config_link_irq(pcie);
556
557 switch (mode) {
558 case PCI_MODE_RC:
559 gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
560 if (IS_ERR(gpiod)) {
561 ret = dev_err_probe(dev, PTR_ERR(gpiod), "Failed to get reset GPIO\n");
562 goto err_get_sync;
563 }
564 pcie->reset_gpio = gpiod;
565
566 ret = cdns_pcie_init_phy(dev, cdns_pcie);
567 if (ret) {
568 dev_err_probe(dev, ret, "Failed to init phy\n");
569 goto err_get_sync;
570 }
571
572 clk = devm_clk_get_optional(dev, "pcie_refclk");
573 if (IS_ERR(clk)) {
574 ret = dev_err_probe(dev, PTR_ERR(clk), "failed to get pcie_refclk\n");
575 goto err_pcie_setup;
576 }
577
578 ret = clk_prepare_enable(clk);
579 if (ret) {
580 dev_err_probe(dev, ret, "failed to enable pcie_refclk\n");
581 goto err_pcie_setup;
582 }
583 pcie->refclk = clk;
584
585 /*
586 * Section 2.2 of the PCI Express Card Electromechanical
587 * Specification (Revision 5.1) mandates that the deassertion
588 * of the PERST# signal should be delayed by 100 ms (TPVPERL).
589 * This shall ensure that the power and the reference clock
590 * are stable.
591 */
592 if (gpiod) {
593 msleep(PCIE_T_PVPERL_MS);
594 gpiod_set_value_cansleep(gpiod, 1);
595 }
596
597 ret = cdns_pcie_host_setup(rc);
598 if (ret < 0) {
599 clk_disable_unprepare(pcie->refclk);
600 goto err_pcie_setup;
601 }
602
603 break;
604 case PCI_MODE_EP:
605 ret = cdns_pcie_init_phy(dev, cdns_pcie);
606 if (ret) {
607 dev_err_probe(dev, ret, "Failed to init phy\n");
608 goto err_get_sync;
609 }
610
611 ret = cdns_pcie_ep_setup(ep);
612 if (ret < 0)
613 goto err_pcie_setup;
614
615 break;
616 }
617
618 return 0;
619
620err_pcie_setup:
621 cdns_pcie_disable_phy(cdns_pcie);
622
623err_get_sync:
624 pm_runtime_put(dev);
625 pm_runtime_disable(dev);
626
627 return ret;
628}
629
630static void j721e_pcie_remove(struct platform_device *pdev)
631{
632 struct j721e_pcie *pcie = platform_get_drvdata(pdev);
633 struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
634 struct device *dev = &pdev->dev;
635
636 clk_disable_unprepare(pcie->refclk);
637 cdns_pcie_disable_phy(cdns_pcie);
638 pm_runtime_put(dev);
639 pm_runtime_disable(dev);
640}
641
642static int j721e_pcie_suspend_noirq(struct device *dev)
643{
644 struct j721e_pcie *pcie = dev_get_drvdata(dev);
645
646 if (pcie->mode == PCI_MODE_RC) {
647 gpiod_set_value_cansleep(pcie->reset_gpio, 0);
648 clk_disable_unprepare(pcie->refclk);
649 }
650
651 cdns_pcie_disable_phy(pcie->cdns_pcie);
652
653 return 0;
654}
655
656static int j721e_pcie_resume_noirq(struct device *dev)
657{
658 struct j721e_pcie *pcie = dev_get_drvdata(dev);
659 struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
660 int ret;
661
662 ret = j721e_pcie_ctrl_init(pcie);
663 if (ret < 0)
664 return ret;
665
666 j721e_pcie_config_link_irq(pcie);
667
668 /*
669 * This is not called explicitly in the probe, it is called by
670 * cdns_pcie_init_phy().
671 */
672 ret = cdns_pcie_enable_phy(pcie->cdns_pcie);
673 if (ret < 0)
674 return ret;
675
676 if (pcie->mode == PCI_MODE_RC) {
677 struct cdns_pcie_rc *rc = cdns_pcie_to_rc(cdns_pcie);
678
679 ret = clk_prepare_enable(pcie->refclk);
680 if (ret < 0)
681 return ret;
682
683 /*
684 * Section 2.2 of the PCI Express Card Electromechanical
685 * Specification (Revision 5.1) mandates that the deassertion
686 * of the PERST# signal should be delayed by 100 ms (TPVPERL).
687 * This shall ensure that the power and the reference clock
688 * are stable.
689 */
690 if (pcie->reset_gpio) {
691 msleep(PCIE_T_PVPERL_MS);
692 gpiod_set_value_cansleep(pcie->reset_gpio, 1);
693 }
694
695 ret = cdns_pcie_host_link_setup(rc);
696 if (ret < 0) {
697 clk_disable_unprepare(pcie->refclk);
698 return ret;
699 }
700
701 /*
702 * Reset internal status of BARs to force reinitialization in
703 * cdns_pcie_host_init().
704 */
705 for (enum cdns_pcie_rp_bar bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
706 rc->avail_ib_bar[bar] = true;
707
708 ret = cdns_pcie_host_init(rc);
709 if (ret) {
710 clk_disable_unprepare(pcie->refclk);
711 return ret;
712 }
713 }
714
715 return 0;
716}
717
718static DEFINE_NOIRQ_DEV_PM_OPS(j721e_pcie_pm_ops,
719 j721e_pcie_suspend_noirq,
720 j721e_pcie_resume_noirq);
721
722static struct platform_driver j721e_pcie_driver = {
723 .probe = j721e_pcie_probe,
724 .remove = j721e_pcie_remove,
725 .driver = {
726 .name = "j721e-pcie",
727 .of_match_table = of_j721e_pcie_match,
728 .suppress_bind_attrs = true,
729 .pm = pm_sleep_ptr(&j721e_pcie_pm_ops),
730 },
731};
732builtin_platform_driver(j721e_pcie_driver);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * pci-j721e - PCIe controller driver for TI's J721E SoCs
4 *
5 * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
7 */
8
9#include <linux/clk.h>
10#include <linux/delay.h>
11#include <linux/gpio/consumer.h>
12#include <linux/io.h>
13#include <linux/irqchip/chained_irq.h>
14#include <linux/irqdomain.h>
15#include <linux/mfd/syscon.h>
16#include <linux/of.h>
17#include <linux/pci.h>
18#include <linux/platform_device.h>
19#include <linux/pm_runtime.h>
20#include <linux/regmap.h>
21
22#include "../../pci.h"
23#include "pcie-cadence.h"
24
25#define ENABLE_REG_SYS_2 0x108
26#define STATUS_REG_SYS_2 0x508
27#define STATUS_CLR_REG_SYS_2 0x708
28#define LINK_DOWN BIT(1)
29#define J7200_LINK_DOWN BIT(10)
30
31#define J721E_PCIE_USER_CMD_STATUS 0x4
32#define LINK_TRAINING_ENABLE BIT(0)
33
34#define J721E_PCIE_USER_LINKSTATUS 0x14
35#define LINK_STATUS GENMASK(1, 0)
36
37enum link_status {
38 NO_RECEIVERS_DETECTED,
39 LINK_TRAINING_IN_PROGRESS,
40 LINK_UP_DL_IN_PROGRESS,
41 LINK_UP_DL_COMPLETED,
42};
43
44#define J721E_MODE_RC BIT(7)
45#define LANE_COUNT(n) ((n) << 8)
46
47#define GENERATION_SEL_MASK GENMASK(1, 0)
48
49struct j721e_pcie {
50 struct cdns_pcie *cdns_pcie;
51 struct clk *refclk;
52 u32 mode;
53 u32 num_lanes;
54 u32 max_lanes;
55 void __iomem *user_cfg_base;
56 void __iomem *intd_cfg_base;
57 u32 linkdown_irq_regfield;
58};
59
60enum j721e_pcie_mode {
61 PCI_MODE_RC,
62 PCI_MODE_EP,
63};
64
65struct j721e_pcie_data {
66 enum j721e_pcie_mode mode;
67 unsigned int quirk_retrain_flag:1;
68 unsigned int quirk_detect_quiet_flag:1;
69 unsigned int quirk_disable_flr:1;
70 u32 linkdown_irq_regfield;
71 unsigned int byte_access_allowed:1;
72 unsigned int max_lanes;
73};
74
75static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
76{
77 return readl(pcie->user_cfg_base + offset);
78}
79
80static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
81 u32 value)
82{
83 writel(value, pcie->user_cfg_base + offset);
84}
85
86static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
87{
88 return readl(pcie->intd_cfg_base + offset);
89}
90
91static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
92 u32 value)
93{
94 writel(value, pcie->intd_cfg_base + offset);
95}
96
97static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
98{
99 struct j721e_pcie *pcie = priv;
100 struct device *dev = pcie->cdns_pcie->dev;
101 u32 reg;
102
103 reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
104 if (!(reg & pcie->linkdown_irq_regfield))
105 return IRQ_NONE;
106
107 dev_err(dev, "LINK DOWN!\n");
108
109 j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
110 return IRQ_HANDLED;
111}
112
113static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
114{
115 u32 reg;
116
117 reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
118 reg |= pcie->linkdown_irq_regfield;
119 j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
120}
121
122static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
123{
124 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
125 u32 reg;
126
127 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
128 reg |= LINK_TRAINING_ENABLE;
129 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
130
131 return 0;
132}
133
134static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
135{
136 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
137 u32 reg;
138
139 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
140 reg &= ~LINK_TRAINING_ENABLE;
141 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
142}
143
144static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
145{
146 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
147 u32 reg;
148
149 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
150 reg &= LINK_STATUS;
151 if (reg == LINK_UP_DL_COMPLETED)
152 return true;
153
154 return false;
155}
156
157static const struct cdns_pcie_ops j721e_pcie_ops = {
158 .start_link = j721e_pcie_start_link,
159 .stop_link = j721e_pcie_stop_link,
160 .link_up = j721e_pcie_link_up,
161};
162
163static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
164 unsigned int offset)
165{
166 struct device *dev = pcie->cdns_pcie->dev;
167 u32 mask = J721E_MODE_RC;
168 u32 mode = pcie->mode;
169 u32 val = 0;
170 int ret = 0;
171
172 if (mode == PCI_MODE_RC)
173 val = J721E_MODE_RC;
174
175 ret = regmap_update_bits(syscon, offset, mask, val);
176 if (ret)
177 dev_err(dev, "failed to set pcie mode\n");
178
179 return ret;
180}
181
182static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
183 struct regmap *syscon, unsigned int offset)
184{
185 struct device *dev = pcie->cdns_pcie->dev;
186 struct device_node *np = dev->of_node;
187 int link_speed;
188 u32 val = 0;
189 int ret;
190
191 link_speed = of_pci_get_max_link_speed(np);
192 if (link_speed < 2)
193 link_speed = 2;
194
195 val = link_speed - 1;
196 ret = regmap_update_bits(syscon, offset, GENERATION_SEL_MASK, val);
197 if (ret)
198 dev_err(dev, "failed to set link speed\n");
199
200 return ret;
201}
202
203static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
204 struct regmap *syscon, unsigned int offset)
205{
206 struct device *dev = pcie->cdns_pcie->dev;
207 u32 lanes = pcie->num_lanes;
208 u32 mask = BIT(8);
209 u32 val = 0;
210 int ret;
211
212 if (pcie->max_lanes == 4)
213 mask = GENMASK(9, 8);
214
215 val = LANE_COUNT(lanes - 1);
216 ret = regmap_update_bits(syscon, offset, mask, val);
217 if (ret)
218 dev_err(dev, "failed to set link count\n");
219
220 return ret;
221}
222
223static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
224{
225 struct device *dev = pcie->cdns_pcie->dev;
226 struct device_node *node = dev->of_node;
227 struct of_phandle_args args;
228 unsigned int offset = 0;
229 struct regmap *syscon;
230 int ret;
231
232 syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
233 if (IS_ERR(syscon)) {
234 dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
235 return PTR_ERR(syscon);
236 }
237
238 /* Do not error out to maintain old DT compatibility */
239 ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-pcie-ctrl", 1,
240 0, &args);
241 if (!ret)
242 offset = args.args[0];
243
244 ret = j721e_pcie_set_mode(pcie, syscon, offset);
245 if (ret < 0) {
246 dev_err(dev, "Failed to set pci mode\n");
247 return ret;
248 }
249
250 ret = j721e_pcie_set_link_speed(pcie, syscon, offset);
251 if (ret < 0) {
252 dev_err(dev, "Failed to set link speed\n");
253 return ret;
254 }
255
256 ret = j721e_pcie_set_lane_count(pcie, syscon, offset);
257 if (ret < 0) {
258 dev_err(dev, "Failed to set num-lanes\n");
259 return ret;
260 }
261
262 return 0;
263}
264
265static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
266 int where, int size, u32 *value)
267{
268 if (pci_is_root_bus(bus))
269 return pci_generic_config_read32(bus, devfn, where, size,
270 value);
271
272 return pci_generic_config_read(bus, devfn, where, size, value);
273}
274
275static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
276 int where, int size, u32 value)
277{
278 if (pci_is_root_bus(bus))
279 return pci_generic_config_write32(bus, devfn, where, size,
280 value);
281
282 return pci_generic_config_write(bus, devfn, where, size, value);
283}
284
285static struct pci_ops cdns_ti_pcie_host_ops = {
286 .map_bus = cdns_pci_map_bus,
287 .read = cdns_ti_pcie_config_read,
288 .write = cdns_ti_pcie_config_write,
289};
290
291static const struct j721e_pcie_data j721e_pcie_rc_data = {
292 .mode = PCI_MODE_RC,
293 .quirk_retrain_flag = true,
294 .byte_access_allowed = false,
295 .linkdown_irq_regfield = LINK_DOWN,
296 .max_lanes = 2,
297};
298
299static const struct j721e_pcie_data j721e_pcie_ep_data = {
300 .mode = PCI_MODE_EP,
301 .linkdown_irq_regfield = LINK_DOWN,
302 .max_lanes = 2,
303};
304
305static const struct j721e_pcie_data j7200_pcie_rc_data = {
306 .mode = PCI_MODE_RC,
307 .quirk_detect_quiet_flag = true,
308 .linkdown_irq_regfield = J7200_LINK_DOWN,
309 .byte_access_allowed = true,
310 .max_lanes = 2,
311};
312
313static const struct j721e_pcie_data j7200_pcie_ep_data = {
314 .mode = PCI_MODE_EP,
315 .quirk_detect_quiet_flag = true,
316 .quirk_disable_flr = true,
317 .max_lanes = 2,
318};
319
320static const struct j721e_pcie_data am64_pcie_rc_data = {
321 .mode = PCI_MODE_RC,
322 .linkdown_irq_regfield = J7200_LINK_DOWN,
323 .byte_access_allowed = true,
324 .max_lanes = 1,
325};
326
327static const struct j721e_pcie_data am64_pcie_ep_data = {
328 .mode = PCI_MODE_EP,
329 .linkdown_irq_regfield = J7200_LINK_DOWN,
330 .max_lanes = 1,
331};
332
333static const struct j721e_pcie_data j784s4_pcie_rc_data = {
334 .mode = PCI_MODE_RC,
335 .quirk_retrain_flag = true,
336 .byte_access_allowed = false,
337 .linkdown_irq_regfield = LINK_DOWN,
338 .max_lanes = 4,
339};
340
341static const struct j721e_pcie_data j784s4_pcie_ep_data = {
342 .mode = PCI_MODE_EP,
343 .linkdown_irq_regfield = LINK_DOWN,
344 .max_lanes = 4,
345};
346
347static const struct of_device_id of_j721e_pcie_match[] = {
348 {
349 .compatible = "ti,j721e-pcie-host",
350 .data = &j721e_pcie_rc_data,
351 },
352 {
353 .compatible = "ti,j721e-pcie-ep",
354 .data = &j721e_pcie_ep_data,
355 },
356 {
357 .compatible = "ti,j7200-pcie-host",
358 .data = &j7200_pcie_rc_data,
359 },
360 {
361 .compatible = "ti,j7200-pcie-ep",
362 .data = &j7200_pcie_ep_data,
363 },
364 {
365 .compatible = "ti,am64-pcie-host",
366 .data = &am64_pcie_rc_data,
367 },
368 {
369 .compatible = "ti,am64-pcie-ep",
370 .data = &am64_pcie_ep_data,
371 },
372 {
373 .compatible = "ti,j784s4-pcie-host",
374 .data = &j784s4_pcie_rc_data,
375 },
376 {
377 .compatible = "ti,j784s4-pcie-ep",
378 .data = &j784s4_pcie_ep_data,
379 },
380 {},
381};
382
383static int j721e_pcie_probe(struct platform_device *pdev)
384{
385 struct device *dev = &pdev->dev;
386 struct device_node *node = dev->of_node;
387 struct pci_host_bridge *bridge;
388 const struct j721e_pcie_data *data;
389 struct cdns_pcie *cdns_pcie;
390 struct j721e_pcie *pcie;
391 struct cdns_pcie_rc *rc = NULL;
392 struct cdns_pcie_ep *ep = NULL;
393 struct gpio_desc *gpiod;
394 void __iomem *base;
395 struct clk *clk;
396 u32 num_lanes;
397 u32 mode;
398 int ret;
399 int irq;
400
401 data = of_device_get_match_data(dev);
402 if (!data)
403 return -EINVAL;
404
405 mode = (u32)data->mode;
406
407 pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
408 if (!pcie)
409 return -ENOMEM;
410
411 switch (mode) {
412 case PCI_MODE_RC:
413 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST))
414 return -ENODEV;
415
416 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
417 if (!bridge)
418 return -ENOMEM;
419
420 if (!data->byte_access_allowed)
421 bridge->ops = &cdns_ti_pcie_host_ops;
422 rc = pci_host_bridge_priv(bridge);
423 rc->quirk_retrain_flag = data->quirk_retrain_flag;
424 rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
425
426 cdns_pcie = &rc->pcie;
427 cdns_pcie->dev = dev;
428 cdns_pcie->ops = &j721e_pcie_ops;
429 pcie->cdns_pcie = cdns_pcie;
430 break;
431 case PCI_MODE_EP:
432 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP))
433 return -ENODEV;
434
435 ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
436 if (!ep)
437 return -ENOMEM;
438
439 ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
440 ep->quirk_disable_flr = data->quirk_disable_flr;
441
442 cdns_pcie = &ep->pcie;
443 cdns_pcie->dev = dev;
444 cdns_pcie->ops = &j721e_pcie_ops;
445 pcie->cdns_pcie = cdns_pcie;
446 break;
447 default:
448 dev_err(dev, "INVALID device type %d\n", mode);
449 return 0;
450 }
451
452 pcie->mode = mode;
453 pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;
454
455 base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
456 if (IS_ERR(base))
457 return PTR_ERR(base);
458 pcie->intd_cfg_base = base;
459
460 base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
461 if (IS_ERR(base))
462 return PTR_ERR(base);
463 pcie->user_cfg_base = base;
464
465 ret = of_property_read_u32(node, "num-lanes", &num_lanes);
466 if (ret || num_lanes > data->max_lanes) {
467 dev_warn(dev, "num-lanes property not provided or invalid, setting num-lanes to 1\n");
468 num_lanes = 1;
469 }
470
471 pcie->num_lanes = num_lanes;
472 pcie->max_lanes = data->max_lanes;
473
474 if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
475 return -EINVAL;
476
477 irq = platform_get_irq_byname(pdev, "link_state");
478 if (irq < 0)
479 return irq;
480
481 dev_set_drvdata(dev, pcie);
482 pm_runtime_enable(dev);
483 ret = pm_runtime_get_sync(dev);
484 if (ret < 0) {
485 dev_err(dev, "pm_runtime_get_sync failed\n");
486 goto err_get_sync;
487 }
488
489 ret = j721e_pcie_ctrl_init(pcie);
490 if (ret < 0) {
491 dev_err(dev, "pm_runtime_get_sync failed\n");
492 goto err_get_sync;
493 }
494
495 ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
496 "j721e-pcie-link-down-irq", pcie);
497 if (ret < 0) {
498 dev_err(dev, "failed to request link state IRQ %d\n", irq);
499 goto err_get_sync;
500 }
501
502 j721e_pcie_config_link_irq(pcie);
503
504 switch (mode) {
505 case PCI_MODE_RC:
506 gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
507 if (IS_ERR(gpiod)) {
508 ret = PTR_ERR(gpiod);
509 if (ret != -EPROBE_DEFER)
510 dev_err(dev, "Failed to get reset GPIO\n");
511 goto err_get_sync;
512 }
513
514 ret = cdns_pcie_init_phy(dev, cdns_pcie);
515 if (ret) {
516 dev_err(dev, "Failed to init phy\n");
517 goto err_get_sync;
518 }
519
520 clk = devm_clk_get_optional(dev, "pcie_refclk");
521 if (IS_ERR(clk)) {
522 ret = PTR_ERR(clk);
523 dev_err(dev, "failed to get pcie_refclk\n");
524 goto err_pcie_setup;
525 }
526
527 ret = clk_prepare_enable(clk);
528 if (ret) {
529 dev_err(dev, "failed to enable pcie_refclk\n");
530 goto err_pcie_setup;
531 }
532 pcie->refclk = clk;
533
534 /*
535 * "Power Sequencing and Reset Signal Timings" table in
536 * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
537 * indicates PERST# should be deasserted after minimum of 100us
538 * once REFCLK is stable. The REFCLK to the connector in RC
539 * mode is selected while enabling the PHY. So deassert PERST#
540 * after 100 us.
541 */
542 if (gpiod) {
543 usleep_range(100, 200);
544 gpiod_set_value_cansleep(gpiod, 1);
545 }
546
547 ret = cdns_pcie_host_setup(rc);
548 if (ret < 0) {
549 clk_disable_unprepare(pcie->refclk);
550 goto err_pcie_setup;
551 }
552
553 break;
554 case PCI_MODE_EP:
555 ret = cdns_pcie_init_phy(dev, cdns_pcie);
556 if (ret) {
557 dev_err(dev, "Failed to init phy\n");
558 goto err_get_sync;
559 }
560
561 ret = cdns_pcie_ep_setup(ep);
562 if (ret < 0)
563 goto err_pcie_setup;
564
565 break;
566 }
567
568 return 0;
569
570err_pcie_setup:
571 cdns_pcie_disable_phy(cdns_pcie);
572
573err_get_sync:
574 pm_runtime_put(dev);
575 pm_runtime_disable(dev);
576
577 return ret;
578}
579
580static void j721e_pcie_remove(struct platform_device *pdev)
581{
582 struct j721e_pcie *pcie = platform_get_drvdata(pdev);
583 struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
584 struct device *dev = &pdev->dev;
585
586 clk_disable_unprepare(pcie->refclk);
587 cdns_pcie_disable_phy(cdns_pcie);
588 pm_runtime_put(dev);
589 pm_runtime_disable(dev);
590}
591
592static struct platform_driver j721e_pcie_driver = {
593 .probe = j721e_pcie_probe,
594 .remove_new = j721e_pcie_remove,
595 .driver = {
596 .name = "j721e-pcie",
597 .of_match_table = of_j721e_pcie_match,
598 .suppress_bind_attrs = true,
599 },
600};
601builtin_platform_driver(j721e_pcie_driver);