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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/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);