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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/of_device.h>
18#include <linux/of_irq.h>
19#include <linux/pci.h>
20#include <linux/pm_runtime.h>
21#include <linux/regmap.h>
22
23#include "../../pci.h"
24#include "pcie-cadence.h"
25
26#define ENABLE_REG_SYS_2 0x108
27#define STATUS_REG_SYS_2 0x508
28#define STATUS_CLR_REG_SYS_2 0x708
29#define LINK_DOWN BIT(1)
30#define J7200_LINK_DOWN BIT(10)
31
32#define J721E_PCIE_USER_CMD_STATUS 0x4
33#define LINK_TRAINING_ENABLE BIT(0)
34
35#define J721E_PCIE_USER_LINKSTATUS 0x14
36#define LINK_STATUS GENMASK(1, 0)
37
38enum link_status {
39 NO_RECEIVERS_DETECTED,
40 LINK_TRAINING_IN_PROGRESS,
41 LINK_UP_DL_IN_PROGRESS,
42 LINK_UP_DL_COMPLETED,
43};
44
45#define J721E_MODE_RC BIT(7)
46#define LANE_COUNT_MASK BIT(8)
47#define LANE_COUNT(n) ((n) << 8)
48
49#define GENERATION_SEL_MASK GENMASK(1, 0)
50
51#define MAX_LANES 2
52
53struct j721e_pcie {
54 struct device *dev;
55 struct clk *refclk;
56 u32 mode;
57 u32 num_lanes;
58 struct cdns_pcie *cdns_pcie;
59 void __iomem *user_cfg_base;
60 void __iomem *intd_cfg_base;
61 u32 linkdown_irq_regfield;
62};
63
64enum j721e_pcie_mode {
65 PCI_MODE_RC,
66 PCI_MODE_EP,
67};
68
69struct j721e_pcie_data {
70 enum j721e_pcie_mode mode;
71 unsigned int quirk_retrain_flag:1;
72 unsigned int quirk_detect_quiet_flag:1;
73 u32 linkdown_irq_regfield;
74 unsigned int byte_access_allowed:1;
75};
76
77static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
78{
79 return readl(pcie->user_cfg_base + offset);
80}
81
82static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
83 u32 value)
84{
85 writel(value, pcie->user_cfg_base + offset);
86}
87
88static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
89{
90 return readl(pcie->intd_cfg_base + offset);
91}
92
93static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
94 u32 value)
95{
96 writel(value, pcie->intd_cfg_base + offset);
97}
98
99static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
100{
101 struct j721e_pcie *pcie = priv;
102 struct device *dev = pcie->dev;
103 u32 reg;
104
105 reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
106 if (!(reg & pcie->linkdown_irq_regfield))
107 return IRQ_NONE;
108
109 dev_err(dev, "LINK DOWN!\n");
110
111 j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
112 return IRQ_HANDLED;
113}
114
115static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
116{
117 u32 reg;
118
119 reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
120 reg |= pcie->linkdown_irq_regfield;
121 j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
122}
123
124static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
125{
126 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
127 u32 reg;
128
129 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
130 reg |= LINK_TRAINING_ENABLE;
131 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
132
133 return 0;
134}
135
136static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
137{
138 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
139 u32 reg;
140
141 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
142 reg &= ~LINK_TRAINING_ENABLE;
143 j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
144}
145
146static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
147{
148 struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
149 u32 reg;
150
151 reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
152 reg &= LINK_STATUS;
153 if (reg == LINK_UP_DL_COMPLETED)
154 return true;
155
156 return false;
157}
158
159static const struct cdns_pcie_ops j721e_pcie_ops = {
160 .start_link = j721e_pcie_start_link,
161 .stop_link = j721e_pcie_stop_link,
162 .link_up = j721e_pcie_link_up,
163};
164
165static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
166 unsigned int offset)
167{
168 struct device *dev = pcie->dev;
169 u32 mask = J721E_MODE_RC;
170 u32 mode = pcie->mode;
171 u32 val = 0;
172 int ret = 0;
173
174 if (mode == PCI_MODE_RC)
175 val = J721E_MODE_RC;
176
177 ret = regmap_update_bits(syscon, offset, mask, val);
178 if (ret)
179 dev_err(dev, "failed to set pcie mode\n");
180
181 return ret;
182}
183
184static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
185 struct regmap *syscon, unsigned int offset)
186{
187 struct device *dev = pcie->dev;
188 struct device_node *np = dev->of_node;
189 int link_speed;
190 u32 val = 0;
191 int ret;
192
193 link_speed = of_pci_get_max_link_speed(np);
194 if (link_speed < 2)
195 link_speed = 2;
196
197 val = link_speed - 1;
198 ret = regmap_update_bits(syscon, offset, GENERATION_SEL_MASK, val);
199 if (ret)
200 dev_err(dev, "failed to set link speed\n");
201
202 return ret;
203}
204
205static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
206 struct regmap *syscon, unsigned int offset)
207{
208 struct device *dev = pcie->dev;
209 u32 lanes = pcie->num_lanes;
210 u32 val = 0;
211 int ret;
212
213 val = LANE_COUNT(lanes - 1);
214 ret = regmap_update_bits(syscon, offset, LANE_COUNT_MASK, val);
215 if (ret)
216 dev_err(dev, "failed to set link count\n");
217
218 return ret;
219}
220
221static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
222{
223 struct device *dev = pcie->dev;
224 struct device_node *node = dev->of_node;
225 struct of_phandle_args args;
226 unsigned int offset = 0;
227 struct regmap *syscon;
228 int ret;
229
230 syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
231 if (IS_ERR(syscon)) {
232 dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
233 return PTR_ERR(syscon);
234 }
235
236 /* Do not error out to maintain old DT compatibility */
237 ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-pcie-ctrl", 1,
238 0, &args);
239 if (!ret)
240 offset = args.args[0];
241
242 ret = j721e_pcie_set_mode(pcie, syscon, offset);
243 if (ret < 0) {
244 dev_err(dev, "Failed to set pci mode\n");
245 return ret;
246 }
247
248 ret = j721e_pcie_set_link_speed(pcie, syscon, offset);
249 if (ret < 0) {
250 dev_err(dev, "Failed to set link speed\n");
251 return ret;
252 }
253
254 ret = j721e_pcie_set_lane_count(pcie, syscon, offset);
255 if (ret < 0) {
256 dev_err(dev, "Failed to set num-lanes\n");
257 return ret;
258 }
259
260 return 0;
261}
262
263static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
264 int where, int size, u32 *value)
265{
266 if (pci_is_root_bus(bus))
267 return pci_generic_config_read32(bus, devfn, where, size,
268 value);
269
270 return pci_generic_config_read(bus, devfn, where, size, value);
271}
272
273static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
274 int where, int size, u32 value)
275{
276 if (pci_is_root_bus(bus))
277 return pci_generic_config_write32(bus, devfn, where, size,
278 value);
279
280 return pci_generic_config_write(bus, devfn, where, size, value);
281}
282
283static struct pci_ops cdns_ti_pcie_host_ops = {
284 .map_bus = cdns_pci_map_bus,
285 .read = cdns_ti_pcie_config_read,
286 .write = cdns_ti_pcie_config_write,
287};
288
289static const struct j721e_pcie_data j721e_pcie_rc_data = {
290 .mode = PCI_MODE_RC,
291 .quirk_retrain_flag = true,
292 .byte_access_allowed = false,
293 .linkdown_irq_regfield = LINK_DOWN,
294};
295
296static const struct j721e_pcie_data j721e_pcie_ep_data = {
297 .mode = PCI_MODE_EP,
298 .linkdown_irq_regfield = LINK_DOWN,
299};
300
301static const struct j721e_pcie_data j7200_pcie_rc_data = {
302 .mode = PCI_MODE_RC,
303 .quirk_detect_quiet_flag = true,
304 .linkdown_irq_regfield = J7200_LINK_DOWN,
305 .byte_access_allowed = true,
306};
307
308static const struct j721e_pcie_data j7200_pcie_ep_data = {
309 .mode = PCI_MODE_EP,
310 .quirk_detect_quiet_flag = true,
311};
312
313static const struct j721e_pcie_data am64_pcie_rc_data = {
314 .mode = PCI_MODE_RC,
315 .linkdown_irq_regfield = J7200_LINK_DOWN,
316 .byte_access_allowed = true,
317};
318
319static const struct j721e_pcie_data am64_pcie_ep_data = {
320 .mode = PCI_MODE_EP,
321 .linkdown_irq_regfield = J7200_LINK_DOWN,
322};
323
324static const struct of_device_id of_j721e_pcie_match[] = {
325 {
326 .compatible = "ti,j721e-pcie-host",
327 .data = &j721e_pcie_rc_data,
328 },
329 {
330 .compatible = "ti,j721e-pcie-ep",
331 .data = &j721e_pcie_ep_data,
332 },
333 {
334 .compatible = "ti,j7200-pcie-host",
335 .data = &j7200_pcie_rc_data,
336 },
337 {
338 .compatible = "ti,j7200-pcie-ep",
339 .data = &j7200_pcie_ep_data,
340 },
341 {
342 .compatible = "ti,am64-pcie-host",
343 .data = &am64_pcie_rc_data,
344 },
345 {
346 .compatible = "ti,am64-pcie-ep",
347 .data = &am64_pcie_ep_data,
348 },
349 {},
350};
351
352static int j721e_pcie_probe(struct platform_device *pdev)
353{
354 struct device *dev = &pdev->dev;
355 struct device_node *node = dev->of_node;
356 struct pci_host_bridge *bridge;
357 struct j721e_pcie_data *data;
358 struct cdns_pcie *cdns_pcie;
359 struct j721e_pcie *pcie;
360 struct cdns_pcie_rc *rc;
361 struct cdns_pcie_ep *ep;
362 struct gpio_desc *gpiod;
363 void __iomem *base;
364 struct clk *clk;
365 u32 num_lanes;
366 u32 mode;
367 int ret;
368 int irq;
369
370 data = (struct j721e_pcie_data *)of_device_get_match_data(dev);
371 if (!data)
372 return -EINVAL;
373
374 mode = (u32)data->mode;
375
376 pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
377 if (!pcie)
378 return -ENOMEM;
379
380 pcie->dev = dev;
381 pcie->mode = mode;
382 pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;
383
384 base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
385 if (IS_ERR(base))
386 return PTR_ERR(base);
387 pcie->intd_cfg_base = base;
388
389 base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
390 if (IS_ERR(base))
391 return PTR_ERR(base);
392 pcie->user_cfg_base = base;
393
394 ret = of_property_read_u32(node, "num-lanes", &num_lanes);
395 if (ret || num_lanes > MAX_LANES)
396 num_lanes = 1;
397 pcie->num_lanes = num_lanes;
398
399 if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
400 return -EINVAL;
401
402 irq = platform_get_irq_byname(pdev, "link_state");
403 if (irq < 0)
404 return irq;
405
406 dev_set_drvdata(dev, pcie);
407 pm_runtime_enable(dev);
408 ret = pm_runtime_get_sync(dev);
409 if (ret < 0) {
410 dev_err(dev, "pm_runtime_get_sync failed\n");
411 goto err_get_sync;
412 }
413
414 ret = j721e_pcie_ctrl_init(pcie);
415 if (ret < 0) {
416 dev_err(dev, "pm_runtime_get_sync failed\n");
417 goto err_get_sync;
418 }
419
420 ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
421 "j721e-pcie-link-down-irq", pcie);
422 if (ret < 0) {
423 dev_err(dev, "failed to request link state IRQ %d\n", irq);
424 goto err_get_sync;
425 }
426
427 j721e_pcie_config_link_irq(pcie);
428
429 switch (mode) {
430 case PCI_MODE_RC:
431 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) {
432 ret = -ENODEV;
433 goto err_get_sync;
434 }
435
436 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
437 if (!bridge) {
438 ret = -ENOMEM;
439 goto err_get_sync;
440 }
441
442 if (!data->byte_access_allowed)
443 bridge->ops = &cdns_ti_pcie_host_ops;
444 rc = pci_host_bridge_priv(bridge);
445 rc->quirk_retrain_flag = data->quirk_retrain_flag;
446 rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
447
448 cdns_pcie = &rc->pcie;
449 cdns_pcie->dev = dev;
450 cdns_pcie->ops = &j721e_pcie_ops;
451 pcie->cdns_pcie = cdns_pcie;
452
453 gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
454 if (IS_ERR(gpiod)) {
455 ret = PTR_ERR(gpiod);
456 if (ret != -EPROBE_DEFER)
457 dev_err(dev, "Failed to get reset GPIO\n");
458 goto err_get_sync;
459 }
460
461 ret = cdns_pcie_init_phy(dev, cdns_pcie);
462 if (ret) {
463 dev_err(dev, "Failed to init phy\n");
464 goto err_get_sync;
465 }
466
467 clk = devm_clk_get_optional(dev, "pcie_refclk");
468 if (IS_ERR(clk)) {
469 ret = PTR_ERR(clk);
470 dev_err(dev, "failed to get pcie_refclk\n");
471 goto err_pcie_setup;
472 }
473
474 ret = clk_prepare_enable(clk);
475 if (ret) {
476 dev_err(dev, "failed to enable pcie_refclk\n");
477 goto err_get_sync;
478 }
479 pcie->refclk = clk;
480
481 /*
482 * "Power Sequencing and Reset Signal Timings" table in
483 * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
484 * indicates PERST# should be deasserted after minimum of 100us
485 * once REFCLK is stable. The REFCLK to the connector in RC
486 * mode is selected while enabling the PHY. So deassert PERST#
487 * after 100 us.
488 */
489 if (gpiod) {
490 usleep_range(100, 200);
491 gpiod_set_value_cansleep(gpiod, 1);
492 }
493
494 ret = cdns_pcie_host_setup(rc);
495 if (ret < 0) {
496 clk_disable_unprepare(pcie->refclk);
497 goto err_pcie_setup;
498 }
499
500 break;
501 case PCI_MODE_EP:
502 if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) {
503 ret = -ENODEV;
504 goto err_get_sync;
505 }
506
507 ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
508 if (!ep) {
509 ret = -ENOMEM;
510 goto err_get_sync;
511 }
512 ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
513
514 cdns_pcie = &ep->pcie;
515 cdns_pcie->dev = dev;
516 cdns_pcie->ops = &j721e_pcie_ops;
517 pcie->cdns_pcie = cdns_pcie;
518
519 ret = cdns_pcie_init_phy(dev, cdns_pcie);
520 if (ret) {
521 dev_err(dev, "Failed to init phy\n");
522 goto err_get_sync;
523 }
524
525 ret = cdns_pcie_ep_setup(ep);
526 if (ret < 0)
527 goto err_pcie_setup;
528
529 break;
530 default:
531 dev_err(dev, "INVALID device type %d\n", mode);
532 }
533
534 return 0;
535
536err_pcie_setup:
537 cdns_pcie_disable_phy(cdns_pcie);
538
539err_get_sync:
540 pm_runtime_put(dev);
541 pm_runtime_disable(dev);
542
543 return ret;
544}
545
546static int j721e_pcie_remove(struct platform_device *pdev)
547{
548 struct j721e_pcie *pcie = platform_get_drvdata(pdev);
549 struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
550 struct device *dev = &pdev->dev;
551
552 clk_disable_unprepare(pcie->refclk);
553 cdns_pcie_disable_phy(cdns_pcie);
554 pm_runtime_put(dev);
555 pm_runtime_disable(dev);
556
557 return 0;
558}
559
560static struct platform_driver j721e_pcie_driver = {
561 .probe = j721e_pcie_probe,
562 .remove = j721e_pcie_remove,
563 .driver = {
564 .name = "j721e-pcie",
565 .of_match_table = of_j721e_pcie_match,
566 .suppress_bind_attrs = true,
567 },
568};
569builtin_platform_driver(j721e_pcie_driver);