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