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0c4ffcfe MK |
1 | /* |
2 | * PCIe host controller driver for Texas Instruments Keystone SoCs | |
3 | * | |
4 | * Copyright (C) 2013-2014 Texas Instruments., Ltd. | |
5 | * http://www.ti.com | |
6 | * | |
7 | * Author: Murali Karicheri <m-karicheri2@ti.com> | |
8 | * Implementation based on pci-exynos.c and pcie-designware.c | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/irqchip/chained_irq.h> | |
16 | #include <linux/clk.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/irqdomain.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/msi.h> | |
21 | #include <linux/of_irq.h> | |
22 | #include <linux/of.h> | |
23 | #include <linux/of_pci.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/phy/phy.h> | |
26 | #include <linux/resource.h> | |
27 | #include <linux/signal.h> | |
28 | ||
29 | #include "pcie-designware.h" | |
30 | #include "pci-keystone.h" | |
31 | ||
32 | #define DRIVER_NAME "keystone-pcie" | |
33 | ||
34 | /* driver specific constants */ | |
35 | #define MAX_MSI_HOST_IRQS 8 | |
36 | #define MAX_LEGACY_HOST_IRQS 4 | |
37 | ||
0c4ffcfe MK |
38 | /* DEV_STAT_CTRL */ |
39 | #define PCIE_CAP_BASE 0x70 | |
40 | ||
c15982df MK |
41 | /* PCIE controller device IDs */ |
42 | #define PCIE_RC_K2HK 0xb008 | |
43 | #define PCIE_RC_K2E 0xb009 | |
44 | #define PCIE_RC_K2L 0xb00a | |
45 | ||
0c4ffcfe MK |
46 | #define to_keystone_pcie(x) container_of(x, struct keystone_pcie, pp) |
47 | ||
c15982df MK |
48 | static void quirk_limit_mrrs(struct pci_dev *dev) |
49 | { | |
50 | struct pci_bus *bus = dev->bus; | |
51 | struct pci_dev *bridge = bus->self; | |
52 | static const struct pci_device_id rc_pci_devids[] = { | |
53 | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK), | |
54 | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | |
55 | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E), | |
56 | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | |
57 | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L), | |
58 | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | |
59 | { 0, }, | |
60 | }; | |
61 | ||
62 | if (pci_is_root_bus(bus)) | |
63 | return; | |
64 | ||
65 | /* look for the host bridge */ | |
66 | while (!pci_is_root_bus(bus)) { | |
67 | bridge = bus->self; | |
68 | bus = bus->parent; | |
69 | } | |
70 | ||
71 | if (bridge) { | |
72 | /* | |
73 | * Keystone PCI controller has a h/w limitation of | |
74 | * 256 bytes maximum read request size. It can't handle | |
75 | * anything higher than this. So force this limit on | |
76 | * all downstream devices. | |
77 | */ | |
78 | if (pci_match_id(rc_pci_devids, bridge)) { | |
79 | if (pcie_get_readrq(dev) > 256) { | |
80 | dev_info(&dev->dev, "limiting MRRS to 256\n"); | |
81 | pcie_set_readrq(dev, 256); | |
82 | } | |
83 | } | |
84 | } | |
85 | } | |
86 | DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs); | |
87 | ||
0c4ffcfe MK |
88 | static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie) |
89 | { | |
90 | struct pcie_port *pp = &ks_pcie->pp; | |
6cbb247e | 91 | unsigned int retries; |
0c4ffcfe MK |
92 | |
93 | dw_pcie_setup_rc(pp); | |
94 | ||
95 | if (dw_pcie_link_up(pp)) { | |
96 | dev_err(pp->dev, "Link already up\n"); | |
97 | return 0; | |
98 | } | |
99 | ||
100 | ks_dw_pcie_initiate_link_train(ks_pcie); | |
101 | /* check if the link is up or not */ | |
6cbb247e BH |
102 | for (retries = 0; retries < 200; retries++) { |
103 | if (dw_pcie_link_up(pp)) | |
104 | return 0; | |
0c4ffcfe | 105 | usleep_range(100, 1000); |
6cbb247e | 106 | ks_dw_pcie_initiate_link_train(ks_pcie); |
0c4ffcfe MK |
107 | } |
108 | ||
6cbb247e BH |
109 | dev_err(pp->dev, "phy link never came up\n"); |
110 | return -EINVAL; | |
0c4ffcfe MK |
111 | } |
112 | ||
bd0b9ac4 | 113 | static void ks_pcie_msi_irq_handler(struct irq_desc *desc) |
0c4ffcfe | 114 | { |
97a85964 | 115 | unsigned int irq = irq_desc_get_irq(desc); |
0c4ffcfe MK |
116 | struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc); |
117 | u32 offset = irq - ks_pcie->msi_host_irqs[0]; | |
118 | struct pcie_port *pp = &ks_pcie->pp; | |
119 | struct irq_chip *chip = irq_desc_get_chip(desc); | |
120 | ||
4808c35e | 121 | dev_dbg(pp->dev, "%s, irq %d\n", __func__, irq); |
0c4ffcfe MK |
122 | |
123 | /* | |
124 | * The chained irq handler installation would have replaced normal | |
125 | * interrupt driver handler so we need to take care of mask/unmask and | |
126 | * ack operation. | |
127 | */ | |
128 | chained_irq_enter(chip, desc); | |
129 | ks_dw_pcie_handle_msi_irq(ks_pcie, offset); | |
130 | chained_irq_exit(chip, desc); | |
131 | } | |
132 | ||
133 | /** | |
134 | * ks_pcie_legacy_irq_handler() - Handle legacy interrupt | |
135 | * @irq: IRQ line for legacy interrupts | |
136 | * @desc: Pointer to irq descriptor | |
137 | * | |
138 | * Traverse through pending legacy interrupts and invoke handler for each. Also | |
139 | * takes care of interrupt controller level mask/ack operation. | |
140 | */ | |
bd0b9ac4 | 141 | static void ks_pcie_legacy_irq_handler(struct irq_desc *desc) |
0c4ffcfe | 142 | { |
97a85964 | 143 | unsigned int irq = irq_desc_get_irq(desc); |
0c4ffcfe MK |
144 | struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc); |
145 | struct pcie_port *pp = &ks_pcie->pp; | |
146 | u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0]; | |
147 | struct irq_chip *chip = irq_desc_get_chip(desc); | |
148 | ||
149 | dev_dbg(pp->dev, ": Handling legacy irq %d\n", irq); | |
150 | ||
151 | /* | |
152 | * The chained irq handler installation would have replaced normal | |
153 | * interrupt driver handler so we need to take care of mask/unmask and | |
154 | * ack operation. | |
155 | */ | |
156 | chained_irq_enter(chip, desc); | |
157 | ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset); | |
158 | chained_irq_exit(chip, desc); | |
159 | } | |
160 | ||
161 | static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie, | |
162 | char *controller, int *num_irqs) | |
163 | { | |
164 | int temp, max_host_irqs, legacy = 1, *host_irqs, ret = -EINVAL; | |
165 | struct device *dev = ks_pcie->pp.dev; | |
166 | struct device_node *np_pcie = dev->of_node, **np_temp; | |
167 | ||
168 | if (!strcmp(controller, "msi-interrupt-controller")) | |
169 | legacy = 0; | |
170 | ||
171 | if (legacy) { | |
172 | np_temp = &ks_pcie->legacy_intc_np; | |
173 | max_host_irqs = MAX_LEGACY_HOST_IRQS; | |
174 | host_irqs = &ks_pcie->legacy_host_irqs[0]; | |
175 | } else { | |
176 | np_temp = &ks_pcie->msi_intc_np; | |
177 | max_host_irqs = MAX_MSI_HOST_IRQS; | |
178 | host_irqs = &ks_pcie->msi_host_irqs[0]; | |
179 | } | |
180 | ||
181 | /* interrupt controller is in a child node */ | |
182 | *np_temp = of_find_node_by_name(np_pcie, controller); | |
183 | if (!(*np_temp)) { | |
184 | dev_err(dev, "Node for %s is absent\n", controller); | |
185 | goto out; | |
186 | } | |
187 | temp = of_irq_count(*np_temp); | |
188 | if (!temp) | |
189 | goto out; | |
190 | if (temp > max_host_irqs) | |
191 | dev_warn(dev, "Too many %s interrupts defined %u\n", | |
192 | (legacy ? "legacy" : "MSI"), temp); | |
193 | ||
194 | /* | |
195 | * support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to | |
196 | * 7 (MSI) | |
197 | */ | |
198 | for (temp = 0; temp < max_host_irqs; temp++) { | |
199 | host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp); | |
ea3651fe | 200 | if (!host_irqs[temp]) |
0c4ffcfe MK |
201 | break; |
202 | } | |
203 | if (temp) { | |
204 | *num_irqs = temp; | |
205 | ret = 0; | |
206 | } | |
207 | out: | |
208 | return ret; | |
209 | } | |
210 | ||
211 | static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie) | |
212 | { | |
213 | int i; | |
214 | ||
215 | /* Legacy IRQ */ | |
216 | for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) { | |
5168a73c TG |
217 | irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i], |
218 | ks_pcie_legacy_irq_handler, | |
219 | ks_pcie); | |
0c4ffcfe MK |
220 | } |
221 | ks_dw_pcie_enable_legacy_irqs(ks_pcie); | |
222 | ||
223 | /* MSI IRQ */ | |
224 | if (IS_ENABLED(CONFIG_PCI_MSI)) { | |
225 | for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) { | |
2cf5a03c TG |
226 | irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i], |
227 | ks_pcie_msi_irq_handler, | |
228 | ks_pcie); | |
0c4ffcfe MK |
229 | } |
230 | } | |
231 | } | |
232 | ||
233 | /* | |
234 | * When a PCI device does not exist during config cycles, keystone host gets a | |
235 | * bus error instead of returning 0xffffffff. This handler always returns 0 | |
236 | * for this kind of faults. | |
237 | */ | |
238 | static int keystone_pcie_fault(unsigned long addr, unsigned int fsr, | |
239 | struct pt_regs *regs) | |
240 | { | |
241 | unsigned long instr = *(unsigned long *) instruction_pointer(regs); | |
242 | ||
243 | if ((instr & 0x0e100090) == 0x00100090) { | |
244 | int reg = (instr >> 12) & 15; | |
245 | ||
246 | regs->uregs[reg] = -1; | |
247 | regs->ARM_pc += 4; | |
248 | } | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
253 | static void __init ks_pcie_host_init(struct pcie_port *pp) | |
254 | { | |
0c4ffcfe | 255 | struct keystone_pcie *ks_pcie = to_keystone_pcie(pp); |
8665a482 | 256 | u32 val; |
0c4ffcfe MK |
257 | |
258 | ks_pcie_establish_link(ks_pcie); | |
259 | ks_dw_pcie_setup_rc_app_regs(ks_pcie); | |
260 | ks_pcie_setup_interrupts(ks_pcie); | |
261 | writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8), | |
262 | pp->dbi_base + PCI_IO_BASE); | |
263 | ||
264 | /* update the Vendor ID */ | |
8665a482 | 265 | writew(ks_pcie->device_id, pp->dbi_base + PCI_DEVICE_ID); |
0c4ffcfe MK |
266 | |
267 | /* update the DEV_STAT_CTRL to publish right mrrs */ | |
268 | val = readl(pp->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL); | |
269 | val &= ~PCI_EXP_DEVCTL_READRQ; | |
270 | /* set the mrrs to 256 bytes */ | |
271 | val |= BIT(12); | |
272 | writel(val, pp->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL); | |
273 | ||
274 | /* | |
275 | * PCIe access errors that result into OCP errors are caught by ARM as | |
276 | * "External aborts" | |
277 | */ | |
278 | hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0, | |
279 | "Asynchronous external abort"); | |
280 | } | |
281 | ||
282 | static struct pcie_host_ops keystone_pcie_host_ops = { | |
283 | .rd_other_conf = ks_dw_pcie_rd_other_conf, | |
284 | .wr_other_conf = ks_dw_pcie_wr_other_conf, | |
285 | .link_up = ks_dw_pcie_link_up, | |
286 | .host_init = ks_pcie_host_init, | |
287 | .msi_set_irq = ks_dw_pcie_msi_set_irq, | |
288 | .msi_clear_irq = ks_dw_pcie_msi_clear_irq, | |
1104528b | 289 | .get_msi_addr = ks_dw_pcie_get_msi_addr, |
0c4ffcfe MK |
290 | .msi_host_init = ks_dw_pcie_msi_host_init, |
291 | .scan_bus = ks_dw_pcie_v3_65_scan_bus, | |
292 | }; | |
293 | ||
294 | static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie, | |
295 | struct platform_device *pdev) | |
296 | { | |
297 | struct pcie_port *pp = &ks_pcie->pp; | |
298 | int ret; | |
299 | ||
300 | ret = ks_pcie_get_irq_controller_info(ks_pcie, | |
301 | "legacy-interrupt-controller", | |
302 | &ks_pcie->num_legacy_host_irqs); | |
303 | if (ret) | |
304 | return ret; | |
305 | ||
306 | if (IS_ENABLED(CONFIG_PCI_MSI)) { | |
307 | ret = ks_pcie_get_irq_controller_info(ks_pcie, | |
308 | "msi-interrupt-controller", | |
309 | &ks_pcie->num_msi_host_irqs); | |
310 | if (ret) | |
311 | return ret; | |
312 | } | |
313 | ||
314 | pp->root_bus_nr = -1; | |
315 | pp->ops = &keystone_pcie_host_ops; | |
316 | ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np); | |
317 | if (ret) { | |
318 | dev_err(&pdev->dev, "failed to initialize host\n"); | |
319 | return ret; | |
320 | } | |
321 | ||
322 | return ret; | |
323 | } | |
324 | ||
325 | static const struct of_device_id ks_pcie_of_match[] = { | |
326 | { | |
327 | .type = "pci", | |
328 | .compatible = "ti,keystone-pcie", | |
329 | }, | |
330 | { }, | |
331 | }; | |
332 | MODULE_DEVICE_TABLE(of, ks_pcie_of_match); | |
333 | ||
334 | static int __exit ks_pcie_remove(struct platform_device *pdev) | |
335 | { | |
336 | struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev); | |
337 | ||
338 | clk_disable_unprepare(ks_pcie->clk); | |
339 | ||
340 | return 0; | |
341 | } | |
342 | ||
343 | static int __init ks_pcie_probe(struct platform_device *pdev) | |
344 | { | |
345 | struct device *dev = &pdev->dev; | |
346 | struct keystone_pcie *ks_pcie; | |
347 | struct pcie_port *pp; | |
348 | struct resource *res; | |
349 | void __iomem *reg_p; | |
350 | struct phy *phy; | |
351 | int ret = 0; | |
0c4ffcfe MK |
352 | |
353 | ks_pcie = devm_kzalloc(&pdev->dev, sizeof(*ks_pcie), | |
354 | GFP_KERNEL); | |
66700707 | 355 | if (!ks_pcie) |
0c4ffcfe | 356 | return -ENOMEM; |
66700707 | 357 | |
0c4ffcfe MK |
358 | pp = &ks_pcie->pp; |
359 | ||
0c4ffcfe MK |
360 | /* initialize SerDes Phy if present */ |
361 | phy = devm_phy_get(dev, "pcie-phy"); | |
362 | if (!IS_ERR_OR_NULL(phy)) { | |
363 | ret = phy_init(phy); | |
364 | if (ret < 0) | |
365 | return ret; | |
366 | } | |
367 | ||
4455efc9 MK |
368 | /* index 2 is to read PCI DEVICE_ID */ |
369 | res = platform_get_resource(pdev, IORESOURCE_MEM, 2); | |
0c4ffcfe MK |
370 | reg_p = devm_ioremap_resource(dev, res); |
371 | if (IS_ERR(reg_p)) | |
372 | return PTR_ERR(reg_p); | |
8665a482 MK |
373 | ks_pcie->device_id = readl(reg_p) >> 16; |
374 | devm_iounmap(dev, reg_p); | |
375 | devm_release_mem_region(dev, res->start, resource_size(res)); | |
0c4ffcfe MK |
376 | |
377 | pp->dev = dev; | |
378 | platform_set_drvdata(pdev, ks_pcie); | |
379 | ks_pcie->clk = devm_clk_get(dev, "pcie"); | |
380 | if (IS_ERR(ks_pcie->clk)) { | |
381 | dev_err(dev, "Failed to get pcie rc clock\n"); | |
382 | return PTR_ERR(ks_pcie->clk); | |
383 | } | |
384 | ret = clk_prepare_enable(ks_pcie->clk); | |
385 | if (ret) | |
386 | return ret; | |
387 | ||
388 | ret = ks_add_pcie_port(ks_pcie, pdev); | |
389 | if (ret < 0) | |
390 | goto fail_clk; | |
391 | ||
392 | return 0; | |
393 | fail_clk: | |
394 | clk_disable_unprepare(ks_pcie->clk); | |
395 | ||
396 | return ret; | |
397 | } | |
398 | ||
399 | static struct platform_driver ks_pcie_driver __refdata = { | |
400 | .probe = ks_pcie_probe, | |
401 | .remove = __exit_p(ks_pcie_remove), | |
402 | .driver = { | |
403 | .name = "keystone-pcie", | |
0c4ffcfe MK |
404 | .of_match_table = of_match_ptr(ks_pcie_of_match), |
405 | }, | |
406 | }; | |
407 | ||
408 | module_platform_driver(ks_pcie_driver); | |
409 | ||
410 | MODULE_AUTHOR("Murali Karicheri <m-karicheri2@ti.com>"); | |
411 | MODULE_DESCRIPTION("Keystone PCIe host controller driver"); | |
412 | MODULE_LICENSE("GPL v2"); |