xref: /linux/drivers/pci/controller/cadence/pcie-cadence-host.c (revision d30c1683aaecb93d2ab95685dc4300a33d3cea7a)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017 Cadence
3 // Cadence PCIe host controller driver.
4 // Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
5 
6 #include <linux/delay.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/list_sort.h>
10 #include <linux/of_address.h>
11 #include <linux/of_pci.h>
12 #include <linux/platform_device.h>
13 
14 #include "pcie-cadence.h"
15 #include "pcie-cadence-host-common.h"
16 
17 static u8 bar_aperture_mask[] = {
18 	[RP_BAR0] = 0x1F,
19 	[RP_BAR1] = 0xF,
20 };
21 
22 void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
23 			       int where)
24 {
25 	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
26 	struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
27 	struct cdns_pcie *pcie = &rc->pcie;
28 	unsigned int busn = bus->number;
29 	u32 addr0, desc0;
30 
31 	if (pci_is_root_bus(bus)) {
32 		/*
33 		 * Only the root port (devfn == 0) is connected to this bus.
34 		 * All other PCI devices are behind some bridge hence on another
35 		 * bus.
36 		 */
37 		if (devfn)
38 			return NULL;
39 
40 		return pcie->reg_base + (where & 0xfff);
41 	}
42 	/* Check that the link is up */
43 	if (!(cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE) & 0x1))
44 		return NULL;
45 	/* Clear AXI link-down status */
46 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_LINKDOWN, 0x0);
47 
48 	/* Update Output registers for AXI region 0. */
49 	addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
50 		CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_DEVFN(devfn) |
51 		CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_BUS(busn);
52 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(0), addr0);
53 
54 	/* Configuration Type 0 or Type 1 access. */
55 	desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_HARDCODED_RID |
56 		CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(0);
57 	/*
58 	 * The bus number was already set once for all in desc1 by
59 	 * cdns_pcie_host_init_address_translation().
60 	 */
61 	if (busn == bridge->busnr + 1)
62 		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE0;
63 	else
64 		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE1;
65 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(0), desc0);
66 
67 	return rc->cfg_base + (where & 0xfff);
68 }
69 EXPORT_SYMBOL_GPL(cdns_pci_map_bus);
70 
71 static struct pci_ops cdns_pcie_host_ops = {
72 	.map_bus	= cdns_pci_map_bus,
73 	.read		= pci_generic_config_read,
74 	.write		= pci_generic_config_write,
75 };
76 
77 static void cdns_pcie_host_disable_ptm_response(struct cdns_pcie *pcie)
78 {
79 	u32 val;
80 
81 	val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
82 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val & ~CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
83 }
84 
85 static void cdns_pcie_host_enable_ptm_response(struct cdns_pcie *pcie)
86 {
87 	u32 val;
88 
89 	val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
90 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val | CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
91 }
92 
93 static void cdns_pcie_host_deinit_root_port(struct cdns_pcie_rc *rc)
94 {
95 	struct cdns_pcie *pcie = &rc->pcie;
96 	u32 value, ctrl;
97 
98 	cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, 0xffff);
99 	cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0xff);
100 	cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0xff);
101 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, 0xffffffff);
102 	cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, 0xffff);
103 	ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
104 	value = ~(CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
105 		CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
106 		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
107 		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
108 		CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
109 		CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS);
110 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
111 }
112 
113 static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
114 {
115 	struct cdns_pcie *pcie = &rc->pcie;
116 	u32 value, ctrl;
117 	u32 id;
118 
119 	/*
120 	 * Set the root complex BAR configuration register:
121 	 * - disable both BAR0 and BAR1.
122 	 * - enable Prefetchable Memory Base and Limit registers in type 1
123 	 *   config space (64 bits).
124 	 * - enable IO Base and Limit registers in type 1 config
125 	 *   space (32 bits).
126 	 */
127 	ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
128 	value = CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
129 		CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
130 		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
131 		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
132 		CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
133 		CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS;
134 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
135 
136 	/* Set root port configuration space */
137 	if (rc->vendor_id != 0xffff) {
138 		id = CDNS_PCIE_LM_ID_VENDOR(rc->vendor_id) |
139 			CDNS_PCIE_LM_ID_SUBSYS(rc->vendor_id);
140 		cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
141 	}
142 
143 	if (rc->device_id != 0xffff)
144 		cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);
145 
146 	cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0);
147 	cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0);
148 	cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, PCI_CLASS_BRIDGE_PCI);
149 
150 	return 0;
151 }
152 
153 int cdns_pcie_host_bar_ib_config(struct cdns_pcie_rc *rc,
154 				 enum cdns_pcie_rp_bar bar,
155 				 u64 cpu_addr,
156 				 u64 size,
157 				 unsigned long flags)
158 {
159 	struct cdns_pcie *pcie = &rc->pcie;
160 	u32 addr0, addr1, aperture, value;
161 
162 	if (!rc->avail_ib_bar[bar])
163 		return -EBUSY;
164 
165 	rc->avail_ib_bar[bar] = false;
166 
167 	aperture = ilog2(size);
168 	addr0 = CDNS_PCIE_AT_IB_RP_BAR_ADDR0_NBITS(aperture) |
169 		(lower_32_bits(cpu_addr) & GENMASK(31, 8));
170 	addr1 = upper_32_bits(cpu_addr);
171 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), addr0);
172 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), addr1);
173 
174 	if (bar == RP_NO_BAR)
175 		return 0;
176 
177 	value = cdns_pcie_readl(pcie, CDNS_PCIE_LM_RC_BAR_CFG);
178 	value &= ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
179 		   LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
180 		   LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
181 		   LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
182 		   LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
183 	if (size + cpu_addr >= SZ_4G) {
184 		if (!(flags & IORESOURCE_PREFETCH))
185 			value |= LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar);
186 		value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
187 	} else {
188 		if (!(flags & IORESOURCE_PREFETCH))
189 			value |= LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
190 		value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
191 	}
192 
193 	value |= LM_RC_BAR_CFG_APERTURE(bar, aperture);
194 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
195 
196 	return 0;
197 }
198 
199 static void cdns_pcie_host_unmap_dma_ranges(struct cdns_pcie_rc *rc)
200 {
201 	struct cdns_pcie *pcie = &rc->pcie;
202 	enum cdns_pcie_rp_bar bar;
203 	u32 value;
204 
205 	/* Reset inbound configuration for all BARs which were being used */
206 	for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
207 		if (rc->avail_ib_bar[bar])
208 			continue;
209 
210 		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), 0);
211 		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), 0);
212 
213 		if (bar == RP_NO_BAR)
214 			continue;
215 
216 		value = ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
217 			  LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
218 			  LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
219 			  LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
220 			  LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
221 		cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
222 	}
223 }
224 
225 static void cdns_pcie_host_deinit_address_translation(struct cdns_pcie_rc *rc)
226 {
227 	struct cdns_pcie *pcie = &rc->pcie;
228 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
229 	struct resource_entry *entry;
230 	int r;
231 
232 	cdns_pcie_host_unmap_dma_ranges(rc);
233 
234 	/*
235 	 * Reset outbound region 0 which was reserved for configuration space
236 	 * accesses.
237 	 */
238 	cdns_pcie_reset_outbound_region(pcie, 0);
239 
240 	/* Reset rest of the outbound regions */
241 	r = 1;
242 	resource_list_for_each_entry(entry, &bridge->windows) {
243 		cdns_pcie_reset_outbound_region(pcie, r);
244 		r++;
245 	}
246 }
247 
248 static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
249 {
250 	struct cdns_pcie *pcie = &rc->pcie;
251 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
252 	struct resource *cfg_res = rc->cfg_res;
253 	struct resource_entry *entry;
254 	u64 cpu_addr = cfg_res->start;
255 	u32 addr0, addr1, desc1;
256 	int r, busnr = 0;
257 
258 	entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
259 	if (entry)
260 		busnr = entry->res->start;
261 
262 	/*
263 	 * Reserve region 0 for PCI configure space accesses:
264 	 * OB_REGION_PCI_ADDR0 and OB_REGION_DESC0 are updated dynamically by
265 	 * cdns_pci_map_bus(), other region registers are set here once for all.
266 	 */
267 	addr1 = 0; /* Should be programmed to zero. */
268 	desc1 = CDNS_PCIE_AT_OB_REGION_DESC1_BUS(busnr);
269 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(0), addr1);
270 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(0), desc1);
271 
272 	if (pcie->ops && pcie->ops->cpu_addr_fixup)
273 		cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
274 
275 	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(12) |
276 		(lower_32_bits(cpu_addr) & GENMASK(31, 8));
277 	addr1 = upper_32_bits(cpu_addr);
278 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(0), addr0);
279 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(0), addr1);
280 
281 	r = 1;
282 	resource_list_for_each_entry(entry, &bridge->windows) {
283 		struct resource *res = entry->res;
284 		u64 pci_addr = res->start - entry->offset;
285 
286 		if (resource_type(res) == IORESOURCE_IO)
287 			cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
288 						      true,
289 						      pci_pio_to_address(res->start),
290 						      pci_addr,
291 						      resource_size(res));
292 		else
293 			cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
294 						      false,
295 						      res->start,
296 						      pci_addr,
297 						      resource_size(res));
298 
299 		r++;
300 	}
301 
302 	return cdns_pcie_host_map_dma_ranges(rc, cdns_pcie_host_bar_ib_config);
303 }
304 
305 static void cdns_pcie_host_deinit(struct cdns_pcie_rc *rc)
306 {
307 	cdns_pcie_host_deinit_address_translation(rc);
308 	cdns_pcie_host_deinit_root_port(rc);
309 }
310 
311 int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
312 {
313 	int err;
314 
315 	err = cdns_pcie_host_init_root_port(rc);
316 	if (err)
317 		return err;
318 
319 	return cdns_pcie_host_init_address_translation(rc);
320 }
321 EXPORT_SYMBOL_GPL(cdns_pcie_host_init);
322 
323 static void cdns_pcie_host_link_disable(struct cdns_pcie_rc *rc)
324 {
325 	struct cdns_pcie *pcie = &rc->pcie;
326 
327 	cdns_pcie_stop_link(pcie);
328 	cdns_pcie_host_disable_ptm_response(pcie);
329 }
330 
331 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
332 {
333 	struct cdns_pcie *pcie = &rc->pcie;
334 	struct device *dev = rc->pcie.dev;
335 	int ret;
336 
337 	if (rc->quirk_detect_quiet_flag)
338 		cdns_pcie_detect_quiet_min_delay_set(&rc->pcie);
339 
340 	cdns_pcie_host_enable_ptm_response(pcie);
341 
342 	ret = cdns_pcie_start_link(pcie);
343 	if (ret) {
344 		dev_err(dev, "Failed to start link\n");
345 		return ret;
346 	}
347 
348 	ret = cdns_pcie_host_start_link(rc, cdns_pcie_link_up);
349 	if (ret)
350 		dev_dbg(dev, "PCIe link never came up\n");
351 
352 	return 0;
353 }
354 EXPORT_SYMBOL_GPL(cdns_pcie_host_link_setup);
355 
356 void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
357 {
358 	struct pci_host_bridge *bridge;
359 
360 	bridge = pci_host_bridge_from_priv(rc);
361 	pci_stop_root_bus(bridge->bus);
362 	pci_remove_root_bus(bridge->bus);
363 
364 	cdns_pcie_host_deinit(rc);
365 	cdns_pcie_host_link_disable(rc);
366 }
367 EXPORT_SYMBOL_GPL(cdns_pcie_host_disable);
368 
369 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
370 {
371 	struct device *dev = rc->pcie.dev;
372 	struct platform_device *pdev = to_platform_device(dev);
373 	struct device_node *np = dev->of_node;
374 	struct pci_host_bridge *bridge;
375 	enum cdns_pcie_rp_bar bar;
376 	struct cdns_pcie *pcie;
377 	struct resource *res;
378 	int ret;
379 
380 	bridge = pci_host_bridge_from_priv(rc);
381 	if (!bridge)
382 		return -ENOMEM;
383 
384 	pcie = &rc->pcie;
385 	pcie->is_rc = true;
386 
387 	rc->vendor_id = 0xffff;
388 	of_property_read_u32(np, "vendor-id", &rc->vendor_id);
389 
390 	rc->device_id = 0xffff;
391 	of_property_read_u32(np, "device-id", &rc->device_id);
392 
393 	pcie->reg_base = devm_platform_ioremap_resource_byname(pdev, "reg");
394 	if (IS_ERR(pcie->reg_base)) {
395 		dev_err(dev, "missing \"reg\"\n");
396 		return PTR_ERR(pcie->reg_base);
397 	}
398 
399 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
400 	rc->cfg_base = devm_pci_remap_cfg_resource(dev, res);
401 	if (IS_ERR(rc->cfg_base))
402 		return PTR_ERR(rc->cfg_base);
403 	rc->cfg_res = res;
404 
405 	ret = cdns_pcie_host_link_setup(rc);
406 	if (ret)
407 		return ret;
408 
409 	for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
410 		rc->avail_ib_bar[bar] = true;
411 
412 	ret = cdns_pcie_host_init(rc);
413 	if (ret)
414 		return ret;
415 
416 	if (!bridge->ops)
417 		bridge->ops = &cdns_pcie_host_ops;
418 
419 	return pci_host_probe(bridge);
420 }
421 EXPORT_SYMBOL_GPL(cdns_pcie_host_setup);
422 
423 MODULE_LICENSE("GPL");
424 MODULE_DESCRIPTION("Cadence PCIe host controller driver");
425 MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@free-electrons.com>");
426