1 // SPDX-License-Identifier: GPL-2.0+
3 * APM X-Gene PCIe Driver
5 * Copyright (c) 2014 Applied Micro Circuits Corporation.
10 #include <linux/delay.h>
12 #include <linux/jiffies.h>
13 #include <linux/memblock.h>
14 #include <linux/init.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <linux/of_pci.h>
19 #include <linux/pci.h>
20 #include <linux/pci-acpi.h>
21 #include <linux/pci-ecam.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
27 #define PCIECORE_CTLANDSTATUS 0x50
35 #define OMR1BARL 0x100
36 #define OMR2BARL 0x118
37 #define OMR3BARL 0x130
42 #define BRIDGE_CFG_0 0x2000
43 #define BRIDGE_CFG_4 0x2010
44 #define BRIDGE_STATUS_0 0x2600
46 #define LINK_UP_MASK 0x00000100
47 #define AXI_EP_CFG_ACCESS 0x10000
48 #define EN_COHERENCY 0xF0000000
49 #define EN_REG 0x00000001
50 #define OB_LO_IO 0x00000002
51 #define XGENE_PCIE_DEVICEID 0xE004
52 #define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe)
54 #define XGENE_V1_PCI_EXP_CAP 0x40
57 #define XGENE_PCIE_IP_VER_UNKN 0
58 #define XGENE_PCIE_IP_VER_1 1
59 #define XGENE_PCIE_IP_VER_2 2
61 #if defined(CONFIG_PCI_XGENE) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
63 struct device_node *node;
66 void __iomem *csr_base;
67 void __iomem *cfg_base;
68 unsigned long cfg_addr;
73 static u32 xgene_pcie_readl(struct xgene_pcie *port, u32 reg)
75 return readl(port->csr_base + reg);
78 static void xgene_pcie_writel(struct xgene_pcie *port, u32 reg, u32 val)
80 writel(val, port->csr_base + reg);
83 static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
85 return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
88 static inline struct xgene_pcie *pcie_bus_to_port(struct pci_bus *bus)
90 struct pci_config_window *cfg;
93 return (struct xgene_pcie *)(bus->sysdata);
96 return (struct xgene_pcie *)(cfg->priv);
100 * When the address bit [17:16] is 2'b01, the Configuration access will be
101 * treated as Type 1 and it will be forwarded to external PCIe device.
103 static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
105 struct xgene_pcie *port = pcie_bus_to_port(bus);
107 if (bus->number >= (bus->primary + 1))
108 return port->cfg_base + AXI_EP_CFG_ACCESS;
110 return port->cfg_base;
114 * For Configuration request, RTDID register is used as Bus Number,
115 * Device Number and Function number of the header fields.
117 static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
119 struct xgene_pcie *port = pcie_bus_to_port(bus);
120 unsigned int b, d, f;
127 if (!pci_is_root_bus(bus))
128 rtdid_val = (b << 8) | (d << 3) | f;
130 xgene_pcie_writel(port, RTDID, rtdid_val);
131 /* read the register back to ensure flush */
132 xgene_pcie_readl(port, RTDID);
136 * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as
137 * the translation from PCI bus to native BUS. Entire DDR region
138 * is mapped into PCIe space using these registers, so it can be
139 * reached by DMA from EP devices. The BAR0/1 of bridge should be
140 * hidden during enumeration to avoid the sizing and resource allocation
143 static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
145 if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) ||
146 (offset == PCI_BASE_ADDRESS_1)))
152 static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
155 if ((pci_is_root_bus(bus) && devfn != 0) ||
156 xgene_pcie_hide_rc_bars(bus, offset))
159 xgene_pcie_set_rtdid_reg(bus, devfn);
160 return xgene_pcie_get_cfg_base(bus) + offset;
163 static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
164 int where, int size, u32 *val)
166 struct xgene_pcie *port = pcie_bus_to_port(bus);
168 if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) !=
170 return PCIBIOS_DEVICE_NOT_FOUND;
173 * The v1 controller has a bug in its Configuration Request Retry
174 * Status (CRS) logic: when CRS Software Visibility is enabled and
175 * we read the Vendor and Device ID of a non-existent device, the
176 * controller fabricates return data of 0xFFFF0001 ("device exists
177 * but is not ready") instead of 0xFFFFFFFF (PCI_ERROR_RESPONSE)
178 * ("device does not exist"). This causes the PCI core to retry
179 * the read until it times out. Avoid this by not claiming to
182 if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
183 ((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
184 *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16);
187 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
189 return PCIBIOS_SUCCESSFUL;
193 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
194 static int xgene_get_csr_resource(struct acpi_device *adev,
195 struct resource *res)
197 struct device *dev = &adev->dev;
198 struct resource_entry *entry;
199 struct list_head list;
203 INIT_LIST_HEAD(&list);
204 flags = IORESOURCE_MEM;
205 ret = acpi_dev_get_resources(adev, &list,
206 acpi_dev_filter_resource_type_cb,
209 dev_err(dev, "failed to parse _CRS method, error code %d\n",
215 dev_err(dev, "no IO and memory resources present in _CRS\n");
219 entry = list_first_entry(&list, struct resource_entry, node);
221 acpi_dev_free_resource_list(&list);
225 static int xgene_pcie_ecam_init(struct pci_config_window *cfg, u32 ipversion)
227 struct device *dev = cfg->parent;
228 struct acpi_device *adev = to_acpi_device(dev);
229 struct xgene_pcie *port;
233 port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
237 ret = xgene_get_csr_resource(adev, &csr);
239 dev_err(dev, "can't get CSR resource\n");
242 port->csr_base = devm_pci_remap_cfg_resource(dev, &csr);
243 if (IS_ERR(port->csr_base))
244 return PTR_ERR(port->csr_base);
246 port->cfg_base = cfg->win;
247 port->version = ipversion;
253 static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
255 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_1);
258 const struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
259 .init = xgene_v1_pcie_ecam_init,
261 .map_bus = xgene_pcie_map_bus,
262 .read = xgene_pcie_config_read32,
263 .write = pci_generic_config_write,
267 static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg)
269 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_2);
272 const struct pci_ecam_ops xgene_v2_pcie_ecam_ops = {
273 .init = xgene_v2_pcie_ecam_init,
275 .map_bus = xgene_pcie_map_bus,
276 .read = xgene_pcie_config_read32,
277 .write = pci_generic_config_write,
282 #if defined(CONFIG_PCI_XGENE)
283 static u64 xgene_pcie_set_ib_mask(struct xgene_pcie *port, u32 addr,
286 u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
290 val32 = xgene_pcie_readl(port, addr);
291 val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
292 xgene_pcie_writel(port, addr, val);
294 val32 = xgene_pcie_readl(port, addr + 0x04);
295 val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
296 xgene_pcie_writel(port, addr + 0x04, val);
298 val32 = xgene_pcie_readl(port, addr + 0x04);
299 val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
300 xgene_pcie_writel(port, addr + 0x04, val);
302 val32 = xgene_pcie_readl(port, addr + 0x08);
303 val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
304 xgene_pcie_writel(port, addr + 0x08, val);
309 static void xgene_pcie_linkup(struct xgene_pcie *port,
310 u32 *lanes, u32 *speed)
314 port->link_up = false;
315 val32 = xgene_pcie_readl(port, PCIECORE_CTLANDSTATUS);
316 if (val32 & LINK_UP_MASK) {
317 port->link_up = true;
318 *speed = PIPE_PHY_RATE_RD(val32);
319 val32 = xgene_pcie_readl(port, BRIDGE_STATUS_0);
320 *lanes = val32 >> 26;
324 static int xgene_pcie_init_port(struct xgene_pcie *port)
326 struct device *dev = port->dev;
329 port->clk = clk_get(dev, NULL);
330 if (IS_ERR(port->clk)) {
331 dev_err(dev, "clock not available\n");
335 rc = clk_prepare_enable(port->clk);
337 dev_err(dev, "clock enable failed\n");
344 static int xgene_pcie_map_reg(struct xgene_pcie *port,
345 struct platform_device *pdev)
347 struct device *dev = port->dev;
348 struct resource *res;
350 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
351 port->csr_base = devm_pci_remap_cfg_resource(dev, res);
352 if (IS_ERR(port->csr_base))
353 return PTR_ERR(port->csr_base);
355 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
356 port->cfg_base = devm_ioremap_resource(dev, res);
357 if (IS_ERR(port->cfg_base))
358 return PTR_ERR(port->cfg_base);
359 port->cfg_addr = res->start;
364 static void xgene_pcie_setup_ob_reg(struct xgene_pcie *port,
365 struct resource *res, u32 offset,
366 u64 cpu_addr, u64 pci_addr)
368 struct device *dev = port->dev;
369 resource_size_t size = resource_size(res);
370 u64 restype = resource_type(res);
375 if (restype == IORESOURCE_MEM) {
382 if (size >= min_size)
383 mask = ~(size - 1) | flag;
385 dev_warn(dev, "res size 0x%llx less than minimum 0x%x\n",
386 (u64)size, min_size);
388 xgene_pcie_writel(port, offset, lower_32_bits(cpu_addr));
389 xgene_pcie_writel(port, offset + 0x04, upper_32_bits(cpu_addr));
390 xgene_pcie_writel(port, offset + 0x08, lower_32_bits(mask));
391 xgene_pcie_writel(port, offset + 0x0c, upper_32_bits(mask));
392 xgene_pcie_writel(port, offset + 0x10, lower_32_bits(pci_addr));
393 xgene_pcie_writel(port, offset + 0x14, upper_32_bits(pci_addr));
396 static void xgene_pcie_setup_cfg_reg(struct xgene_pcie *port)
398 u64 addr = port->cfg_addr;
400 xgene_pcie_writel(port, CFGBARL, lower_32_bits(addr));
401 xgene_pcie_writel(port, CFGBARH, upper_32_bits(addr));
402 xgene_pcie_writel(port, CFGCTL, EN_REG);
405 static int xgene_pcie_map_ranges(struct xgene_pcie *port)
407 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
408 struct resource_entry *window;
409 struct device *dev = port->dev;
411 resource_list_for_each_entry(window, &bridge->windows) {
412 struct resource *res = window->res;
413 u64 restype = resource_type(res);
415 dev_dbg(dev, "%pR\n", res);
419 xgene_pcie_setup_ob_reg(port, res, OMR3BARL,
420 pci_pio_to_address(res->start),
421 res->start - window->offset);
424 if (res->flags & IORESOURCE_PREFETCH)
425 xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
430 xgene_pcie_setup_ob_reg(port, res, OMR1BARL,
438 dev_err(dev, "invalid resource %pR\n", res);
442 xgene_pcie_setup_cfg_reg(port);
446 static void xgene_pcie_setup_pims(struct xgene_pcie *port, u32 pim_reg,
449 xgene_pcie_writel(port, pim_reg, lower_32_bits(pim));
450 xgene_pcie_writel(port, pim_reg + 0x04,
451 upper_32_bits(pim) | EN_COHERENCY);
452 xgene_pcie_writel(port, pim_reg + 0x10, lower_32_bits(size));
453 xgene_pcie_writel(port, pim_reg + 0x14, upper_32_bits(size));
457 * X-Gene PCIe support maximum 3 inbound memory regions
458 * This function helps to select a region based on size of region
460 static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
462 if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) {
463 *ib_reg_mask |= (1 << 1);
467 if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
468 *ib_reg_mask |= (1 << 0);
472 if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) {
473 *ib_reg_mask |= (1 << 2);
480 static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
481 struct of_pci_range *range, u8 *ib_reg_mask)
483 void __iomem *cfg_base = port->cfg_base;
484 struct device *dev = port->dev;
485 void __iomem *bar_addr;
487 u64 cpu_addr = range->cpu_addr;
488 u64 pci_addr = range->pci_addr;
489 u64 size = range->size;
490 u64 mask = ~(size - 1) | EN_REG;
491 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
495 region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
497 dev_warn(dev, "invalid pcie dma-range config\n");
501 if (range->flags & IORESOURCE_PREFETCH)
502 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
504 bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
507 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size);
508 bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
509 writel(bar_low, bar_addr);
510 writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
514 xgene_pcie_writel(port, IBAR2, bar_low);
515 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
519 xgene_pcie_writel(port, IBAR3L, bar_low);
520 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
521 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
522 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
527 xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
530 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie *port)
532 struct device_node *np = port->node;
533 struct of_pci_range range;
534 struct of_pci_range_parser parser;
535 struct device *dev = port->dev;
538 if (of_pci_dma_range_parser_init(&parser, np)) {
539 dev_err(dev, "missing dma-ranges property\n");
543 /* Get the dma-ranges from DT */
544 for_each_of_pci_range(&parser, &range) {
545 u64 end = range.cpu_addr + range.size - 1;
547 dev_dbg(dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
548 range.flags, range.cpu_addr, end, range.pci_addr);
549 xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
554 /* clear BAR configuration which was done by firmware */
555 static void xgene_pcie_clear_config(struct xgene_pcie *port)
559 for (i = PIM1_1L; i <= CFGCTL; i += 4)
560 xgene_pcie_writel(port, i, 0);
563 static int xgene_pcie_setup(struct xgene_pcie *port)
565 struct device *dev = port->dev;
566 u32 val, lanes = 0, speed = 0;
569 xgene_pcie_clear_config(port);
571 /* setup the vendor and device IDs correctly */
572 val = (XGENE_PCIE_DEVICEID << 16) | PCI_VENDOR_ID_AMCC;
573 xgene_pcie_writel(port, BRIDGE_CFG_0, val);
575 ret = xgene_pcie_map_ranges(port);
579 ret = xgene_pcie_parse_map_dma_ranges(port);
583 xgene_pcie_linkup(port, &lanes, &speed);
585 dev_info(dev, "(rc) link down\n");
587 dev_info(dev, "(rc) x%d gen-%d link up\n", lanes, speed + 1);
591 static struct pci_ops xgene_pcie_ops = {
592 .map_bus = xgene_pcie_map_bus,
593 .read = xgene_pcie_config_read32,
594 .write = pci_generic_config_write32,
597 static int xgene_pcie_probe(struct platform_device *pdev)
599 struct device *dev = &pdev->dev;
600 struct device_node *dn = dev->of_node;
601 struct xgene_pcie *port;
602 struct pci_host_bridge *bridge;
605 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
609 port = pci_host_bridge_priv(bridge);
611 port->node = of_node_get(dn);
614 port->version = XGENE_PCIE_IP_VER_UNKN;
615 if (of_device_is_compatible(port->node, "apm,xgene-pcie"))
616 port->version = XGENE_PCIE_IP_VER_1;
618 ret = xgene_pcie_map_reg(port, pdev);
622 ret = xgene_pcie_init_port(port);
626 ret = xgene_pcie_setup(port);
630 bridge->sysdata = port;
631 bridge->ops = &xgene_pcie_ops;
633 return pci_host_probe(bridge);
636 static const struct of_device_id xgene_pcie_match_table[] = {
637 {.compatible = "apm,xgene-pcie",},
641 static struct platform_driver xgene_pcie_driver = {
643 .name = "xgene-pcie",
644 .of_match_table = xgene_pcie_match_table,
645 .suppress_bind_attrs = true,
647 .probe = xgene_pcie_probe,
649 builtin_platform_driver(xgene_pcie_driver);