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_VENDORID 0x10E8
52 #define XGENE_PCIE_DEVICEID 0xE004
53 #define SZ_1T (SZ_1G*1024ULL)
54 #define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe)
56 #define XGENE_V1_PCI_EXP_CAP 0x40
59 #define XGENE_PCIE_IP_VER_UNKN 0
60 #define XGENE_PCIE_IP_VER_1 1
61 #define XGENE_PCIE_IP_VER_2 2
63 #if defined(CONFIG_PCI_XGENE) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
64 struct xgene_pcie_port {
65 struct device_node *node;
68 void __iomem *csr_base;
69 void __iomem *cfg_base;
70 unsigned long cfg_addr;
75 static u32 xgene_pcie_readl(struct xgene_pcie_port *port, u32 reg)
77 return readl(port->csr_base + reg);
80 static void xgene_pcie_writel(struct xgene_pcie_port *port, u32 reg, u32 val)
82 writel(val, port->csr_base + reg);
85 static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
87 return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
90 static inline struct xgene_pcie_port *pcie_bus_to_port(struct pci_bus *bus)
92 struct pci_config_window *cfg;
95 return (struct xgene_pcie_port *)(bus->sysdata);
98 return (struct xgene_pcie_port *)(cfg->priv);
102 * When the address bit [17:16] is 2'b01, the Configuration access will be
103 * treated as Type 1 and it will be forwarded to external PCIe device.
105 static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
107 struct xgene_pcie_port *port = pcie_bus_to_port(bus);
109 if (bus->number >= (bus->primary + 1))
110 return port->cfg_base + AXI_EP_CFG_ACCESS;
112 return port->cfg_base;
116 * For Configuration request, RTDID register is used as Bus Number,
117 * Device Number and Function number of the header fields.
119 static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
121 struct xgene_pcie_port *port = pcie_bus_to_port(bus);
122 unsigned int b, d, f;
129 if (!pci_is_root_bus(bus))
130 rtdid_val = (b << 8) | (d << 3) | f;
132 xgene_pcie_writel(port, RTDID, rtdid_val);
133 /* read the register back to ensure flush */
134 xgene_pcie_readl(port, RTDID);
138 * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as
139 * the translation from PCI bus to native BUS. Entire DDR region
140 * is mapped into PCIe space using these registers, so it can be
141 * reached by DMA from EP devices. The BAR0/1 of bridge should be
142 * hidden during enumeration to avoid the sizing and resource allocation
145 static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
147 if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) ||
148 (offset == PCI_BASE_ADDRESS_1)))
154 static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
157 if ((pci_is_root_bus(bus) && devfn != 0) ||
158 xgene_pcie_hide_rc_bars(bus, offset))
161 xgene_pcie_set_rtdid_reg(bus, devfn);
162 return xgene_pcie_get_cfg_base(bus) + offset;
165 static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
166 int where, int size, u32 *val)
168 struct xgene_pcie_port *port = pcie_bus_to_port(bus);
170 if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) !=
172 return PCIBIOS_DEVICE_NOT_FOUND;
175 * The v1 controller has a bug in its Configuration Request
176 * Retry Status (CRS) logic: when CRS Software Visibility is
177 * enabled and we read the Vendor and Device ID of a non-existent
178 * device, the controller fabricates return data of 0xFFFF0001
179 * ("device exists but is not ready") instead of 0xFFFFFFFF
180 * ("device does not exist"). This causes the PCI core to retry
181 * the read until it times out. Avoid this by not claiming to
184 if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
185 ((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
186 *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16);
189 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
191 return PCIBIOS_SUCCESSFUL;
195 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
196 static int xgene_get_csr_resource(struct acpi_device *adev,
197 struct resource *res)
199 struct device *dev = &adev->dev;
200 struct resource_entry *entry;
201 struct list_head list;
205 INIT_LIST_HEAD(&list);
206 flags = IORESOURCE_MEM;
207 ret = acpi_dev_get_resources(adev, &list,
208 acpi_dev_filter_resource_type_cb,
211 dev_err(dev, "failed to parse _CRS method, error code %d\n",
217 dev_err(dev, "no IO and memory resources present in _CRS\n");
221 entry = list_first_entry(&list, struct resource_entry, node);
223 acpi_dev_free_resource_list(&list);
227 static int xgene_pcie_ecam_init(struct pci_config_window *cfg, u32 ipversion)
229 struct device *dev = cfg->parent;
230 struct acpi_device *adev = to_acpi_device(dev);
231 struct xgene_pcie_port *port;
235 port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
239 ret = xgene_get_csr_resource(adev, &csr);
241 dev_err(dev, "can't get CSR resource\n");
244 port->csr_base = devm_pci_remap_cfg_resource(dev, &csr);
245 if (IS_ERR(port->csr_base))
246 return PTR_ERR(port->csr_base);
248 port->cfg_base = cfg->win;
249 port->version = ipversion;
255 static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
257 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_1);
260 const struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
261 .init = xgene_v1_pcie_ecam_init,
263 .map_bus = xgene_pcie_map_bus,
264 .read = xgene_pcie_config_read32,
265 .write = pci_generic_config_write,
269 static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg)
271 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_2);
274 const struct pci_ecam_ops xgene_v2_pcie_ecam_ops = {
275 .init = xgene_v2_pcie_ecam_init,
277 .map_bus = xgene_pcie_map_bus,
278 .read = xgene_pcie_config_read32,
279 .write = pci_generic_config_write,
284 #if defined(CONFIG_PCI_XGENE)
285 static u64 xgene_pcie_set_ib_mask(struct xgene_pcie_port *port, u32 addr,
288 u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
292 val32 = xgene_pcie_readl(port, addr);
293 val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
294 xgene_pcie_writel(port, addr, val);
296 val32 = xgene_pcie_readl(port, addr + 0x04);
297 val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
298 xgene_pcie_writel(port, addr + 0x04, val);
300 val32 = xgene_pcie_readl(port, addr + 0x04);
301 val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
302 xgene_pcie_writel(port, addr + 0x04, val);
304 val32 = xgene_pcie_readl(port, addr + 0x08);
305 val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
306 xgene_pcie_writel(port, addr + 0x08, val);
311 static void xgene_pcie_linkup(struct xgene_pcie_port *port,
312 u32 *lanes, u32 *speed)
316 port->link_up = false;
317 val32 = xgene_pcie_readl(port, PCIECORE_CTLANDSTATUS);
318 if (val32 & LINK_UP_MASK) {
319 port->link_up = true;
320 *speed = PIPE_PHY_RATE_RD(val32);
321 val32 = xgene_pcie_readl(port, BRIDGE_STATUS_0);
322 *lanes = val32 >> 26;
326 static int xgene_pcie_init_port(struct xgene_pcie_port *port)
328 struct device *dev = port->dev;
331 port->clk = clk_get(dev, NULL);
332 if (IS_ERR(port->clk)) {
333 dev_err(dev, "clock not available\n");
337 rc = clk_prepare_enable(port->clk);
339 dev_err(dev, "clock enable failed\n");
346 static int xgene_pcie_map_reg(struct xgene_pcie_port *port,
347 struct platform_device *pdev)
349 struct device *dev = port->dev;
350 struct resource *res;
352 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
353 port->csr_base = devm_pci_remap_cfg_resource(dev, res);
354 if (IS_ERR(port->csr_base))
355 return PTR_ERR(port->csr_base);
357 port->cfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg");
358 if (IS_ERR(port->cfg_base))
359 return PTR_ERR(port->cfg_base);
360 port->cfg_addr = res->start;
365 static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port,
366 struct resource *res, u32 offset,
367 u64 cpu_addr, u64 pci_addr)
369 struct device *dev = port->dev;
370 resource_size_t size = resource_size(res);
371 u64 restype = resource_type(res);
376 if (restype == IORESOURCE_MEM) {
383 if (size >= min_size)
384 mask = ~(size - 1) | flag;
386 dev_warn(dev, "res size 0x%llx less than minimum 0x%x\n",
387 (u64)size, min_size);
389 xgene_pcie_writel(port, offset, lower_32_bits(cpu_addr));
390 xgene_pcie_writel(port, offset + 0x04, upper_32_bits(cpu_addr));
391 xgene_pcie_writel(port, offset + 0x08, lower_32_bits(mask));
392 xgene_pcie_writel(port, offset + 0x0c, upper_32_bits(mask));
393 xgene_pcie_writel(port, offset + 0x10, lower_32_bits(pci_addr));
394 xgene_pcie_writel(port, offset + 0x14, upper_32_bits(pci_addr));
397 static void xgene_pcie_setup_cfg_reg(struct xgene_pcie_port *port)
399 u64 addr = port->cfg_addr;
401 xgene_pcie_writel(port, CFGBARL, lower_32_bits(addr));
402 xgene_pcie_writel(port, CFGBARH, upper_32_bits(addr));
403 xgene_pcie_writel(port, CFGCTL, EN_REG);
406 static int xgene_pcie_map_ranges(struct xgene_pcie_port *port)
408 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
409 struct resource_entry *window;
410 struct device *dev = port->dev;
412 resource_list_for_each_entry(window, &bridge->windows) {
413 struct resource *res = window->res;
414 u64 restype = resource_type(res);
416 dev_dbg(dev, "%pR\n", res);
420 xgene_pcie_setup_ob_reg(port, res, OMR3BARL,
421 pci_pio_to_address(res->start),
422 res->start - window->offset);
425 if (res->flags & IORESOURCE_PREFETCH)
426 xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
431 xgene_pcie_setup_ob_reg(port, res, OMR1BARL,
439 dev_err(dev, "invalid resource %pR\n", res);
443 xgene_pcie_setup_cfg_reg(port);
447 static void xgene_pcie_setup_pims(struct xgene_pcie_port *port, u32 pim_reg,
450 xgene_pcie_writel(port, pim_reg, lower_32_bits(pim));
451 xgene_pcie_writel(port, pim_reg + 0x04,
452 upper_32_bits(pim) | EN_COHERENCY);
453 xgene_pcie_writel(port, pim_reg + 0x10, lower_32_bits(size));
454 xgene_pcie_writel(port, pim_reg + 0x14, upper_32_bits(size));
458 * X-Gene PCIe support maximum 3 inbound memory regions
459 * This function helps to select a region based on size of region
461 static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
463 if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) {
464 *ib_reg_mask |= (1 << 1);
468 if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
469 *ib_reg_mask |= (1 << 0);
473 if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) {
474 *ib_reg_mask |= (1 << 2);
481 static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port,
482 struct resource_entry *entry,
485 void __iomem *cfg_base = port->cfg_base;
486 struct device *dev = port->dev;
489 u64 cpu_addr = entry->res->start;
490 u64 pci_addr = cpu_addr - entry->offset;
491 u64 size = resource_size(entry->res);
492 u64 mask = ~(size - 1) | EN_REG;
493 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
497 region = xgene_pcie_select_ib_reg(ib_reg_mask, size);
499 dev_warn(dev, "invalid pcie dma-range config\n");
503 if (entry->res->flags & IORESOURCE_PREFETCH)
504 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
506 bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
509 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size);
510 bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
511 writel(bar_low, bar_addr);
512 writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
516 xgene_pcie_writel(port, IBAR2, bar_low);
517 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
521 xgene_pcie_writel(port, IBAR3L, bar_low);
522 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
523 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
524 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
529 xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
532 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie_port *port)
534 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
535 struct resource_entry *entry;
538 resource_list_for_each_entry(entry, &bridge->dma_ranges)
539 xgene_pcie_setup_ib_reg(port, entry, &ib_reg_mask);
544 /* clear BAR configuration which was done by firmware */
545 static void xgene_pcie_clear_config(struct xgene_pcie_port *port)
549 for (i = PIM1_1L; i <= CFGCTL; i += 4)
550 xgene_pcie_writel(port, i, 0);
553 static int xgene_pcie_setup(struct xgene_pcie_port *port)
555 struct device *dev = port->dev;
556 u32 val, lanes = 0, speed = 0;
559 xgene_pcie_clear_config(port);
561 /* setup the vendor and device IDs correctly */
562 val = (XGENE_PCIE_DEVICEID << 16) | XGENE_PCIE_VENDORID;
563 xgene_pcie_writel(port, BRIDGE_CFG_0, val);
565 ret = xgene_pcie_map_ranges(port);
569 ret = xgene_pcie_parse_map_dma_ranges(port);
573 xgene_pcie_linkup(port, &lanes, &speed);
575 dev_info(dev, "(rc) link down\n");
577 dev_info(dev, "(rc) x%d gen-%d link up\n", lanes, speed + 1);
581 static struct pci_ops xgene_pcie_ops = {
582 .map_bus = xgene_pcie_map_bus,
583 .read = xgene_pcie_config_read32,
584 .write = pci_generic_config_write32,
587 static int xgene_pcie_probe(struct platform_device *pdev)
589 struct device *dev = &pdev->dev;
590 struct device_node *dn = dev->of_node;
591 struct xgene_pcie_port *port;
592 struct pci_host_bridge *bridge;
595 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
599 port = pci_host_bridge_priv(bridge);
601 port->node = of_node_get(dn);
604 port->version = XGENE_PCIE_IP_VER_UNKN;
605 if (of_device_is_compatible(port->node, "apm,xgene-pcie"))
606 port->version = XGENE_PCIE_IP_VER_1;
608 ret = xgene_pcie_map_reg(port, pdev);
612 ret = xgene_pcie_init_port(port);
616 ret = xgene_pcie_setup(port);
620 bridge->sysdata = port;
621 bridge->ops = &xgene_pcie_ops;
623 return pci_host_probe(bridge);
626 static const struct of_device_id xgene_pcie_match_table[] = {
627 {.compatible = "apm,xgene-pcie",},
631 static struct platform_driver xgene_pcie_driver = {
633 .name = "xgene-pcie",
634 .of_match_table = of_match_ptr(xgene_pcie_match_table),
635 .suppress_bind_attrs = true,
637 .probe = xgene_pcie_probe,
639 builtin_platform_driver(xgene_pcie_driver);