2 * Copyright Altera Corporation (C) 2013-2015. All rights reserved
5 * Description: Altera PCIe host controller driver
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/irqchip/chained_irq.h>
23 #include <linux/init.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_pci.h>
27 #include <linux/pci.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
31 #define RP_TX_REG0 0x2000
32 #define RP_TX_REG1 0x2004
33 #define RP_TX_CNTRL 0x2008
36 #define RP_RXCPL_STATUS 0x2010
37 #define RP_RXCPL_EOP 0x2
38 #define RP_RXCPL_SOP 0x1
39 #define RP_RXCPL_REG0 0x2014
40 #define RP_RXCPL_REG1 0x2018
41 #define P2A_INT_STATUS 0x3060
42 #define P2A_INT_STS_ALL 0xf
43 #define P2A_INT_ENABLE 0x3070
44 #define P2A_INT_ENA_ALL 0xf
45 #define RP_LTSSM 0x3c64
46 #define RP_LTSSM_MASK 0x1f
49 #define PCIE_CAP_OFFSET 0x80
50 /* TLP configuration type 0 and 1 */
51 #define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
52 #define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
53 #define TLP_FMTTYPE_CFGRD1 0x05 /* Configuration Read Type 1 */
54 #define TLP_FMTTYPE_CFGWR1 0x45 /* Configuration Write Type 1 */
55 #define TLP_PAYLOAD_SIZE 0x01
56 #define TLP_READ_TAG 0x1d
57 #define TLP_WRITE_TAG 0x10
59 #define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
60 #define TLP_CFG_DW0(pcie, bus) \
61 ((((bus == pcie->root_bus_nr) ? TLP_FMTTYPE_CFGRD0 \
62 : TLP_FMTTYPE_CFGRD1) << 24) | \
64 #define TLP_CFG_DW1(pcie, tag, be) \
65 (((TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN)) << 16) | (tag << 8) | (be))
66 #define TLP_CFG_DW2(bus, devfn, offset) \
67 (((bus) << 24) | ((devfn) << 16) | (offset))
68 #define TLP_COMP_STATUS(s) (((s) >> 12) & 7)
69 #define TLP_HDR_SIZE 3
72 #define LINK_UP_TIMEOUT HZ
73 #define LINK_RETRAIN_TIMEOUT HZ
80 struct platform_device *pdev;
81 void __iomem *cra_base; /* DT Cra */
84 struct irq_domain *irq_domain;
85 struct resource bus_range;
86 struct list_head resources;
89 struct tlp_rp_regpair_t {
95 static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
98 writel_relaxed(value, pcie->cra_base + reg);
101 static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
103 return readl_relaxed(pcie->cra_base + reg);
106 static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
108 return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
112 * Altera PCIe port uses BAR0 of RC's configuration space as the translation
113 * from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
114 * using these registers, so it can be reached by DMA from EP devices.
115 * This BAR0 will also access to MSI vector when receiving MSI/MSIX interrupt
116 * from EP devices, eventually trigger interrupt to GIC. The BAR0 of bridge
117 * should be hidden during enumeration to avoid the sizing and resource
118 * allocation by PCIe core.
120 static bool altera_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int devfn,
123 if (pci_is_root_bus(bus) && (devfn == 0) &&
124 (offset == PCI_BASE_ADDRESS_0))
130 static void tlp_write_tx(struct altera_pcie *pcie,
131 struct tlp_rp_regpair_t *tlp_rp_regdata)
133 cra_writel(pcie, tlp_rp_regdata->reg0, RP_TX_REG0);
134 cra_writel(pcie, tlp_rp_regdata->reg1, RP_TX_REG1);
135 cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
138 static bool altera_pcie_valid_device(struct altera_pcie *pcie,
139 struct pci_bus *bus, int dev)
141 /* If there is no link, then there is no device */
142 if (bus->number != pcie->root_bus_nr) {
143 if (!altera_pcie_link_is_up(pcie))
147 /* access only one slot on each root port */
148 if (bus->number == pcie->root_bus_nr && dev > 0)
154 static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
163 * Minimum 2 loops to read TLP headers and 1 loop to read data
166 for (i = 0; i < TLP_LOOP; i++) {
167 ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
168 if ((ctrl & RP_RXCPL_SOP) || (ctrl & RP_RXCPL_EOP) || sop) {
169 reg0 = cra_readl(pcie, RP_RXCPL_REG0);
170 reg1 = cra_readl(pcie, RP_RXCPL_REG1);
172 if (ctrl & RP_RXCPL_SOP) {
174 comp_status = TLP_COMP_STATUS(reg1);
177 if (ctrl & RP_RXCPL_EOP) {
179 return PCIBIOS_DEVICE_NOT_FOUND;
184 return PCIBIOS_SUCCESSFUL;
190 return PCIBIOS_DEVICE_NOT_FOUND;
193 static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
194 u32 data, bool align)
196 struct tlp_rp_regpair_t tlp_rp_regdata;
198 tlp_rp_regdata.reg0 = headers[0];
199 tlp_rp_regdata.reg1 = headers[1];
200 tlp_rp_regdata.ctrl = RP_TX_SOP;
201 tlp_write_tx(pcie, &tlp_rp_regdata);
204 tlp_rp_regdata.reg0 = headers[2];
205 tlp_rp_regdata.reg1 = 0;
206 tlp_rp_regdata.ctrl = 0;
207 tlp_write_tx(pcie, &tlp_rp_regdata);
209 tlp_rp_regdata.reg0 = data;
210 tlp_rp_regdata.reg1 = 0;
212 tlp_rp_regdata.reg0 = headers[2];
213 tlp_rp_regdata.reg1 = data;
216 tlp_rp_regdata.ctrl = RP_TX_EOP;
217 tlp_write_tx(pcie, &tlp_rp_regdata);
220 static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
221 int where, u8 byte_en, u32 *value)
223 u32 headers[TLP_HDR_SIZE];
225 headers[0] = TLP_CFG_DW0(pcie, bus);
226 headers[1] = TLP_CFG_DW1(pcie, TLP_READ_TAG, byte_en);
227 headers[2] = TLP_CFG_DW2(bus, devfn, where);
229 tlp_write_packet(pcie, headers, 0, false);
231 return tlp_read_packet(pcie, value);
234 static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
235 int where, u8 byte_en, u32 value)
237 u32 headers[TLP_HDR_SIZE];
240 headers[0] = TLP_CFG_DW0(pcie, bus);
241 headers[1] = TLP_CFG_DW1(pcie, TLP_WRITE_TAG, byte_en);
242 headers[2] = TLP_CFG_DW2(bus, devfn, where);
244 /* check alignment to Qword */
245 if ((where & 0x7) == 0)
246 tlp_write_packet(pcie, headers, value, true);
248 tlp_write_packet(pcie, headers, value, false);
250 ret = tlp_read_packet(pcie, NULL);
251 if (ret != PCIBIOS_SUCCESSFUL)
255 * Monitor changes to PCI_PRIMARY_BUS register on root port
256 * and update local copy of root bus number accordingly.
258 if ((bus == pcie->root_bus_nr) && (where == PCI_PRIMARY_BUS))
259 pcie->root_bus_nr = (u8)(value);
261 return PCIBIOS_SUCCESSFUL;
264 static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
265 unsigned int devfn, int where, int size,
274 byte_en = 1 << (where & 3);
277 byte_en = 3 << (where & 3);
284 ret = tlp_cfg_dword_read(pcie, busno, devfn,
285 (where & ~DWORD_MASK), byte_en, &data);
286 if (ret != PCIBIOS_SUCCESSFUL)
291 *value = (data >> (8 * (where & 0x3))) & 0xff;
294 *value = (data >> (8 * (where & 0x2))) & 0xffff;
301 return PCIBIOS_SUCCESSFUL;
304 static int _altera_pcie_cfg_write(struct altera_pcie *pcie, u8 busno,
305 unsigned int devfn, int where, int size,
309 u32 shift = 8 * (where & 3);
314 data32 = (value & 0xff) << shift;
315 byte_en = 1 << (where & 3);
318 data32 = (value & 0xffff) << shift;
319 byte_en = 3 << (where & 3);
327 return tlp_cfg_dword_write(pcie, busno, devfn, (where & ~DWORD_MASK),
331 static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn,
332 int where, int size, u32 *value)
334 struct altera_pcie *pcie = bus->sysdata;
336 if (altera_pcie_hide_rc_bar(bus, devfn, where))
337 return PCIBIOS_BAD_REGISTER_NUMBER;
339 if (!altera_pcie_valid_device(pcie, bus, PCI_SLOT(devfn))) {
341 return PCIBIOS_DEVICE_NOT_FOUND;
344 return _altera_pcie_cfg_read(pcie, bus->number, devfn, where, size,
348 static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn,
349 int where, int size, u32 value)
351 struct altera_pcie *pcie = bus->sysdata;
353 if (altera_pcie_hide_rc_bar(bus, devfn, where))
354 return PCIBIOS_BAD_REGISTER_NUMBER;
356 if (!altera_pcie_valid_device(pcie, bus, PCI_SLOT(devfn)))
357 return PCIBIOS_DEVICE_NOT_FOUND;
359 return _altera_pcie_cfg_write(pcie, bus->number, devfn, where, size,
363 static struct pci_ops altera_pcie_ops = {
364 .read = altera_pcie_cfg_read,
365 .write = altera_pcie_cfg_write,
368 static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
369 unsigned int devfn, int offset, u16 *value)
374 ret = _altera_pcie_cfg_read(pcie, busno, devfn,
375 PCIE_CAP_OFFSET + offset, sizeof(*value),
381 static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
382 unsigned int devfn, int offset, u16 value)
384 return _altera_pcie_cfg_write(pcie, busno, devfn,
385 PCIE_CAP_OFFSET + offset, sizeof(value),
389 static void altera_wait_link_retrain(struct altera_pcie *pcie)
391 struct device *dev = &pcie->pdev->dev;
393 unsigned long start_jiffies;
395 /* Wait for link training end. */
396 start_jiffies = jiffies;
398 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
399 PCI_EXP_LNKSTA, ®16);
400 if (!(reg16 & PCI_EXP_LNKSTA_LT))
403 if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) {
404 dev_err(dev, "link retrain timeout\n");
410 /* Wait for link is up */
411 start_jiffies = jiffies;
413 if (altera_pcie_link_is_up(pcie))
416 if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
417 dev_err(dev, "link up timeout\n");
424 static void altera_pcie_retrain(struct altera_pcie *pcie)
426 u16 linkcap, linkstat, linkctl;
428 if (!altera_pcie_link_is_up(pcie))
432 * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
433 * current speed is 2.5 GB/s.
435 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKCAP,
437 if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
440 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKSTA,
442 if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
443 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
444 PCI_EXP_LNKCTL, &linkctl);
445 linkctl |= PCI_EXP_LNKCTL_RL;
446 altera_write_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
447 PCI_EXP_LNKCTL, linkctl);
449 altera_wait_link_retrain(pcie);
453 static int altera_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
454 irq_hw_number_t hwirq)
456 irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
457 irq_set_chip_data(irq, domain->host_data);
461 static const struct irq_domain_ops intx_domain_ops = {
462 .map = altera_pcie_intx_map,
465 static void altera_pcie_isr(struct irq_desc *desc)
467 struct irq_chip *chip = irq_desc_get_chip(desc);
468 struct altera_pcie *pcie;
470 unsigned long status;
474 chained_irq_enter(chip, desc);
475 pcie = irq_desc_get_handler_data(desc);
476 dev = &pcie->pdev->dev;
478 while ((status = cra_readl(pcie, P2A_INT_STATUS)
479 & P2A_INT_STS_ALL) != 0) {
480 for_each_set_bit(bit, &status, INTX_NUM) {
481 /* clear interrupts */
482 cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
484 virq = irq_find_mapping(pcie->irq_domain, bit + 1);
486 generic_handle_irq(virq);
488 dev_err(dev, "unexpected IRQ, INT%d\n", bit);
492 chained_irq_exit(chip, desc);
495 static int altera_pcie_parse_request_of_pci_ranges(struct altera_pcie *pcie)
497 int err, res_valid = 0;
498 struct device *dev = &pcie->pdev->dev;
499 struct device_node *np = dev->of_node;
500 struct resource_entry *win;
502 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
507 err = devm_request_pci_bus_resources(dev, &pcie->resources);
509 goto out_release_res;
511 resource_list_for_each_entry(win, &pcie->resources) {
512 struct resource *res = win->res;
514 if (resource_type(res) == IORESOURCE_MEM)
515 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
521 dev_err(dev, "non-prefetchable memory resource required\n");
525 pci_free_resource_list(&pcie->resources);
529 static int altera_pcie_init_irq_domain(struct altera_pcie *pcie)
531 struct device *dev = &pcie->pdev->dev;
532 struct device_node *node = dev->of_node;
535 pcie->irq_domain = irq_domain_add_linear(node, INTX_NUM + 1,
536 &intx_domain_ops, pcie);
537 if (!pcie->irq_domain) {
538 dev_err(dev, "Failed to get a INTx IRQ domain\n");
545 static int altera_pcie_parse_dt(struct altera_pcie *pcie)
547 struct device *dev = &pcie->pdev->dev;
548 struct platform_device *pdev = pcie->pdev;
549 struct resource *cra;
551 cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
552 pcie->cra_base = devm_ioremap_resource(dev, cra);
553 if (IS_ERR(pcie->cra_base))
554 return PTR_ERR(pcie->cra_base);
557 pcie->irq = platform_get_irq(pdev, 0);
558 if (pcie->irq <= 0) {
559 dev_err(dev, "failed to get IRQ: %d\n", pcie->irq);
563 irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
567 static void altera_pcie_host_init(struct altera_pcie *pcie)
569 altera_pcie_retrain(pcie);
572 static int altera_pcie_probe(struct platform_device *pdev)
574 struct device *dev = &pdev->dev;
575 struct altera_pcie *pcie;
577 struct pci_bus *child;
580 pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
586 ret = altera_pcie_parse_dt(pcie);
588 dev_err(dev, "Parsing DT failed\n");
592 INIT_LIST_HEAD(&pcie->resources);
594 ret = altera_pcie_parse_request_of_pci_ranges(pcie);
596 dev_err(dev, "Failed add resources\n");
600 ret = altera_pcie_init_irq_domain(pcie);
602 dev_err(dev, "Failed creating IRQ Domain\n");
606 /* clear all interrupts */
607 cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
608 /* enable all interrupts */
609 cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
610 altera_pcie_host_init(pcie);
612 bus = pci_scan_root_bus(dev, pcie->root_bus_nr, &altera_pcie_ops,
613 pcie, &pcie->resources);
617 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
618 pci_assign_unassigned_bus_resources(bus);
620 /* Configure PCI Express setting. */
621 list_for_each_entry(child, &bus->children, node)
622 pcie_bus_configure_settings(child);
624 pci_bus_add_devices(bus);
628 static const struct of_device_id altera_pcie_of_match[] = {
629 { .compatible = "altr,pcie-root-port-1.0", },
633 static struct platform_driver altera_pcie_driver = {
634 .probe = altera_pcie_probe,
636 .name = "altera-pcie",
637 .of_match_table = altera_pcie_of_match,
638 .suppress_bind_attrs = true,
642 builtin_platform_driver(altera_pcie_driver);